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
);
94 /* A timeout is a normal result. */
95 if (r
&& errno
== ETIMEDOUT
)
101 #ifndef RECURSIVE_MUTEX_IS_DEFAULT
104 _Jv_MutexInit (_Jv_Mutex_t
*mu
)
106 #ifdef HAVE_RECURSIVE_MUTEX
107 pthread_mutexattr_t
*val
= NULL
;
109 #if defined (HAVE_PTHREAD_MUTEXATTR_SETTYPE)
110 pthread_mutexattr_t attr
;
112 // If this is slow, then allocate it statically and only initialize
114 pthread_mutexattr_init (&attr
);
115 pthread_mutexattr_settype (&attr
, PTHREAD_MUTEX_RECURSIVE
);
117 #elif defined (HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
118 pthread_mutexattr_t attr
;
119 pthread_mutexattr_init (&attr
);
120 pthread_mutexattr_setkind_np (&attr
, PTHREAD_MUTEX_RECURSIVE_NP
);
124 pthread_mutex_init (mu
, val
);
126 #if defined (HAVE_PTHREAD_MUTEXATTR_SETTYPE) || defined (HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
127 pthread_mutexattr_destroy (&attr
);
130 #else /* HAVE_RECURSIVE_MUTEX */
132 // No recursive mutex, so simulate one.
133 pthread_mutex_init (&mu
->mutex
, NULL
);
134 pthread_mutex_init (&mu
->mutex2
, NULL
);
135 pthread_cond_init (&mu
->cond
, 0);
138 #endif /* HAVE_RECURSIVE_MUTEX */
141 #endif /* not RECURSIVE_MUTEX_IS_DEFAULT */
143 #if ! defined (LINUX_THREADS) && ! defined (HAVE_RECURSIVE_MUTEX)
146 _Jv_MutexDestroy (_Jv_Mutex_t
*mu
)
148 pthread_mutex_destroy (&mu
->mutex
);
149 pthread_mutex_destroy (&mu
->mutex2
);
150 pthread_cond_destroy (&mu
->cond
);
154 _Jv_MutexLock (_Jv_Mutex_t
*mu
)
156 if (pthread_mutex_lock (&mu
->mutex
))
163 mu
->thread
= pthread_self ();
165 pthread_mutex_lock (&mu
->mutex2
);
168 else if (pthread_self () == mu
->thread
)
170 // Already have the lock.
176 // Try to acquire the lock.
177 pthread_cond_wait (&mu
->cond
, &mu
->mutex
);
180 pthread_mutex_unlock (&mu
->mutex
);
185 _Jv_MutexUnlock (_Jv_Mutex_t
*mu
)
187 if (pthread_mutex_lock (&mu
->mutex
))
190 if (mu
->count
== 0 || pthread_self () != mu
->thread
)
197 pthread_mutex_unlock (&mu
->mutex2
);
198 pthread_cond_signal (&mu
->cond
);
201 pthread_mutex_unlock (&mu
->mutex
);
205 #endif /* not LINUX_THREADS and not HAVE_RECURSIVE_MUTEX */
214 _Jv_InitThreads (void)
216 pthread_key_create (&_Jv_ThreadKey
, NULL
);
217 pthread_mutex_init (&daemon_mutex
, NULL
);
218 pthread_cond_init (&daemon_cond
, 0);
219 non_daemon_count
= 0;
221 // Arrange for the interrupt signal to interrupt system calls.
222 struct sigaction act
;
223 act
.sa_handler
= handle_intr
;
224 sigemptyset (&act
.sa_mask
);
226 sigaction (INTR
, &act
, NULL
);
228 // Arrange for SIGINT to be blocked to all threads. It is only
229 // deliverable to the master thread.
232 sigaddset (&mask
, SIGINT
);
233 pthread_sigmask (SIG_BLOCK
, &mask
, NULL
);
237 _Jv_ThreadInitData (_Jv_Thread_t
**data
, java::lang::Thread
*)
239 _Jv_Thread_t
*info
= new _Jv_Thread_t
;
242 info
->exception
= NULL
;
244 // FIXME register a finalizer for INFO here.
245 // FIXME also must mark INFO somehow.
251 _Jv_ThreadSetPriority (_Jv_Thread_t
*data
, jint prio
)
253 if (data
->flags
& FLAG_START
)
255 struct sched_param param
;
257 param
.sched_priority
= prio
;
258 pthread_setschedparam (data
->thread
, SCHED_RR
, ¶m
);
263 // This is called as a cleanup handler when a thread is exiting. We
264 // use it to throw the requested exception. It's entirely possible
265 // that this approach is doomed to failure, in which case we'll need
266 // to adopt some alternate. For instance, use a signal to implement
269 throw_cleanup (void *data
)
271 _Jv_Thread_t
*td
= (_Jv_Thread_t
*) data
;
272 _Jv_Throw ((java::lang::Throwable
*) td
->exception
);
276 _Jv_ThreadCancel (_Jv_Thread_t
*data
, void *error
)
278 data
->exception
= error
;
279 pthread_cancel (data
->thread
);
282 // This function is called when a thread is started. We don't arrange
283 // to call the `run' method directly, because this function must
286 really_start (void *x
)
288 struct starter
*info
= (struct starter
*) x
;
290 pthread_cleanup_push (throw_cleanup
, info
->data
);
291 pthread_setspecific (_Jv_ThreadKey
, info
->object
);
292 info
->method (info
->object
);
293 pthread_cleanup_pop (0);
295 if (! (info
->data
->flags
& FLAG_DAEMON
))
297 pthread_mutex_lock (&daemon_mutex
);
299 if (! non_daemon_count
)
300 pthread_cond_signal (&daemon_cond
);
301 pthread_mutex_unlock (&daemon_mutex
);
308 _Jv_ThreadStart (java::lang::Thread
*thread
, _Jv_Thread_t
*data
,
309 _Jv_ThreadStartFunc
*meth
)
311 struct sched_param param
;
313 struct starter
*info
;
315 if (data
->flags
& FLAG_START
)
317 data
->flags
|= FLAG_START
;
319 param
.sched_priority
= thread
->getPriority();
321 pthread_attr_init (&attr
);
322 pthread_attr_setschedparam (&attr
, ¶m
);
324 // FIXME: handle marking the info object for GC.
325 info
= (struct starter
*) _Jv_AllocBytes (sizeof (struct starter
));
327 info
->object
= thread
;
330 if (! thread
->isDaemon())
332 pthread_mutex_lock (&daemon_mutex
);
334 pthread_mutex_unlock (&daemon_mutex
);
337 data
->flags
|= FLAG_DAEMON
;
338 pthread_create (&data
->thread
, &attr
, really_start
, (void *) info
);
340 pthread_attr_destroy (&attr
);
344 _Jv_ThreadWait (void)
346 // Arrange for SIGINT to be delivered to the master thread.
349 sigaddset (&mask
, SIGINT
);
350 pthread_sigmask (SIG_UNBLOCK
, &mask
, NULL
);
352 pthread_mutex_lock (&daemon_mutex
);
353 if (non_daemon_count
)
354 pthread_cond_wait (&daemon_cond
, &daemon_mutex
);
355 pthread_mutex_unlock (&daemon_mutex
);
359 _Jv_ThreadInterrupt (_Jv_Thread_t
*data
)
361 pthread_kill (data
->thread
, INTR
);