~drizzle-trunk/drizzle/development

/* Copyright (c) 2008 PrimeBase Technologies GmbH, Germany

 *

 * PrimeBase Media Stream for MySQL

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 *

 * Original author: Paul McCullagh (H&G2JCtL)

 * Continued development: Barry Leslie

 *

 * 2007-05-20

 *

 * CORE SYSTEM:

 * A independently running thread.

 *

 */

#include "CSConfig.h"

#ifdef OS_WINDOWS

#include <signal.h>

#include "uniwin.h"

#else

#include <signal.h>

#include <sys/signal.h>

#endif

#include <unistd.h>

#include <errno.h>

#include "CSGlobal.h"

#include "CSLog.h"

#include "CSException.h"

#include "CSThread.h"

#include "CSStrUtil.h"

#include "CSMemory.h"

/*

 * ---------------------------------------------------------------

 * SIGNAL HANDLERS

 */

extern "C" {

static void td_catch_signal(int sig)

{

	CSThread *self;

	if ((self = CSThread::getSelf())) {

		if (self->isMain()) {

			/* The main thread will pass on a signal to all threads: */

			if (self->myThreadList)

				self->myThreadList->signalAllThreads(sig);

			self->setSignalPending(sig);

		}

	}

}

static  void td_throw_signal(int sig)

{

	CSThread *self;

	if ((self = CSThread::getSelf())) {

		if (self->isMain()) {

			/* The main thread will pass on a signal to all threads: */

			if (self->myThreadList)

				self->myThreadList->signalAllThreads(sig);

		}

		self->setSignalPending(sig);

		self->interrupted();

	}

}

static bool td_setup_signals(CSThread *thread)

{

#ifdef OS_WINDOWS

	return true;

#else

	struct sigaction action;

    sigemptyset(&action.sa_mask);

    action.sa_flags = 0;

    action.sa_handler = td_catch_signal;

	if (sigaction(SIGUSR2, &action, NULL) == -1)

		goto error_occurred;

    action.sa_handler = td_throw_signal;

	return true;

	error_occurred:

	if (thread) {

		thread->myException.initOSError(CS_CONTEXT, errno);

		thread->myException.setStackTrace(thread);

	}

	else

		CSException::throwOSError(CS_CONTEXT, errno);

	return false;

#endif

}

}

/*

 * ---------------------------------------------------------------

 * THREAD LISTS

 */

void CSThreadList::signalAllThreads(int sig)

{

	CSThread *ptr;

	enter_();

	lock_(this);

	ptr = (CSThread *) getBack();

	while (ptr) {

		if (ptr != self)

			ptr->signal(sig);

		ptr = (CSThread *) ptr->getNextLink();

	}

	unlock_(this);

	exit_();

}

void CSThreadList::quitAllThreads()

{

	CSThread *ptr;

	enter_();

	lock_(this);

	ptr = (CSThread *) getBack();

	while (ptr) {

		if (ptr != self)

			ptr->myMustQuit = true;

		ptr = (CSThread *) ptr->getNextLink();

	}

	unlock_(this);

	exit_();

}

void CSThreadList::stopAllThreads()

{

	CSThread *thread;

	enter_();

	for (;;) {

		/* Get a thread that is not self! */

		lock_(this);

		if ((thread = (CSThread *) getBack())) {

			while (thread) {

				if (thread != self)

					break;

				thread = (CSThread *) thread->getNextLink();

			}

		}

		if (thread)

			thread->retain();

		unlock_(this);

		if (!thread)

			break;

		push_(thread);

		thread->stop();

		release_(thread);

	}

	exit_();

}

/*

 * ---------------------------------------------------------------

 * CSTHREAD

 */

void CSThread::addToList()

{

	if (myThreadList) {

		enter_();

		ASSERT(self == this);

		lock_(myThreadList);

		myThreadList->addFront(self);

		isRunning = true;

		unlock_(myThreadList);

		exit_();

	}

	else

		isRunning = true;

}

void CSThread::removeFromList()

{

	if (myThreadList && isRunning) {

		enter_();

		/* Retain the thread in order to ensure

		 * that after it is removed from the list,

		 * that it is not freed! This would make the

		 * unlock_() call invalid, because it requires

		 * on the thread.

		 */

		push_(this);

		lock_(myThreadList);

		myThreadList->remove(RETAIN(this));

		unlock_(myThreadList);

		pop_(this);

		outer_();

	}

	this->release();

}

void *CSThread::dispatch(void *arg)

{

	CSThread		*self;

	void			*return_data = NULL;

	int				err;

	/* Get a reference to myself: */

	self = reinterpret_cast<CSThread*>(arg);

	ASSERT(self);

	/* Store my thread in the thread key: */

	if ((err = pthread_setspecific(CSThread::sThreadKey, self))) {

		CSException::logOSError(self, CS_CONTEXT, err);

		return NULL;

	}

	/*

	 * Make sure the thread is not freed while we

	 * are running:

	 */

	self->retain();

	try_(a) {

		td_setup_signals(NULL);

		/* Add the thread to the list: */

		self->addToList();

		// Run the task from the correct context

		return_data = self->run();

	}

	catch_(a) {

		self->logException();

	}

	cont_(a);

	/*

	 * Removing from the thread list will also release the thread.

	 */

	self->removeFromList();

	// Exit the thread

	return return_data;

}

extern "C"

{

static void *dispatch_wrapper(void *arg)

{

	return CSThread::dispatch(arg);

}

}

void *CSThread::run()

{

	if (iRunFunc)

		return iRunFunc();

	return NULL;

}

void CSThread::start()

{

	int err;

	err = pthread_create(&iThread, NULL, dispatch_wrapper, (void *) this);

	if (err)

		CSException::throwOSError(CS_CONTEXT, err);

	while (!isRunning) {

		/* Check if the thread is still alive,

		 * so we don't hang forever.

		 */

		if (pthread_kill(iThread, 0))

			break;

		usleep(10);

	}

}

void CSThread::stop()

{

	signal(SIGTERM);

	join();

}

void *CSThread::join()

{

	void	*return_data;

	int		err;

	enter_();

	if ((err = pthread_join(iThread, &return_data)))

		CSException::throwOSError(CS_CONTEXT, err);

	return_(return_data);

}

void CSThread::setSignalPending(unsigned int sig)

{

	if (sig == SIGTERM)

		/* The terminate signal takes priority: */

		signalPending = SIGTERM;

	else if (!signalPending)

		/* Otherwise, first signal wins... */

		signalPending = sig;

}

void CSThread::signal(unsigned int sig)

{

	int err;

	setSignalPending(sig);

	if ((err = pthread_kill(iThread, SIGUSR2)))

	{

		/* Ignore the error if the process does not exist! */

		if (err != ESRCH) /* No such process */

			CSException::throwOSError(CS_CONTEXT, err);

	}

}

void CSThread::throwSignal()

{

	int sig;

	if ((sig = signalPending) && !ignoreSignals) {

		signalPending = 0;

		CSException::throwSignal(CS_CONTEXT, sig);

	}

}

bool CSThread::isMain()

{

	return iIsMain;

}

/*

 * -----------------------------------------------------------------------

 * THROWING EXCEPTIONS

 */

/* 

 * When an exception is .

 */

void CSThread::releaseObjects(CSReleasePtr top)

{

	CSObject *obj;

	while (relTop > top) {

		/* Remove and release or unlock the object on the top of the stack: */

		relTop--;

		switch(relTop->r_type) {

			case CS_RELEASE_OBJECT:

				if ((obj = relTop->x.r_object))

					obj->release();

				break;

			case CS_RELEASE_MUTEX:

				if (relTop->x.r_mutex)

					relTop->x.r_mutex->unlock();

				break;

			case CS_RELEASE_POOLED:

				if (relTop->x.r_pooled)

					relTop->x.r_pooled->returnToPool();

				break;

		}

	}

}

/* Throw an already registered error: */

void CSThread::throwException()

{

	/* Record the stack trace: */

	if (this->jumpDepth > 0 && this->jumpDepth <= CS_JUMP_STACK_SIZE) {

		/*

		 * As recommended by Barry:

		 * release the objects before we jump!

		 * This has the advantage that the stack context is still

		 * valid when the resources are released.

		 */

		releaseObjects(this->jumpEnv[this->jumpDepth-1].jb_res_top);

		/* Then do the longjmp: */

		longjmp(this->jumpEnv[this->jumpDepth-1].jb_buffer, 1);

	}

}

void CSThread::logStack(int depth, const char *msg)

{

	char buffer[CS_EXC_CONTEXT_SIZE +1];

	CSL.lock();

	CSL.log(this, CSLog::Trace, msg);

	for (int i= callTop-1; i>=0 && depth; i--, depth--) {

		cs_format_context(CS_EXC_CONTEXT_SIZE, buffer,

			callStack[i].cs_func, callStack[i].cs_file, callStack[i].cs_line);

		strcat(buffer, "\n");

		CSL.log(this, CSLog::Trace, buffer);

	}

	CSL.unlock();

}

void CSThread::logException()

{

	myException.log(this);

}

/*

 * This function is called when an exception is caught.

 * It restores the function call top and frees

 * any resource allocated by lower levels.

 */

void CSThread::caught()

{

	/* Restore the call top: */

	this->callTop = this->jumpEnv[this->jumpDepth].jb_call_top;

	/* 

	 * Release all all objects that were pushed after

	 * this jump position was set:

	 */

	releaseObjects(this->jumpEnv[this->jumpDepth].jb_res_top);

}

/*

 * ---------------------------------------------------------------

 * STATIC METHODS

 */

pthread_key_t	CSThread::sThreadKey;

bool			CSThread::isUp = false;

bool CSThread::startUp()

{

	int err;

	isUp = false;

	if ((err = pthread_key_create(&sThreadKey, NULL))) {

		CSException::logOSError(CS_CONTEXT, errno);

		return false;

	} else

		isUp = true;

	return isUp;

}

void CSThread::shutDown()

{

	isUp = false;

}

bool CSThread::attach(CSThread *thread)

{

	ASSERT(!getSelf());

	if (!thread) {

		CSException::logOSError(CS_CONTEXT, ENOMEM);

		return false;

	}

	if (!setSelf(thread))

		return false;

	/* Now we are ready to receive signals: */

	if (!td_setup_signals(thread))

		return false;

	thread->addToList();

	thread->retain();

	return true;

}

void CSThread::detach(CSThread *thread)

{

	ASSERT(!getSelf() || getSelf() == thread);

	thread->removeFromList();

	thread->release();

	pthread_setspecific(sThreadKey, NULL);

}

CSThread* CSThread::getSelf()

{

	CSThread* self = NULL;

	if ((!isUp) || !(self = (CSThread*) pthread_getspecific(sThreadKey)))

		return (CSThread*) NULL;

#ifdef DEBUG

	if (self->iRefCount == 0) {

		pthread_setspecific(sThreadKey, NULL);

		CSException::throwAssertion(CS_CONTEXT, "Bad self pointer.");

	}	

#endif

	return self;

}

bool CSThread::setSelf(CSThread *self)

{

	int err;

	if (self) {

		self->iThread = pthread_self();

		/* Store my thread in the thread key: */

		if ((err = pthread_setspecific(sThreadKey, self))) {

			self->myException.initOSError(CS_CONTEXT, err);

			self->myException.setStackTrace(self);

			return false;

		}

	}

	else

		pthread_setspecific(sThreadKey, NULL);

	return true;

}

/* timeout is in milliseconds */

void CSThread::sleep(unsigned long timeout)

{

	enter_();

	usleep(timeout * 1000);

	self->interrupted();

	exit_();

}

#ifdef DEBUG

int cs_assert(const char *func, const char *file, int line, const char *message)

{

	CSException::throwAssertion(func, file, line, message);

	return 0;

}

int cs_hope(const char *func, const char *file, int line, const char *message)

{

	CSException e;

	e.initAssertion(func, file, line, message);

	e.log(NULL);

	return 0;

}

#endif

CSThread *CSThread::newThread(CSString *name, ThreadRunFunc run_func, CSThreadList *list)

{

	CSThread *thd;

	enter_();

	if (!(thd = new CSThread(list))) {

		name->release();

		CSException::throwOSError(CS_CONTEXT, ENOMEM);

	}

	thd->threadName = name;

	thd->iRunFunc = run_func;

	return_(thd);

}

CSThread *CSThread::newCSThread()

{

	CSThread *thd = NULL;

	if (!(thd = new CSThread(NULL))) {

		CSException::throwOSError(CS_CONTEXT, ENOMEM);

	}

	return thd;

}

/*

 * ---------------------------------------------------------------

 * DAEMON THREADS

 */

CSDaemon::CSDaemon(time_t wait_time, CSThreadList *list):

CSThread(list),

CSSync(),

myWaitTime(wait_time),

iSuspended(false),

iSuspendCount(0)

{

}

CSDaemon::CSDaemon(CSThreadList *list):

CSThread(list),

CSSync(),

myWaitTime(0),

iSuspended(false),

iSuspendCount(0)

{

}

void *CSDaemon::run()

{

	bool must_sleep = false;

	CLOBBER_PROTECT(must_sleep);

	enter_();

	CLOBBER_PROTECT(self);

	myMustQuit = !initializeWork();

	restart:

	try_(a) {

		while (!myMustQuit) {

			if (must_sleep) {

				lock_(this);

				if (myWaitTime)

					suspendedWait(myWaitTime);

				else

					suspendedWait();

				unlock_(this);

				if (myMustQuit)

					break;

			}

			must_sleep = doWork();

		}

	}

	catch_(a) {

		if (!handleException())

			myMustQuit = true;

	}

	cont_(a);

	if (!myMustQuit) {

		must_sleep = true;

		goto restart;

	}

	/* Prevent signals from going off in completeWork! */

	ignoreSignals = true;

	return_(completeWork());

}

bool CSDaemon::doWork()

{

	if (iRunFunc)

		(void) iRunFunc();

	return true;

}

bool CSDaemon::handleException()

{

	if (!myMustQuit)

		logException();

	return true;

}

void CSDaemon::wakeup()

{

	CSSync::wakeup();

}

void CSDaemon::stop()

{

	myMustQuit = true;

	wakeup();

	signal(SIGTERM);

	join();

}

void CSDaemon::suspend()

{

	enter_();

	lock_(this);

	iSuspendCount++;

	while (!iSuspended && !myMustQuit)

		wait(500);

	if (!iSuspended)

		iSuspendCount--;

	unlock_(this);

	exit_();

}

void CSDaemon::resume()

{

	enter_();

	lock_(this);

	if (iSuspendCount > 0)

		iSuspendCount--;

	wakeup();

	unlock_(this);

	exit_();

}

void CSDaemon::suspended()

{

	if (!iSuspendCount || myMustQuit) {

		iSuspended = false;

		return;

	}

	enter_();

	lock_(this);

	while (iSuspendCount && !myMustQuit) {

		iSuspended = true;

		wait(500);

	}

	iSuspended = false;

	unlock_(this);

	exit_();

}

void CSDaemon::suspendedWait()

{

	iSuspended = true;

	wait();

	if (iSuspendCount)

		suspended();

}

void CSDaemon::suspendedWait(time_t milli_sec)

{

	iSuspended = true;

	wait(milli_sec);

	if (iSuspendCount)

		suspended();

	else

		iSuspended = false;

}

/*

 * ---------------------------------------------------------------

 * THREAD POOLS

 */