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authorTom Tromey <tromey@cygnus.com>1999-09-01 21:03:18 +0000
committerTom Tromey <tromey@gcc.gnu.org>1999-09-01 21:03:18 +0000
commit45329b398e53033647ba465cacc256f32ff7daf4 (patch)
tree03902269d263d5fdbf51b709ce65fe57c0a73bb6
parent4499762c6e6403127bd8f9a1932ac64940fca20f (diff)
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posix-threads.cc (_Jv_CondWait): Use _Jv_PthreadGetMutex.
* posix-threads.cc (_Jv_CondWait): Use _Jv_PthreadGetMutex. * include/posix-threads.h (_Jv_Mutex_t): Define as structure, except on Linux. (_Jv_PthreadGetMutex): New function. (_Jv_PthreadCheckMonitor): Use it. (_Jv_MutexInit): Likewise. ALso, initialize `count'. (_Jv_MutexLock): Update `count'. (_Jv_MutexUnlock): Likewise. (_Jv_PthreadCheckMonitor): Use Linux-specific knowledge when appropriate. From-SVN: r29032
-rw-r--r--libjava/ChangeLog13
-rw-r--r--libjava/include/posix-threads.h83
-rw-r--r--libjava/posix-threads.cc7
3 files changed, 80 insertions, 23 deletions
diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 958a838..c2f8b0a 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,16 @@
+1999-09-01 Tom Tromey <tromey@cygnus.com>
+
+ * posix-threads.cc (_Jv_CondWait): Use _Jv_PthreadGetMutex.
+ * include/posix-threads.h (_Jv_Mutex_t): Define as structure,
+ except on Linux.
+ (_Jv_PthreadGetMutex): New function.
+ (_Jv_PthreadCheckMonitor): Use it.
+ (_Jv_MutexInit): Likewise. ALso, initialize `count'.
+ (_Jv_MutexLock): Update `count'.
+ (_Jv_MutexUnlock): Likewise.
+ (_Jv_PthreadCheckMonitor): Use Linux-specific knowledge when
+ appropriate.
+
1999-09-01 Kresten Krab Thorup <krab@gnu.org>
* Makefile.am (.java.lo): Add rule.
diff --git a/libjava/include/posix-threads.h b/libjava/include/posix-threads.h
index 2ad6c06..e3b3f4f 100644
--- a/libjava/include/posix-threads.h
+++ b/libjava/include/posix-threads.h
@@ -30,15 +30,25 @@ details. */
//
typedef pthread_cond_t _Jv_ConditionVariable_t;
-#ifdef HAVE_RECURSIVE_MUTEX
+
+// FIXME: it is ugly to use LINUX_THREADS as the define. Instead
+// think of a better scheme.
+#ifdef LINUX_THREADS
+
+// On Linux we use implementation details of mutexes in order to get
+// faster results.
typedef pthread_mutex_t _Jv_Mutex_t;
-#else
-// Some systems do not have recursive mutexes, so we must simulate
-// them. Solaris is one such system.
+
+#else /* LINUX_THREADS */
+
typedef struct
{
// Mutex used when locking this structure transiently.
pthread_mutex_t mutex;
+#ifndef HAVE_RECURSIVE_MUTEX
+ // Some systems do not have recursive mutexes, so we must simulate
+ // them. Solaris is one such system.
+
// Mutex the thread holds the entire time this mutex is held. This
// is used to make condition variables work properly.
pthread_mutex_t mutex2;
@@ -46,10 +56,18 @@ typedef struct
pthread_cond_t cond;
// Thread holding this mutex. If COUNT is 0, no thread is holding.
pthread_t thread;
- // Number of times mutex is held. If 0, the lock is not held.
+#endif /* HAVE_RECURSIVE_MUTEX */
+
+ // Number of times mutex is held. If 0, the lock is not held. We
+ // do this even if we have a native recursive mutex so that we can
+ // keep track of whether the lock is held; this lets us do error
+ // checking. FIXME it would be nice to optimize this; on some
+ // systems we could do so by relying on implementation details of
+ // recursive mutexes.
int count;
} _Jv_Mutex_t;
-#endif /* HAVE_RECURSIVE_MUTEX */
+
+#endif /* LINUX_THREADS */
typedef struct
{
@@ -65,23 +83,41 @@ typedef struct
typedef void _Jv_ThreadStartFunc (java::lang::Thread *);
+// This convenience function is used to return the POSIX mutex
+// corresponding to our mutex.
+inline pthread_mutex_t *
+_Jv_PthreadGetMutex (_Jv_Mutex_t *mu)
+{
+#if defined (LINUX_THREADS)
+ return mu;
+#elif defined (HAVE_RECURSIVE_MUTEX)
+ return &mu->mutex;
+#else
+ return &mu->mutex2;
+#endif
+}
+
+#include <stdio.h>
+
// This is a convenience function used only by the pthreads thread
// implementation. This is slow, but that's too bad -- we need to do
// the checks for correctness. It might be nice to be able to compile
// this out.
-inline int _Jv_PthreadCheckMonitor (_Jv_Mutex_t *mu)
+inline int
+_Jv_PthreadCheckMonitor (_Jv_Mutex_t *mu)
{
- pthread_mutex_t *pmu;
-#ifdef HAVE_RECURSIVE_MUTEX
- pmu = mu;
-#else
- pmu = &mu->mutex2;
-#endif
+ pthread_mutex_t *pmu = _Jv_PthreadGetMutex (mu);
// See if the mutex is locked by this thread.
if (pthread_mutex_trylock (pmu))
return 1;
+#ifdef LINUX_THREADS
+ // On Linux we exploit knowledge of the implementation.
+ int r = pmu->m_count == 1;
+#else
+ int r = mu->count == 0;
+#endif
pthread_mutex_unlock (pmu);
- return 0;
+ return r;
}
//
@@ -133,7 +169,10 @@ _Jv_CondNotifyAll (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu)
inline void
_Jv_MutexInit (_Jv_Mutex_t *mu)
{
- pthread_mutex_init (mu, NULL);
+ pthread_mutex_init (_Jv_PthreadGetMutex (mu), NULL);
+#ifndef LINUX_THREADS
+ mu->count = 0;
+#endif
}
#else
void _Jv_MutexInit (_Jv_Mutex_t *mu);
@@ -166,13 +205,23 @@ extern void _Jv_MutexDestroy (_Jv_Mutex_t *mu);
inline int
_Jv_MutexLock (_Jv_Mutex_t *mu)
{
- return pthread_mutex_lock (mu);
+ int r = pthread_mutex_lock (mu);
+#ifndef LINUX_THREADS
+ if (! r)
+ ++mu->count;
+#endif
+ return r;
}
inline int
_Jv_MutexUnlock (_Jv_Mutex_t *mu)
{
- return pthread_mutex_unlock (mu);
+ int r = pthread_mutex_unlock (mu);
+#ifndef LINUX_THREADS
+ if (! r)
+ --mu->count;
+#endif
+ return r;
}
#else /* HAVE_RECURSIVE_MUTEX */
diff --git a/libjava/posix-threads.cc b/libjava/posix-threads.cc
index 413f7c3..9701596 100644
--- a/libjava/posix-threads.cc
+++ b/libjava/posix-threads.cc
@@ -79,12 +79,7 @@ _Jv_CondWait (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu,
return 1;
int r;
- pthread_mutex_t *pmu;
-#ifdef HAVE_RECURSIVE_MUTEX
- pmu = mu;
-#else
- pmu = &mu->mutex2;
-#endif
+ pthread_mutex_t *pmu = _Jv_PthreadGetMutex (mu);
if (millis == 0 && nanos == 0)
r = pthread_cond_wait (cv, pmu);