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Diffstat (limited to 'libjava/posix-threads.cc')
| -rw-r--r-- | libjava/posix-threads.cc | 412 |
1 files changed, 0 insertions, 412 deletions
diff --git a/libjava/posix-threads.cc b/libjava/posix-threads.cc deleted file mode 100644 index e6b4b256720..00000000000 --- a/libjava/posix-threads.cc +++ /dev/null @@ -1,412 +0,0 @@ -// posix-threads.cc - interface between libjava and POSIX threads. - -/* Copyright (C) 1998, 1999 Free Software Foundation - - This file is part of libgcj. - -This software is copyrighted work licensed under the terms of the -Libgcj License. Please consult the file "LIBGCJ_LICENSE" for -details. */ - -// TO DO: -// * Document signal handling limitations - -#include <config.h> - -// If we're using the Boehm GC, then we need to override some of the -// thread primitives. This is fairly gross. -#ifdef HAVE_BOEHM_GC -extern "C" -{ -#include <gcconfig.h> -#include <gc.h> -}; -#endif /* HAVE_BOEHM_GC */ - -#include <stdlib.h> -#include <time.h> -#include <signal.h> -#include <errno.h> -#include <limits.h> - -#include <gcj/cni.h> -#include <jvm.h> -#include <java/lang/Thread.h> -#include <java/lang/System.h> -#include <java/lang/Long.h> -#include <java/lang/OutOfMemoryError.h> - -// This is used to implement thread startup. -struct starter -{ - _Jv_ThreadStartFunc *method; - _Jv_Thread_t *data; -}; - -// This is the key used to map from the POSIX thread value back to the -// Java object representing the thread. The key is global to all -// threads, so it is ok to make it a global here. -pthread_key_t _Jv_ThreadKey; - -// This is the key used to map from the POSIX thread value back to the -// _Jv_Thread_t* representing the thread. -pthread_key_t _Jv_ThreadDataKey; - -// We keep a count of all non-daemon threads which are running. When -// this reaches zero, _Jv_ThreadWait returns. -static pthread_mutex_t daemon_mutex; -static pthread_cond_t daemon_cond; -static int non_daemon_count; - -// The signal to use when interrupting a thread. -#ifdef LINUX_THREADS - // LinuxThreads (prior to glibc 2.1) usurps both SIGUSR1 and SIGUSR2. -# define INTR SIGHUP -#else /* LINUX_THREADS */ -# define INTR SIGUSR2 -#endif /* LINUX_THREADS */ - -// -// These are the flags that can appear in _Jv_Thread_t. -// - -// Thread started. -#define FLAG_START 0x01 -// Thread is daemon. -#define FLAG_DAEMON 0x02 - - - -// Wait for the condition variable "CV" to be notified. -// Return values: -// 0: the condition was notified, or the timeout expired. -// _JV_NOT_OWNER: the thread does not own the mutex "MU". -// _JV_INTERRUPTED: the thread was interrupted. Its interrupted flag is set. -int -_Jv_CondWait (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu, - jlong millis, jint nanos) -{ - pthread_t self = pthread_self(); - if (mu->owner != self) - return _JV_NOT_OWNER; - - struct timespec ts; - jlong m, startTime; - - if (millis > 0 || nanos > 0) - { - startTime = java::lang::System::currentTimeMillis(); - m = millis + startTime; - ts.tv_sec = m / 1000; - ts.tv_nsec = ((m % 1000) * 1000000) + nanos; - } - - _Jv_Thread_t *current = _Jv_ThreadCurrentData (); - java::lang::Thread *current_obj = _Jv_ThreadCurrent (); - - // Add this thread to the cv's wait set. - current->next = NULL; - - if (cv->first == NULL) - cv->first = current; - else - for (_Jv_Thread_t *t = cv->first;; t = t->next) - { - if (t->next == NULL) - { - t->next = current; - break; - } - } - - pthread_mutex_lock (¤t->wait_mutex); - - // Now that we hold the wait mutex, check if this thread has been - // interrupted already. - if (current_obj->interrupt_flag) - { - pthread_mutex_unlock (¤t->wait_mutex); - return _JV_INTERRUPTED; - } - - // Record the current lock depth, so it can be restored when we re-aquire it. - int count = mu->count; - - // Release the monitor mutex. - mu->count = 0; - mu->owner = 0; - pthread_mutex_unlock (&mu->mutex); - - int r = 0; - bool done_sleeping = false; - - while (! done_sleeping) - { - if (millis == 0 && nanos == 0) - r = pthread_cond_wait (¤t->wait_cond, ¤t->wait_mutex); - else - r = pthread_cond_timedwait (¤t->wait_cond, ¤t->wait_mutex, - &ts); - - // In older glibc's (prior to 2.1.3), the cond_wait functions may - // spuriously wake up on a signal. Catch that here. - if (r != EINTR) - done_sleeping = true; - } - - // Check for an interrupt *before* unlocking the wait mutex. - jboolean interrupted = current_obj->interrupt_flag; - - pthread_mutex_unlock (¤t->wait_mutex); - - // Reaquire the monitor mutex, and restore the lock count. - pthread_mutex_lock (&mu->mutex); - mu->owner = self; - mu->count = count; - - // If we were interrupted, or if a timeout occured, remove ourself from - // the cv wait list now. (If we were notified normally, notify() will have - // already taken care of this) - if (r == ETIMEDOUT || interrupted) - { - _Jv_Thread_t *prev = NULL; - for (_Jv_Thread_t *t = cv->first; t != NULL; t = t->next) - { - if (t == current) - { - if (prev != NULL) - prev->next = t->next; - else - cv->first = t->next; - t->next = NULL; - break; - } - prev = t; - } - if (interrupted) - return _JV_INTERRUPTED; - } - - return 0; -} - -int -_Jv_CondNotify (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu) -{ - if (_Jv_PthreadCheckMonitor (mu)) - return _JV_NOT_OWNER; - - _Jv_Thread_t *target; - _Jv_Thread_t *prev = NULL; - - for (target = cv->first; target != NULL; target = target->next) - { - pthread_mutex_lock (&target->wait_mutex); - - if (target->thread_obj->interrupt_flag) - { - // Don't notify a thread that has already been interrupted. - pthread_mutex_unlock (&target->wait_mutex); - prev = target; - continue; - } - - pthread_cond_signal (&target->wait_cond); - pthread_mutex_unlock (&target->wait_mutex); - - // Two successive notify() calls should not be delivered to the same - // thread, so we remove the target thread from the cv wait list now. - if (prev == NULL) - cv->first = target->next; - else - prev->next = target->next; - - target->next = NULL; - - break; - } - - return 0; -} - -int -_Jv_CondNotifyAll (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu) -{ - if (_Jv_PthreadCheckMonitor (mu)) - return _JV_NOT_OWNER; - - _Jv_Thread_t *target; - _Jv_Thread_t *prev = NULL; - - for (target = cv->first; target != NULL; target = target->next) - { - pthread_mutex_lock (&target->wait_mutex); - pthread_cond_signal (&target->wait_cond); - pthread_mutex_unlock (&target->wait_mutex); - - if (prev != NULL) - prev->next = NULL; - prev = target; - } - if (prev != NULL) - prev->next = NULL; - - cv->first = NULL; - - return 0; -} - -void -_Jv_ThreadInterrupt (_Jv_Thread_t *data) -{ - pthread_mutex_lock (&data->wait_mutex); - - // Set the thread's interrupted flag *after* aquiring its wait_mutex. This - // ensures that there are no races with the interrupt flag being set after - // the waiting thread checks it and before pthread_cond_wait is entered. - data->thread_obj->interrupt_flag = true; - - // Interrupt blocking system calls using a signal. -// pthread_kill (data->thread, INTR); - - pthread_cond_signal (&data->wait_cond); - - pthread_mutex_unlock (&data->wait_mutex); -} - -static void -handle_intr (int) -{ - // Do nothing. -} - -void -_Jv_InitThreads (void) -{ - pthread_key_create (&_Jv_ThreadKey, NULL); - pthread_key_create (&_Jv_ThreadDataKey, NULL); - pthread_mutex_init (&daemon_mutex, NULL); - pthread_cond_init (&daemon_cond, 0); - non_daemon_count = 0; - - // Arrange for the interrupt signal to interrupt system calls. - struct sigaction act; - act.sa_handler = handle_intr; - sigemptyset (&act.sa_mask); - act.sa_flags = 0; - sigaction (INTR, &act, NULL); -} - -void -_Jv_ThreadInitData (_Jv_Thread_t **data, java::lang::Thread *obj) -{ - _Jv_Thread_t *info = new _Jv_Thread_t; - info->flags = 0; - info->thread_obj = obj; - - pthread_mutex_init (&info->wait_mutex, NULL); - pthread_cond_init (&info->wait_cond, NULL); - - // FIXME register a finalizer for INFO here. - // FIXME also must mark INFO somehow. - - *data = info; -} - -void -_Jv_ThreadSetPriority (_Jv_Thread_t *data, jint prio) -{ - if (data->flags & FLAG_START) - { - struct sched_param param; - - param.sched_priority = prio; - pthread_setschedparam (data->thread, SCHED_RR, ¶m); - } -} - -// This function is called when a thread is started. We don't arrange -// to call the `run' method directly, because this function must -// return a value. -static void * -really_start (void *x) -{ - struct starter *info = (struct starter *) x; - - pthread_setspecific (_Jv_ThreadKey, info->data->thread_obj); - pthread_setspecific (_Jv_ThreadDataKey, info->data); - - // glibc 2.1.3 doesn't set the value of `thread' until after start_routine - // is called. Since it may need to be accessed from the new thread, work - // around the potential race here by explicitly setting it again. - info->data->thread = pthread_self (); - - info->method (info->data->thread_obj); - - if (! (info->data->flags & FLAG_DAEMON)) - { - pthread_mutex_lock (&daemon_mutex); - --non_daemon_count; - if (! non_daemon_count) - pthread_cond_signal (&daemon_cond); - pthread_mutex_unlock (&daemon_mutex); - } - -#ifndef LINUX_THREADS - // Clean up. These calls do nothing on Linux. - pthread_mutex_destroy (&info->data->wait_mutex); - pthread_cond_destroy (&info->data->wait_cond); -#endif /* ! LINUX_THREADS */ - - return NULL; -} - -void -_Jv_ThreadStart (java::lang::Thread *thread, _Jv_Thread_t *data, - _Jv_ThreadStartFunc *meth) -{ - struct sched_param param; - pthread_attr_t attr; - struct starter *info; - - if (data->flags & FLAG_START) - return; - data->flags |= FLAG_START; - - param.sched_priority = thread->getPriority(); - - pthread_attr_init (&attr); - pthread_attr_setschedparam (&attr, ¶m); - - // FIXME: handle marking the info object for GC. - info = (struct starter *) _Jv_AllocBytes (sizeof (struct starter)); - info->method = meth; - info->data = data; - - if (! thread->isDaemon()) - { - pthread_mutex_lock (&daemon_mutex); - ++non_daemon_count; - pthread_mutex_unlock (&daemon_mutex); - } - else - data->flags |= FLAG_DAEMON; - int r = pthread_create (&data->thread, &attr, really_start, (void *) info); - - pthread_attr_destroy (&attr); - - if (r) - { - const char* msg = "Cannot create additional threads"; - JvThrow (new java::lang::OutOfMemoryError (JvNewStringUTF (msg))); - } -} - -void -_Jv_ThreadWait (void) -{ - pthread_mutex_lock (&daemon_mutex); - if (non_daemon_count) - pthread_cond_wait (&daemon_cond, &daemon_mutex); - pthread_mutex_unlock (&daemon_mutex); -} |