/* Threads compatibility routines for libgcc2 and libobjc. */
/* Compile this one with gcc. */
-/* Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc.
+
+/* Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005
+ Free Software Foundation, Inc.
Contributed by Mumit Khan <khan@xraylith.wisc.edu>.
This file is part of GCC.
This may cause incorrect error return due to truncation values on
hw where sizeof (DWORD) > sizeof (int).
- 3. We might consider using Critical Sections instead of Windows32
- mutexes for better performance, but emulating __gthread_mutex_trylock
- interface becomes more complicated (Win9x does not support
- TryEnterCriticalSectioni, while NT does).
+ 3. We are currently using a special mutex instead of the Critical
+ Sections, since Win9x does not support TryEnterCriticalSection
+ (while NT does).
The basic framework should work well enough. In the long term, GCC
needs to use Structured Exception Handling on Windows32. */
#ifdef _LIBOBJC
/* This is necessary to prevent windef.h (included from windows.h) from
- defining it's own BOOL as a typedef. */
+ defining its own BOOL as a typedef. */
#ifndef __OBJC__
#define __OBJC__
#endif
int
__gthread_objc_init_thread_system (void)
{
- /* Initialize the thread storage key */
+ /* Initialize the thread storage key. */
if ((__gthread_objc_data_tls = TlsAlloc ()) != (DWORD) -1)
return 0;
else
long started;
} __gthread_once_t;
-typedef void* __gthread_mutex_t;
+typedef struct {
+ long counter;
+ void *sema;
+} __gthread_mutex_t;
+
+typedef struct {
+ long counter;
+ long depth;
+ unsigned long owner;
+ void *sema;
+} __gthread_recursive_mutex_t;
#define __GTHREAD_ONCE_INIT {0, -1}
#define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function
-#define __GTHREAD_MUTEX_INIT_DEFAULT 0
+#define __GTHREAD_MUTEX_INIT_DEFAULT {-1, 0}
+#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION \
+ __gthread_recursive_mutex_init_function
+#define __GTHREAD_RECURSIVE_MUTEX_INIT_DEFAULT {-1, 0, 0, 0}
#if __MINGW32_MAJOR_VERSION >= 1 || \
(__MINGW32_MAJOR_VERSION == 0 && __MINGW32_MINOR_VERSION > 2)
extern int __mingwthr_key_dtor (unsigned long, void (*) (void *));
#endif /* __MINGW32__ version */
+/* The Windows95 kernel does not export InterlockedCompareExchange.
+ This provides a substitute. When building apps that reference
+ gthread_mutex_try_lock, the __GTHREAD_I486_INLINE_LOCK_PRIMITIVES
+ macro must be defined if Windows95 is a target. Currently
+ gthread_mutex_try_lock is not referenced by libgcc or libstdc++. */
+#ifdef __GTHREAD_I486_INLINE_LOCK_PRIMITIVES
+static inline long
+__gthr_i486_lock_cmp_xchg(long *dest, long xchg, long comperand)
+{
+ long result;
+ __asm__ __volatile__ ("\n\
+ lock\n\
+ cmpxchg{l} {%4, %1|%1, %4}\n"
+ : "=a" (result), "=m" (*dest)
+ : "0" (comperand), "m" (*dest), "r" (xchg)
+ : "cc");
+ return result;
+}
+#define __GTHR_W32_InterlockedCompareExchange __gthr_i486_lock_cmp_xchg
+#else /* __GTHREAD_I486_INLINE_LOCK_PRIMITIVES */
+#define __GTHR_W32_InterlockedCompareExchange InterlockedCompareExchange
+#endif /* __GTHREAD_I486_INLINE_LOCK_PRIMITIVES */
+
static inline int
__gthread_active_p (void)
{
#endif
}
-#ifdef __GTHREAD_HIDE_WIN32API
+#if __GTHREAD_HIDE_WIN32API
/* The implementations are in config/i386/gthr-win32.c in libgcc.a.
Only stubs are exposed to avoid polluting the C++ namespace with
extern int __gthr_win32_mutex_lock (__gthread_mutex_t *);
extern int __gthr_win32_mutex_trylock (__gthread_mutex_t *);
extern int __gthr_win32_mutex_unlock (__gthread_mutex_t *);
+extern void
+ __gthr_win32_recursive_mutex_init_function (__gthread_recursive_mutex_t *);
+extern int __gthr_win32_recursive_mutex_lock (__gthread_recursive_mutex_t *);
+extern int
+ __gthr_win32_recursive_mutex_trylock (__gthread_recursive_mutex_t *);
+extern int __gthr_win32_recursive_mutex_unlock (__gthread_recursive_mutex_t *);
static inline int
__gthread_once (__gthread_once_t *once, void (*func) (void))
return 0;
}
+static inline void
+__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
+{
+ __gthr_win32_recursive_mutex_init_function (mutex);
+}
+
+static inline int
+__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ return __gthr_win32_recursive_mutex_lock (mutex);
+ else
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ return __gthr_win32_recursive_mutex_trylock (mutex);
+ else
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ return __gthr_win32_recursive_mutex_unlock (mutex);
+ else
+ return 0;
+}
+
#else /* ! __GTHREAD_HIDE_WIN32API */
#include <windows.h>
static inline void
__gthread_mutex_init_function (__gthread_mutex_t *mutex)
{
- /* Create unnamed mutex with default security attr and no initial owner. */
- *mutex = CreateMutex (NULL, 0, NULL);
+ mutex->counter = -1;
+ mutex->sema = CreateSemaphore (NULL, 0, 65535, NULL);
}
static inline int
if (__gthread_active_p ())
{
- if (WaitForSingleObject (*mutex, INFINITE) == WAIT_OBJECT_0)
+ if (InterlockedIncrement (&mutex->counter) == 0 ||
+ WaitForSingleObject (mutex->sema, INFINITE) == WAIT_OBJECT_0)
status = 0;
else
- status = 1;
+ {
+ /* WaitForSingleObject returns WAIT_FAILED, and we can only do
+ some best-effort cleanup here. */
+ InterlockedDecrement (&mutex->counter);
+ status = 1;
+ }
}
return status;
}
if (__gthread_active_p ())
{
- if (WaitForSingleObject (*mutex, 0) == WAIT_OBJECT_0)
+ if (__GTHR_W32_InterlockedCompareExchange (&mutex->counter, 0, -1) < 0)
status = 0;
else
status = 1;
__gthread_mutex_unlock (__gthread_mutex_t *mutex)
{
if (__gthread_active_p ())
- return (ReleaseMutex (*mutex) != 0) ? 0 : 1;
- else
- return 0;
+ {
+ if (InterlockedDecrement (&mutex->counter) >= 0)
+ return ReleaseSemaphore (mutex->sema, 1, NULL) ? 0 : 1;
+ }
+ return 0;
+}
+
+static inline void
+__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
+{
+ mutex->counter = -1;
+ mutex->depth = 0;
+ mutex->owner = 0;
+ mutex->sema = CreateSemaphore (NULL, 0, 65535, NULL);
+}
+
+static inline int
+__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ {
+ DWORD me = GetCurrentThreadId();
+ if (InterlockedIncrement (&mutex->counter) == 0)
+ {
+ mutex->depth = 1;
+ mutex->owner = me;
+ }
+ else if (mutex->owner == me)
+ {
+ InterlockedDecrement (&mutex->counter);
+ ++(mutex->depth);
+ }
+ else if (WaitForSingleObject (mutex->sema, INFINITE) == WAIT_OBJECT_0)
+ {
+ mutex->depth = 1;
+ mutex->owner = me;
+ }
+ else
+ {
+ /* WaitForSingleObject returns WAIT_FAILED, and we can only do
+ some best-effort cleanup here. */
+ InterlockedDecrement (&mutex->counter);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ {
+ DWORD me = GetCurrentThreadId();
+ if (__GTHR_W32_InterlockedCompareExchange (&mutex->counter, 0, -1) < 0)
+ {
+ mutex->depth = 1;
+ mutex->owner = me;
+ }
+ else if (mutex->owner == me)
+ ++(mutex->depth);
+ else
+ return 1;
+ }
+ return 0;
+}
+
+static inline int
+__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
+{
+ if (__gthread_active_p ())
+ {
+ --(mutex->depth);
+ if (mutex->depth == 0)
+ {
+ mutex->owner = 0;
+
+ if (InterlockedDecrement (&mutex->counter) >= 0)
+ return ReleaseSemaphore (mutex->sema, 1, NULL) ? 0 : 1;
+ }
+ }
+ return 0;
}
#endif /* __GTHREAD_HIDE_WIN32API */
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