1 # This file is part of NIT (http://www.nitlanguage.org).
3 # Copyright 2014 Alexis Laferrière <alexis.laf@xymus.net>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # Main POSIX threads support and intro the classes `Thread`, `Mutex` and `Barrier`
22 new_annotation threaded
28 # Nity part at the bottom of the module.
36 // TODO protect with: #ifdef WITH_LIBGC
37 // We might have to add the next line to gc_chooser.c too, especially
38 // if we get an error like "thread not registered with GC".
47 # `NativePthread` for running thread
48 private fun native_pthread_self
: NativePthread `{
49 pthread_t *id = malloc(sizeof(pthread_t));
54 private var self_thread_key
= new NativePthreadKey
56 private var main_thread_cache
: nullable MainThread = null
57 private var main_thread_mutex
= new Mutex
59 # Handle to the program's main thread
60 fun main_thread
: MainThread
62 var cache
= main_thread_cache
63 if cache
!= null then return cache
65 main_thread_mutex
.lock
67 # Recheck if cache has been updated since lock has been unlocked/locked
68 cache
= main_thread_cache
70 main_thread_mutex
.unlock
74 # Create a `MainThread` exactly once
75 var thread
= new MainThread
76 thread
.native
= sys
.native_pthread_self
77 main_thread_cache
= thread
79 main_thread_mutex
.unlock
84 private extern class NativePthread in "C" `{ pthread_t * `}
86 new create(nit_thread: Thread) import Thread.main_intern `{
88 pthread_attr_init
(&attr
);
91 int r
= pthread_create
(&thread
, &attr
, (void
* (*)(void
*))&Thread_main_intern, nit_thread
);
94 pthread_t
*pthread
= malloc
(sizeof
(pthread_t
));
95 memmove
(pthread
, &thread
, sizeof
(pthread_t
));
101 new create_ex(nit_thread: Thread, attr: NativePthreadAttr) import Thread.main_intern `{
103 int r
= pthread_create
(&thread
, attr
, (void
* (*)(void
*))&Thread_main_intern, nit_thread
);
106 pthread_t
*pthread
= malloc
(sizeof
(pthread_t
));
107 memmove
(pthread
, &thread
, sizeof
(pthread_t
));
113 fun join: nullable Object `{
115 pthread_join
(*recv
, &thread_return
);
116 if(thread_return
== NULL) thread_return
= null_Object
();
117 return (nullable_Object
)thread_return
;
120 fun equal(other: NativePthread): Bool `{ return pthread_equal(*recv, *other); `}
122 fun kill
(signal
: Int) `{ pthread_kill(*recv, signal); `}
125 private extern class NativePthreadAttr in "C" `{ pthread_attr_t * `}
128 int r = pthread_attr_init(&attr);
130 pthread_attr_t *pattr = malloc(sizeof(pthread_attr_t));
131 memmove(pattr, &attr, sizeof(pthread_attr_t));
138 pthread_attr_destroy(recv);
141 # Most features of this class are still TODO
143 # * pthread_attr_setaffinity_np(3)
144 # * pthread_attr_setdetachstate
145 # * pthread_attr_setguardsize
146 # * pthread_attr_setinheritsched
147 # * pthread_attr_setschedparam
148 # * pthread_attr_setschedpolicy
149 # * pthread_attr_setscope
150 # * pthread_attr_setstack
151 # * pthread_attr_setstackaddr
152 # * pthread_attr_setstacksize
155 private extern class NativePthreadMutex in "C" `{ pthread_mutex_t * `}
156 new (attr: NativePthreadMutexAttr) `{
157 pthread_mutex_t
*mutex
= malloc
(sizeof
(pthread_mutex_t
));
158 int res
= pthread_mutex_init
(mutex
, attr
);
162 fun destroy `{ pthread_mutex_destroy(recv); `}
164 fun lock
`{ pthread_mutex_lock(recv); `}
165 fun try_lock: Bool `{ return pthread_mutex_trylock(recv); `}
166 fun unlock
`{ pthread_mutex_unlock(recv); `}
169 private extern class NativePthreadMutexAttr in "C" `{ pthread_mutexattr_t * `}
171 pthread_mutexattr_t *attr = malloc(sizeof(pthread_mutexattr_t));
172 int res = pthread_mutexattr_init(attr);
176 fun destroy
`{ pthread_mutexattr_destroy(recv); `}
178 fun set_type_normal `{ pthread_mutexattr_settype(recv, PTHREAD_MUTEX_NORMAL); `}
179 fun set_type_recursive
`{ pthread_mutexattr_settype(recv, PTHREAD_MUTEX_RECURSIVE); `}
180 fun set_type_errorcheck `{ pthread_mutexattr_settype(recv, PTHREAD_MUTEX_ERRORCHECK); `}
182 # pthread_mutexattr_setpshared
183 # pthread_mutexattr_setprotocol
184 # pthread_mutexattr_setproceiling
185 # pthread_mutexattr_setrobust_np
188 private extern class NativePthreadKey in "C" `{ pthread_key_t * `}
190 pthread_key_t
*key
= malloc
(sizeof
(pthread_key_t
));
191 int res
= pthread_key_create
(key
, NULL);
195 fun get: nullable Object `{
196 void
*val
= pthread_getspecific
(*recv
);
197 if (val
== NULL) val
= null_Object
();
201 fun set(val: nullable Object) `{
202 pthread_setspecific
(*recv
, val
);
206 private extern class NativePthreadCond in "C" `{ pthread_cond_t * `}
209 int r = pthread_cond_init(&cond, NULL);
211 pthread_cond_t *pcond = malloc(sizeof(pthread_cond_t));
212 memmove(pcond, &cond, sizeof(pthread_cond_t));
218 fun destroy
`{ pthread_cond_destroy(recv); `}
220 fun signal `{ pthread_cond_signal(recv); `}
222 fun broadcast
`{ pthread_cond_broadcast(recv); `}
224 fun wait(mutex: NativePthreadMutex) `{ pthread_cond_wait(recv, mutex); `}
230 # Cannot be extracted from this module because of the callback from C to `Thread::run`
235 # Instances of this class are each used to launch and control a thread.
236 abstract class Thread
239 private var native
: nullable NativePthread = null
241 # Main method of this thread
243 # The returned valued is passed to the caller of `join`.
244 fun main
: nullable Object do return null
246 private fun main_intern
: nullable Object
248 # Register thread local data
249 sys
.self_thread_key
.set
self
254 # Start executing this thread
256 # Will launch `main` on a different thread.
259 if native
!= null then return
260 native
= new NativePthread.create
(self)
263 # Join this thread to the calling thread
265 # Blocks until the method `main` returns or the target thread calls
266 # `Sys::thread_exit`. Returns the object returned from the other thread.
268 # Stats the thread if now already done by a call to `start`.
269 fun join
: nullable Object
271 if native
== null then start
279 if native
== null then return
285 # The main thread of the program
292 # Exit current thread and return `value` to caller of `Thread::join`
293 fun exit_thread
(value
: nullable Object) `{ pthread_exit(value); `}
295 # Returns the handle to the running `Thread`
298 var key = sys.self_thread_key
301 # This is the original thread, get `Sys::main_thread
` and store it
302 var thread = sys.main_thread
307 assert val isa Thread
311 # Mutual exclusion synchronization tool
313 # Instances of this class can only be acquired by a single thread at any one
314 # point in time. Uses the recursive protocol so they can be locked many time by
315 # the same thread, must then be unlocked as many time.
319 private var native: nullable NativePthreadMutex is noinit
323 var attr = new NativePthreadMutexAttr
324 attr.set_type_recursive
325 native = new NativePthreadMutex(attr)
330 # Acquire this lock, wait until it is available
331 fun lock do native.lock
333 # Acquire this lock only if it is available
335 # Returns `true` if the lock has been acquired.
336 fun try_lock: Bool do return native.try_lock
338 # Release this lock, unblocking all callers of `lock
`
339 fun unlock do native.unlock
343 var native = self.native
344 if native != null then
352 # Barrier synchronization tool
354 # Ensures that `count
` threads call and block on `wait
` before releasing them.
358 private var mutex = new Mutex
359 private var cond: nullable NativePthreadCond = new NativePthreadCond
361 # Number of threads that must be waiting for `wait
` to unblock
364 private var threads_waiting = 0
366 # Wait at this barrier and block until there are a `count
` threads waiting
371 if threads_waiting == count then
375 cond.wait(mutex.native.as(not null))
391 # Print `object
` and '\n' with the same system call
392 redef fun print(object)
394 sys.stdout.write(object.to_s+"\n")