1 // posix-threads.cc - interface between libjava and POSIX threads.
3 /* Copyright (C) 1998, 1999 Cygnus Solutions
5 This file is part of libgcj.
7 This software is copyrighted work licensed under the terms of the
8 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
12 // * Document signal handling limitations
16 // If we're using the Boehm GC, then we need to override some of the
17 // thread primitives. This is fairly gross.
21 #include <boehm-config.h>
24 #endif /* HAVE_BOEHM_GC */
32 #include <java/lang/Thread.h>
33 #include <java/lang/System.h>
35 // This is used to implement thread startup.
38 _Jv_ThreadStartFunc *method;
39 java::lang::Thread *object;
43 // This is the key used to map from the POSIX thread value back to the
44 // Java object representing the thread. The key is global to all
45 // threads, so it is ok to make it a global here.
46 pthread_key_t _Jv_ThreadKey;
48 // We keep a count of all non-daemon threads which are running. When
49 // this reaches zero, _Jv_ThreadWait returns.
50 static pthread_mutex_t daemon_mutex;
51 static pthread_cond_t daemon_cond;
52 static int non_daemon_count;
54 // The signal to use when interrupting a thread.
56 // LinuxThreads usurps both SIGUSR1 and SIGUSR2.
58 #else /* LINUX_THREADS */
60 #endif /* LINUX_THREADS */
63 // These are the flags that can appear in _Jv_Thread_t.
67 #define FLAG_START 0x01
69 #define FLAG_DAEMON 0x02
74 _Jv_CondWait (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu,
75 jlong millis, jint nanos)
79 #ifdef HAVE_RECURSIVE_MUTEX
84 if (millis == 0 && nanos == 0)
85 r = pthread_cond_wait (cv, pmu);
89 jlong m = millis + java::lang::System::currentTimeMillis ();
91 ts.tv_nsec = ((m % 1000) * 1000000) + nanos;
93 r = pthread_cond_timedwait (cv, pmu, &ts);
98 #ifndef RECURSIVE_MUTEX_IS_DEFAULT
101 _Jv_MutexInit (_Jv_Mutex_t *mu)
103 #ifdef HAVE_RECURSIVE_MUTEX
104 pthread_mutexattr_t *val = NULL;
106 #if defined (HAVE_PTHREAD_MUTEXATTR_SETTYPE)
107 pthread_mutexattr_t attr;
109 // If this is slow, then allocate it statically and only initialize
111 pthread_mutexattr_init (&attr);
112 pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
114 #elif defined (HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
115 pthread_mutexattr_t attr;
116 pthread_mutexattr_init (&attr);
117 pthread_mutexattr_setkind_np (&attr, PTHREAD_MUTEX_RECURSIVE_NP);
121 pthread_mutex_init (mu, val);
123 #if defined (HAVE_PTHREAD_MUTEXATTR_SETTYPE) || defined (HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
124 pthread_mutexattr_destroy (&attr);
127 #else /* HAVE_RECURSIVE_MUTEX */
129 // No recursive mutex, so simulate one.
130 pthread_mutex_init (&mu->mutex, NULL);
131 pthread_mutex_init (&mu->mutex2, NULL);
132 pthread_cond_init (&mu->cond, 0);
135 #endif /* HAVE_RECURSIVE_MUTEX */
138 #endif /* not RECURSIVE_MUTEX_IS_DEFAULT */
140 #if ! defined (LINUX_THREADS) && ! defined (HAVE_RECURSIVE_MUTEX)
143 _Jv_MutexDestroy (_Jv_Mutex_t *mu)
145 pthread_mutex_destroy (&mu->mutex);
146 pthread_mutex_destroy (&mu->mutex2);
147 pthread_cond_destroy (&mu->cond);
151 _Jv_MutexLock (_Jv_Mutex_t *mu)
153 if (pthread_mutex_lock (&mu->mutex))
160 mu->thread = pthread_self ();
162 pthread_mutex_lock (&mu->mutex2);
165 else if (pthread_self () == mu->thread)
167 // Already have the lock.
173 // Try to acquire the lock.
174 pthread_cond_wait (&mu->cond, &mu->mutex);
177 pthread_mutex_unlock (&mu->mutex);
182 _Jv_MutexUnlock (_Jv_Mutex_t *mu)
184 if (pthread_mutex_lock (&mu->mutex))
187 if (mu->count == 0 || pthread_self () != mu->thread)
194 pthread_mutex_unlock (&mu->mutex2);
195 pthread_cond_signal (&mu->cond);
198 pthread_mutex_unlock (&mu->mutex);
202 #endif /* not LINUX_THREADS and not HAVE_RECURSIVE_MUTEX */
211 _Jv_InitThreads (void)
213 pthread_key_create (&_Jv_ThreadKey, NULL);
214 pthread_mutex_init (&daemon_mutex, NULL);
215 pthread_cond_init (&daemon_cond, 0);
216 non_daemon_count = 0;
218 // Arrange for the interrupt signal to interrupt system calls.
219 struct sigaction act;
220 act.sa_handler = handle_intr;
221 sigemptyset (&act.sa_mask);
223 sigaction (INTR, &act, NULL);
225 // Arrange for SIGINT to be blocked to all threads. It is only
226 // deliverable to the master thread.
229 sigaddset (&mask, SIGINT);
230 pthread_sigmask (SIG_BLOCK, &mask, NULL);
234 _Jv_ThreadInitData (_Jv_Thread_t **data, java::lang::Thread *)
236 _Jv_Thread_t *info = new _Jv_Thread_t;
239 info->exception = NULL;
241 // FIXME register a finalizer for INFO here.
242 // FIXME also must mark INFO somehow.
248 _Jv_ThreadSetPriority (_Jv_Thread_t *data, jint prio)
250 if (data->flags & FLAG_START)
252 struct sched_param param;
254 param.sched_priority = prio;
255 pthread_setschedparam (data->thread, SCHED_RR, ¶m);
260 // This is called as a cleanup handler when a thread is exiting. We
261 // use it to throw the requested exception. It's entirely possible
262 // that this approach is doomed to failure, in which case we'll need
263 // to adopt some alternate. For instance, use a signal to implement
266 throw_cleanup (void *data)
268 _Jv_Thread_t *td = (_Jv_Thread_t *) data;
269 _Jv_Throw ((java::lang::Throwable *) td->exception);
273 _Jv_ThreadCancel (_Jv_Thread_t *data, void *error)
275 data->exception = error;
276 pthread_cancel (data->thread);
279 // This function is called when a thread is started. We don't arrange
280 // to call the `run' method directly, because this function must
283 really_start (void *x)
285 struct starter *info = (struct starter *) x;
287 pthread_cleanup_push (throw_cleanup, info->data);
288 pthread_setspecific (_Jv_ThreadKey, info->object);
289 info->method (info->object);
290 pthread_cleanup_pop (0);
292 if (! (info->data->flags & FLAG_DAEMON))
294 pthread_mutex_lock (&daemon_mutex);
296 if (! non_daemon_count)
297 pthread_cond_signal (&daemon_cond);
298 pthread_mutex_unlock (&daemon_mutex);
305 _Jv_ThreadStart (java::lang::Thread *thread, _Jv_Thread_t *data,
306 _Jv_ThreadStartFunc *meth)
308 struct sched_param param;
310 struct starter *info;
312 if (data->flags & FLAG_START)
314 data->flags |= FLAG_START;
316 param.sched_priority = thread->getPriority();
318 pthread_attr_init (&attr);
319 pthread_attr_setschedparam (&attr, ¶m);
321 // FIXME: handle marking the info object for GC.
322 info = (struct starter *) _Jv_AllocBytes (sizeof (struct starter));
324 info->object = thread;
327 if (! thread->isDaemon())
329 pthread_mutex_lock (&daemon_mutex);
331 pthread_mutex_unlock (&daemon_mutex);
334 data->flags |= FLAG_DAEMON;
335 pthread_create (&data->thread, &attr, really_start, (void *) info);
337 pthread_attr_destroy (&attr);
341 _Jv_ThreadWait (void)
343 // Arrange for SIGINT to be delivered to the master thread.
346 sigaddset (&mask, SIGINT);
347 pthread_sigmask (SIG_UNBLOCK, &mask, NULL);
349 pthread_mutex_lock (&daemon_mutex);
350 if (non_daemon_count)
351 pthread_cond_wait (&daemon_cond, &daemon_mutex);
352 pthread_mutex_unlock (&daemon_mutex);
356 _Jv_ThreadInterrupt (_Jv_Thread_t *data)
358 pthread_kill (data->thread, INTR);