diff options
Diffstat (limited to 'Python/thread_nt.h')
| -rw-r--r-- | Python/thread_nt.h | 63 |
1 files changed, 5 insertions, 58 deletions
diff --git a/Python/thread_nt.h b/Python/thread_nt.h index 27fca72..9445529 100644 --- a/Python/thread_nt.h +++ b/Python/thread_nt.h @@ -15,72 +15,16 @@ typedef struct NRMUTEX { 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 ; - DWORD dwSleep = 0; - - /* Acqire spinlock (yielding control to other threads if cant aquire for the moment) */ - while(InterlockedExchange(&spinlock, 1)) - { - // Using Sleep(0) can cause a priority inversion. - // Sleep(0) only yields the processor if there's - // another thread of the same priority that's - // ready to run. If a high-priority thread is - // trying to acquire the lock, which is held by - // a low-priority thread, then the low-priority - // thread may never get scheduled and hence never - // free the lock. NT attempts to avoid priority - // inversions by temporarily boosting the priority - // of low-priority runnable threads, but the problem - // can still occur if there's a medium-priority - // thread that's always runnable. If Sleep(1) is used, - // then the thread unconditionally yields the CPU. We - // only do this for the second and subsequent even - // iterations, since a millisecond is a long time to wait - // if the thread can be scheduled in again sooner - // (~100,000 instructions). - // Avoid priority inversion: 0, 1, 0, 1,... - Sleep(dwSleep); - dwSleep = !dwSleep; - } - 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 */ } -#ifdef InterlockedCompareExchange -#undef InterlockedCompareExchange -#endif -#define InterlockedCompareExchange(dest,exchange,comperand) (ixchg((dest), (exchange), (comperand))) - VOID DeleteNonRecursiveMutex(PNRMUTEX mutex) { @@ -98,7 +42,7 @@ EnterNonRecursiveMutex(PNRMUTEX mutex, BOOL wait) /* 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) + if (InterlockedCompareExchange(&mutex->owned, 0, -1) != -1) return WAIT_TIMEOUT ; ret = WAIT_OBJECT_0 ; } @@ -196,7 +140,10 @@ PyThread_start_new_thread(void (*func)(void *), void *arg) if (obj.done == NULL) return -1; - rv = _beginthread(bootstrap, _pythread_stacksize, &obj); + rv = _beginthread(bootstrap, + Py_SAFE_DOWNCAST(_pythread_stacksize, + Py_ssize_t, int), + &obj); if (rv == (Py_uintptr_t)-1) { /* I've seen errno == EAGAIN here, which means "there are * too many threads". |