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/*
* Copyright 2009-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef _WIN32
#ifndef _WIN32_WINNT
/* Minimum required for InitializeCriticalSectionAndSpinCount */
#define _WIN32_WINNT 0x0403
#endif
#include <winsock2.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#include <sys/locking.h>
#endif
struct event_base;
#include "event2/thread.h"
#include "mm-internal.h"
#include "evthread-internal.h"
#define SPIN_COUNT 2000
static void *
evthread_win32_lock_create(unsigned locktype)
{
CRITICAL_SECTION *lock = mm_malloc(sizeof(CRITICAL_SECTION));
if (!lock)
return NULL;
if (InitializeCriticalSectionAndSpinCount(lock, SPIN_COUNT) == 0) {
mm_free(lock);
return NULL;
}
return lock;
}
static void
evthread_win32_lock_free(void *lock_, unsigned locktype)
{
CRITICAL_SECTION *lock = lock_;
DeleteCriticalSection(lock);
mm_free(lock);
}
static int
evthread_win32_lock(unsigned mode, void *lock_)
{
CRITICAL_SECTION *lock = lock_;
if ((mode & EVTHREAD_TRY)) {
return ! TryEnterCriticalSection(lock);
} else {
EnterCriticalSection(lock);
return 0;
}
}
static int
evthread_win32_unlock(unsigned mode, void *lock_)
{
CRITICAL_SECTION *lock = lock_;
LeaveCriticalSection(lock);
return 0;
}
static unsigned long
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;
goto out;
} else if (res != WAIT_OBJECT_0) {
result = (res==WAIT_TIMEOUT) ? 1 : -1;
--cond->n_waiting;
waiting = 0;
goto out;
} else if (ms != INFINITE) {
endTime = GetTickCount();
if (startTime + ms_orig <= endTime) {
result = 1; /* Timeout */
--cond->n_waiting;
waiting = 0;
goto out;
} else {
ms = startTime + ms_orig - endTime;
}
}
/* If we make it here, we are still waiting. */
if (cond->n_to_wake == 0) {
/* There is nobody else who should wake up; reset
* the event. */
ResetEvent(cond->event);
}
out:
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)
{
struct evthread_lock_callbacks cbs = {
EVTHREAD_LOCK_API_VERSION,
EVTHREAD_LOCKTYPE_RECURSIVE,
evthread_win32_lock_create,
evthread_win32_lock_free,
evthread_win32_lock,
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;
}
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