diff options
| -rw-r--r-- | common/threads.c | 158 | ||||
| -rw-r--r-- | include/threads.h | 22 |
2 files changed, 170 insertions, 10 deletions
diff --git a/common/threads.c b/common/threads.c index b2db1682..d9c32267 100644 --- a/common/threads.c +++ b/common/threads.c @@ -230,6 +230,164 @@ int almtx_timedlock(almtx_t *mtx, const struct timespec *ts) return ret; } +#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0600 +int alcnd_init(alcnd_t *cond) +{ + InitializeConditionVariable(cond); + return althrd_success; +} + +int alcnd_signal(alcnd_t *cond) +{ + WakeConditionVariable(cond); + return althrd_success; +} + +int alcnd_broadcast(alcnd_t *cond) +{ + WakeAllConditionVariable(cond); + return althrd_success; +} + +int alcnd_wait(alcnd_t *cond, almtx_t *mtx) +{ + if(SleepConditionVariableCS(cond, mtx, INFINITE) != 0) + return althrd_success; + return althrd_error; +} + +int alcnd_timedwait(alcnd_t *cond, almtx_t *mtx, const struct timespec *time_point) +{ + struct timespec curtime; + DWORD sleeptime; + + if(altimespec_get(&curtime, AL_TIME_UTC) != AL_TIME_UTC) + return althrd_error; + + sleeptime = (time_point->tv_nsec - curtime.tv_nsec + 999999)/1000000; + sleeptime += (time_point->tv_sec - curtime.tv_sec)*1000; + if(SleepConditionVariableCS(cond, mtx, sleeptime) != 0) + return althrd_success; + return (GetLastError()==ERROR_TIMEOUT) ? althrd_timedout : althrd_error; +} + +void alcnd_destroy(alcnd_t* UNUSED(cond)) +{ + /* Nothing to delete? */ +} + +#else + +/* WARNING: This is a rather poor implementation of condition variables, with + * known problems. However, it's simple, efficient, and good enough for now to + * not require Vista. Based on "Strategies for Implementing POSIX Condition + * Variables" by Douglas C. Schmidt and Irfan Pyarali: + * http://www.cs.wustl.edu/~schmidt/win32-cv-1.html + */ +/* A better solution may be using Wine's implementation. It requires internals + * (NtCreateKeyedEvent, NtReleaseKeyedEvent, and NtWaitForKeyedEvent) from + * ntdll, and implemention of exchange and compare-exchange for RefCounts. + */ + +typedef struct { + RefCount wait_count; + + HANDLE events[2]; +} _int_alcnd_t; +enum { + SIGNAL = 0, + BROADCAST = 1 +}; + +int alcnd_init(alcnd_t *cond) +{ + _int_alcnd_t *icond = calloc(1, sizeof(*icond)); + if(!icond) return althrd_nomem; + + InitRef(&icond->wait_count, 0); + + icond->events[SIGNAL] = CreateEvent(NULL, FALSE, FALSE, NULL); + icond->events[BROADCAST] = CreateEvent(NULL, TRUE, FALSE, NULL); + if(!icond->events[SIGNAL] || !icond->events[BROADCAST]) + { + if(icond->events[SIGNAL]) + CloseHandle(icond->events[SIGNAL]); + if(icond->events[BROADCAST]) + CloseHandle(icond->events[BROADCAST]); + free(icond); + return althrd_error; + } + + cond->Ptr = icond; + return althrd_success; +} + +int alcnd_signal(alcnd_t *cond) +{ + _int_alcnd_t *icond = cond->Ptr; + if(ReadRef(&icond->wait_count) > 0) + SetEvent(icond->events[SIGNAL]); + return althrd_success; +} + +int alcnd_broadcast(alcnd_t *cond) +{ + _int_alcnd_t *icond = cond->Ptr; + if(ReadRef(&icond->wait_count) > 0) + SetEvent(icond->events[BROADCAST]); + return althrd_success; +} + +int alcnd_wait(alcnd_t *cond, almtx_t *mtx) +{ + _int_alcnd_t *icond = cond->Ptr; + int res, last; + + IncrementRef(&icond->wait_count); + LeaveCriticalSection(mtx); + + res = WaitForMultipleObjects(2, icond->events, FALSE, INFINITE); + + last = DecrementRef(&icond->wait_count) == 0 && res == WAIT_OBJECT_0+BROADCAST; + if(last) ResetEvent(icond->events[BROADCAST]); + EnterCriticalSection(mtx); + + return althrd_success; +} + +int alcnd_timedwait(alcnd_t *cond, almtx_t *mtx, const struct timespec *time_point) +{ + _int_alcnd_t *icond = cond->Ptr; + struct timespec curtime; + DWORD sleeptime; + int res, last; + + if(altimespec_get(&curtime, AL_TIME_UTC) != AL_TIME_UTC) + return althrd_error; + sleeptime = (time_point->tv_nsec - curtime.tv_nsec + 999999)/1000000; + sleeptime += (time_point->tv_sec - curtime.tv_sec)*1000; + + IncrementRef(&icond->wait_count); + LeaveCriticalSection(mtx); + + res = WaitForMultipleObjects(2, icond->events, FALSE, sleeptime); + + last = DecrementRef(&icond->wait_count) == 0 && res == WAIT_OBJECT_0+BROADCAST; + if(last) ResetEvent(icond->events[BROADCAST]); + EnterCriticalSection(mtx); + + return (res == WAIT_TIMEOUT) ? althrd_timedout : althrd_success; +} + +void alcnd_destroy(alcnd_t *cond) +{ + _int_alcnd_t *icond = cond->Ptr; + CloseHandle(icond->events[SIGNAL]); + CloseHandle(icond->events[BROADCAST]); + free(icond); +} +#endif /* defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0600 */ + /* An associative map of uint:void* pairs. The key is the TLS index (given by * TlsAlloc), and the value is the altss_dtor_t callback. When a thread exits, diff --git a/include/threads.h b/include/threads.h index 8b633f33..4a974b53 100644 --- a/include/threads.h +++ b/include/threads.h @@ -39,6 +39,11 @@ struct timespec { typedef DWORD althrd_t; typedef CRITICAL_SECTION almtx_t; +#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0600 +typedef CONDITION_VARIABLE alcnd_t; +#else +typedef struct { void *Ptr; } alcnd_t; +#endif typedef DWORD altss_t; typedef LONG alonce_flag; @@ -120,16 +125,6 @@ typedef pthread_once_t alonce_flag; #define AL_ONCE_FLAG_INIT PTHREAD_ONCE_INIT -/* NOTE: Condition variables are POSIX-only at the moment, as Windows requires - * Vista or newer for them (without slow, hacky work-arounds). */ -int alcnd_init(alcnd_t *cond); -int alcnd_signal(alcnd_t *cond); -int alcnd_broadcast(alcnd_t *cond); -int alcnd_wait(alcnd_t *cond, almtx_t *mtx); -int alcnd_timedwait(alcnd_t *cond, almtx_t *mtx, const struct timespec *time_point); -void alcnd_destroy(alcnd_t *cond); - - inline althrd_t althrd_current(void) { return pthread_self(); @@ -218,6 +213,13 @@ int almtx_init(almtx_t *mtx, int type); void almtx_destroy(almtx_t *mtx); int almtx_timedlock(almtx_t *mtx, const struct timespec *ts); +int alcnd_init(alcnd_t *cond); +int alcnd_signal(alcnd_t *cond); +int alcnd_broadcast(alcnd_t *cond); +int alcnd_wait(alcnd_t *cond, almtx_t *mtx); +int alcnd_timedwait(alcnd_t *cond, almtx_t *mtx, const struct timespec *time_point); +void alcnd_destroy(alcnd_t *cond); + int altss_create(altss_t *tss_id, altss_dtor_t callback); void altss_delete(altss_t tss_id); |