/********************************************************************** cont.c - $Author$ created at: Thu May 23 09:03:43 2007 Copyright (C) 2007 Koichi Sasada **********************************************************************/ #include "ruby/internal/config.h" #ifndef _WIN32 #include #include #endif // On Solaris, madvise() is NOT declared for SUS (XPG4v2) or later, // but MADV_* macros are defined when __EXTENSIONS__ is defined. #ifdef NEED_MADVICE_PROTOTYPE_USING_CADDR_T #include extern int madvise(caddr_t, size_t, int); #endif #include COROUTINE_H #include "eval_intern.h" #include "gc.h" #include "internal.h" #include "internal/cont.h" #include "internal/proc.h" #include "internal/warnings.h" #include "ruby/fiber/scheduler.h" #include "mjit.h" #include "vm_core.h" #include "id_table.h" #include "ractor_core.h" static const int DEBUG = 0; #define RB_PAGE_SIZE (pagesize) #define RB_PAGE_MASK (~(RB_PAGE_SIZE - 1)) static long pagesize; static const rb_data_type_t cont_data_type, fiber_data_type; static VALUE rb_cContinuation; static VALUE rb_cFiber; static VALUE rb_eFiberError; #ifdef RB_EXPERIMENTAL_FIBER_POOL static VALUE rb_cFiberPool; #endif #define CAPTURE_JUST_VALID_VM_STACK 1 // Defined in `coroutine/$arch/Context.h`: #ifdef COROUTINE_LIMITED_ADDRESS_SPACE #define FIBER_POOL_ALLOCATION_FREE #define FIBER_POOL_INITIAL_SIZE 8 #define FIBER_POOL_ALLOCATION_MAXIMUM_SIZE 32 #else #define FIBER_POOL_INITIAL_SIZE 32 #define FIBER_POOL_ALLOCATION_MAXIMUM_SIZE 1024 #endif enum context_type { CONTINUATION_CONTEXT = 0, FIBER_CONTEXT = 1 }; struct cont_saved_vm_stack { VALUE *ptr; #ifdef CAPTURE_JUST_VALID_VM_STACK size_t slen; /* length of stack (head of ec->vm_stack) */ size_t clen; /* length of control frames (tail of ec->vm_stack) */ #endif }; struct fiber_pool; // Represents a single stack. struct fiber_pool_stack { // A pointer to the memory allocation (lowest address) for the stack. void * base; // The current stack pointer, taking into account the direction of the stack. void * current; // The size of the stack excluding any guard pages. size_t size; // The available stack capacity w.r.t. the current stack offset. size_t available; // The pool this stack should be allocated from. struct fiber_pool * pool; // If the stack is allocated, the allocation it came from. struct fiber_pool_allocation * allocation; }; // A linked list of vacant (unused) stacks. // This structure is stored in the first page of a stack if it is not in use. // @sa fiber_pool_vacancy_pointer struct fiber_pool_vacancy { // Details about the vacant stack: struct fiber_pool_stack stack; // The vacancy linked list. #ifdef FIBER_POOL_ALLOCATION_FREE struct fiber_pool_vacancy * previous; #endif struct fiber_pool_vacancy * next; }; // Manages singly linked list of mapped regions of memory which contains 1 more more stack: // // base = +-------------------------------+-----------------------+ + // |VM Stack |VM Stack | | | // | | | | | // | | | | | // +-------------------------------+ | | // |Machine Stack |Machine Stack | | | // | | | | | // | | | | | // | | | . . . . | | size // | | | | | // | | | | | // | | | | | // | | | | | // | | | | | // +-------------------------------+ | | // |Guard Page |Guard Page | | | // +-------------------------------+-----------------------+ v // // +-------------------------------------------------------> // // count // struct fiber_pool_allocation { // A pointer to the memory mapped region. void * base; // The size of the individual stacks. size_t size; // The stride of individual stacks (including any guard pages or other accounting details). size_t stride; // The number of stacks that were allocated. size_t count; #ifdef FIBER_POOL_ALLOCATION_FREE // The number of stacks used in this allocation. size_t used; #endif struct fiber_pool * pool; // The allocation linked list. #ifdef FIBER_POOL_ALLOCATION_FREE struct fiber_pool_allocation * previous; #endif struct fiber_pool_allocation * next; }; // A fiber pool manages vacant stacks to reduce the overhead of creating fibers. struct fiber_pool { // A singly-linked list of allocations which contain 1 or more stacks each. struct fiber_pool_allocation * allocations; // Provides O(1) stack "allocation": struct fiber_pool_vacancy * vacancies; // The size of the stack allocations (excluding any guard page). size_t size; // The total number of stacks that have been allocated in this pool. size_t count; // The initial number of stacks to allocate. size_t initial_count; // Whether to madvise(free) the stack or not: int free_stacks; // The number of stacks that have been used in this pool. size_t used; // The amount to allocate for the vm_stack: size_t vm_stack_size; }; typedef struct rb_context_struct { enum context_type type; int argc; int kw_splat; VALUE self; VALUE value; struct cont_saved_vm_stack saved_vm_stack; struct { VALUE *stack; VALUE *stack_src; size_t stack_size; } machine; rb_execution_context_t saved_ec; rb_jmpbuf_t jmpbuf; rb_ensure_entry_t *ensure_array; /* Pointer to MJIT info about the continuation. */ struct mjit_cont *mjit_cont; } rb_context_t; /* * Fiber status: * [Fiber.new] ------> FIBER_CREATED * | [Fiber#resume] * v * +--> FIBER_RESUMED ----+ * [Fiber#resume] | | [Fiber.yield] | * | v | * +-- FIBER_SUSPENDED | [Terminate] * | * FIBER_TERMINATED <-+ */ enum fiber_status { FIBER_CREATED, FIBER_RESUMED, FIBER_SUSPENDED, FIBER_TERMINATED }; #define FIBER_CREATED_P(fiber) ((fiber)->status == FIBER_CREATED) #define FIBER_RESUMED_P(fiber) ((fiber)->status == FIBER_RESUMED) #define FIBER_SUSPENDED_P(fiber) ((fiber)->status == FIBER_SUSPENDED) #define FIBER_TERMINATED_P(fiber) ((fiber)->status == FIBER_TERMINATED) #define FIBER_RUNNABLE_P(fiber) (FIBER_CREATED_P(fiber) || FIBER_SUSPENDED_P(fiber)) struct rb_fiber_struct { rb_context_t cont; VALUE first_proc; struct rb_fiber_struct *prev; struct rb_fiber_struct *resuming_fiber; BITFIELD(enum fiber_status, status, 2); /* Whether the fiber is allowed to implicitly yield. */ unsigned int yielding : 1; unsigned int blocking : 1; struct coroutine_context context; struct fiber_pool_stack stack; }; static struct fiber_pool shared_fiber_pool = {NULL, NULL, 0, 0, 0, 0}; static ID fiber_initialize_keywords[2] = {0}; /* * FreeBSD require a first (i.e. addr) argument of mmap(2) is not NULL * if MAP_STACK is passed. * http://www.FreeBSD.org/cgi/query-pr.cgi?pr=158755 */ #if defined(MAP_STACK) && !defined(__FreeBSD__) && !defined(__FreeBSD_kernel__) #define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON | MAP_STACK) #else #define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON) #endif #define ERRNOMSG strerror(errno) // Locates the stack vacancy details for the given stack. // Requires that fiber_pool_vacancy fits within one page. inline static struct fiber_pool_vacancy * fiber_pool_vacancy_pointer(void * base, size_t size) { STACK_GROW_DIR_DETECTION; return (struct fiber_pool_vacancy *)( (char*)base + STACK_DIR_UPPER(0, size - RB_PAGE_SIZE) ); } // Reset the current stack pointer and available size of the given stack. inline static void fiber_pool_stack_reset(struct fiber_pool_stack * stack) { STACK_GROW_DIR_DETECTION; stack->current = (char*)stack->base + STACK_DIR_UPPER(0, stack->size); stack->available = stack->size; } // A pointer to the base of the current unused portion of the stack. inline static void * fiber_pool_stack_base(struct fiber_pool_stack * stack) { STACK_GROW_DIR_DETECTION; VM_ASSERT(stack->current); return STACK_DIR_UPPER(stack->current, (char*)stack->current - stack->available); } // Allocate some memory from the stack. Used to allocate vm_stack inline with machine stack. // @sa fiber_initialize_coroutine inline static void * fiber_pool_stack_alloca(struct fiber_pool_stack * stack, size_t offset) { STACK_GROW_DIR_DETECTION; if (DEBUG) fprintf(stderr, "fiber_pool_stack_alloca(%p): %"PRIuSIZE"/%"PRIuSIZE"\n", (void*)stack, offset, stack->available); VM_ASSERT(stack->available >= offset); // The pointer to the memory being allocated: void * pointer = STACK_DIR_UPPER(stack->current, (char*)stack->current - offset); // Move the stack pointer: stack->current = STACK_DIR_UPPER((char*)stack->current + offset, (char*)stack->current - offset); stack->available -= offset; return pointer; } // Reset the current stack pointer and available size of the given stack. inline static void fiber_pool_vacancy_reset(struct fiber_pool_vacancy * vacancy) { fiber_pool_stack_reset(&vacancy->stack); // Consume one page of the stack because it's used for the vacancy list: fiber_pool_stack_alloca(&vacancy->stack, RB_PAGE_SIZE); } inline static struct fiber_pool_vacancy * fiber_pool_vacancy_push(struct fiber_pool_vacancy * vacancy, struct fiber_pool_vacancy * head) { vacancy->next = head; #ifdef FIBER_POOL_ALLOCATION_FREE if (head) { head->previous = vacancy; vacancy->previous = NULL; } #endif return vacancy; } #ifdef FIBER_POOL_ALLOCATION_FREE static void fiber_pool_vacancy_remove(struct fiber_pool_vacancy * vacancy) { if (vacancy->next) { vacancy->next->previous = vacancy->previous; } if (vacancy->previous) { vacancy->previous->next = vacancy->next; } else { // It's the head of the list: vacancy->stack.pool->vacancies = vacancy->next; } } inline static struct fiber_pool_vacancy * fiber_pool_vacancy_pop(struct fiber_pool * pool) { struct fiber_pool_vacancy * vacancy = pool->vacancies; if (vacancy) { fiber_pool_vacancy_remove(vacancy); } return vacancy; } #else inline static struct fiber_pool_vacancy * fiber_pool_vacancy_pop(struct fiber_pool * pool) { struct fiber_pool_vacancy * vacancy = pool->vacancies; if (vacancy) { pool->vacancies = vacancy->next; } return vacancy; } #endif // Initialize the vacant stack. The [base, size] allocation should not include the guard page. // @param base The pointer to the lowest address of the allocated memory. // @param size The size of the allocated memory. inline static struct fiber_pool_vacancy * fiber_pool_vacancy_initialize(struct fiber_pool * fiber_pool, struct fiber_pool_vacancy * vacancies, void * base, size_t size) { struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(base, size); vacancy->stack.base = base; vacancy->stack.size = size; fiber_pool_vacancy_reset(vacancy); vacancy->stack.pool = fiber_pool; return fiber_pool_vacancy_push(vacancy, vacancies); } // Allocate a maximum of count stacks, size given by stride. // @param count the number of stacks to allocate / were allocated. // @param stride the size of the individual stacks. // @return [void *] the allocated memory or NULL if allocation failed. inline static void * fiber_pool_allocate_memory(size_t * count, size_t stride) { // We use a divide-by-2 strategy to try and allocate memory. We are trying // to allocate `count` stacks. In normal situation, this won't fail. But // if we ran out of address space, or we are allocating more memory than // the system would allow (e.g. overcommit * physical memory + swap), we // divide count by two and try again. This condition should only be // encountered in edge cases, but we handle it here gracefully. while (*count > 1) { #if defined(_WIN32) void * base = VirtualAlloc(0, (*count)*stride, MEM_COMMIT, PAGE_READWRITE); if (!base) { *count = (*count) >> 1; } else { return base; } #else errno = 0; void * base = mmap(NULL, (*count)*stride, PROT_READ | PROT_WRITE, FIBER_STACK_FLAGS, -1, 0); if (base == MAP_FAILED) { // If the allocation fails, count = count / 2, and try again. *count = (*count) >> 1; } else { #if defined(MADV_FREE_REUSE) // On Mac MADV_FREE_REUSE is necessary for the task_info api // to keep the accounting accurate as possible when a page is marked as reusable // it can possibly not occurring at first call thus re-iterating if necessary. while (madvise(base, (*count)*stride, MADV_FREE_REUSE) == -1 && errno == EAGAIN); #endif return base; } #endif } return NULL; } // Given an existing fiber pool, expand it by the specified number of stacks. // @param count the maximum number of stacks to allocate. // @return the allocated fiber pool. // @sa fiber_pool_allocation_free static struct fiber_pool_allocation * fiber_pool_expand(struct fiber_pool * fiber_pool, size_t count) { STACK_GROW_DIR_DETECTION; size_t size = fiber_pool->size; size_t stride = size + RB_PAGE_SIZE; // Allocate the memory required for the stacks: void * base = fiber_pool_allocate_memory(&count, stride); if (base == NULL) { rb_raise(rb_eFiberError, "can't alloc machine stack to fiber (%"PRIuSIZE" x %"PRIuSIZE" bytes): %s", count, size, ERRNOMSG); } struct fiber_pool_vacancy * vacancies = fiber_pool->vacancies; struct fiber_pool_allocation * allocation = RB_ALLOC(struct fiber_pool_allocation); // Initialize fiber pool allocation: allocation->base = base; allocation->size = size; allocation->stride = stride; allocation->count = count; #ifdef FIBER_POOL_ALLOCATION_FREE allocation->used = 0; #endif allocation->pool = fiber_pool; if (DEBUG) { fprintf(stderr, "fiber_pool_expand(%"PRIuSIZE"): %p, %"PRIuSIZE"/%"PRIuSIZE" x [%"PRIuSIZE":%"PRIuSIZE"]\n", count, (void*)fiber_pool, fiber_pool->used, fiber_pool->count, size, fiber_pool->vm_stack_size); } // Iterate over all stacks, initializing the vacancy list: for (size_t i = 0; i < count; i += 1) { void * base = (char*)allocation->base + (stride * i); void * page = (char*)base + STACK_DIR_UPPER(size, 0); #if defined(_WIN32) DWORD old_protect; if (!VirtualProtect(page, RB_PAGE_SIZE, PAGE_READWRITE | PAGE_GUARD, &old_protect)) { VirtualFree(allocation->base, 0, MEM_RELEASE); rb_raise(rb_eFiberError, "can't set a guard page: %s", ERRNOMSG); } #else if (mprotect(page, RB_PAGE_SIZE, PROT_NONE) < 0) { munmap(allocation->base, count*stride); rb_raise(rb_eFiberError, "can't set a guard page: %s", ERRNOMSG); } #endif vacancies = fiber_pool_vacancy_initialize( fiber_pool, vacancies, (char*)base + STACK_DIR_UPPER(0, RB_PAGE_SIZE), size ); #ifdef FIBER_POOL_ALLOCATION_FREE vacancies->stack.allocation = allocation; #endif } // Insert the allocation into the head of the pool: allocation->next = fiber_pool->allocations; #ifdef FIBER_POOL_ALLOCATION_FREE if (allocation->next) { allocation->next->previous = allocation; } allocation->previous = NULL; #endif fiber_pool->allocations = allocation; fiber_pool->vacancies = vacancies; fiber_pool->count += count; return allocation; } // Initialize the specified fiber pool with the given number of stacks. // @param vm_stack_size The size of the vm stack to allocate. static void fiber_pool_initialize(struct fiber_pool * fiber_pool, size_t size, size_t count, size_t vm_stack_size) { VM_ASSERT(vm_stack_size < size); fiber_pool->allocations = NULL; fiber_pool->vacancies = NULL; fiber_pool->size = ((size / RB_PAGE_SIZE) + 1) * RB_PAGE_SIZE; fiber_pool->count = 0; fiber_pool->initial_count = count; fiber_pool->free_stacks = 1; fiber_pool->used = 0; fiber_pool->vm_stack_size = vm_stack_size; fiber_pool_expand(fiber_pool, count); } #ifdef FIBER_POOL_ALLOCATION_FREE // Free the list of fiber pool allocations. static void fiber_pool_allocation_free(struct fiber_pool_allocation * allocation) { STACK_GROW_DIR_DETECTION; VM_ASSERT(allocation->used == 0); if (DEBUG) fprintf(stderr, "fiber_pool_allocation_free: %p base=%p count=%"PRIuSIZE"\n", (void*)allocation, allocation->base, allocation->count); size_t i; for (i = 0; i < allocation->count; i += 1) { void * base = (char*)allocation->base + (allocation->stride * i) + STACK_DIR_UPPER(0, RB_PAGE_SIZE); struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(base, allocation->size); // Pop the vacant stack off the free list: fiber_pool_vacancy_remove(vacancy); } #ifdef _WIN32 VirtualFree(allocation->base, 0, MEM_RELEASE); #else munmap(allocation->base, allocation->stride * allocation->count); #endif if (allocation->previous) { allocation->previous->next = allocation->next; } else { // We are the head of the list, so update the pool: allocation->pool->allocations = allocation->next; } if (allocation->next) { allocation->next->previous = allocation->previous; } allocation->pool->count -= allocation->count; ruby_xfree(allocation); } #endif // Acquire a stack from the given fiber pool. If none are available, allocate more. static struct fiber_pool_stack fiber_pool_stack_acquire(struct fiber_pool * fiber_pool) { struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pop(fiber_pool); if (DEBUG) fprintf(stderr, "fiber_pool_stack_acquire: %p used=%"PRIuSIZE"\n", (void*)fiber_pool->vacancies, fiber_pool->used); if (!vacancy) { const size_t maximum = FIBER_POOL_ALLOCATION_MAXIMUM_SIZE; const size_t minimum = fiber_pool->initial_count; size_t count = fiber_pool->count; if (count > maximum) count = maximum; if (count < minimum) count = minimum; fiber_pool_expand(fiber_pool, count); // The free list should now contain some stacks: VM_ASSERT(fiber_pool->vacancies); vacancy = fiber_pool_vacancy_pop(fiber_pool); } VM_ASSERT(vacancy); VM_ASSERT(vacancy->stack.base); // Take the top item from the free list: fiber_pool->used += 1; #ifdef FIBER_POOL_ALLOCATION_FREE vacancy->stack.allocation->used += 1; #endif fiber_pool_stack_reset(&vacancy->stack); return vacancy->stack; } // We advise the operating system that the stack memory pages are no longer being used. // This introduce some performance overhead but allows system to relaim memory when there is pressure. static inline void fiber_pool_stack_free(struct fiber_pool_stack * stack) { void * base = fiber_pool_stack_base(stack); size_t size = stack->available; // If this is not true, the vacancy information will almost certainly be destroyed: VM_ASSERT(size <= (stack->size - RB_PAGE_SIZE)); if (DEBUG) fprintf(stderr, "fiber_pool_stack_free: %p+%"PRIuSIZE" [base=%p, size=%"PRIuSIZE"]\n", base, size, stack->base, stack->size); #if VM_CHECK_MODE > 0 && defined(MADV_DONTNEED) // This immediately discards the pages and the memory is reset to zero. madvise(base, size, MADV_DONTNEED); #elif defined(POSIX_MADV_DONTNEED) posix_madvise(base, size, POSIX_MADV_DONTNEED); #elif defined(MADV_FREE_REUSABLE) // Acknowledge the kernel down to the task info api we make this // page reusable for future use. // As for MADV_FREE_REUSE below we ensure in the rare occasions the task was not // completed at the time of the call to re-iterate. while (madvise(base, size, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN); #elif defined(MADV_FREE) madvise(base, size, MADV_FREE); #elif defined(MADV_DONTNEED) madvise(base, size, MADV_DONTNEED); #elif defined(_WIN32) VirtualAlloc(base, size, MEM_RESET, PAGE_READWRITE); // Not available in all versions of Windows. //DiscardVirtualMemory(base, size); #endif } // Release and return a stack to the vacancy list. static void fiber_pool_stack_release(struct fiber_pool_stack * stack) { struct fiber_pool * pool = stack->pool; struct fiber_pool_vacancy * vacancy = fiber_pool_vacancy_pointer(stack->base, stack->size); if (DEBUG) fprintf(stderr, "fiber_pool_stack_release: %p used=%"PRIuSIZE"\n", stack->base, stack->pool->used); // Copy the stack details into the vacancy area: vacancy->stack = *stack; // After this point, be careful about updating/using state in stack, since it's copied to the vacancy area. // Reset the stack pointers and reserve space for the vacancy data: fiber_pool_vacancy_reset(vacancy); // Push the vacancy into the vancancies list: pool->vacancies = fiber_pool_vacancy_push(vacancy, stack->pool->vacancies); pool->used -= 1; #ifdef FIBER_POOL_ALLOCATION_FREE struct fiber_pool_allocation * allocation = stack->allocation; allocation->used -= 1; // Release address space and/or dirty memory: if (allocation->used == 0) { fiber_pool_allocation_free(allocation); } else if (stack->pool->free_stacks) { fiber_pool_stack_free(&vacancy->stack); } #else // This is entirely optional, but clears the dirty flag from the stack memory, so it won't get swapped to disk when there is memory pressure: if (stack->pool->free_stacks) { fiber_pool_stack_free(&vacancy->stack); } #endif } static inline void ec_switch(rb_thread_t *th, rb_fiber_t *fiber) { rb_execution_context_t *ec = &fiber->cont.saved_ec; rb_ractor_set_current_ec(th->ractor, th->ec = ec); // ruby_current_execution_context_ptr = th->ec = ec; /* * timer-thread may set trap interrupt on previous th->ec at any time; * ensure we do not delay (or lose) the trap interrupt handling. */ if (th->vm->ractor.main_thread == th && rb_signal_buff_size() > 0) { RUBY_VM_SET_TRAP_INTERRUPT(ec); } VM_ASSERT(ec->fiber_ptr->cont.self == 0 || ec->vm_stack != NULL); } static inline void fiber_restore_thread(rb_thread_t *th, rb_fiber_t *fiber) { ec_switch(th, fiber); VM_ASSERT(th->ec->fiber_ptr == fiber); } static COROUTINE fiber_entry(struct coroutine_context * from, struct coroutine_context * to) { rb_fiber_t *fiber = to->argument; rb_thread_t *thread = fiber->cont.saved_ec.thread_ptr; #ifdef COROUTINE_PTHREAD_CONTEXT ruby_thread_set_native(thread); #endif fiber_restore_thread(thread, fiber); rb_fiber_start(fiber); #ifndef COROUTINE_PTHREAD_CONTEXT VM_UNREACHABLE(fiber_entry); #endif } // Initialize a fiber's coroutine's machine stack and vm stack. static VALUE * fiber_initialize_coroutine(rb_fiber_t *fiber, size_t * vm_stack_size) { struct fiber_pool * fiber_pool = fiber->stack.pool; rb_execution_context_t *sec = &fiber->cont.saved_ec; void * vm_stack = NULL; VM_ASSERT(fiber_pool != NULL); fiber->stack = fiber_pool_stack_acquire(fiber_pool); vm_stack = fiber_pool_stack_alloca(&fiber->stack, fiber_pool->vm_stack_size); *vm_stack_size = fiber_pool->vm_stack_size; coroutine_initialize(&fiber->context, fiber_entry, fiber_pool_stack_base(&fiber->stack), fiber->stack.available); // The stack for this execution context is the one we allocated: sec->machine.stack_start = fiber->stack.current; sec->machine.stack_maxsize = fiber->stack.available; fiber->context.argument = (void*)fiber; return vm_stack; } // Release the stack from the fiber, it's execution context, and return it to the fiber pool. static void fiber_stack_release(rb_fiber_t * fiber) { rb_execution_context_t *ec = &fiber->cont.saved_ec; if (DEBUG) fprintf(stderr, "fiber_stack_release: %p, stack.base=%p\n", (void*)fiber, fiber->stack.base); // Return the stack back to the fiber pool if it wasn't already: if (fiber->stack.base) { fiber_pool_stack_release(&fiber->stack); fiber->stack.base = NULL; } // The stack is no longer associated with this execution context: rb_ec_clear_vm_stack(ec); } static const char * fiber_status_name(enum fiber_status s) { switch (s) { case FIBER_CREATED: return "created"; case FIBER_RESUMED: return "resumed"; case FIBER_SUSPENDED: return "suspended"; case FIBER_TERMINATED: return "terminated"; } VM_UNREACHABLE(fiber_status_name); return NULL; } static void fiber_verify(const rb_fiber_t *fiber) { #if VM_CHECK_MODE > 0 VM_ASSERT(fiber->cont.saved_ec.fiber_ptr == fiber); switch (fiber->status) { case FIBER_RESUMED: VM_ASSERT(fiber->cont.saved_ec.vm_stack != NULL); break; case FIBER_SUSPENDED: VM_ASSERT(fiber->cont.saved_ec.vm_stack != NULL); break; case FIBER_CREATED: case FIBER_TERMINATED: /* TODO */ break; default: VM_UNREACHABLE(fiber_verify); } #endif } inline static void fiber_status_set(rb_fiber_t *fiber, enum fiber_status s) { // if (DEBUG) fprintf(stderr, "fiber: %p, status: %s -> %s\n", (void *)fiber, fiber_status_name(fiber->status), fiber_status_name(s)); VM_ASSERT(!FIBER_TERMINATED_P(fiber)); VM_ASSERT(fiber->status != s); fiber_verify(fiber); fiber->status = s; } static rb_context_t * cont_ptr(VALUE obj) { rb_context_t *cont; TypedData_Get_Struct(obj, rb_context_t, &cont_data_type, cont); return cont; } static rb_fiber_t * fiber_ptr(VALUE obj) { rb_fiber_t *fiber; TypedData_Get_Struct(obj, rb_fiber_t, &fiber_data_type, fiber); if (!fiber) rb_raise(rb_eFiberError, "uninitialized fiber"); return fiber; } NOINLINE(static VALUE cont_capture(volatile int *volatile stat)); #define THREAD_MUST_BE_RUNNING(th) do { \ if (!(th)->ec->tag) rb_raise(rb_eThreadError, "not running thread"); \ } while (0) rb_thread_t* rb_fiber_threadptr(const rb_fiber_t *fiber) { return fiber->cont.saved_ec.thread_ptr; } static VALUE cont_thread_value(const rb_context_t *cont) { return cont->saved_ec.thread_ptr->self; } static void cont_compact(void *ptr) { rb_context_t *cont = ptr; if (cont->self) { cont->self = rb_gc_location(cont->self); } cont->value = rb_gc_location(cont->value); rb_execution_context_update(&cont->saved_ec); } static void cont_mark(void *ptr) { rb_context_t *cont = ptr; RUBY_MARK_ENTER("cont"); if (cont->self) { rb_gc_mark_movable(cont->self); } rb_gc_mark_movable(cont->value); rb_execution_context_mark(&cont->saved_ec); rb_gc_mark(cont_thread_value(cont)); if (cont->saved_vm_stack.ptr) { #ifdef CAPTURE_JUST_VALID_VM_STACK rb_gc_mark_locations(cont->saved_vm_stack.ptr, cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); #else rb_gc_mark_locations(cont->saved_vm_stack.ptr, cont->saved_vm_stack.ptr, cont->saved_ec.stack_size); #endif } if (cont->machine.stack) { if (cont->type == CONTINUATION_CONTEXT) { /* cont */ rb_gc_mark_locations(cont->machine.stack, cont->machine.stack + cont->machine.stack_size); } else { /* fiber */ const rb_fiber_t *fiber = (rb_fiber_t*)cont; if (!FIBER_TERMINATED_P(fiber)) { rb_gc_mark_locations(cont->machine.stack, cont->machine.stack + cont->machine.stack_size); } } } RUBY_MARK_LEAVE("cont"); } #if 0 static int fiber_is_root_p(const rb_fiber_t *fiber) { return fiber == fiber->cont.saved_ec.thread_ptr->root_fiber; } #endif static void cont_free(void *ptr) { rb_context_t *cont = ptr; RUBY_FREE_ENTER("cont"); if (cont->type == CONTINUATION_CONTEXT) { ruby_xfree(cont->saved_ec.vm_stack); ruby_xfree(cont->ensure_array); RUBY_FREE_UNLESS_NULL(cont->machine.stack); } else { rb_fiber_t *fiber = (rb_fiber_t*)cont; coroutine_destroy(&fiber->context); fiber_stack_release(fiber); } RUBY_FREE_UNLESS_NULL(cont->saved_vm_stack.ptr); if (mjit_enabled) { VM_ASSERT(cont->mjit_cont != NULL); mjit_cont_free(cont->mjit_cont); } /* free rb_cont_t or rb_fiber_t */ ruby_xfree(ptr); RUBY_FREE_LEAVE("cont"); } static size_t cont_memsize(const void *ptr) { const rb_context_t *cont = ptr; size_t size = 0; size = sizeof(*cont); if (cont->saved_vm_stack.ptr) { #ifdef CAPTURE_JUST_VALID_VM_STACK size_t n = (cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); #else size_t n = cont->saved_ec.vm_stack_size; #endif size += n * sizeof(*cont->saved_vm_stack.ptr); } if (cont->machine.stack) { size += cont->machine.stack_size * sizeof(*cont->machine.stack); } return size; } void rb_fiber_update_self(rb_fiber_t *fiber) { if (fiber->cont.self) { fiber->cont.self = rb_gc_location(fiber->cont.self); } else { rb_execution_context_update(&fiber->cont.saved_ec); } } void rb_fiber_mark_self(const rb_fiber_t *fiber) { if (fiber->cont.self) { rb_gc_mark_movable(fiber->cont.self); } else { rb_execution_context_mark(&fiber->cont.saved_ec); } } static void fiber_compact(void *ptr) { rb_fiber_t *fiber = ptr; fiber->first_proc = rb_gc_location(fiber->first_proc); if (fiber->prev) rb_fiber_update_self(fiber->prev); cont_compact(&fiber->cont); fiber_verify(fiber); } static void fiber_mark(void *ptr) { rb_fiber_t *fiber = ptr; RUBY_MARK_ENTER("cont"); fiber_verify(fiber); rb_gc_mark_movable(fiber->first_proc); if (fiber->prev) rb_fiber_mark_self(fiber->prev); cont_mark(&fiber->cont); RUBY_MARK_LEAVE("cont"); } static void fiber_free(void *ptr) { rb_fiber_t *fiber = ptr; RUBY_FREE_ENTER("fiber"); if (DEBUG) fprintf(stderr, "fiber_free: %p[%p]\n", (void *)fiber, fiber->stack.base); if (fiber->cont.saved_ec.local_storage) { rb_id_table_free(fiber->cont.saved_ec.local_storage); } cont_free(&fiber->cont); RUBY_FREE_LEAVE("fiber"); } static size_t fiber_memsize(const void *ptr) { const rb_fiber_t *fiber = ptr; size_t size = sizeof(*fiber); const rb_execution_context_t *saved_ec = &fiber->cont.saved_ec; const rb_thread_t *th = rb_ec_thread_ptr(saved_ec); /* * vm.c::thread_memsize already counts th->ec->local_storage */ if (saved_ec->local_storage && fiber != th->root_fiber) { size += rb_id_table_memsize(saved_ec->local_storage); } size += cont_memsize(&fiber->cont); return size; } VALUE rb_obj_is_fiber(VALUE obj) { return RBOOL(rb_typeddata_is_kind_of(obj, &fiber_data_type)); } static void cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont) { size_t size; SET_MACHINE_STACK_END(&th->ec->machine.stack_end); if (th->ec->machine.stack_start > th->ec->machine.stack_end) { size = cont->machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end; cont->machine.stack_src = th->ec->machine.stack_end; } else { size = cont->machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start; cont->machine.stack_src = th->ec->machine.stack_start; } if (cont->machine.stack) { REALLOC_N(cont->machine.stack, VALUE, size); } else { cont->machine.stack = ALLOC_N(VALUE, size); } FLUSH_REGISTER_WINDOWS; MEMCPY(cont->machine.stack, cont->machine.stack_src, VALUE, size); } static const rb_data_type_t cont_data_type = { "continuation", {cont_mark, cont_free, cont_memsize, cont_compact}, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static inline void cont_save_thread(rb_context_t *cont, rb_thread_t *th) { rb_execution_context_t *sec = &cont->saved_ec; VM_ASSERT(th->status == THREAD_RUNNABLE); /* save thread context */ *sec = *th->ec; /* saved_ec->machine.stack_end should be NULL */ /* because it may happen GC afterward */ sec->machine.stack_end = NULL; } static void cont_init_mjit_cont(rb_context_t *cont) { VM_ASSERT(cont->mjit_cont == NULL); if (mjit_enabled) { cont->mjit_cont = mjit_cont_new(&(cont->saved_ec)); } } static void cont_init(rb_context_t *cont, rb_thread_t *th) { /* save thread context */ cont_save_thread(cont, th); cont->saved_ec.thread_ptr = th; cont->saved_ec.local_storage = NULL; cont->saved_ec.local_storage_recursive_hash = Qnil; cont->saved_ec.local_storage_recursive_hash_for_trace = Qnil; cont_init_mjit_cont(cont); } static rb_context_t * cont_new(VALUE klass) { rb_context_t *cont; volatile VALUE contval; rb_thread_t *th = GET_THREAD(); THREAD_MUST_BE_RUNNING(th); contval = TypedData_Make_Struct(klass, rb_context_t, &cont_data_type, cont); cont->self = contval; cont_init(cont, th); return cont; } VALUE rb_fiberptr_self(struct rb_fiber_struct *fiber) { return fiber->cont.self; } unsigned int rb_fiberptr_blocking(struct rb_fiber_struct *fiber) { return fiber->blocking; } // This is used for root_fiber because other fibers call cont_init_mjit_cont through cont_new. void rb_fiber_init_mjit_cont(struct rb_fiber_struct *fiber) { cont_init_mjit_cont(&fiber->cont); } #if 0 void show_vm_stack(const rb_execution_context_t *ec) { VALUE *p = ec->vm_stack; while (p < ec->cfp->sp) { fprintf(stderr, "%3d ", (int)(p - ec->vm_stack)); rb_obj_info_dump(*p); p++; } } void show_vm_pcs(const rb_control_frame_t *cfp, const rb_control_frame_t *end_of_cfp) { int i=0; while (cfp != end_of_cfp) { int pc = 0; if (cfp->iseq) { pc = cfp->pc - cfp->iseq->body->iseq_encoded; } fprintf(stderr, "%2d pc: %d\n", i++, pc); cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp); } } #endif COMPILER_WARNING_PUSH #ifdef __clang__ COMPILER_WARNING_IGNORED(-Wduplicate-decl-specifier) #endif static VALUE cont_capture(volatile int *volatile stat) { rb_context_t *volatile cont; rb_thread_t *th = GET_THREAD(); volatile VALUE contval; const rb_execution_context_t *ec = th->ec; THREAD_MUST_BE_RUNNING(th); rb_vm_stack_to_heap(th->ec); cont = cont_new(rb_cContinuation); contval = cont->self; #ifdef CAPTURE_JUST_VALID_VM_STACK cont->saved_vm_stack.slen = ec->cfp->sp - ec->vm_stack; cont->saved_vm_stack.clen = ec->vm_stack + ec->vm_stack_size - (VALUE*)ec->cfp; cont->saved_vm_stack.ptr = ALLOC_N(VALUE, cont->saved_vm_stack.slen + cont->saved_vm_stack.clen); MEMCPY(cont->saved_vm_stack.ptr, ec->vm_stack, VALUE, cont->saved_vm_stack.slen); MEMCPY(cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen, (VALUE*)ec->cfp, VALUE, cont->saved_vm_stack.clen); #else cont->saved_vm_stack.ptr = ALLOC_N(VALUE, ec->vm_stack_size); MEMCPY(cont->saved_vm_stack.ptr, ec->vm_stack, VALUE, ec->vm_stack_size); #endif // At this point, `cfp` is valid but `vm_stack` should be cleared: rb_ec_set_vm_stack(&cont->saved_ec, NULL, 0); VM_ASSERT(cont->saved_ec.cfp != NULL); cont_save_machine_stack(th, cont); /* backup ensure_list to array for search in another context */ { rb_ensure_list_t *p; int size = 0; rb_ensure_entry_t *entry; for (p=th->ec->ensure_list; p; p=p->next) size++; entry = cont->ensure_array = ALLOC_N(rb_ensure_entry_t,size+1); for (p=th->ec->ensure_list; p; p=p->next) { if (!p->entry.marker) p->entry.marker = rb_ary_tmp_new(0); /* dummy object */ *entry++ = p->entry; } entry->marker = 0; } if (ruby_setjmp(cont->jmpbuf)) { VALUE value; VAR_INITIALIZED(cont); value = cont->value; if (cont->argc == -1) rb_exc_raise(value); cont->value = Qnil; *stat = 1; return value; } else { *stat = 0; return contval; } } COMPILER_WARNING_POP static inline void cont_restore_thread(rb_context_t *cont) { rb_thread_t *th = GET_THREAD(); /* restore thread context */ if (cont->type == CONTINUATION_CONTEXT) { /* continuation */ rb_execution_context_t *sec = &cont->saved_ec; rb_fiber_t *fiber = NULL; if (sec->fiber_ptr != NULL) { fiber = sec->fiber_ptr; } else if (th->root_fiber) { fiber = th->root_fiber; } if (fiber && th->ec != &fiber->cont.saved_ec) { ec_switch(th, fiber); } if (th->ec->trace_arg != sec->trace_arg) { rb_raise(rb_eRuntimeError, "can't call across trace_func"); } /* copy vm stack */ #ifdef CAPTURE_JUST_VALID_VM_STACK MEMCPY(th->ec->vm_stack, cont->saved_vm_stack.ptr, VALUE, cont->saved_vm_stack.slen); MEMCPY(th->ec->vm_stack + th->ec->vm_stack_size - cont->saved_vm_stack.clen, cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen, VALUE, cont->saved_vm_stack.clen); #else MEMCPY(th->ec->vm_stack, cont->saved_vm_stack.ptr, VALUE, sec->vm_stack_size); #endif /* other members of ec */ th->ec->cfp = sec->cfp; th->ec->raised_flag = sec->raised_flag; th->ec->tag = sec->tag; th->ec->root_lep = sec->root_lep; th->ec->root_svar = sec->root_svar; th->ec->ensure_list = sec->ensure_list; th->ec->errinfo = sec->errinfo; VM_ASSERT(th->ec->vm_stack != NULL); } else { /* fiber */ fiber_restore_thread(th, (rb_fiber_t*)cont); } } NOINLINE(static void fiber_setcontext(rb_fiber_t *new_fiber, rb_fiber_t *old_fiber)); static void fiber_setcontext(rb_fiber_t *new_fiber, rb_fiber_t *old_fiber) { rb_thread_t *th = GET_THREAD(); /* save old_fiber's machine stack - to ensure efficient garbage collection */ if (!FIBER_TERMINATED_P(old_fiber)) { STACK_GROW_DIR_DETECTION; SET_MACHINE_STACK_END(&th->ec->machine.stack_end); if (STACK_DIR_UPPER(0, 1)) { old_fiber->cont.machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end; old_fiber->cont.machine.stack = th->ec->machine.stack_end; } else { old_fiber->cont.machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start; old_fiber->cont.machine.stack = th->ec->machine.stack_start; } } /* exchange machine_stack_start between old_fiber and new_fiber */ old_fiber->cont.saved_ec.machine.stack_start = th->ec->machine.stack_start; /* old_fiber->machine.stack_end should be NULL */ old_fiber->cont.saved_ec.machine.stack_end = NULL; // if (DEBUG) fprintf(stderr, "fiber_setcontext: %p[%p] -> %p[%p]\n", (void*)old_fiber, old_fiber->stack.base, (void*)new_fiber, new_fiber->stack.base); /* swap machine context */ struct coroutine_context * from = coroutine_transfer(&old_fiber->context, &new_fiber->context); if (from == NULL) { rb_syserr_fail(errno, "coroutine_transfer"); } /* restore thread context */ fiber_restore_thread(th, old_fiber); // It's possible to get here, and new_fiber is already freed. // if (DEBUG) fprintf(stderr, "fiber_setcontext: %p[%p] <- %p[%p]\n", (void*)old_fiber, old_fiber->stack.base, (void*)new_fiber, new_fiber->stack.base); } NOINLINE(NORETURN(static void cont_restore_1(rb_context_t *))); static void cont_restore_1(rb_context_t *cont) { cont_restore_thread(cont); /* restore machine stack */ #ifdef _M_AMD64 { /* workaround for x64 SEH */ jmp_buf buf; setjmp(buf); _JUMP_BUFFER *bp = (void*)&cont->jmpbuf; bp->Frame = ((_JUMP_BUFFER*)((void*)&buf))->Frame; } #endif if (cont->machine.stack_src) { FLUSH_REGISTER_WINDOWS; MEMCPY(cont->machine.stack_src, cont->machine.stack, VALUE, cont->machine.stack_size); } ruby_longjmp(cont->jmpbuf, 1); } NORETURN(NOINLINE(static void cont_restore_0(rb_context_t *, VALUE *))); static void cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame) { if (cont->machine.stack_src) { #ifdef HAVE_ALLOCA #define STACK_PAD_SIZE 1 #else #define STACK_PAD_SIZE 1024 #endif VALUE space[STACK_PAD_SIZE]; #if !STACK_GROW_DIRECTION if (addr_in_prev_frame > &space[0]) { /* Stack grows downward */ #endif #if STACK_GROW_DIRECTION <= 0 volatile VALUE *const end = cont->machine.stack_src; if (&space[0] > end) { # ifdef HAVE_ALLOCA volatile VALUE *sp = ALLOCA_N(VALUE, &space[0] - end); space[0] = *sp; # else cont_restore_0(cont, &space[0]); # endif } #endif #if !STACK_GROW_DIRECTION } else { /* Stack grows upward */ #endif #if STACK_GROW_DIRECTION >= 0 volatile VALUE *const end = cont->machine.stack_src + cont->machine.stack_size; if (&space[STACK_PAD_SIZE] < end) { # ifdef HAVE_ALLOCA volatile VALUE *sp = ALLOCA_N(VALUE, end - &space[STACK_PAD_SIZE]); space[0] = *sp; # else cont_restore_0(cont, &space[STACK_PAD_SIZE-1]); # endif } #endif #if !STACK_GROW_DIRECTION } #endif } cont_restore_1(cont); } /* * Document-class: Continuation * * Continuation objects are generated by Kernel#callcc, * after having +require+d continuation. They hold * a return address and execution context, allowing a nonlocal return * to the end of the #callcc block from anywhere within a * program. Continuations are somewhat analogous to a structured * version of C's setjmp/longjmp (although they contain * more state, so you might consider them closer to threads). * * For instance: * * require "continuation" * arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] * callcc{|cc| $cc = cc} * puts(message = arr.shift) * $cc.call unless message =~ /Max/ * * produces: * * Freddie * Herbie * Ron * Max * * Also you can call callcc in other methods: * * require "continuation" * * def g * arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] * cc = callcc { |cc| cc } * puts arr.shift * return cc, arr.size * end * * def f * c, size = g * c.call(c) if size > 1 * end * * f * * This (somewhat contrived) example allows the inner loop to abandon * processing early: * * require "continuation" * callcc {|cont| * for i in 0..4 * print "#{i}: " * for j in i*5...(i+1)*5 * cont.call() if j == 17 * printf "%3d", j * end * end * } * puts * * produces: * * 0: 0 1 2 3 4 * 1: 5 6 7 8 9 * 2: 10 11 12 13 14 * 3: 15 16 */ /* * call-seq: * callcc {|cont| block } -> obj * * Generates a Continuation object, which it passes to * the associated block. You need to require * 'continuation' before using this method. Performing a * cont.call will cause the #callcc * to return (as will falling through the end of the block). The * value returned by the #callcc is the value of the * block, or the value passed to cont.call. See * class Continuation for more details. Also see * Kernel#throw for an alternative mechanism for * unwinding a call stack. */ static VALUE rb_callcc(VALUE self) { volatile int called; volatile VALUE val = cont_capture(&called); if (called) { return val; } else { return rb_yield(val); } } static VALUE make_passing_arg(int argc, const VALUE *argv) { switch (argc) { case -1: return argv[0]; case 0: return Qnil; case 1: return argv[0]; default: return rb_ary_new4(argc, argv); } } typedef VALUE e_proc(VALUE); /* CAUTION!! : Currently, error in rollback_func is not supported */ /* same as rb_protect if set rollback_func to NULL */ void ruby_register_rollback_func_for_ensure(e_proc *ensure_func, e_proc *rollback_func) { st_table **table_p = &GET_VM()->ensure_rollback_table; if (UNLIKELY(*table_p == NULL)) { *table_p = st_init_numtable(); } st_insert(*table_p, (st_data_t)ensure_func, (st_data_t)rollback_func); } static inline e_proc * lookup_rollback_func(e_proc *ensure_func) { st_table *table = GET_VM()->ensure_rollback_table; st_data_t val; if (table && st_lookup(table, (st_data_t)ensure_func, &val)) return (e_proc *) val; return (e_proc *) Qundef; } static inline void rollback_ensure_stack(VALUE self,rb_ensure_list_t *current,rb_ensure_entry_t *target) { rb_ensure_list_t *p; rb_ensure_entry_t *entry; size_t i, j; size_t cur_size; size_t target_size; size_t base_point; e_proc *func; cur_size = 0; for (p=current; p; p=p->next) cur_size++; target_size = 0; for (entry=target; entry->marker; entry++) target_size++; /* search common stack point */ p = current; base_point = cur_size; while (base_point) { if (target_size >= base_point && p->entry.marker == target[target_size - base_point].marker) break; base_point --; p = p->next; } /* rollback function check */ for (i=0; i < target_size - base_point; i++) { if (!lookup_rollback_func(target[i].e_proc)) { rb_raise(rb_eRuntimeError, "continuation called from out of critical rb_ensure scope"); } } /* pop ensure stack */ while (cur_size > base_point) { /* escape from ensure block */ (*current->entry.e_proc)(current->entry.data2); current = current->next; cur_size--; } /* push ensure stack */ for (j = 0; j < i; j++) { func = lookup_rollback_func(target[i - j - 1].e_proc); if ((VALUE)func != Qundef) { (*func)(target[i - j - 1].data2); } } } NORETURN(static VALUE rb_cont_call(int argc, VALUE *argv, VALUE contval)); /* * call-seq: * cont.call(args, ...) * cont[args, ...] * * Invokes the continuation. The program continues from the end of * the #callcc block. If no arguments are given, the original #callcc * returns +nil+. If one argument is given, #callcc returns * it. Otherwise, an array containing args is returned. * * callcc {|cont| cont.call } #=> nil * callcc {|cont| cont.call 1 } #=> 1 * callcc {|cont| cont.call 1, 2, 3 } #=> [1, 2, 3] */ static VALUE rb_cont_call(int argc, VALUE *argv, VALUE contval) { rb_context_t *cont = cont_ptr(contval); rb_thread_t *th = GET_THREAD(); if (cont_thread_value(cont) != th->self) { rb_raise(rb_eRuntimeError, "continuation called across threads"); } if (cont->saved_ec.fiber_ptr) { if (th->ec->fiber_ptr != cont->saved_ec.fiber_ptr) { rb_raise(rb_eRuntimeError, "continuation called across fiber"); } } rollback_ensure_stack(contval, th->ec->ensure_list, cont->ensure_array); cont->argc = argc; cont->value = make_passing_arg(argc, argv); cont_restore_0(cont, &contval); UNREACHABLE_RETURN(Qnil); } /*********/ /* fiber */ /*********/ /* * Document-class: Fiber * * Fibers are primitives for implementing light weight cooperative * concurrency in Ruby. Basically they are a means of creating code blocks * that can be paused and resumed, much like threads. The main difference * is that they are never preempted and that the scheduling must be done by * the programmer and not the VM. * * As opposed to other stackless light weight concurrency models, each fiber * comes with a stack. This enables the fiber to be paused from deeply * nested function calls within the fiber block. See the ruby(1) * manpage to configure the size of the fiber stack(s). * * When a fiber is created it will not run automatically. Rather it must * be explicitly asked to run using the Fiber#resume method. * The code running inside the fiber can give up control by calling * Fiber.yield in which case it yields control back to caller (the * caller of the Fiber#resume). * * Upon yielding or termination the Fiber returns the value of the last * executed expression * * For instance: * * fiber = Fiber.new do * Fiber.yield 1 * 2 * end * * puts fiber.resume * puts fiber.resume * puts fiber.resume * * produces * * 1 * 2 * FiberError: dead fiber called * * The Fiber#resume method accepts an arbitrary number of parameters, * if it is the first call to #resume then they will be passed as * block arguments. Otherwise they will be the return value of the * call to Fiber.yield * * Example: * * fiber = Fiber.new do |first| * second = Fiber.yield first + 2 * end * * puts fiber.resume 10 * puts fiber.resume 1_000_000 * puts fiber.resume "The fiber will be dead before I can cause trouble" * * produces * * 12 * 1000000 * FiberError: dead fiber called * * == Non-blocking Fibers * * The concept of non-blocking fiber was introduced in Ruby 3.0. * A non-blocking fiber, when reaching a operation that would normally block * the fiber (like sleep, or wait for another process or I/O) * will yield control to other fibers and allow the scheduler to * handle blocking and waking up (resuming) this fiber when it can proceed. * * For a Fiber to behave as non-blocking, it need to be created in Fiber.new with * blocking: false (which is the default), and Fiber.scheduler * should be set with Fiber.set_scheduler. If Fiber.scheduler is not set in * the current thread, blocking and non-blocking fibers' behavior is identical. * * Ruby doesn't provide a scheduler class: it is expected to be implemented by * the user and correspond to Fiber::SchedulerInterface. * * There is also Fiber.schedule method, which is expected to immediately perform * the given block in a non-blocking manner. Its actual implementation is up to * the scheduler. * */ static const rb_data_type_t fiber_data_type = { "fiber", {fiber_mark, fiber_free, fiber_memsize, fiber_compact,}, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static VALUE fiber_alloc(VALUE klass) { return TypedData_Wrap_Struct(klass, &fiber_data_type, 0); } static rb_fiber_t* fiber_t_alloc(VALUE fiber_value, unsigned int blocking) { rb_fiber_t *fiber; rb_thread_t *th = GET_THREAD(); if (DATA_PTR(fiber_value) != 0) { rb_raise(rb_eRuntimeError, "cannot initialize twice"); } THREAD_MUST_BE_RUNNING(th); fiber = ZALLOC(rb_fiber_t); fiber->cont.self = fiber_value; fiber->cont.type = FIBER_CONTEXT; fiber->blocking = blocking; cont_init(&fiber->cont, th); fiber->cont.saved_ec.fiber_ptr = fiber; rb_ec_clear_vm_stack(&fiber->cont.saved_ec); fiber->prev = NULL; /* fiber->status == 0 == CREATED * So that we don't need to set status: fiber_status_set(fiber, FIBER_CREATED); */ VM_ASSERT(FIBER_CREATED_P(fiber)); DATA_PTR(fiber_value) = fiber; return fiber; } static VALUE fiber_initialize(VALUE self, VALUE proc, struct fiber_pool * fiber_pool, unsigned int blocking) { rb_fiber_t *fiber = fiber_t_alloc(self, blocking); fiber->first_proc = proc; fiber->stack.base = NULL; fiber->stack.pool = fiber_pool; return self; } static void fiber_prepare_stack(rb_fiber_t *fiber) { rb_context_t *cont = &fiber->cont; rb_execution_context_t *sec = &cont->saved_ec; size_t vm_stack_size = 0; VALUE *vm_stack = fiber_initialize_coroutine(fiber, &vm_stack_size); /* initialize cont */ cont->saved_vm_stack.ptr = NULL; rb_ec_initialize_vm_stack(sec, vm_stack, vm_stack_size / sizeof(VALUE)); sec->tag = NULL; sec->local_storage = NULL; sec->local_storage_recursive_hash = Qnil; sec->local_storage_recursive_hash_for_trace = Qnil; } static struct fiber_pool * rb_fiber_pool_default(VALUE pool) { return &shared_fiber_pool; } /* :nodoc: */ static VALUE rb_fiber_initialize_kw(int argc, VALUE* argv, VALUE self, int kw_splat) { VALUE pool = Qnil; VALUE blocking = Qfalse; if (kw_splat != RB_NO_KEYWORDS) { VALUE options = Qnil; VALUE arguments[2] = {Qundef}; argc = rb_scan_args_kw(kw_splat, argc, argv, ":", &options); rb_get_kwargs(options, fiber_initialize_keywords, 0, 2, arguments); if (arguments[0] != Qundef) { blocking = arguments[0]; } if (arguments[1] != Qundef) { pool = arguments[1]; } } return fiber_initialize(self, rb_block_proc(), rb_fiber_pool_default(pool), RTEST(blocking)); } /* * call-seq: * Fiber.new(blocking: false) { |*args| ... } -> fiber * * Creates new Fiber. Initially, the fiber is not running and can be resumed with * #resume. Arguments to the first #resume call will be passed to the block: * * f = Fiber.new do |initial| * current = initial * loop do * puts "current: #{current.inspect}" * current = Fiber.yield * end * end * f.resume(100) # prints: current: 100 * f.resume(1, 2, 3) # prints: current: [1, 2, 3] * f.resume # prints: current: nil * # ... and so on ... * * If blocking: false is passed to Fiber.new, _and_ current thread * has a Fiber.scheduler defined, the Fiber becomes non-blocking (see "Non-blocking * Fibers" section in class docs). */ static VALUE rb_fiber_initialize(int argc, VALUE* argv, VALUE self) { return rb_fiber_initialize_kw(argc, argv, self, rb_keyword_given_p()); } VALUE rb_fiber_new(rb_block_call_func_t func, VALUE obj) { return fiber_initialize(fiber_alloc(rb_cFiber), rb_proc_new(func, obj), rb_fiber_pool_default(Qnil), 1); } static VALUE rb_fiber_s_schedule_kw(int argc, VALUE* argv, int kw_splat) { rb_thread_t * th = GET_THREAD(); VALUE scheduler = th->scheduler; VALUE fiber = Qnil; if (scheduler != Qnil) { fiber = rb_funcall_passing_block_kw(scheduler, rb_intern("fiber"), argc, argv, kw_splat); } else { rb_raise(rb_eRuntimeError, "No scheduler is available!"); } return fiber; } /* * call-seq: * Fiber.schedule { |*args| ... } -> fiber * * The method is expected to immediately run the provided block of code in a * separate non-blocking fiber. * * puts "Go to sleep!" * * Fiber.set_scheduler(MyScheduler.new) * * Fiber.schedule do * puts "Going to sleep" * sleep(1) * puts "I slept well" * end * * puts "Wakey-wakey, sleepyhead" * * Assuming MyScheduler is properly implemented, this program will produce: * * Go to sleep! * Going to sleep * Wakey-wakey, sleepyhead * ...1 sec pause here... * I slept well * * ...e.g. on the first blocking operation inside the Fiber (sleep(1)), * the control is yielded to the outside code (main fiber), and at the end * of that execution, the scheduler takes care of properly resuming all the * blocked fibers. * * Note that the behavior described above is how the method is expected * to behave, actual behavior is up to the current scheduler's implementation of * Fiber::SchedulerInterface#fiber method. Ruby doesn't enforce this method to * behave in any particular way. * * If the scheduler is not set, the method raises * RuntimeError (No scheduler is available!). * */ static VALUE rb_fiber_s_schedule(int argc, VALUE *argv, VALUE obj) { return rb_fiber_s_schedule_kw(argc, argv, rb_keyword_given_p()); } /* * call-seq: * Fiber.scheduler -> obj or nil * * Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler. * Returns +nil+ if no scheduler is set (which is the default), and non-blocking fibers' # behavior is the same as blocking. * (see "Non-blocking fibers" section in class docs for details about the scheduler concept). * */ static VALUE rb_fiber_s_scheduler(VALUE klass) { return rb_fiber_scheduler_get(); } /* * call-seq: * Fiber.current_scheduler -> obj or nil * * Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler * if and only if the current fiber is non-blocking. * */ static VALUE rb_fiber_current_scheduler(VALUE klass) { return rb_fiber_scheduler_current(); } /* * call-seq: * Fiber.set_scheduler(scheduler) -> scheduler * * Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking * fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) * call that scheduler's hook methods on potentially blocking operations, and the current * thread will call scheduler's +close+ method on finalization (allowing the scheduler to * properly manage all non-finished fibers). * * +scheduler+ can be an object of any class corresponding to Fiber::SchedulerInterface. Its * implementation is up to the user. * * See also the "Non-blocking fibers" section in class docs. * */ static VALUE rb_fiber_set_scheduler(VALUE klass, VALUE scheduler) { return rb_fiber_scheduler_set(scheduler); } static void rb_fiber_terminate(rb_fiber_t *fiber, int need_interrupt, VALUE err); void rb_fiber_start(rb_fiber_t *fiber) { rb_thread_t * volatile th = fiber->cont.saved_ec.thread_ptr; rb_proc_t *proc; enum ruby_tag_type state; int need_interrupt = TRUE; VM_ASSERT(th->ec == GET_EC()); VM_ASSERT(FIBER_RESUMED_P(fiber)); if (fiber->blocking) { th->blocking += 1; } EC_PUSH_TAG(th->ec); if ((state = EC_EXEC_TAG()) == TAG_NONE) { rb_context_t *cont = &VAR_FROM_MEMORY(fiber)->cont; int argc; const VALUE *argv, args = cont->value; GetProcPtr(fiber->first_proc, proc); argv = (argc = cont->argc) > 1 ? RARRAY_CONST_PTR(args) : &args; cont->value = Qnil; th->ec->errinfo = Qnil; th->ec->root_lep = rb_vm_proc_local_ep(fiber->first_proc); th->ec->root_svar = Qfalse; EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil); cont->value = rb_vm_invoke_proc(th->ec, proc, argc, argv, cont->kw_splat, VM_BLOCK_HANDLER_NONE); } EC_POP_TAG(); VALUE err = Qfalse; if (state) { err = th->ec->errinfo; VM_ASSERT(FIBER_RESUMED_P(fiber)); if (state == TAG_RAISE) { // noop... } else if (state == TAG_FATAL) { rb_threadptr_pending_interrupt_enque(th, err); } else { err = rb_vm_make_jump_tag_but_local_jump(state, err); } need_interrupt = TRUE; } rb_fiber_terminate(fiber, need_interrupt, err); } static rb_fiber_t * root_fiber_alloc(rb_thread_t *th) { VALUE fiber_value = fiber_alloc(rb_cFiber); rb_fiber_t *fiber = th->ec->fiber_ptr; VM_ASSERT(DATA_PTR(fiber_value) == NULL); VM_ASSERT(fiber->cont.type == FIBER_CONTEXT); VM_ASSERT(fiber->status == FIBER_RESUMED); th->root_fiber = fiber; DATA_PTR(fiber_value) = fiber; fiber->cont.self = fiber_value; coroutine_initialize_main(&fiber->context); return fiber; } void rb_threadptr_root_fiber_setup(rb_thread_t *th) { rb_fiber_t *fiber = ruby_mimmalloc(sizeof(rb_fiber_t)); if (!fiber) { rb_bug("%s", strerror(errno)); /* ... is it possible to call rb_bug here? */ } MEMZERO(fiber, rb_fiber_t, 1); fiber->cont.type = FIBER_CONTEXT; fiber->cont.saved_ec.fiber_ptr = fiber; fiber->cont.saved_ec.thread_ptr = th; fiber->blocking = 1; fiber_status_set(fiber, FIBER_RESUMED); /* skip CREATED */ th->ec = &fiber->cont.saved_ec; // This skips mjit_cont_new for the initial thread because mjit_enabled is always false // at this point. mjit_init calls rb_fiber_init_mjit_cont again for this root_fiber. rb_fiber_init_mjit_cont(fiber); } void rb_threadptr_root_fiber_release(rb_thread_t *th) { if (th->root_fiber) { /* ignore. A root fiber object will free th->ec */ } else { rb_execution_context_t *ec = GET_EC(); VM_ASSERT(th->ec->fiber_ptr->cont.type == FIBER_CONTEXT); VM_ASSERT(th->ec->fiber_ptr->cont.self == 0); if (th->ec == ec) { rb_ractor_set_current_ec(th->ractor, NULL); } fiber_free(th->ec->fiber_ptr); th->ec = NULL; } } void rb_threadptr_root_fiber_terminate(rb_thread_t *th) { rb_fiber_t *fiber = th->ec->fiber_ptr; fiber->status = FIBER_TERMINATED; // The vm_stack is `alloca`ed on the thread stack, so it's gone too: rb_ec_clear_vm_stack(th->ec); } static inline rb_fiber_t* fiber_current(void) { rb_execution_context_t *ec = GET_EC(); if (ec->fiber_ptr->cont.self == 0) { root_fiber_alloc(rb_ec_thread_ptr(ec)); } return ec->fiber_ptr; } static inline rb_fiber_t* return_fiber(bool terminate) { rb_fiber_t *fiber = fiber_current(); rb_fiber_t *prev = fiber->prev; if (prev) { fiber->prev = NULL; prev->resuming_fiber = NULL; return prev; } else { if (!terminate) { rb_raise(rb_eFiberError, "attempt to yield on a not resumed fiber"); } rb_thread_t *th = GET_THREAD(); rb_fiber_t *root_fiber = th->root_fiber; VM_ASSERT(root_fiber != NULL); // search resuming fiber for (fiber = root_fiber; fiber->resuming_fiber; fiber = fiber->resuming_fiber) { } return fiber; } } VALUE rb_fiber_current(void) { return fiber_current()->cont.self; } // Prepare to execute next_fiber on the given thread. static inline void fiber_store(rb_fiber_t *next_fiber, rb_thread_t *th) { rb_fiber_t *fiber; if (th->ec->fiber_ptr != NULL) { fiber = th->ec->fiber_ptr; } else { /* create root fiber */ fiber = root_fiber_alloc(th); } if (FIBER_CREATED_P(next_fiber)) { fiber_prepare_stack(next_fiber); } VM_ASSERT(FIBER_RESUMED_P(fiber) || FIBER_TERMINATED_P(fiber)); VM_ASSERT(FIBER_RUNNABLE_P(next_fiber)); if (FIBER_RESUMED_P(fiber)) fiber_status_set(fiber, FIBER_SUSPENDED); fiber_status_set(next_fiber, FIBER_RESUMED); fiber_setcontext(next_fiber, fiber); } static inline VALUE fiber_switch(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat, rb_fiber_t *resuming_fiber, bool yielding) { VALUE value; rb_context_t *cont = &fiber->cont; rb_thread_t *th = GET_THREAD(); /* make sure the root_fiber object is available */ if (th->root_fiber == NULL) root_fiber_alloc(th); if (th->ec->fiber_ptr == fiber) { /* ignore fiber context switch * because destination fiber is the same as current fiber */ return make_passing_arg(argc, argv); } if (cont_thread_value(cont) != th->self) { rb_raise(rb_eFiberError, "fiber called across threads"); } if (FIBER_TERMINATED_P(fiber)) { value = rb_exc_new2(rb_eFiberError, "dead fiber called"); if (!FIBER_TERMINATED_P(th->ec->fiber_ptr)) { rb_exc_raise(value); VM_UNREACHABLE(fiber_switch); } else { /* th->ec->fiber_ptr is also dead => switch to root fiber */ /* (this means we're being called from rb_fiber_terminate, */ /* and the terminated fiber's return_fiber() is already dead) */ VM_ASSERT(FIBER_SUSPENDED_P(th->root_fiber)); cont = &th->root_fiber->cont; cont->argc = -1; cont->value = value; fiber_setcontext(th->root_fiber, th->ec->fiber_ptr); VM_UNREACHABLE(fiber_switch); } } VM_ASSERT(FIBER_RUNNABLE_P(fiber)); rb_fiber_t *current_fiber = fiber_current(); VM_ASSERT(!current_fiber->resuming_fiber); if (resuming_fiber) { current_fiber->resuming_fiber = resuming_fiber; fiber->prev = fiber_current(); fiber->yielding = 0; } VM_ASSERT(!current_fiber->yielding); if (yielding) { current_fiber->yielding = 1; } if (current_fiber->blocking) { th->blocking -= 1; } cont->argc = argc; cont->kw_splat = kw_splat; cont->value = make_passing_arg(argc, argv); fiber_store(fiber, th); // We cannot free the stack until the pthread is joined: #ifndef COROUTINE_PTHREAD_CONTEXT if (resuming_fiber && FIBER_TERMINATED_P(fiber)) { fiber_stack_release(fiber); } #endif if (fiber_current()->blocking) { th->blocking += 1; } RUBY_VM_CHECK_INTS(th->ec); EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil); current_fiber = th->ec->fiber_ptr; value = current_fiber->cont.value; if (current_fiber->cont.argc == -1) rb_exc_raise(value); return value; } VALUE rb_fiber_transfer(VALUE fiber_value, int argc, const VALUE *argv) { return fiber_switch(fiber_ptr(fiber_value), argc, argv, RB_NO_KEYWORDS, NULL, false); } /* * call-seq: * fiber.blocking? -> true or false * * Returns +true+ if +fiber+ is blocking and +false+ otherwise. * Fiber is non-blocking if it was created via passing blocking: false * to Fiber.new, or via Fiber.schedule. * * Note that, even if the method returns +false+, the fiber behaves differently * only if Fiber.scheduler is set in the current thread. * * See the "Non-blocking fibers" section in class docs for details. * */ VALUE rb_fiber_blocking_p(VALUE fiber) { return RBOOL(fiber_ptr(fiber)->blocking != 0); } /* * call-seq: * Fiber.blocking? -> false or 1 * * Returns +false+ if the current fiber is non-blocking. * Fiber is non-blocking if it was created via passing blocking: false * to Fiber.new, or via Fiber.schedule. * * If the current Fiber is blocking, the method returns 1. * Future developments may allow for situations where larger integers * could be returned. * * Note that, even if the method returns +false+, Fiber behaves differently * only if Fiber.scheduler is set in the current thread. * * See the "Non-blocking fibers" section in class docs for details. * */ static VALUE rb_fiber_s_blocking_p(VALUE klass) { rb_thread_t *thread = GET_THREAD(); unsigned blocking = thread->blocking; if (blocking == 0) return Qfalse; return INT2NUM(blocking); } void rb_fiber_close(rb_fiber_t *fiber) { fiber_status_set(fiber, FIBER_TERMINATED); } static void rb_fiber_terminate(rb_fiber_t *fiber, int need_interrupt, VALUE error) { VALUE value = fiber->cont.value; VM_ASSERT(FIBER_RESUMED_P(fiber)); rb_fiber_close(fiber); fiber->cont.machine.stack = NULL; fiber->cont.machine.stack_size = 0; rb_fiber_t *next_fiber = return_fiber(true); if (need_interrupt) RUBY_VM_SET_INTERRUPT(&next_fiber->cont.saved_ec); if (RTEST(error)) fiber_switch(next_fiber, -1, &error, RB_NO_KEYWORDS, NULL, false); else fiber_switch(next_fiber, 1, &value, RB_NO_KEYWORDS, NULL, false); } static VALUE fiber_resume_kw(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat) { rb_fiber_t *current_fiber = fiber_current(); if (argc == -1 && FIBER_CREATED_P(fiber)) { rb_raise(rb_eFiberError, "cannot raise exception on unborn fiber"); } else if (FIBER_TERMINATED_P(fiber)) { rb_raise(rb_eFiberError, "attempt to resume a terminated fiber"); } else if (fiber == current_fiber) { rb_raise(rb_eFiberError, "attempt to resume the current fiber"); } else if (fiber->prev != NULL) { rb_raise(rb_eFiberError, "attempt to resume a resumed fiber (double resume)"); } else if (fiber->resuming_fiber) { rb_raise(rb_eFiberError, "attempt to resume a resuming fiber"); } else if (fiber->prev == NULL && (!fiber->yielding && fiber->status != FIBER_CREATED)) { rb_raise(rb_eFiberError, "attempt to resume a transferring fiber"); } VALUE result = fiber_switch(fiber, argc, argv, kw_splat, fiber, false); return result; } VALUE rb_fiber_resume_kw(VALUE self, int argc, const VALUE *argv, int kw_splat) { return fiber_resume_kw(fiber_ptr(self), argc, argv, kw_splat); } VALUE rb_fiber_resume(VALUE self, int argc, const VALUE *argv) { return fiber_resume_kw(fiber_ptr(self), argc, argv, RB_NO_KEYWORDS); } VALUE rb_fiber_yield_kw(int argc, const VALUE *argv, int kw_splat) { return fiber_switch(return_fiber(false), argc, argv, kw_splat, NULL, true); } VALUE rb_fiber_yield(int argc, const VALUE *argv) { return fiber_switch(return_fiber(false), argc, argv, RB_NO_KEYWORDS, NULL, true); } void rb_fiber_reset_root_local_storage(rb_thread_t *th) { if (th->root_fiber && th->root_fiber != th->ec->fiber_ptr) { th->ec->local_storage = th->root_fiber->cont.saved_ec.local_storage; } } /* * call-seq: * fiber.alive? -> true or false * * Returns true if the fiber can still be resumed (or transferred * to). After finishing execution of the fiber block this method will * always return +false+. */ VALUE rb_fiber_alive_p(VALUE fiber_value) { return FIBER_TERMINATED_P(fiber_ptr(fiber_value)) ? Qfalse : Qtrue; } /* * call-seq: * fiber.resume(args, ...) -> obj * * Resumes the fiber from the point at which the last Fiber.yield was * called, or starts running it if it is the first call to * #resume. Arguments passed to resume will be the value of the * Fiber.yield expression or will be passed as block parameters to * the fiber's block if this is the first #resume. * * Alternatively, when resume is called it evaluates to the arguments passed * to the next Fiber.yield statement inside the fiber's block * or to the block value if it runs to completion without any * Fiber.yield */ static VALUE rb_fiber_m_resume(int argc, VALUE *argv, VALUE fiber) { return rb_fiber_resume_kw(fiber, argc, argv, rb_keyword_given_p()); } /* * call-seq: * fiber.backtrace -> array * fiber.backtrace(start) -> array * fiber.backtrace(start, count) -> array * fiber.backtrace(start..end) -> array * * Returns the current execution stack of the fiber. +start+, +count+ and +end+ allow * to select only parts of the backtrace. * * def level3 * Fiber.yield * end * * def level2 * level3 * end * * def level1 * level2 * end * * f = Fiber.new { level1 } * * # It is empty before the fiber started * f.backtrace * #=> [] * * f.resume * * f.backtrace * #=> ["test.rb:2:in `yield'", "test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'", "test.rb:13:in `block in
'"] * p f.backtrace(1) # start from the item 1 * #=> ["test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'", "test.rb:13:in `block in
'"] * p f.backtrace(2, 2) # start from item 2, take 2 * #=> ["test.rb:6:in `level2'", "test.rb:10:in `level1'"] * p f.backtrace(1..3) # take items from 1 to 3 * #=> ["test.rb:2:in `level3'", "test.rb:6:in `level2'", "test.rb:10:in `level1'"] * * f.resume * * # It is nil after the fiber is finished * f.backtrace * #=> nil * */ static VALUE rb_fiber_backtrace(int argc, VALUE *argv, VALUE fiber) { return rb_vm_backtrace(argc, argv, &fiber_ptr(fiber)->cont.saved_ec); } /* * call-seq: * fiber.backtrace_locations -> array * fiber.backtrace_locations(start) -> array * fiber.backtrace_locations(start, count) -> array * fiber.backtrace_locations(start..end) -> array * * Like #backtrace, but returns each line of the execution stack as a * Thread::Backtrace::Location. Accepts the same arguments as #backtrace. * * f = Fiber.new { Fiber.yield } * f.resume * loc = f.backtrace_locations.first * loc.label #=> "yield" * loc.path #=> "test.rb" * loc.lineno #=> 1 * * */ static VALUE rb_fiber_backtrace_locations(int argc, VALUE *argv, VALUE fiber) { return rb_vm_backtrace_locations(argc, argv, &fiber_ptr(fiber)->cont.saved_ec); } /* * call-seq: * fiber.transfer(args, ...) -> obj * * Transfer control to another fiber, resuming it from where it last * stopped or starting it if it was not resumed before. The calling * fiber will be suspended much like in a call to * Fiber.yield. * * The fiber which receives the transfer call treats it much like * a resume call. Arguments passed to transfer are treated like those * passed to resume. * * The two style of control passing to and from fiber (one is #resume and * Fiber::yield, another is #transfer to and from fiber) can't be freely * mixed. * * * If the Fiber's lifecycle had started with transfer, it will never * be able to yield or be resumed control passing, only * finish or transfer back. (It still can resume other fibers that * are allowed to be resumed.) * * If the Fiber's lifecycle had started with resume, it can yield * or transfer to another Fiber, but can receive control back only * the way compatible with the way it was given away: if it had * transferred, it only can be transferred back, and if it had * yielded, it only can be resumed back. After that, it again can * transfer or yield. * * If those rules are broken FiberError is raised. * * For an individual Fiber design, yield/resume is easier to use * (the Fiber just gives away control, it doesn't need to think * about who the control is given to), while transfer is more flexible * for complex cases, allowing to build arbitrary graphs of Fibers * dependent on each other. * * * Example: * * manager = nil # For local var to be visible inside worker block * * # This fiber would be started with transfer * # It can't yield, and can't be resumed * worker = Fiber.new { |work| * puts "Worker: starts" * puts "Worker: Performed #{work.inspect}, transferring back" * # Fiber.yield # this would raise FiberError: attempt to yield on a not resumed fiber * # manager.resume # this would raise FiberError: attempt to resume a resumed fiber (double resume) * manager.transfer(work.capitalize) * } * * # This fiber would be started with resume * # It can yield or transfer, and can be transferred * # back or resumed * manager = Fiber.new { * puts "Manager: starts" * puts "Manager: transferring 'something' to worker" * result = worker.transfer('something') * puts "Manager: worker returned #{result.inspect}" * # worker.resume # this would raise FiberError: attempt to resume a transferring fiber * Fiber.yield # this is OK, the fiber transferred from and to, now it can yield * puts "Manager: finished" * } * * puts "Starting the manager" * manager.resume * puts "Resuming the manager" * # manager.transfer # this would raise FiberError: attempt to transfer to a yielding fiber * manager.resume * * produces * * Starting the manager * Manager: starts * Manager: transferring 'something' to worker * Worker: starts * Worker: Performed "something", transferring back * Manager: worker returned "Something" * Resuming the manager * Manager: finished * */ static VALUE rb_fiber_m_transfer(int argc, VALUE *argv, VALUE self) { return rb_fiber_transfer_kw(self, argc, argv, rb_keyword_given_p()); } static VALUE fiber_transfer_kw(rb_fiber_t *fiber, int argc, const VALUE *argv, int kw_splat) { if (fiber->resuming_fiber) { rb_raise(rb_eFiberError, "attempt to transfer to a resuming fiber"); } if (fiber->yielding) { rb_raise(rb_eFiberError, "attempt to transfer to a yielding fiber"); } return fiber_switch(fiber, argc, argv, kw_splat, NULL, false); } VALUE rb_fiber_transfer_kw(VALUE self, int argc, const VALUE *argv, int kw_splat) { return fiber_transfer_kw(fiber_ptr(self), argc, argv, kw_splat); } /* * call-seq: * Fiber.yield(args, ...) -> obj * * Yields control back to the context that resumed the fiber, passing * along any arguments that were passed to it. The fiber will resume * processing at this point when #resume is called next. * Any arguments passed to the next #resume will be the value that * this Fiber.yield expression evaluates to. */ static VALUE rb_fiber_s_yield(int argc, VALUE *argv, VALUE klass) { return rb_fiber_yield_kw(argc, argv, rb_keyword_given_p()); } static VALUE fiber_raise(rb_fiber_t *fiber, int argc, const VALUE *argv) { VALUE exception = rb_make_exception(argc, argv); if (fiber->resuming_fiber) { rb_raise(rb_eFiberError, "attempt to raise a resuming fiber"); } else if (FIBER_SUSPENDED_P(fiber) && !fiber->yielding) { return fiber_transfer_kw(fiber, -1, &exception, RB_NO_KEYWORDS); } else { return fiber_resume_kw(fiber, -1, &exception, RB_NO_KEYWORDS); } } VALUE rb_fiber_raise(VALUE fiber, int argc, const VALUE *argv) { return fiber_raise(fiber_ptr(fiber), argc, argv); } /* * call-seq: * fiber.raise -> obj * fiber.raise(string) -> obj * fiber.raise(exception [, string [, array]]) -> obj * * Raises an exception in the fiber at the point at which the last * +Fiber.yield+ was called. If the fiber has not been started or has * already run to completion, raises +FiberError+. If the fiber is * yielding, it is resumed. If it is transferring, it is transferred into. * But if it is resuming, raises +FiberError+. * * With no arguments, raises a +RuntimeError+. With a single +String+ * argument, raises a +RuntimeError+ with the string as a message. Otherwise, * the first parameter should be the name of an +Exception+ class (or an * object that returns an +Exception+ object when sent an +exception+ * message). The optional second parameter sets the message associated with * the exception, and the third parameter is an array of callback information. * Exceptions are caught by the +rescue+ clause of begin...end * blocks. */ static VALUE rb_fiber_m_raise(int argc, VALUE *argv, VALUE self) { return rb_fiber_raise(self, argc, argv); } /* * call-seq: * Fiber.current -> fiber * * Returns the current fiber. If you are not running in the context of * a fiber this method will return the root fiber. */ static VALUE rb_fiber_s_current(VALUE klass) { return rb_fiber_current(); } static VALUE fiber_to_s(VALUE fiber_value) { const rb_fiber_t *fiber = fiber_ptr(fiber_value); const rb_proc_t *proc; char status_info[0x20]; if (fiber->resuming_fiber) { snprintf(status_info, 0x20, " (%s by resuming)", fiber_status_name(fiber->status)); } else { snprintf(status_info, 0x20, " (%s)", fiber_status_name(fiber->status)); } if (!rb_obj_is_proc(fiber->first_proc)) { VALUE str = rb_any_to_s(fiber_value); strlcat(status_info, ">", sizeof(status_info)); rb_str_set_len(str, RSTRING_LEN(str)-1); rb_str_cat_cstr(str, status_info); return str; } GetProcPtr(fiber->first_proc, proc); return rb_block_to_s(fiber_value, &proc->block, status_info); } #ifdef HAVE_WORKING_FORK void rb_fiber_atfork(rb_thread_t *th) { if (th->root_fiber) { if (&th->root_fiber->cont.saved_ec != th->ec) { th->root_fiber = th->ec->fiber_ptr; } th->root_fiber->prev = 0; } } #endif #ifdef RB_EXPERIMENTAL_FIBER_POOL static void fiber_pool_free(void *ptr) { struct fiber_pool * fiber_pool = ptr; RUBY_FREE_ENTER("fiber_pool"); fiber_pool_free_allocations(fiber_pool->allocations); ruby_xfree(fiber_pool); RUBY_FREE_LEAVE("fiber_pool"); } static size_t fiber_pool_memsize(const void *ptr) { const struct fiber_pool * fiber_pool = ptr; size_t size = sizeof(*fiber_pool); size += fiber_pool->count * fiber_pool->size; return size; } static const rb_data_type_t FiberPoolDataType = { "fiber_pool", {NULL, fiber_pool_free, fiber_pool_memsize,}, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static VALUE fiber_pool_alloc(VALUE klass) { struct fiber_pool * fiber_pool = RB_ALLOC(struct fiber_pool); return TypedData_Wrap_Struct(klass, &FiberPoolDataType, fiber_pool); } static VALUE rb_fiber_pool_initialize(int argc, VALUE* argv, VALUE self) { rb_thread_t *th = GET_THREAD(); VALUE size = Qnil, count = Qnil, vm_stack_size = Qnil; struct fiber_pool * fiber_pool = NULL; // Maybe these should be keyword arguments. rb_scan_args(argc, argv, "03", &size, &count, &vm_stack_size); if (NIL_P(size)) { size = INT2NUM(th->vm->default_params.fiber_machine_stack_size); } if (NIL_P(count)) { count = INT2NUM(128); } if (NIL_P(vm_stack_size)) { vm_stack_size = INT2NUM(th->vm->default_params.fiber_vm_stack_size); } TypedData_Get_Struct(self, struct fiber_pool, &FiberPoolDataType, fiber_pool); fiber_pool_initialize(fiber_pool, NUM2SIZET(size), NUM2SIZET(count), NUM2SIZET(vm_stack_size)); return self; } #endif /* * Document-class: FiberError * * Raised when an invalid operation is attempted on a Fiber, in * particular when attempting to call/resume a dead fiber, * attempting to yield from the root fiber, or calling a fiber across * threads. * * fiber = Fiber.new{} * fiber.resume #=> nil * fiber.resume #=> FiberError: dead fiber called */ /* * Document-class: Fiber::SchedulerInterface * * This is not an existing class, but documentation of the interface that Scheduler * object should comply to in order to be used as argument to Fiber.scheduler and handle non-blocking * fibers. See also the "Non-blocking fibers" section in Fiber class docs for explanations * of some concepts. * * Scheduler's behavior and usage are expected to be as follows: * * * When the execution in the non-blocking Fiber reaches some blocking operation (like * sleep, wait for a process, or a non-ready I/O), it calls some of the scheduler's * hook methods, listed below. * * Scheduler somehow registers what the current fiber is waiting on, and yields control * to other fibers with Fiber.yield (so the fiber would be suspended while expecting its * wait to end, and other fibers in the same thread can perform) * * At the end of the current thread execution, the scheduler's method #close is called * * The scheduler runs into a wait loop, checking all the blocked fibers (which it has * registered on hook calls) and resuming them when the awaited resource is ready * (e.g. I/O ready or sleep time elapsed). * * A typical implementation would probably rely for this closing loop on a gem like * EventMachine[https://github.com/eventmachine/eventmachine] or * Async[https://github.com/socketry/async]. * * This way concurrent execution will be achieved transparently for every * individual Fiber's code. * * Hook methods are: * * * #io_wait, #io_read, and #io_write * * #process_wait * * #kernel_sleep * * #timeout_after * * #address_resolve * * #block and #unblock * * (the list is expanded as Ruby developers make more methods having non-blocking calls) * * When not specified otherwise, the hook implementations are mandatory: if they are not * implemented, the methods trying to call hook will fail. To provide backward compatibility, * in the future hooks will be optional (if they are not implemented, due to the scheduler * being created for the older Ruby version, the code which needs this hook will not fail, * and will just behave in a blocking fashion). * * It is also strongly recommended that the scheduler implements the #fiber method, which is * delegated to by Fiber.schedule. * * Sample _toy_ implementation of the scheduler can be found in Ruby's code, in * test/fiber/scheduler.rb * */ #if 0 /* for RDoc */ /* * * Document-method: Fiber::SchedulerInterface#close * * Called when the current thread exits. The scheduler is expected to implement this * method in order to allow all waiting fibers to finalize their execution. * * The suggested pattern is to implement the main event loop in the #close method. * */ static VALUE rb_fiber_scheduler_interface_close(VALUE self) { } /* * Document-method: SchedulerInterface#process_wait * call-seq: process_wait(pid, flags) * * Invoked by Process::Status.wait in order to wait for a specified process. * See that method description for arguments description. * * Suggested minimal implementation: * * Thread.new do * Process::Status.wait(pid, flags) * end.value * * This hook is optional: if it is not present in the current scheduler, * Process::Status.wait will behave as a blocking method. * * Expected to return a Process::Status instance. */ static VALUE rb_fiber_scheduler_interface_process_wait(VALUE self) { } /* * Document-method: SchedulerInterface#io_wait * call-seq: io_wait(io, events, timeout) * * Invoked by IO#wait, IO#wait_readable, IO#wait_writable to ask whether the * specified descriptor is ready for specified events within * the specified +timeout+. * * +events+ is a bit mask of IO::READABLE, IO::WRITABLE, and * IO::PRIORITY. * * Suggested implementation should register which Fiber is waiting for which * resources and immediately calling Fiber.yield to pass control to other * fibers. Then, in the #close method, the scheduler might dispatch all the * I/O resources to fibers waiting for it. * * Expected to return the subset of events that are ready immediately. * */ static VALUE rb_fiber_scheduler_interface_io_wait(VALUE self) { } /* * Document-method: SchedulerInterface#io_read * call-seq: io_read(io, buffer, length) -> read length or -errno * * Invoked by IO#read to read +length+ bytes from +io+ into a specified * +buffer+ (see IO::Buffer). * * The +length+ argument is the "minimum length to be read". * If the IO buffer size is 8KiB, but the +length+ is +1024+ (1KiB), up to * 8KiB might be read, but at least 1KiB will be. * Generally, the only case where less data than +length+ will be read is if * there is an error reading the data. * * Specifying a +length+ of 0 is valid and means try reading at least once * and return any available data. * * Suggested implementation should try to read from +io+ in a non-blocking * manner and call #io_wait if the +io+ is not ready (which will yield control * to other fibers). * * See IO::Buffer for an interface available to return data. * * Expected to return number of bytes read, or, in case of an error, -errno * (negated number corresponding to system's error code). * * The method should be considered _experimental_. */ static VALUE rb_fiber_scheduler_interface_io_read(VALUE self) { } /* * Document-method: SchedulerInterface#io_write * call-seq: io_write(io, buffer, length) -> written length or -errno * * Invoked by IO#write to write +length+ bytes to +io+ from * from a specified +buffer+ (see IO::Buffer). * * The +length+ argument is the "(minimum) length to be written". * If the IO buffer size is 8KiB, but the +length+ specified is 1024 (1KiB), * at most 8KiB will be written, but at least 1KiB will be. * Generally, the only case where less data than +length+ will be written is if * there is an error writing the data. * * Specifying a +length+ of 0 is valid and means try writing at least once, * as much data as possible. * * Suggested implementation should try to write to +io+ in a non-blocking * manner and call #io_wait if the +io+ is not ready (which will yield control * to other fibers). * * See IO::Buffer for an interface available to get data from buffer efficiently. * * Expected to return number of bytes written, or, in case of an error, -errno * (negated number corresponding to system's error code). * * The method should be considered _experimental_. */ static VALUE rb_fiber_scheduler_interface_io_write(VALUE self) { } /* * Document-method: SchedulerInterface#kernel_sleep * call-seq: kernel_sleep(duration = nil) * * Invoked by Kernel#sleep and Mutex#sleep and is expected to provide * an implementation of sleeping in a non-blocking way. Implementation might * register the current fiber in some list of "which fiber wait until what * moment", call Fiber.yield to pass control, and then in #close resume * the fibers whose wait period has elapsed. * */ static VALUE rb_fiber_scheduler_interface_kernel_sleep(VALUE self) { } /* * Document-method: SchedulerInterface#address_resolve * call-seq: address_resolve(hostname) -> array_of_stings or nil * * Invoked by Socket::getaddrinfo and is expected to provide hostname resolution * in a non-blocking way. * * The method is expected to return an array of strings corresponding to ip * addresses the +hostname+ is resolved to, or +nil+ if it can not be resolved. * * The method support should be considered _experimental_. */ static VALUE rb_fiber_scheduler_interface_address_resolve(VALUE self) { } /* * Document-method: SchedulerInterface#address_resolve * call-seq: timeout_after(duration, exception_class, *exception_arguments, &block) -> result of block * * Limit the execution time of a given +block+ to the given +duration+ if * possible. When a non-blocking operation causes the +block+'s execution time * to exceed the specified +duration+, that non-blocking operation should be * interrupted by raising the specified +exception_class+ constructed with the * given +exception_arguments+. * * General execution timeouts are often considered risky. This implementation * will only interrupt non-blocking operations. This is by design because it's * expected that non-blocking operations can fail for a variety of * unpredictable reasons, so applications should already be robust in handling * these conditions. * * However, as a result of this design, if the +block+ does not invoke any * non-blocking operations, it will be impossible to interrupt it. If you * desire to provide predictable points for timeouts, consider adding * +sleep(0)+. * * This hook is invoked by Timeout.timeout and can also be invoked directly by * the scheduler. * * If the block is executed successfully, its result will be returned. * * The exception will typically be raised using Fiber#raise. */ static VALUE rb_fiber_scheduler_interface_timeout_after(VALUE self) { } /* * Document-method: SchedulerInterface#block * call-seq: block(blocker, timeout = nil) * * Invoked by methods like Thread.join, and by Mutex, to signify that current * Fiber is blocked until further notice (e.g. #unblock) or until +timeout+ has * elapsed. * * +blocker+ is what we are waiting on, informational only (for debugging and * logging). There are no guarantee about its value. * * Expected to return boolean, specifying whether the blocking operation was * successful or not. */ static VALUE rb_fiber_scheduler_interface_block(VALUE self) { } /* * Document-method: SchedulerInterface#unblock * call-seq: unblock(blocker, fiber) * * Invoked to wake up Fiber previously blocked with #block (for example, Mutex#lock * calls #block and Mutex#unlock calls #unblock). The scheduler should use * the +fiber+ parameter to understand which fiber is unblocked. * * +blocker+ is what was awaited for, but it is informational only (for debugging * and logging), and it is not guaranteed to be the same value as the +blocker+ for * #block. * */ static VALUE rb_fiber_scheduler_interface_unblock(VALUE self) { } /* * Document-method: SchedulerInterface#fiber * call-seq: fiber(&block) * * Implementation of the Fiber.schedule. The method is expected to immediately * run the given block of code in a separate non-blocking fiber, and to return that Fiber. * * Minimal suggested implementation is: * * def fiber(&block) * fiber = Fiber.new(blocking: false, &block) * fiber.resume * fiber * end */ static VALUE rb_fiber_scheduler_interface_fiber(VALUE self) { } #endif void Init_Cont(void) { rb_thread_t *th = GET_THREAD(); size_t vm_stack_size = th->vm->default_params.fiber_vm_stack_size; size_t machine_stack_size = th->vm->default_params.fiber_machine_stack_size; size_t stack_size = machine_stack_size + vm_stack_size; #ifdef _WIN32 SYSTEM_INFO info; GetSystemInfo(&info); pagesize = info.dwPageSize; #else /* not WIN32 */ pagesize = sysconf(_SC_PAGESIZE); #endif SET_MACHINE_STACK_END(&th->ec->machine.stack_end); fiber_pool_initialize(&shared_fiber_pool, stack_size, FIBER_POOL_INITIAL_SIZE, vm_stack_size); fiber_initialize_keywords[0] = rb_intern_const("blocking"); fiber_initialize_keywords[1] = rb_intern_const("pool"); const char *fiber_shared_fiber_pool_free_stacks = getenv("RUBY_SHARED_FIBER_POOL_FREE_STACKS"); if (fiber_shared_fiber_pool_free_stacks) { shared_fiber_pool.free_stacks = atoi(fiber_shared_fiber_pool_free_stacks); } rb_cFiber = rb_define_class("Fiber", rb_cObject); rb_define_alloc_func(rb_cFiber, fiber_alloc); rb_eFiberError = rb_define_class("FiberError", rb_eStandardError); rb_define_singleton_method(rb_cFiber, "yield", rb_fiber_s_yield, -1); rb_define_singleton_method(rb_cFiber, "current", rb_fiber_s_current, 0); rb_define_method(rb_cFiber, "initialize", rb_fiber_initialize, -1); rb_define_method(rb_cFiber, "blocking?", rb_fiber_blocking_p, 0); rb_define_method(rb_cFiber, "resume", rb_fiber_m_resume, -1); rb_define_method(rb_cFiber, "raise", rb_fiber_m_raise, -1); rb_define_method(rb_cFiber, "backtrace", rb_fiber_backtrace, -1); rb_define_method(rb_cFiber, "backtrace_locations", rb_fiber_backtrace_locations, -1); rb_define_method(rb_cFiber, "to_s", fiber_to_s, 0); rb_define_alias(rb_cFiber, "inspect", "to_s"); rb_define_method(rb_cFiber, "transfer", rb_fiber_m_transfer, -1); rb_define_method(rb_cFiber, "alive?", rb_fiber_alive_p, 0); rb_define_singleton_method(rb_cFiber, "blocking?", rb_fiber_s_blocking_p, 0); rb_define_singleton_method(rb_cFiber, "scheduler", rb_fiber_s_scheduler, 0); rb_define_singleton_method(rb_cFiber, "set_scheduler", rb_fiber_set_scheduler, 1); rb_define_singleton_method(rb_cFiber, "current_scheduler", rb_fiber_current_scheduler, 0); rb_define_singleton_method(rb_cFiber, "schedule", rb_fiber_s_schedule, -1); #if 0 /* for RDoc */ rb_cFiberScheduler = rb_define_class_under(rb_cFiber, "SchedulerInterface", rb_cObject); rb_define_method(rb_cFiberScheduler, "close", rb_fiber_scheduler_interface_close, 0); rb_define_method(rb_cFiberScheduler, "process_wait", rb_fiber_scheduler_interface_process_wait, 0); rb_define_method(rb_cFiberScheduler, "io_wait", rb_fiber_scheduler_interface_io_wait, 0); rb_define_method(rb_cFiberScheduler, "io_read", rb_fiber_scheduler_interface_io_read, 0); rb_define_method(rb_cFiberScheduler, "io_write", rb_fiber_scheduler_interface_io_write, 0); rb_define_method(rb_cFiberScheduler, "kernel_sleep", rb_fiber_scheduler_interface_kernel_sleep, 0); rb_define_method(rb_cFiberScheduler, "address_resolve", rb_fiber_scheduler_interface_address_resolve, 0); rb_define_method(rb_cFiberScheduler, "timeout_after", rb_fiber_scheduler_interface_timeout_after, 0); rb_define_method(rb_cFiberScheduler, "block", rb_fiber_scheduler_interface_block, 0); rb_define_method(rb_cFiberScheduler, "unblock", rb_fiber_scheduler_interface_unblock, 0); rb_define_method(rb_cFiberScheduler, "fiber", rb_fiber_scheduler_interface_fiber, 0); #endif #ifdef RB_EXPERIMENTAL_FIBER_POOL rb_cFiberPool = rb_define_class("Pool", rb_cFiber); rb_define_alloc_func(rb_cFiberPool, fiber_pool_alloc); rb_define_method(rb_cFiberPool, "initialize", rb_fiber_pool_initialize, -1); #endif rb_provide("fiber.so"); } RUBY_SYMBOL_EXPORT_BEGIN void ruby_Init_Continuation_body(void) { rb_cContinuation = rb_define_class("Continuation", rb_cObject); rb_undef_alloc_func(rb_cContinuation); rb_undef_method(CLASS_OF(rb_cContinuation), "new"); rb_define_method(rb_cContinuation, "call", rb_cont_call, -1); rb_define_method(rb_cContinuation, "[]", rb_cont_call, -1); rb_define_global_function("callcc", rb_callcc, 0); } RUBY_SYMBOL_EXPORT_END