diff options
Diffstat (limited to 'libevent-2.0.20-stable/evthread_win32.c')
| -rw-r--r-- | libevent-2.0.20-stable/evthread_win32.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/libevent-2.0.20-stable/evthread_win32.c b/libevent-2.0.20-stable/evthread_win32.c new file mode 100644 index 0000000..2389d72 --- /dev/null +++ b/libevent-2.0.20-stable/evthread_win32.c @@ -0,0 +1,339 @@ +/* + * 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" + +#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; +} + |