michael@0: /*
michael@0:  * Copyright 2009-2012 Niels Provos and Nick Mathewson
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. The name of the author may not be used to endorse or promote products
michael@0:  *    derived from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
michael@0:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
michael@0:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
michael@0:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
michael@0:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
michael@0:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: #include "event2/event-config.h"
michael@0: 
michael@0: #ifdef WIN32
michael@0: #ifndef _WIN32_WINNT
michael@0: /* Minimum required for InitializeCriticalSectionAndSpinCount */
michael@0: #define _WIN32_WINNT 0x0403
michael@0: #endif
michael@0: #include <winsock2.h>
michael@0: #define WIN32_LEAN_AND_MEAN
michael@0: #include <windows.h>
michael@0: #undef WIN32_LEAN_AND_MEAN
michael@0: #include <sys/locking.h>
michael@0: #endif
michael@0: 
michael@0: struct event_base;
michael@0: #include "event2/thread.h"
michael@0: 
michael@0: #include "mm-internal.h"
michael@0: #include "evthread-internal.h"
michael@0: 
michael@0: #define SPIN_COUNT 2000
michael@0: 
michael@0: static void *
michael@0: evthread_win32_lock_create(unsigned locktype)
michael@0: {
michael@0: 	CRITICAL_SECTION *lock = mm_malloc(sizeof(CRITICAL_SECTION));
michael@0: 	if (!lock)
michael@0: 		return NULL;
michael@0: 	if (InitializeCriticalSectionAndSpinCount(lock, SPIN_COUNT) == 0) {
michael@0: 		mm_free(lock);
michael@0: 		return NULL;
michael@0: 	}
michael@0: 	return lock;
michael@0: }
michael@0: 
michael@0: static void
michael@0: evthread_win32_lock_free(void *_lock, unsigned locktype)
michael@0: {
michael@0: 	CRITICAL_SECTION *lock = _lock;
michael@0: 	DeleteCriticalSection(lock);
michael@0: 	mm_free(lock);
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_lock(unsigned mode, void *_lock)
michael@0: {
michael@0: 	CRITICAL_SECTION *lock = _lock;
michael@0: 	if ((mode & EVTHREAD_TRY)) {
michael@0: 		return ! TryEnterCriticalSection(lock);
michael@0: 	} else {
michael@0: 		EnterCriticalSection(lock);
michael@0: 		return 0;
michael@0: 	}
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_unlock(unsigned mode, void *_lock)
michael@0: {
michael@0: 	CRITICAL_SECTION *lock = _lock;
michael@0: 	LeaveCriticalSection(lock);
michael@0: 	return 0;
michael@0: }
michael@0: 
michael@0: static unsigned long
michael@0: evthread_win32_get_id(void)
michael@0: {
michael@0: 	return (unsigned long) GetCurrentThreadId();
michael@0: }
michael@0: 
michael@0: #ifdef WIN32_HAVE_CONDITION_VARIABLES
michael@0: static void WINAPI (*InitializeConditionVariable_fn)(PCONDITION_VARIABLE)
michael@0: 	= NULL;
michael@0: static BOOL WINAPI (*SleepConditionVariableCS_fn)(
michael@0: 	PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD) = NULL;
michael@0: static void WINAPI (*WakeAllConditionVariable_fn)(PCONDITION_VARIABLE) = NULL;
michael@0: static void WINAPI (*WakeConditionVariable_fn)(PCONDITION_VARIABLE) = NULL;
michael@0: 
michael@0: static int
michael@0: evthread_win32_condvar_init(void)
michael@0: {
michael@0: 	HANDLE lib;
michael@0: 
michael@0: 	lib = GetModuleHandle(TEXT("kernel32.dll"));
michael@0: 	if (lib == NULL)
michael@0: 		return 0;
michael@0: 
michael@0: #define LOAD(name)				\
michael@0: 	name##_fn = GetProcAddress(lib, #name)
michael@0: 	LOAD(InitializeConditionVariable);
michael@0: 	LOAD(SleepConditionVariable);
michael@0: 	LOAD(WakeAllConditionVariable);
michael@0: 	LOAD(WakeConditionVariable);
michael@0: 
michael@0: 	return InitializeConditionVariable_fn && SleepConditionVariableCS_fn &&
michael@0: 	    WakeAllConditionVariable_fn && WakeConditionVariable_fn;
michael@0: }
michael@0: 
michael@0: /* XXXX Even if we can build this, we don't necessarily want to: the functions
michael@0:  * in question didn't exist before Vista, so we'd better LoadProc them. */
michael@0: static void *
michael@0: evthread_win32_condvar_alloc(unsigned condflags)
michael@0: {
michael@0: 	CONDITION_VARIABLE *cond = mm_malloc(sizeof(CONDITION_VARIABLE));
michael@0: 	if (!cond)
michael@0: 		return NULL;
michael@0: 	InitializeConditionVariable_fn(cond);
michael@0: 	return cond;
michael@0: }
michael@0: 
michael@0: static void
michael@0: evthread_win32_condvar_free(void *_cond)
michael@0: {
michael@0: 	CONDITION_VARIABLE *cond = _cond;
michael@0: 	/* There doesn't _seem_ to be a cleaup fn here... */
michael@0: 	mm_free(cond);
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_condvar_signal(void *_cond, int broadcast)
michael@0: {
michael@0: 	CONDITION_VARIABLE *cond = _cond;
michael@0: 	if (broadcast)
michael@0: 		WakeAllConditionVariable_fn(cond);
michael@0: 	else
michael@0: 		WakeConditionVariable_fn(cond);
michael@0: 	return 0;
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_condvar_wait(void *_cond, void *_lock, const struct timeval *tv)
michael@0: {
michael@0: 	CONDITION_VARIABLE *cond = _cond;
michael@0: 	CRITICAL_SECTION *lock = _lock;
michael@0: 	DWORD ms, err;
michael@0: 	BOOL result;
michael@0: 
michael@0: 	if (tv)
michael@0: 		ms = evutil_tv_to_msec(tv);
michael@0: 	else
michael@0: 		ms = INFINITE;
michael@0: 	result = SleepConditionVariableCS_fn(cond, lock, ms);
michael@0: 	if (result) {
michael@0: 		if (GetLastError() == WAIT_TIMEOUT)
michael@0: 			return 1;
michael@0: 		else
michael@0: 			return -1;
michael@0: 	} else {
michael@0: 		return 0;
michael@0: 	}
michael@0: }
michael@0: #endif
michael@0: 
michael@0: struct evthread_win32_cond {
michael@0: 	HANDLE event;
michael@0: 
michael@0: 	CRITICAL_SECTION lock;
michael@0: 	int n_waiting;
michael@0: 	int n_to_wake;
michael@0: 	int generation;
michael@0: };
michael@0: 
michael@0: static void *
michael@0: evthread_win32_cond_alloc(unsigned flags)
michael@0: {
michael@0: 	struct evthread_win32_cond *cond;
michael@0: 	if (!(cond = mm_malloc(sizeof(struct evthread_win32_cond))))
michael@0: 		return NULL;
michael@0: 	if (InitializeCriticalSectionAndSpinCount(&cond->lock, SPIN_COUNT)==0) {
michael@0: 		mm_free(cond);
michael@0: 		return NULL;
michael@0: 	}
michael@0: 	if ((cond->event = CreateEvent(NULL,TRUE,FALSE,NULL)) == NULL) {
michael@0: 		DeleteCriticalSection(&cond->lock);
michael@0: 		mm_free(cond);
michael@0: 		return NULL;
michael@0: 	}
michael@0: 	cond->n_waiting = cond->n_to_wake = cond->generation = 0;
michael@0: 	return cond;
michael@0: }
michael@0: 
michael@0: static void
michael@0: evthread_win32_cond_free(void *_cond)
michael@0: {
michael@0: 	struct evthread_win32_cond *cond = _cond;
michael@0: 	DeleteCriticalSection(&cond->lock);
michael@0: 	CloseHandle(cond->event);
michael@0: 	mm_free(cond);
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_cond_signal(void *_cond, int broadcast)
michael@0: {
michael@0: 	struct evthread_win32_cond *cond = _cond;
michael@0: 	EnterCriticalSection(&cond->lock);
michael@0: 	if (broadcast)
michael@0: 		cond->n_to_wake = cond->n_waiting;
michael@0: 	else
michael@0: 		++cond->n_to_wake;
michael@0: 	cond->generation++;
michael@0: 	SetEvent(cond->event);
michael@0: 	LeaveCriticalSection(&cond->lock);
michael@0: 	return 0;
michael@0: }
michael@0: 
michael@0: static int
michael@0: evthread_win32_cond_wait(void *_cond, void *_lock, const struct timeval *tv)
michael@0: {
michael@0: 	struct evthread_win32_cond *cond = _cond;
michael@0: 	CRITICAL_SECTION *lock = _lock;
michael@0: 	int generation_at_start;
michael@0: 	int waiting = 1;
michael@0: 	int result = -1;
michael@0: 	DWORD ms = INFINITE, ms_orig = INFINITE, startTime, endTime;
michael@0: 	if (tv)
michael@0: 		ms_orig = ms = evutil_tv_to_msec(tv);
michael@0: 
michael@0: 	EnterCriticalSection(&cond->lock);
michael@0: 	++cond->n_waiting;
michael@0: 	generation_at_start = cond->generation;
michael@0: 	LeaveCriticalSection(&cond->lock);
michael@0: 
michael@0: 	LeaveCriticalSection(lock);
michael@0: 
michael@0: 	startTime = GetTickCount();
michael@0: 	do {
michael@0: 		DWORD res;
michael@0: 		res = WaitForSingleObject(cond->event, ms);
michael@0: 		EnterCriticalSection(&cond->lock);
michael@0: 		if (cond->n_to_wake &&
michael@0: 		    cond->generation != generation_at_start) {
michael@0: 			--cond->n_to_wake;
michael@0: 			--cond->n_waiting;
michael@0: 			result = 0;
michael@0: 			waiting = 0;
michael@0: 			goto out;
michael@0: 		} else if (res != WAIT_OBJECT_0) {
michael@0: 			result = (res==WAIT_TIMEOUT) ? 1 : -1;
michael@0: 			--cond->n_waiting;
michael@0: 			waiting = 0;
michael@0: 			goto out;
michael@0: 		} else if (ms != INFINITE) {
michael@0: 			endTime = GetTickCount();
michael@0: 			if (startTime + ms_orig <= endTime) {
michael@0: 				result = 1; /* Timeout */
michael@0: 				--cond->n_waiting;
michael@0: 				waiting = 0;
michael@0: 				goto out;
michael@0: 			} else {
michael@0: 				ms = startTime + ms_orig - endTime;
michael@0: 			}
michael@0: 		}
michael@0: 		/* If we make it here, we are still waiting. */
michael@0: 		if (cond->n_to_wake == 0) {
michael@0: 			/* There is nobody else who should wake up; reset
michael@0: 			 * the event. */
michael@0: 			ResetEvent(cond->event);
michael@0: 		}
michael@0: 	out:
michael@0: 		LeaveCriticalSection(&cond->lock);
michael@0: 	} while (waiting);
michael@0: 
michael@0: 	EnterCriticalSection(lock);
michael@0: 
michael@0: 	EnterCriticalSection(&cond->lock);
michael@0: 	if (!cond->n_waiting)
michael@0: 		ResetEvent(cond->event);
michael@0: 	LeaveCriticalSection(&cond->lock);
michael@0: 
michael@0: 	return result;
michael@0: }
michael@0: 
michael@0: int
michael@0: evthread_use_windows_threads(void)
michael@0: {
michael@0: 	struct evthread_lock_callbacks cbs = {
michael@0: 		EVTHREAD_LOCK_API_VERSION,
michael@0: 		EVTHREAD_LOCKTYPE_RECURSIVE,
michael@0: 		evthread_win32_lock_create,
michael@0: 		evthread_win32_lock_free,
michael@0: 		evthread_win32_lock,
michael@0: 		evthread_win32_unlock
michael@0: 	};
michael@0: 
michael@0: 
michael@0: 	struct evthread_condition_callbacks cond_cbs = {
michael@0: 		EVTHREAD_CONDITION_API_VERSION,
michael@0: 		evthread_win32_cond_alloc,
michael@0: 		evthread_win32_cond_free,
michael@0: 		evthread_win32_cond_signal,
michael@0: 		evthread_win32_cond_wait
michael@0: 	};
michael@0: #ifdef WIN32_HAVE_CONDITION_VARIABLES
michael@0: 	struct evthread_condition_callbacks condvar_cbs = {
michael@0: 		EVTHREAD_CONDITION_API_VERSION,
michael@0: 		evthread_win32_condvar_alloc,
michael@0: 		evthread_win32_condvar_free,
michael@0: 		evthread_win32_condvar_signal,
michael@0: 		evthread_win32_condvar_wait
michael@0: 	};
michael@0: #endif
michael@0: 
michael@0: 	evthread_set_lock_callbacks(&cbs);
michael@0: 	evthread_set_id_callback(evthread_win32_get_id);
michael@0: #ifdef WIN32_HAVE_CONDITION_VARIABLES
michael@0: 	if (evthread_win32_condvar_init()) {
michael@0: 		evthread_set_condition_callbacks(&condvar_cbs);
michael@0: 		return 0;
michael@0: 	}
michael@0: #endif
michael@0: 	evthread_set_condition_callbacks(&cond_cbs);
michael@0: 
michael@0: 	return 0;
michael@0: }
michael@0: