This patch introduce M:N thread scheduler for Ractor system.
In general, M:N thread scheduler employs N native threads (OS threads)
to manage M user-level threads (Ruby threads in this case).
On the Ruby interpreter, 1 native thread is provided for 1 Ractor
and all Ruby threads are managed by the native thread.
From Ruby 1.9, the interpreter uses 1:1 thread scheduler which means
1 Ruby thread has 1 native thread. M:N scheduler change this strategy.
Because of compatibility issue (and stableness issue of the implementation)
main Ractor doesn't use M:N scheduler on default. On the other words,
threads on the main Ractor will be managed with 1:1 thread scheduler.
There are additional settings by environment variables:
`RUBY_MN_THREADS=1` enables M:N thread scheduler on the main ractor.
Note that non-main ractors use the M:N scheduler without this
configuration. With this configuration, single ractor applications
run threads on M:1 thread scheduler (green threads, user-level threads).
`RUBY_MAX_CPU=n` specifies maximum number of native threads for
M:N scheduler (default: 8).
This patch will be reverted soon if non-easy issues are found.
[Bug #19842]
On Win32, currently, rb_nativethread_cond_t is an incomplete type
because it's a typedef for `struct rb_thread_cond_struct`. That means
you can't actually allocate a rb_nativethread_cond_t unless you also
include THREAD_IMPL_H (since its defined in thread_win32.h)
(alternatively, including vm_core.h also works).
Move the definition of rb_thread_cond_struct into thread_native.h to
alleviate this.
`rb_thread_t` contained `native_thread_data_t` to represent
thread implementation dependent data. This patch separates
them and rename it `rb_native_thread` and point it from
`rb_thraed_t`.
Now, 1 Ruby thread (`rb_thread_t`) has 1 native thread (`rb_native_thread`).
Now GVL is not process *Global* so this patch try to use
another words.
* `rb_global_vm_lock_t` -> `struct rb_thread_sched`
* `gvl->owner` -> `sched->running`
* `gvl->waitq` -> `sched->readyq`
* `rb_gvl_init` -> `rb_thread_sched_init`
* `gvl_destroy` -> `rb_thread_sched_destroy`
* `gvl_acquire` -> `thread_sched_to_running` # waiting -> ready -> running
* `gvl_release` -> `thread_sched_to_waiting` # running -> waiting
* `gvl_yield` -> `thread_sched_yield`
* `GVL_UNLOCK_BEGIN` -> `THREAD_BLOCKING_BEGIN`
* `GVL_UNLOCK_END` -> `THREAD_BLOCKING_END`
* removed
* `rb_ractor_gvl`
* `rb_vm_gvl_destroy` (not used)
There are GVL functions such as `rb_thread_call_without_gvl()` yet
but I don't have good name to replace them. Maybe GVL stands for
"Greate Valuable Lock" or something like that.
To make some kind of Ractor related extensions, some functions
should be exposed.
* include/ruby/thread_native.h
* rb_native_mutex_*
* rb_native_cond_*
* include/ruby/ractor.h
* RB_OBJ_SHAREABLE_P(obj)
* rb_ractor_shareable_p(obj)
* rb_ractor_std*()
* rb_cRactor
and rm ractor_pub.h
and rename srcdir/ractor.h to srcdir/ractor_core.h
(to avoid conflict with include/ruby/ractor.h)
The timer function used on windows system set timer interrupt
flag of current main ractor's executing ec and thread can detect
the end of time slice. However, to set all ec->interrupt_flag for
all running ractors, it is requires to synchronize with other ractors.
However, timer thread can not acquire the ractor-wide lock because
of some limitation.
To solve this issue, this patch introduces USE_VM_CLOCK compile option
to introduce rb_vm_t::clock. This clock will be incremented by the
timer thread and each thread can check the incrementing by comparison
with previous checked clock. At last, on windows platform this patch
introduces some overhead, but I think there is no critical performance
issue because of this modification.
To access TLS, it is faster to use language TLS specifier instead
of using pthread_get/setspecific functions.
Original proposal is: Use native thread locals. #3665
This commit introduces Ractor mechanism to run Ruby program in
parallel. See doc/ractor.md for more details about Ractor.
See ticket [Feature #17100] to see the implementation details
and discussions.
[Feature #17100]
This commit does not complete the implementation. You can find
many bugs on using Ractor. Also the specification will be changed
so that this feature is experimental. You will see a warning when
you make the first Ractor with `Ractor.new`.
I hope this feature can help programmers from thread-safety issues.
According to MSVC manual (*1), cl.exe can skip including a header file
when that:
- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.
GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).
Sun C lacked #pragma once for a looong time. Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.
This changeset modifies header files so that each of them include
strictly one #ifndef...#endif. I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]
*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
Move native thread related lines from vm_core.h.
And declare several functions "rb_nativethread_lock_*",
manipulate locking.
* common.mk: add thread_native.h.
* thread.c: add functions "rb_nativethread_lock_*".
* thraed.c, thread_[pthread,win32].[ch]: rename rb_thread_lock_t
to rb_nativethread_lock_t to make it clear that this lock is for
native thraeds, not for ruby threads.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42133 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* thread_win32.h (rb_thread_lock_t): make a union for USE_WIN32_MUTEX.
this internal is used only in thread_win32.c, but has to be complete
to define rb_thread_t.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36119 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* thread_win32.h (rb_thread_cond_struct): add prev field instead of last.
(ie cond_event_entry is now using double linked list instead of single)
* thread_win32.c (cond_event_entry): add prev field.
* thread_win32.c (__cond_timedwait): remove entry properly if timeout
was happen.
* thread_win32.c (native_cond_signal): change for double linked list.
* thread_win32.c (native_cond_broadcast): ditto.
* thread_win32.c (native_cond_initialize): ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31459 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
APIs to modularize GVL implementation.
* thread_pthread.c, thread_pthread.h: Two GVL implementations.
(1) Simple locking GVL which is same as existing GVL.
(2) Wake-up queued threads. The wake-up order is simple FIFO.
(We can make several queues to support exact priorities, however
this causes some issues such as priority inversion and so on.)
This impl. prevents spin-loop (*1) caused on SMP environemnts.
*1: Only one Ruby thread acqures GVL again and again.
Bug #2359 [ruby-core:26694]
* thread_win32.c, thread_win32.h: Using simple lock
not by CRITICAL_SECTION but by Mutex.
Bug #3890 [ruby-dev:42315]
* vm.c (ruby_vm_destruct): ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29956 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
r18239 because r18245 made the changes unnecessary.
* thread.c (rb_mutex_struct): define after including thread_{pthread,
win32}.c.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@18248 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
rb_thread_cond_struct from .c to .h because rb_thread_cond_struct
is used in vm_core.h.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@18238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_win32.c: make some functions static functions.
a patch from Tadashi Saito <shiba AT mail2.accsnet.ne.jp>
in [ruby-core:14407]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* thread_win32.ci, thread_win32.h, thread_pthread.ci, thread_pthread.h:
prepare native_cond_*() which are based on pthread_cond_*() spec.
* prelude.rb: fix Mutex#synchronize method.
* vm_core.h, include/ruby/intern.h: change unblock function interface
(to pass some user data).
* file.c, process.c: ditto.
* benchmark/bm_vm2_mutex.rb: add a benchmark for mutex.
* benchmark/bm_vm3_thread_mutex.rb: add a benchmark for mutex
with contension.
* benchmark/run.rb: fix to remove ENV['RUBYLIB'] for matzruby.
* test/ruby/test_thread.rb: add a test.
* common.mk: fix benchmark options.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13290 b2dd03c8-39d4-4d8f-98ff-823fe69b080e