diff options
Diffstat (limited to 'evthread_win32.c')
-rw-r--r-- | evthread_win32.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/evthread_win32.c b/evthread_win32.c index 7b226a0c..12b8c1e6 100644 --- a/evthread_win32.c +++ b/evthread_win32.c @@ -37,6 +37,7 @@ struct event_base; #include <event2/thread.h> #include "mm-internal.h" +#include "evthread-internal.h" #define SPIN_COUNT 2000 @@ -87,6 +88,198 @@ evthread_win32_get_id(void) return (unsigned long) GetCurrentThreadId(); } +#ifdef WIN32_HAVE_CONDITION_VARIABLES +static void WINAPI (*InitializeConditionVariable_fn)(PCONDITION_VARIABLE) + = NULL; +static BOOL WINAPI (*SleepConditionVariableCS_fn)( + PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD) = NULL; +static void WINAPI (*WakeAllConditionVariable_fn)(PCONDITION_VARIABLE) = NULL; +static void WINAPI (*WakeConditionVariable_fn)(PCONDITION_VARIABLE) = NULL; + +static int +evthread_win32_condvar_init(void) +{ + HANDLE lib; + + lib = GetModuleHandle(TEXT("kernel32.dll")); + if (lib == NULL) + return 0; + +#define LOAD(name) \ + name##_fn = GetProcAddress(lib, #name) + LOAD(InitializeConditionVariable); + LOAD(SleepConditionVariable); + LOAD(WakeAllConditionVariable); + LOAD(WakeConditionVariable); + + return InitializeConditionVariable_fn && SleepConditionVariableCS_fn && + WakeAllConditionVariable_fn && WakeConditionVariable_fn; +} + +/* XXXX Even if we can build this, we don't necessarily want to: the functions + * in question didn't exist before Vista, so we'd better LoadProc them. */ +static void * +evthread_win32_condvar_alloc(unsigned condflags) +{ + CONDITION_VARIABLE *cond = mm_malloc(sizeof(CONDITION_VARIABLE)); + if (!cond) + return NULL; + InitializeConditionVariable_fn(cond); + return cond; +} + +static void +evthread_win32_condvar_free(void *_cond) +{ + CONDITION_VARIABLE *cond = _cond; + /* There doesn't _seem_ to be a cleaup fn here... */ + mm_free(cond); +} + +static int +evthread_win32_condvar_signal(void *_cond, int broadcast) +{ + CONDITION_VARIABLE *cond = _cond; + if (broadcast) + WakeAllConditionVariable_fn(cond); + else + WakeConditionVariable_fn(cond); + return 0; +} + +static int +evthread_win32_condvar_wait(void *_cond, void *_lock, const struct timeval *tv) +{ + CONDITION_VARIABLE *cond = _cond; + CRITICAL_SECTION *lock = _lock; + DWORD ms, err; + BOOL result; + + if (tv) + ms = evutil_tv_to_msec(tv); + else + ms = INFINITE; + result = SleepConditionVariableCS_fn(cond, lock, ms); + if (result) { + if (GetLastError() == WAIT_TIMEOUT) + return 1; + else + return -1; + } else { + return 0; + } +} +#endif + +struct evthread_win32_cond { + HANDLE event; + + CRITICAL_SECTION lock; + int n_waiting; + int n_to_wake; + int generation; +}; + +static void * +evthread_win32_cond_alloc(unsigned flags) +{ + struct evthread_win32_cond *cond; + if (!(cond = mm_malloc(sizeof(struct evthread_win32_cond)))) + return NULL; + if (InitializeCriticalSectionAndSpinCount(&cond->lock, SPIN_COUNT)==0) { + mm_free(cond); + return NULL; + } + if ((cond->event = CreateEvent(NULL,TRUE,FALSE,NULL)) == NULL) { + DeleteCriticalSection(&cond->lock); + mm_free(cond); + return NULL; + } + cond->n_waiting = cond->n_to_wake = cond->generation = 0; + return cond; +} + +static void +evthread_win32_cond_free(void *_cond) +{ + struct evthread_win32_cond *cond = _cond; + DeleteCriticalSection(&cond->lock); + CloseHandle(cond->event); + mm_free(cond); +} + +static int +evthread_win32_cond_signal(void *_cond, int broadcast) +{ + struct evthread_win32_cond *cond = _cond; + EnterCriticalSection(&cond->lock); + if (broadcast) + cond->n_to_wake = cond->n_waiting; + else + ++cond->n_to_wake; + cond->generation++; + SetEvent(cond->event); + LeaveCriticalSection(&cond->lock); + return 0; +} + +static int +evthread_win32_cond_wait(void *_cond, void *_lock, const struct timeval *tv) +{ + struct evthread_win32_cond *cond = _cond; + CRITICAL_SECTION *lock = _lock; + int generation_at_start; + int waiting = 1; + int result = -1; + DWORD ms = INFINITE, ms_orig = INFINITE, startTime, endTime; + if (tv) + ms_orig = ms = evutil_tv_to_msec(tv); + + EnterCriticalSection(&cond->lock); + ++cond->n_waiting; + generation_at_start = cond->generation; + LeaveCriticalSection(&cond->lock); + + LeaveCriticalSection(lock); + + startTime = GetTickCount(); + do { + DWORD res; + res = WaitForSingleObject(cond->event, ms); + EnterCriticalSection(&cond->lock); + if (cond->n_to_wake && + cond->generation != generation_at_start) { + --cond->n_to_wake; + --cond->n_waiting; + result = 0; + waiting = 0; + } else if (res != WAIT_OBJECT_0) { + result = (res==WAIT_TIMEOUT) ? 1 : -1; + --cond->n_waiting; + waiting = 0; + } else if (ms != INFINITE) { + endTime = GetTickCount(); + if (startTime + ms_orig <= endTime) { + result = 1; /* Timeout */ + --cond->n_waiting; + waiting = 0; + } else { + ms = startTime + ms_orig - endTime; + } + } + LeaveCriticalSection(&cond->lock); + } while (waiting); + + EnterCriticalSection(lock); + + EnterCriticalSection(&cond->lock); + if (!cond->n_waiting) + ResetEvent(cond->event); + LeaveCriticalSection(&cond->lock); + + return result; +} + int evthread_use_windows_threads(void) { @@ -99,8 +292,34 @@ evthread_use_windows_threads(void) evthread_win32_unlock }; + + struct evthread_condition_callbacks cond_cbs = { + EVTHREAD_CONDITION_API_VERSION, + evthread_win32_cond_alloc, + evthread_win32_cond_free, + evthread_win32_cond_signal, + evthread_win32_cond_wait + }; +#ifdef WIN32_HAVE_CONDITION_VARIABLES + struct evthread_condition_callbacks condvar_cbs = { + EVTHREAD_CONDITION_API_VERSION, + evthread_win32_condvar_alloc, + evthread_win32_condvar_free, + evthread_win32_condvar_signal, + evthread_win32_condvar_wait + }; +#endif + evthread_set_lock_callbacks(&cbs); evthread_set_id_callback(evthread_win32_get_id); +#ifdef WIN32_HAVE_CONDITION_VARIABLES + if (evthread_win32_condvar_init()) { + evthread_set_condition_callbacks(&condvar_cbs); + return 0; + } +#endif + evthread_set_condition_callbacks(&cond_cbs); + return 0; } |