111 строки
3.0 KiB
C++
111 строки
3.0 KiB
C++
#include <assert.h>
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#include <stdio.h>
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#include <pthread.h>
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#include <emscripten.h>
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#include <emscripten/threading.h>
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// This file tests the old GCC built-in atomic operations.
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// See https://gcc.gnu.org/onlinedocs/gcc-4.6.4/gcc/Atomic-Builtins.html
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#define NUM_THREADS 8
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#define T int
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// TEMP: Fastcomp backend doesn't implement these as atomic, so #define these to library
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// implementations that are properly atomic. TODO: Implement these in fastcomp.
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#define __sync_lock_test_and_set(...) emscripten_atomic_fence()
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#define __sync_lock_release(...) emscripten_atomic_fence()
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#define Bool int
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Bool atomic_bool_cas_u32(T *ptr, T oldVal, T newVal)
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{
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T old = emscripten_atomic_cas_u32(ptr, oldVal, newVal);
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return old == oldVal;
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}
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// Test __sync_val_compare_and_swap.
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T nand_and_fetch(T *ptr, T x)
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{
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for(;;)
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{
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T old = emscripten_atomic_load_u32(ptr);
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T newVal = ~(old & x);
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T old2 = __sync_val_compare_and_swap(ptr, old, newVal);
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if (old2 == old) return newVal;
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}
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}
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// Test __sync_bool_compare_and_swap.
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T nand_and_fetch_bool(T *ptr, T x)
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{
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for(;;)
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{
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T old = emscripten_atomic_load_u32(ptr);
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T newVal = ~(old & x);
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Bool success = __sync_bool_compare_and_swap(ptr, old, newVal);
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if (success) return newVal;
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}
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}
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volatile int nand_and_fetch_data = 0;
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void *thread_nand_and_fetch(void *arg)
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{
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for(int i = 0; i < 999; ++i) // Odd number of times so that the operation doesn't cancel itself out.
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nand_and_fetch((int*)&nand_and_fetch_data, (int)arg);
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pthread_exit(0);
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}
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void *thread_nand_and_fetch_bool(void *arg)
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{
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for(int i = 0; i < 999; ++i) // Odd number of times so that the operation doesn't cancel itself out.
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nand_and_fetch_bool((int*)&nand_and_fetch_data, (int)arg);
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pthread_exit(0);
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}
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pthread_t thread[NUM_THREADS];
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int main()
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{
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{
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T x = 5;
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T y = nand_and_fetch(&x, 9);
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assert(y == -2);
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assert(x == -2);
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const int oddNThreads = NUM_THREADS-1;
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for(int x = 0; x < 100; ++x) // Test a few times for robustness, since this test is so short-lived.
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{
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nand_and_fetch_data = 0;
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__sync_synchronize(); // This has no effect in this code, but called in here just to test that the compiler generates a valid expression for this.
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if (emscripten_has_threading_support())
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{
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for(int i = 0; i < oddNThreads; ++i) pthread_create(&thread[i], NULL, thread_nand_and_fetch, (void*)-1);
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for(int i = 0; i < oddNThreads; ++i) pthread_join(thread[i], NULL);
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assert(nand_and_fetch_data == -1);
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}
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}
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}
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{
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T x = 5;
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T y = nand_and_fetch_bool(&x, 9);
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assert(y == -2);
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assert(x == -2);
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const int oddNThreads = NUM_THREADS-1;
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for(int x = 0; x < 100; ++x) // Test a few times for robustness, since this test is so short-lived.
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{
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nand_and_fetch_data = 0;
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if (emscripten_has_threading_support())
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{
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for(int i = 0; i < oddNThreads; ++i) pthread_create(&thread[i], NULL, thread_nand_and_fetch_bool, (void*)-1);
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for(int i = 0; i < oddNThreads; ++i) pthread_join(thread[i], NULL);
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assert(nand_and_fetch_data == -1);
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}
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}
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}
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#ifdef REPORT_RESULT
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int result = 0;
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REPORT_RESULT();
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#endif
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}
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