Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

340 lines (302 sloc) 8.534 kb
/*
* Copyright 2009-2010 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"
#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;
}
Jump to Line
Something went wrong with that request. Please try again.