barrier/lib/arch/CArchMultithreadPosix.cpp
crs 848aee7a3a Checkpoint. Code does not run. Still converting over to new
event loop model.  Streams, stream filters, and sockets are
converted.  Client proxies are almost converted.  CServer is
in progress.  Removed all HTTP code.  Haven't converted the
necessary win32 arch stuff.
2004-02-01 21:09:22 +00:00

797 lines
17 KiB
C++

/*
* synergy -- mouse and keyboard sharing utility
* Copyright (C) 2002 Chris Schoeneman
*
* This package is free software you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* found in the file COPYING that should have accompanied this file.
*
* This package 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.
*/
#include "CArchMultithreadPosix.h"
#include "CArch.h"
#include "XArch.h"
#include <signal.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#include <cerrno>
#define SIGWAKEUP SIGUSR1
#if !HAVE_PTHREAD_SIGNAL
// boy, is this platform broken. forget about pthread signal
// handling and let signals through to every process. synergy
// will not terminate cleanly when it gets SIGTERM or SIGINT.
# define pthread_sigmask sigprocmask
# define pthread_kill(tid_, sig_) kill(0, (sig_))
# define sigwait(set_, sig_)
# undef HAVE_POSIX_SIGWAIT
# define HAVE_POSIX_SIGWAIT 1
#endif
//
// CArchThreadImpl
//
class CArchThreadImpl {
public:
CArchThreadImpl();
public:
int m_refCount;
IArchMultithread::ThreadID m_id;
pthread_t m_thread;
IArchMultithread::ThreadFunc m_func;
void* m_userData;
bool m_cancel;
bool m_cancelling;
bool m_exited;
void* m_result;
};
CArchThreadImpl::CArchThreadImpl() :
m_refCount(1),
m_id(0),
m_func(NULL),
m_userData(NULL),
m_cancel(false),
m_cancelling(false),
m_exited(false),
m_result(NULL)
{
// do nothing
}
//
// CArchMultithreadPosix
//
CArchMultithreadPosix* CArchMultithreadPosix::s_instance = NULL;
CArchMultithreadPosix::CArchMultithreadPosix() :
m_newThreadCalled(false),
m_nextID(0),
m_signalFunc(NULL),
m_signalUserData(NULL)
{
assert(s_instance == NULL);
s_instance = this;
// create mutex for thread list
m_threadMutex = newMutex();
// create thread for calling (main) thread and add it to our
// list. no need to lock the mutex since we're the only thread.
m_mainThread = new CArchThreadImpl;
m_mainThread->m_thread = pthread_self();
insert(m_mainThread);
// install SIGWAKEUP handler. this causes SIGWAKEUP to interrupt
// system calls. we use that when cancelling a thread to force it
// to wake up immediately if it's blocked in a system call. we
// won't need this until another thread is created but it's fine
// to install it now.
struct sigaction act;
sigemptyset(&act.sa_mask);
# if defined(SA_INTERRUPT)
act.sa_flags = SA_INTERRUPT;
# else
act.sa_flags = 0;
# endif
act.sa_handler = &threadCancel;
sigaction(SIGWAKEUP, &act, NULL);
// set desired signal dispositions. let SIGWAKEUP through but
// ignore SIGPIPE (we'll handle EPIPE).
sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, SIGWAKEUP);
pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
sigemptyset(&sigset);
sigaddset(&sigset, SIGPIPE);
pthread_sigmask(SIG_BLOCK, &sigset, NULL);
}
CArchMultithreadPosix::~CArchMultithreadPosix()
{
assert(s_instance != NULL);
closeMutex(m_threadMutex);
s_instance = NULL;
}
CArchCond
CArchMultithreadPosix::newCondVar()
{
CArchCondImpl* cond = new CArchCondImpl;
int status = pthread_cond_init(&cond->m_cond, NULL);
assert(status == 0);
return cond;
}
void
CArchMultithreadPosix::closeCondVar(CArchCond cond)
{
int status = pthread_cond_destroy(&cond->m_cond);
assert(status == 0);
delete cond;
}
void
CArchMultithreadPosix::signalCondVar(CArchCond cond)
{
int status = pthread_cond_signal(&cond->m_cond);
assert(status == 0);
}
void
CArchMultithreadPosix::broadcastCondVar(CArchCond cond)
{
int status = pthread_cond_broadcast(&cond->m_cond);
assert(status == 0);
}
bool
CArchMultithreadPosix::waitCondVar(CArchCond cond,
CArchMutex mutex, double timeout)
{
// get final time
struct timeval now;
gettimeofday(&now, NULL);
struct timespec finalTime;
finalTime.tv_sec = now.tv_sec;
finalTime.tv_nsec = now.tv_usec * 1000;
if (timeout >= 0.0) {
const long timeout_sec = (long)timeout;
const long timeout_nsec = (long)(1.0e+9 * (timeout - timeout_sec));
finalTime.tv_sec += timeout_sec;
finalTime.tv_nsec += timeout_nsec;
if (finalTime.tv_nsec >= 1000000000) {
finalTime.tv_nsec -= 1000000000;
finalTime.tv_sec += 1;
}
}
// repeat until we reach the final time
int status;
for (;;) {
// get current time
gettimeofday(&now, NULL);
struct timespec endTime;
endTime.tv_sec = now.tv_sec;
endTime.tv_nsec = now.tv_usec * 1000;
// done if past final timeout
if (timeout >= 0.0) {
if (endTime.tv_sec > finalTime.tv_sec ||
(endTime.tv_sec == finalTime.tv_sec &&
endTime.tv_nsec >= finalTime.tv_nsec)) {
status = ETIMEDOUT;
break;
}
}
// compute the next timeout
endTime.tv_nsec += 50000000;
if (endTime.tv_nsec >= 1000000000) {
endTime.tv_nsec -= 1000000000;
endTime.tv_sec += 1;
}
// don't wait past final timeout
if (timeout >= 0.0) {
if (endTime.tv_sec > finalTime.tv_sec ||
(endTime.tv_sec == finalTime.tv_sec &&
endTime.tv_nsec >= finalTime.tv_nsec)) {
endTime = finalTime;
}
}
// see if we should cancel this thread
testCancelThread();
// wait
status = pthread_cond_timedwait(&cond->m_cond,
&mutex->m_mutex, &endTime);
// check for cancel again
testCancelThread();
// check wait status
if (status != ETIMEDOUT && status != EINTR) {
break;
}
}
switch (status) {
case 0:
// success
return true;
case ETIMEDOUT:
return false;
default:
assert(0 && "condition variable wait error");
return false;
}
}
CArchMutex
CArchMultithreadPosix::newMutex()
{
pthread_mutexattr_t attr;
int status = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
assert(status == 0);
CArchMutexImpl* mutex = new CArchMutexImpl;
status = pthread_mutex_init(&mutex->m_mutex, &attr);
assert(status == 0);
return mutex;
}
void
CArchMultithreadPosix::closeMutex(CArchMutex mutex)
{
int status = pthread_mutex_destroy(&mutex->m_mutex);
assert(status == 0);
delete mutex;
}
void
CArchMultithreadPosix::lockMutex(CArchMutex mutex)
{
int status = pthread_mutex_lock(&mutex->m_mutex);
switch (status) {
case 0:
// success
return;
case EDEADLK:
assert(0 && "lock already owned");
break;
case EAGAIN:
assert(0 && "too many recursive locks");
break;
default:
assert(0 && "unexpected error");
break;
}
}
void
CArchMultithreadPosix::unlockMutex(CArchMutex mutex)
{
int status = pthread_mutex_unlock(&mutex->m_mutex);
switch (status) {
case 0:
// success
return;
case EPERM:
assert(0 && "thread doesn't own a lock");
break;
default:
assert(0 && "unexpected error");
break;
}
}
CArchThread
CArchMultithreadPosix::newThread(ThreadFunc func, void* data)
{
assert(func != NULL);
// initialize signal handler. we do this here instead of the
// constructor so we can avoid daemonizing (using fork())
// when there are multiple threads. clients can safely
// use condition variables and mutexes before creating a
// new thread and they can safely use the only thread
// they have access to, the main thread, so they really
// can't tell the difference.
if (!m_newThreadCalled) {
m_newThreadCalled = true;
#if HAVE_PTHREAD_SIGNAL
startSignalHandler();
#endif
}
lockMutex(m_threadMutex);
// create thread impl for new thread
CArchThreadImpl* thread = new CArchThreadImpl;
thread->m_func = func;
thread->m_userData = data;
// mask some signals in all threads except the main thread
sigset_t sigset, oldsigset;
sigemptyset(&sigset);
sigaddset(&sigset, SIGINT);
sigaddset(&sigset, SIGTERM);
pthread_sigmask(SIG_BLOCK, &sigset, &oldsigset);
// create the thread. pthread_create() on RedHat 7.2 smp fails
// if passed a NULL attr so use a default attr.
pthread_attr_t attr;
int status = pthread_attr_init(&attr);
if (status == 0) {
status = pthread_create(&thread->m_thread, &attr,
&CArchMultithreadPosix::threadFunc, thread);
pthread_attr_destroy(&attr);
}
// restore signals
pthread_sigmask(SIG_SETMASK, &oldsigset, NULL);
// check if thread was started
if (status != 0) {
// failed to start thread so clean up
delete thread;
thread = NULL;
}
else {
// add thread to list
insert(thread);
// increment ref count to account for the thread itself
refThread(thread);
}
// note that the child thread will wait until we release this mutex
unlockMutex(m_threadMutex);
return thread;
}
CArchThread
CArchMultithreadPosix::newCurrentThread()
{
lockMutex(m_threadMutex);
CArchThreadImpl* thread = find(pthread_self());
unlockMutex(m_threadMutex);
assert(thread != NULL);
return thread;
}
void
CArchMultithreadPosix::closeThread(CArchThread thread)
{
assert(thread != NULL);
// decrement ref count and clean up thread if no more references
if (--thread->m_refCount == 0) {
// detach from thread (unless it's the main thread)
if (thread->m_func != NULL) {
pthread_detach(thread->m_thread);
}
// remove thread from list
lockMutex(m_threadMutex);
assert(findNoRef(thread->m_thread) == thread);
erase(thread);
unlockMutex(m_threadMutex);
// done with thread
delete thread;
}
}
CArchThread
CArchMultithreadPosix::copyThread(CArchThread thread)
{
refThread(thread);
return thread;
}
void
CArchMultithreadPosix::cancelThread(CArchThread thread)
{
assert(thread != NULL);
// set cancel and wakeup flags if thread can be cancelled
bool wakeup = false;
lockMutex(m_threadMutex);
if (!thread->m_exited && !thread->m_cancelling) {
thread->m_cancel = true;
wakeup = true;
}
unlockMutex(m_threadMutex);
// force thread to exit system calls if wakeup is true
if (wakeup) {
pthread_kill(thread->m_thread, SIGWAKEUP);
}
}
void
CArchMultithreadPosix::setPriorityOfThread(CArchThread thread, int /*n*/)
{
assert(thread != NULL);
// FIXME
}
void
CArchMultithreadPosix::testCancelThread()
{
// find current thread
lockMutex(m_threadMutex);
CArchThreadImpl* thread = findNoRef(pthread_self());
unlockMutex(m_threadMutex);
// test cancel on thread
testCancelThreadImpl(thread);
}
bool
CArchMultithreadPosix::wait(CArchThread target, double timeout)
{
assert(target != NULL);
lockMutex(m_threadMutex);
// find current thread
CArchThreadImpl* self = findNoRef(pthread_self());
// ignore wait if trying to wait on ourself
if (target == self) {
unlockMutex(m_threadMutex);
return false;
}
// ref the target so it can't go away while we're watching it
refThread(target);
unlockMutex(m_threadMutex);
try {
// do first test regardless of timeout
testCancelThreadImpl(self);
if (isExitedThread(target)) {
closeThread(target);
return true;
}
// wait and repeat test if there's a timeout
if (timeout != 0.0) {
const double start = ARCH->time();
do {
// wait a little
ARCH->sleep(0.05);
// repeat test
testCancelThreadImpl(self);
if (isExitedThread(target)) {
closeThread(target);
return true;
}
// repeat wait and test until timed out
} while (timeout < 0.0 || (ARCH->time() - start) <= timeout);
}
closeThread(target);
return false;
}
catch (...) {
closeThread(target);
throw;
}
}
IArchMultithread::EWaitResult
CArchMultithreadPosix::waitForEvent(CArchThread, double /*timeout*/)
{
// not implemented
return kTimeout;
}
void
CArchMultithreadPosix::unblockThread(CArchThread thread)
{
pthread_kill(thread->m_thread, SIGWAKEUP);
}
bool
CArchMultithreadPosix::isSameThread(CArchThread thread1, CArchThread thread2)
{
return (thread1 == thread2);
}
bool
CArchMultithreadPosix::isExitedThread(CArchThread thread)
{
lockMutex(m_threadMutex);
bool exited = thread->m_exited;
unlockMutex(m_threadMutex);
return exited;
}
void*
CArchMultithreadPosix::getResultOfThread(CArchThread thread)
{
lockMutex(m_threadMutex);
void* result = thread->m_result;
unlockMutex(m_threadMutex);
return result;
}
IArchMultithread::ThreadID
CArchMultithreadPosix::getIDOfThread(CArchThread thread)
{
return thread->m_id;
}
void
CArchMultithreadPosix::setInterruptHandler(InterruptFunc func, void* userData)
{
lockMutex(m_threadMutex);
m_signalFunc = func;
m_signalUserData = userData;
unlockMutex(m_threadMutex);
}
void
CArchMultithreadPosix::interrupt()
{
lockMutex(m_threadMutex);
if (m_signalFunc != NULL) {
m_signalFunc(m_signalUserData);
}
else {
ARCH->cancelThread(m_mainThread);
}
unlockMutex(m_threadMutex);
}
void
CArchMultithreadPosix::startSignalHandler()
{
// set signal mask. the main thread blocks these signals and
// the signal handler thread will listen for them.
sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, SIGINT);
sigaddset(&sigset, SIGTERM);
pthread_sigmask(SIG_BLOCK, &sigset, NULL);
// fire up the INT and TERM signal handler thread. we could
// instead arrange to catch and handle these signals but
// we'd be unable to cancel the main thread since no pthread
// calls are allowed in a signal handler.
pthread_attr_t attr;
int status = pthread_attr_init(&attr);
if (status == 0) {
status = pthread_create(&m_signalThread, &attr,
&CArchMultithreadPosix::threadSignalHandler,
NULL);
pthread_attr_destroy(&attr);
}
if (status != 0) {
// can't create thread to wait for signal so don't block
// the signals.
sigemptyset(&sigset);
sigaddset(&sigset, SIGINT);
sigaddset(&sigset, SIGTERM);
pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
}
}
CArchThreadImpl*
CArchMultithreadPosix::find(pthread_t thread)
{
CArchThreadImpl* impl = findNoRef(thread);
if (impl != NULL) {
refThread(impl);
}
return impl;
}
CArchThreadImpl*
CArchMultithreadPosix::findNoRef(pthread_t thread)
{
// linear search
for (CThreadList::const_iterator index = m_threadList.begin();
index != m_threadList.end(); ++index) {
if ((*index)->m_thread == thread) {
return *index;
}
}
return NULL;
}
void
CArchMultithreadPosix::insert(CArchThreadImpl* thread)
{
assert(thread != NULL);
// thread shouldn't already be on the list
assert(findNoRef(thread->m_thread) == NULL);
// set thread id. note that we don't worry about m_nextID
// wrapping back to 0 and duplicating thread ID's since the
// likelihood of synergy running that long is vanishingly
// small.
thread->m_id = ++m_nextID;
// append to list
m_threadList.push_back(thread);
}
void
CArchMultithreadPosix::erase(CArchThreadImpl* thread)
{
for (CThreadList::iterator index = m_threadList.begin();
index != m_threadList.end(); ++index) {
if (*index == thread) {
m_threadList.erase(index);
break;
}
}
}
void
CArchMultithreadPosix::refThread(CArchThreadImpl* thread)
{
assert(thread != NULL);
assert(findNoRef(thread->m_thread) != NULL);
++thread->m_refCount;
}
void
CArchMultithreadPosix::testCancelThreadImpl(CArchThreadImpl* thread)
{
assert(thread != NULL);
// update cancel state
lockMutex(m_threadMutex);
bool cancel = false;
if (thread->m_cancel && !thread->m_cancelling) {
thread->m_cancelling = true;
thread->m_cancel = false;
cancel = true;
}
unlockMutex(m_threadMutex);
// unwind thread's stack if cancelling
if (cancel) {
throw XThreadCancel();
}
}
void*
CArchMultithreadPosix::threadFunc(void* vrep)
{
// get the thread
CArchThreadImpl* thread = reinterpret_cast<CArchThreadImpl*>(vrep);
// setup pthreads
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
// run thread
s_instance->doThreadFunc(thread);
// terminate the thread
return NULL;
}
void
CArchMultithreadPosix::doThreadFunc(CArchThread thread)
{
// default priority is slightly below normal
setPriorityOfThread(thread, 1);
// wait for parent to initialize this object
lockMutex(m_threadMutex);
unlockMutex(m_threadMutex);
void* result = NULL;
try {
// go
result = (*thread->m_func)(thread->m_userData);
}
catch (XThreadCancel&) {
// client called cancel()
}
catch (...) {
// note -- don't catch (...) to avoid masking bugs
lockMutex(m_threadMutex);
thread->m_exited = true;
unlockMutex(m_threadMutex);
closeThread(thread);
throw;
}
// thread has exited
lockMutex(m_threadMutex);
thread->m_result = result;
thread->m_exited = true;
unlockMutex(m_threadMutex);
// done with thread
closeThread(thread);
}
void
CArchMultithreadPosix::threadCancel(int)
{
// do nothing
}
void*
CArchMultithreadPosix::threadSignalHandler(void*)
{
// detach
pthread_detach(pthread_self());
// add signal to mask
sigset_t sigset;
sigemptyset(&sigset);
sigaddset(&sigset, SIGINT);
sigaddset(&sigset, SIGTERM);
// also wait on SIGABRT. on linux (others?) this thread (process)
// will persist after all the other threads evaporate due to an
// assert unless we wait on SIGABRT. that means our resources (like
// the socket we're listening on) are not released and never will be
// until the lingering thread is killed. i don't know why sigwait()
// should protect the thread from being killed. note that sigwait()
// doesn't actually return if we receive SIGABRT and, for some
// reason, we don't have to block SIGABRT.
sigaddset(&sigset, SIGABRT);
// we exit the loop via thread cancellation in sigwait()
for (;;) {
// wait
#if HAVE_POSIX_SIGWAIT
int signal;
sigwait(&sigset, &signal);
#else
sigwait(&sigset);
#endif
// if we get here then the signal was raised
ARCH->interrupt();
}
}