diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/thread_nt.h | 138 |
1 files changed, 113 insertions, 25 deletions
diff --git a/Python/thread_nt.h b/Python/thread_nt.h index 7e2ccbc..4fa9165 100644 --- a/Python/thread_nt.h +++ b/Python/thread_nt.h @@ -30,11 +30,113 @@ PERFORMANCE OF THIS SOFTWARE. ******************************************************************/ /* This code implemented by Dag.Gruneau@elsa.preseco.comm.se */ +/* Fast NonRecursiveMutex support by Yakov Markovitch, markovitch@iso.ru */ #include <windows.h> #include <limits.h> #include <process.h> +typedef struct NRMUTEX { + LONG owned ; + DWORD thread_id ; + HANDLE hevent ; +} NRMUTEX, *PNRMUTEX ; + + +typedef PVOID WINAPI interlocked_cmp_xchg_t(PVOID *dest, PVOID exc, PVOID comperand) ; + +/* Sorry mate, but we haven't got InterlockedCompareExchange in Win95! */ +static PVOID WINAPI interlocked_cmp_xchg(PVOID *dest, PVOID exc, PVOID comperand) +{ + static LONG spinlock = 0 ; + PVOID result ; + + /* Acqire spinlock (yielding control to other threads if cant aquire for the moment) */ + while(InterlockedExchange(&spinlock, 1)) Sleep(0) ; + result = *dest ; + if (result == comperand) + *dest = exc ; + /* Release spinlock */ + spinlock = 0 ; + return result ; +} ; + +static interlocked_cmp_xchg_t *ixchg ; +BOOL InitializeNonRecursiveMutex(PNRMUTEX mutex) +{ + if (!ixchg) + { + /* Sorely, Win95 has no InterlockedCompareExchange API (Win98 has), so we have to use emulation */ + HANDLE kernel = GetModuleHandle("kernel32.dll") ; + if (!kernel || (ixchg = (interlocked_cmp_xchg_t *)GetProcAddress(kernel, "InterlockedCompareExchange")) == NULL) + ixchg = interlocked_cmp_xchg ; + } + + mutex->owned = -1 ; /* No threads have entered NonRecursiveMutex */ + mutex->thread_id = 0 ; + mutex->hevent = CreateEvent(NULL, FALSE, FALSE, NULL) ; + return mutex->hevent != NULL ; /* TRUE if the mutex is created */ +} + +#define InterlockedCompareExchange(dest,exchange,comperand) (ixchg((dest), (exchange), (comperand))) + +VOID DeleteNonRecursiveMutex(PNRMUTEX mutex) +{ + /* No in-use check */ + CloseHandle(mutex->hevent) ; + mutex->hevent = NULL ; /* Just in case */ +} + +DWORD EnterNonRecursiveMutex(PNRMUTEX mutex, BOOL wait) +{ + /* Assume that the thread waits successfully */ + DWORD ret ; + + /* InterlockedIncrement(&mutex->owned) == 0 means that no thread currently owns the mutex */ + if (!wait) + { + if (InterlockedCompareExchange((PVOID *)&mutex->owned, (PVOID)0, (PVOID)-1) != (PVOID)-1) + return WAIT_TIMEOUT ; + ret = WAIT_OBJECT_0 ; + } + else + ret = InterlockedIncrement(&mutex->owned) ? + /* Some thread owns the mutex, let's wait... */ + WaitForSingleObject(mutex->hevent, INFINITE) : WAIT_OBJECT_0 ; + + mutex->thread_id = GetCurrentThreadId() ; /* We own it */ + return ret ; +} + +BOOL LeaveNonRecursiveMutex(PNRMUTEX mutex) +{ + /* We don't own the mutex */ + mutex->thread_id = 0 ; + return + InterlockedDecrement(&mutex->owned) < 0 || + SetEvent(mutex->hevent) ; /* Other threads are waiting, wake one on them up */ +} + +PNRMUTEX AllocNonRecursiveMutex() +{ + PNRMUTEX mutex = (PNRMUTEX)malloc(sizeof(NRMUTEX)) ; + if (mutex && !InitializeNonRecursiveMutex(mutex)) + { + free(mutex) ; + mutex = NULL ; + } + return mutex ; +} + +void FreeNonRecursiveMutex(PNRMUTEX mutex) +{ + if (mutex) + { + DeleteNonRecursiveMutex(mutex) ; + free(mutex) ; + } +} + long PyThread_get_thread_ident(void); /* @@ -65,7 +167,7 @@ int PyThread_start_new_thread(void (*func)(void *), void *arg) if (rv != -1) { success = 1; - dprintf(("%ld: PyThread_start_new_thread succeeded: %ld\n", PyThread_get_thread_ident(), rv)); + dprintf(("%ld: PyThread_start_new_thread succeeded: %ld\n", PyThread_get_thread_ident(), aThreadId)); } return success; @@ -79,7 +181,7 @@ long PyThread_get_thread_ident(void) { if (!initialized) PyThread_init_thread(); - + return GetCurrentThreadId(); } @@ -133,17 +235,13 @@ void PyThread__exit_prog _P1(int status) */ PyThread_type_lock PyThread_allocate_lock(void) { - HANDLE aLock; + PNRMUTEX aLock; dprintf(("PyThread_allocate_lock called\n")); if (!initialized) PyThread_init_thread(); - aLock = CreateSemaphore(NULL, /* Security attributes */ - 1, /* Initial value */ - 1, /* Maximum value */ - NULL); - /* Name of semaphore */ + aLock = AllocNonRecursiveMutex() ; dprintf(("%ld: PyThread_allocate_lock() -> %lx\n", PyThread_get_thread_ident(), (long)aLock)); @@ -154,7 +252,7 @@ void PyThread_free_lock(PyThread_type_lock aLock) { dprintf(("%ld: PyThread_free_lock(%lx) called\n", PyThread_get_thread_ident(),(long)aLock)); - CloseHandle((HANDLE) aLock); + FreeNonRecursiveMutex(aLock) ; } /* @@ -165,16 +263,11 @@ void PyThread_free_lock(PyThread_type_lock aLock) */ int PyThread_acquire_lock(PyThread_type_lock aLock, int waitflag) { - int success = 1; - DWORD waitResult; + int success ; dprintf(("%ld: PyThread_acquire_lock(%lx, %d) called\n", PyThread_get_thread_ident(),(long)aLock, waitflag)); - waitResult = WaitForSingleObject((HANDLE) aLock, (waitflag == 1 ? INFINITE : 0)); - - if (waitResult != WAIT_OBJECT_0) { - success = 0; /* We failed */ - } + success = aLock && EnterNonRecursiveMutex((PNRMUTEX) aLock, (waitflag == 1 ? INFINITE : 0)) == WAIT_OBJECT_0 ; dprintf(("%ld: PyThread_acquire_lock(%lx, %d) -> %d\n", PyThread_get_thread_ident(),(long)aLock, waitflag, success)); @@ -185,13 +278,8 @@ void PyThread_release_lock(PyThread_type_lock aLock) { dprintf(("%ld: PyThread_release_lock(%lx) called\n", PyThread_get_thread_ident(),(long)aLock)); - if (!ReleaseSemaphore( - (HANDLE) aLock, /* Handle of semaphore */ - 1, /* increment count by one */ - NULL)) /* not interested in previous count */ - { + if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock))) dprintf(("%ld: Could not PyThread_release_lock(%lx) error: %l\n", PyThread_get_thread_ident(), (long)aLock, GetLastError())); - } } /* @@ -206,9 +294,9 @@ PyThread_type_sema PyThread_allocate_sema(int value) PyThread_init_thread(); aSemaphore = CreateSemaphore( NULL, /* Security attributes */ - value, /* Initial value */ - INT_MAX, /* Maximum value */ - NULL); /* Name of semaphore */ + value, /* Initial value */ + INT_MAX, /* Maximum value */ + NULL); /* Name of semaphore */ dprintf(("%ld: PyThread_allocate_sema() -> %lx\n", PyThread_get_thread_ident(), (long)aSemaphore)); |