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firebird-mirror/src/common/classes/semaphore.cpp

354 lines
7.0 KiB
C++

/*
* PROGRAM: Client/Server Common Code
* MODULE: locks.cpp
* DESCRIPTION: Darwin specific semaphore support
*
* The contents of this file are subject to the Initial
* Developer's Public License Version 1.0 (the "License");
* you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
* http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
*
* Software distributed under the License is distributed AS IS,
* WITHOUT WARRANTY OF ANY KIND, either express or implied.
* See the License for the specific language governing rights
* and limitations under the License.
*
* The Original Code was created by Alexander Peshkoff
* for the Firebird Open Source RDBMS project.
*
* Copyright (c) 2007 Alexander Peshkoff <peshkoff@mail.ru>
* and all contributors signed below.
*
* All Rights Reserved.
* Contributor(s): ______________________________________.
*/
#include "firebird.h"
#include "../common/classes/semaphore.h"
#include "../common/classes/alloc.h"
#include "gen/iberror.h"
#ifdef HAVE_SYS_TIMES_H
#include <sys/times.h>
#endif
#ifdef HAVE_SYS_TIMEB_H
#include <sys/timeb.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#if defined(COMMON_CLASSES_SEMAPHORE_POSIX_RT) || defined(COMMON_CLASSES_SEMAPHORE_COND_VAR)
static timespec getCurrentTime()
{
timespec rc;
#ifdef HAVE_GETTIMEOFDAY
struct timeval tp;
GETTIMEOFDAY(&tp);
rc.tv_sec = tp.tv_sec;
rc.tv_nsec = tp.tv_usec * 1000;
#else
struct timeb time_buffer;
ftime(&time_buffer);
rc.tv_sec = time_buffer.time;
rc.tv_nsec = time_buffer.millitm * 1000000;
#endif
return rc;
}
#endif // semaphore kind defined
namespace Firebird {
#ifdef COMMON_CLASSES_SEMAPHORE_MACH
void SignalSafeSemaphore::init()
{
semaphore = dispatch_semaphore_create(0);
if (!semaphore) // With const zero parameter this means OOM
{
BadAlloc::raise();
}
}
SignalSafeSemaphore::~SignalSafeSemaphore()
{
dispatch_release(semaphore);
}
#endif // COMMON_CLASSES_SEMAPHORE_MACH
#ifdef COMMON_CLASSES_SEMAPHORE_POSIX_RT
#ifndef WORKING_SEM_INIT
static const char* semName = "/firebird_temp_sem";
#endif
#ifndef SEM_FAILED
#define SEM_FAILED ((sem_t*) (-1))
#endif
void SignalSafeSemaphore::init()
{
#ifdef WORKING_SEM_INIT
if (sem_init(sem, 0, 0) == -1) {
system_call_failed::raise("sem_init");
}
#else
sem = sem_open(semName, O_CREAT | O_EXCL, 0700, 0);
if (sem == (sem_t*) SEM_FAILED) {
system_call_failed::raise("sem_open");
}
sem_unlink(semName);
#endif
}
SignalSafeSemaphore::~SignalSafeSemaphore()
{
#ifdef WORKING_SEM_INIT
if (sem_destroy(sem) == -1) {
system_call_failed::raise("sem_destroy");
}
#else
if (sem_close(sem) == -1) {
system_call_failed::raise("sem_close");
}
#endif
}
void SignalSafeSemaphore::enter()
{
do {
if (sem_wait(sem) != -1)
return;
} while (errno == EINTR);
system_call_failed::raise("semaphore.h: enter: sem_wait()");
}
#ifdef HAVE_SEM_TIMEDWAIT
bool SignalSafeSemaphore::tryEnter(const int seconds, int milliseconds)
{
long nanoseconds = long(milliseconds + seconds * 1000) * 1000000l;
// Return true in case of success
if (nanoseconds == 0)
{
// Instant try
do {
if (sem_trywait(sem) != -1)
return true;
} while (errno == EINTR);
if (errno == EAGAIN)
return false;
system_call_failed::raise("sem_trywait");
}
if (nanoseconds < 0)
{
// Unlimited wait, like enter()
do {
if (sem_wait(sem) != -1)
return true;
} while (errno == EINTR);
system_call_failed::raise("sem_wait");
}
// Wait with timeout
timespec timeout = getCurrentTime();
nanoseconds += timeout.tv_nsec;
timeout.tv_sec += nanoseconds / 1000000000l;
timeout.tv_nsec = nanoseconds % 1000000000l;
int errcode = 0;
do {
int rc = sem_timedwait(sem, &timeout);
if (rc == 0)
return true;
// fix for CORE-988, also please see
// http://carcino.gen.nz/tech/linux/glibc_sem_timedwait_errors.php
errcode = rc > 0 ? rc : errno;
} while (errcode == EINTR);
if (errcode == ETIMEDOUT) {
return false;
}
system_call_failed::raise("sem_timedwait", errcode);
return false; // avoid warnings
}
#endif // HAVE_SEM_TIMEDWAIT
#endif // COMMON_CLASSES_SEMAPHORE_POSIX_RT
#ifdef COMMON_CLASSES_SEMAPHORE_COND_VAR
void Semaphore::init()
{
value = 0;
int err = pthread_mutex_init(&mu, NULL);
if (err != 0) {
//gds__log("Error on semaphore.h: constructor");
system_call_failed::raise("pthread_mutex_init", err);
}
err = pthread_cond_init(&cv, NULL);
if (err != 0) {
//gds__log("Error on semaphore.h: constructor");
system_call_failed::raise("pthread_cond_init", err);
}
}
void Semaphore::mtxLock()
{
int err = pthread_mutex_lock(&mu);
if (err != 0)
{
system_call_failed::raise("pthread_mutex_lock", err);
}
}
void Semaphore::mtxUnlock()
{
int err = pthread_mutex_unlock(&mu);
if (err != 0)
{
system_call_failed::raise("pthread_mutex_unlock", err);
}
}
Semaphore::~Semaphore()
{
fb_assert(value == 0);
int err = pthread_mutex_destroy(&mu);
if (err != 0) {
//gds__log("Error on semaphore.h: destructor");
//system_call_failed::raise("pthread_mutex_destroy", err);
}
err = pthread_cond_destroy(&cv);
if (err != 0) {
//gds__log("Error on semaphore.h: destructor");
//system_call_failed::raise("pthread_cond_destroy", err);
}
}
bool Semaphore::tryEnter(const int seconds, int milliseconds)
{
bool rt = false; // Return true in case of success
int err = 0;
milliseconds += seconds * 1000;
if (milliseconds == 0)
{
// Instant try
err = pthread_mutex_trylock(&mu);
if (err != 0)
{
if (err == EBUSY)
{
return false;
}
system_call_failed::raise("pthread_mutex_trylock", err);
}
if (value > 0)
{
--value;
rt = true;
}
mtxUnlock();
return rt;
}
if (milliseconds < 0)
{
// Unlimited wait
enter();
return true;
}
// Wait with timeout
mtxLock();
if (--value >= 0)
{
mtxUnlock();
return true;
}
timespec timeout = getCurrentTime();
nanoseconds += timeout.tv_nsec;
timeout.tv_sec += nanoseconds / 1000000000l;
timeout.tv_nsec = nanoseconds % 1000000000l;
err = pthread_cond_timedwait(&cv, &mu, &timeout);
mtxUnlock();
if (err == ETIMEDOUT)
{
++value;
}
else if (err != 0)
{
system_call_failed::raise("pthread_cond_timedwait", err);
}
else
{
rt = true;
}
return rt;
}
void Semaphore::enter()
{
mtxLock();
if (--value >= 0)
{
mtxUnlock();
return;
}
int err = pthread_cond_wait(&cv, &mu);
mtxUnlock();
if (err != 0)
{
system_call_failed::raise("pthread_cond_timedwait", err);
}
}
void Semaphore::release(SLONG count)
{
int err = 0;
for (int i = 0; i < count; i++)
{
mtxLock();
if (++value > 0)
{
mtxUnlock();
continue;
}
err = pthread_cond_signal(&cv);
mtxUnlock();
if (err != 0)
{
system_call_failed::raise("pthread_cond_broadcast", err);
}
}
}
#endif // COMMON_CLASSES_SEMAPHORE_COND_VAR
}