barrier/lib/arch/CArchMultithreadWindows.cpp

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/*
* synergy -- mouse and keyboard sharing utility
* Copyright (C) 2002 Chris Schoeneman, Nick Bolton, Sorin Sbarnea
*
2010-06-20 17:38:51 +00:00
* 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,
2010-06-20 17:38:51 +00:00
* 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.
2010-06-20 17:38:51 +00:00
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#if defined(_MSC_VER) && !defined(_MT)
# error multithreading compile option is required
#endif
#include "CArchMultithreadWindows.h"
#include "CArch.h"
#include "XArch.h"
#include <process.h>
//
// note -- implementation of condition variable taken from:
// http://www.cs.wustl.edu/~schmidt/win32-cv-1.html
// titled "Strategies for Implementing POSIX Condition Variables
// on Win32." it also provides an implementation that doesn't
// suffer from the incorrectness problem described in our
// corresponding header but it is slower, still unfair, and
// can cause busy waiting.
//
//
// CArchThreadImpl
//
class CArchThreadImpl {
public:
CArchThreadImpl();
~CArchThreadImpl();
public:
int m_refCount;
HANDLE m_thread;
DWORD m_id;
IArchMultithread::ThreadFunc m_func;
void* m_userData;
HANDLE m_cancel;
bool m_cancelling;
HANDLE m_exit;
void* m_result;
void* m_networkData;
};
CArchThreadImpl::CArchThreadImpl() :
m_refCount(1),
m_thread(NULL),
m_id(0),
m_func(NULL),
m_userData(NULL),
m_cancelling(false),
m_result(NULL),
m_networkData(NULL)
{
m_exit = CreateEvent(NULL, TRUE, FALSE, NULL);
m_cancel = CreateEvent(NULL, TRUE, FALSE, NULL);
}
CArchThreadImpl::~CArchThreadImpl()
{
CloseHandle(m_exit);
CloseHandle(m_cancel);
}
//
// CArchMultithreadWindows
//
CArchMultithreadWindows* CArchMultithreadWindows::s_instance = NULL;
CArchMultithreadWindows::CArchMultithreadWindows()
{
assert(s_instance == NULL);
s_instance = this;
// no signal handlers
for (size_t i = 0; i < kNUM_SIGNALS; ++i) {
m_signalFunc[i] = NULL;
m_signalUserData[i] = NULL;
}
// 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 = NULL;
m_mainThread->m_id = GetCurrentThreadId();
insert(m_mainThread);
}
CArchMultithreadWindows::~CArchMultithreadWindows()
{
s_instance = NULL;
// clean up thread list
for (CThreadList::iterator index = m_threadList.begin();
index != m_threadList.end(); ++index) {
delete *index;
}
// done with mutex
delete m_threadMutex;
}
void
CArchMultithreadWindows::setNetworkDataForCurrentThread(void* data)
{
lockMutex(m_threadMutex);
CArchThreadImpl* thread = findNoRef(GetCurrentThreadId());
thread->m_networkData = data;
unlockMutex(m_threadMutex);
}
void*
CArchMultithreadWindows::getNetworkDataForThread(CArchThread thread)
{
lockMutex(m_threadMutex);
void* data = thread->m_networkData;
unlockMutex(m_threadMutex);
return data;
}
HANDLE
CArchMultithreadWindows::getCancelEventForCurrentThread()
{
lockMutex(m_threadMutex);
CArchThreadImpl* thread = findNoRef(GetCurrentThreadId());
unlockMutex(m_threadMutex);
return thread->m_cancel;
}
CArchMultithreadWindows*
CArchMultithreadWindows::getInstance()
{
return s_instance;
}
CArchCond
CArchMultithreadWindows::newCondVar()
{
CArchCondImpl* cond = new CArchCondImpl;
cond->m_events[CArchCondImpl::kSignal] = CreateEvent(NULL,
FALSE, FALSE, NULL);
cond->m_events[CArchCondImpl::kBroadcast] = CreateEvent(NULL,
TRUE, FALSE, NULL);
cond->m_waitCountMutex = newMutex();
cond->m_waitCount = 0;
return cond;
}
void
CArchMultithreadWindows::closeCondVar(CArchCond cond)
{
CloseHandle(cond->m_events[CArchCondImpl::kSignal]);
CloseHandle(cond->m_events[CArchCondImpl::kBroadcast]);
closeMutex(cond->m_waitCountMutex);
delete cond;
}
void
CArchMultithreadWindows::signalCondVar(CArchCond cond)
{
// is anybody waiting?
lockMutex(cond->m_waitCountMutex);
const bool hasWaiter = (cond->m_waitCount > 0);
unlockMutex(cond->m_waitCountMutex);
// wake one thread if anybody is waiting
if (hasWaiter) {
SetEvent(cond->m_events[CArchCondImpl::kSignal]);
}
}
void
CArchMultithreadWindows::broadcastCondVar(CArchCond cond)
{
// is anybody waiting?
lockMutex(cond->m_waitCountMutex);
const bool hasWaiter = (cond->m_waitCount > 0);
unlockMutex(cond->m_waitCountMutex);
// wake all threads if anybody is waiting
if (hasWaiter) {
SetEvent(cond->m_events[CArchCondImpl::kBroadcast]);
}
}
bool
CArchMultithreadWindows::waitCondVar(CArchCond cond,
CArchMutex mutex, double timeout)
{
// prepare to wait
const DWORD winTimeout = (timeout < 0.0) ? INFINITE :
static_cast<DWORD>(1000.0 * timeout);
// make a list of the condition variable events and the cancel event
// for the current thread.
HANDLE handles[4];
handles[0] = cond->m_events[CArchCondImpl::kSignal];
handles[1] = cond->m_events[CArchCondImpl::kBroadcast];
handles[2] = getCancelEventForCurrentThread();
// update waiter count
lockMutex(cond->m_waitCountMutex);
++cond->m_waitCount;
unlockMutex(cond->m_waitCountMutex);
// release mutex. this should be atomic with the wait so that it's
// impossible for another thread to signal us between the unlock and
// the wait, which would lead to a lost signal on broadcasts.
// however, we're using a manual reset event for broadcasts which
// stays set until we reset it, so we don't lose the broadcast.
unlockMutex(mutex);
// wait for a signal or broadcast
DWORD result = WaitForMultipleObjects(3, handles, FALSE, winTimeout);
// cancel takes priority
if (result != WAIT_OBJECT_0 + 2 &&
WaitForSingleObject(handles[2], 0) == WAIT_OBJECT_0) {
result = WAIT_OBJECT_0 + 2;
}
// update the waiter count and check if we're the last waiter
lockMutex(cond->m_waitCountMutex);
--cond->m_waitCount;
const bool last = (result == WAIT_OBJECT_0 + 1 && cond->m_waitCount == 0);
unlockMutex(cond->m_waitCountMutex);
// reset the broadcast event if we're the last waiter
if (last) {
ResetEvent(cond->m_events[CArchCondImpl::kBroadcast]);
}
// reacquire the mutex
lockMutex(mutex);
// cancel thread if necessary
if (result == WAIT_OBJECT_0 + 2) {
ARCH->testCancelThread();
}
// return success or failure
return (result == WAIT_OBJECT_0 + 0 ||
result == WAIT_OBJECT_0 + 1);
}
CArchMutex
CArchMultithreadWindows::newMutex()
{
CArchMutexImpl* mutex = new CArchMutexImpl;
InitializeCriticalSection(&mutex->m_mutex);
return mutex;
}
void
CArchMultithreadWindows::closeMutex(CArchMutex mutex)
{
DeleteCriticalSection(&mutex->m_mutex);
delete mutex;
}
void
CArchMultithreadWindows::lockMutex(CArchMutex mutex)
{
EnterCriticalSection(&mutex->m_mutex);
}
void
CArchMultithreadWindows::unlockMutex(CArchMutex mutex)
{
LeaveCriticalSection(&mutex->m_mutex);
}
CArchThread
CArchMultithreadWindows::newThread(ThreadFunc func, void* data)
{
lockMutex(m_threadMutex);
// create thread impl for new thread
CArchThreadImpl* thread = new CArchThreadImpl;
thread->m_func = func;
thread->m_userData = data;
// create thread
unsigned int id = 0;
thread->m_thread = reinterpret_cast<HANDLE>(_beginthreadex(NULL, 0,
threadFunc, (void*)thread, 0, &id));
thread->m_id = static_cast<DWORD>(id);
// check if thread was started
if (thread->m_thread == 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
CArchMultithreadWindows::newCurrentThread()
{
lockMutex(m_threadMutex);
CArchThreadImpl* thread = find(GetCurrentThreadId());
unlockMutex(m_threadMutex);
assert(thread != NULL);
return thread;
}
void
CArchMultithreadWindows::closeThread(CArchThread thread)
{
assert(thread != NULL);
// decrement ref count and clean up thread if no more references
if (--thread->m_refCount == 0) {
// close the handle (main thread has a NULL handle)
if (thread->m_thread != NULL) {
CloseHandle(thread->m_thread);
}
// remove thread from list
lockMutex(m_threadMutex);
assert(findNoRefOrCreate(thread->m_id) == thread);
erase(thread);
unlockMutex(m_threadMutex);
// done with thread
delete thread;
}
}
CArchThread
CArchMultithreadWindows::copyThread(CArchThread thread)
{
refThread(thread);
return thread;
}
void
CArchMultithreadWindows::cancelThread(CArchThread thread)
{
assert(thread != NULL);
// set cancel flag
SetEvent(thread->m_cancel);
}
void
CArchMultithreadWindows::setPriorityOfThread(CArchThread thread, int n)
{
struct CPriorityInfo {
public:
DWORD m_class;
int m_level;
};
static const CPriorityInfo s_pClass[] = {
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_IDLE },
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_LOWEST },
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_BELOW_NORMAL },
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_NORMAL },
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_ABOVE_NORMAL },
{ IDLE_PRIORITY_CLASS, THREAD_PRIORITY_HIGHEST },
{ NORMAL_PRIORITY_CLASS, THREAD_PRIORITY_LOWEST },
{ NORMAL_PRIORITY_CLASS, THREAD_PRIORITY_BELOW_NORMAL },
{ NORMAL_PRIORITY_CLASS, THREAD_PRIORITY_NORMAL },
{ NORMAL_PRIORITY_CLASS, THREAD_PRIORITY_ABOVE_NORMAL },
{ NORMAL_PRIORITY_CLASS, THREAD_PRIORITY_HIGHEST },
{ HIGH_PRIORITY_CLASS, THREAD_PRIORITY_LOWEST },
{ HIGH_PRIORITY_CLASS, THREAD_PRIORITY_BELOW_NORMAL },
{ HIGH_PRIORITY_CLASS, THREAD_PRIORITY_NORMAL },
{ HIGH_PRIORITY_CLASS, THREAD_PRIORITY_ABOVE_NORMAL },
{ HIGH_PRIORITY_CLASS, THREAD_PRIORITY_HIGHEST },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_IDLE },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_LOWEST },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_BELOW_NORMAL },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_NORMAL },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_ABOVE_NORMAL },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_HIGHEST },
{ REALTIME_PRIORITY_CLASS, THREAD_PRIORITY_TIME_CRITICAL}
};
#if defined(_DEBUG)
// don't use really high priorities when debugging
static const size_t s_pMax = 13;
#else
static const size_t s_pMax = sizeof(s_pClass) / sizeof(s_pClass[0]) - 1;
#endif
static const size_t s_pBase = 8; // index of normal priority
assert(thread != NULL);
size_t index;
if (n > 0 && s_pBase < (size_t)n) {
// lowest priority
index = 0;
}
else {
index = (size_t)((int)s_pBase - n);
if (index > s_pMax) {
// highest priority
index = s_pMax;
}
}
SetPriorityClass(GetCurrentProcess(), s_pClass[index].m_class);
SetThreadPriority(thread->m_thread, s_pClass[index].m_level);
}
void
CArchMultithreadWindows::testCancelThread()
{
// find current thread
lockMutex(m_threadMutex);
CArchThreadImpl* thread = findNoRef(GetCurrentThreadId());
unlockMutex(m_threadMutex);
// test cancel on thread
testCancelThreadImpl(thread);
}
bool
CArchMultithreadWindows::wait(CArchThread target, double timeout)
{
assert(target != NULL);
lockMutex(m_threadMutex);
// find current thread
CArchThreadImpl* self = findNoRef(GetCurrentThreadId());
// 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);
// convert timeout
DWORD t;
if (timeout < 0.0) {
t = INFINITE;
}
else {
t = (DWORD)(1000.0 * timeout);
}
// wait for this thread to be cancelled or woken up or for the
// target thread to terminate.
HANDLE handles[2];
handles[0] = target->m_exit;
handles[1] = self->m_cancel;
DWORD result = WaitForMultipleObjects(2, handles, FALSE, t);
// cancel takes priority
if (result != WAIT_OBJECT_0 + 1 &&
WaitForSingleObject(handles[1], 0) == WAIT_OBJECT_0) {
result = WAIT_OBJECT_0 + 1;
}
// release target
closeThread(target);
// handle result
switch (result) {
case WAIT_OBJECT_0 + 0:
// target thread terminated
return true;
case WAIT_OBJECT_0 + 1:
// this thread was cancelled. does not return.
testCancelThreadImpl(self);
default:
// timeout or error
return false;
}
}
bool
CArchMultithreadWindows::isSameThread(CArchThread thread1, CArchThread thread2)
{
return (thread1 == thread2);
}
bool
CArchMultithreadWindows::isExitedThread(CArchThread thread)
{
// poll exit event
return (WaitForSingleObject(thread->m_exit, 0) == WAIT_OBJECT_0);
}
void*
CArchMultithreadWindows::getResultOfThread(CArchThread thread)
{
lockMutex(m_threadMutex);
void* result = thread->m_result;
unlockMutex(m_threadMutex);
return result;
}
IArchMultithread::ThreadID
CArchMultithreadWindows::getIDOfThread(CArchThread thread)
{
return static_cast<ThreadID>(thread->m_id);
}
void
CArchMultithreadWindows::setSignalHandler(
ESignal signal, SignalFunc func, void* userData)
{
lockMutex(m_threadMutex);
m_signalFunc[signal] = func;
m_signalUserData[signal] = userData;
unlockMutex(m_threadMutex);
}
void
CArchMultithreadWindows::raiseSignal(ESignal signal)
{
lockMutex(m_threadMutex);
if (m_signalFunc[signal] != NULL) {
m_signalFunc[signal](signal, m_signalUserData[signal]);
ARCH->unblockPollSocket(m_mainThread);
}
else if (signal == kINTERRUPT || signal == kTERMINATE) {
ARCH->cancelThread(m_mainThread);
}
unlockMutex(m_threadMutex);
}
CArchThreadImpl*
CArchMultithreadWindows::find(DWORD id)
{
CArchThreadImpl* impl = findNoRef(id);
if (impl != NULL) {
refThread(impl);
}
return impl;
}
CArchThreadImpl*
CArchMultithreadWindows::findNoRef(DWORD id)
{
CArchThreadImpl* impl = findNoRefOrCreate(id);
if (impl == NULL) {
// create thread for calling thread which isn't in our list and
// add it to the list. this won't normally happen but it can if
// the system calls us under a new thread, like it does when we
// run as a service.
impl = new CArchThreadImpl;
impl->m_thread = NULL;
impl->m_id = GetCurrentThreadId();
insert(impl);
}
return impl;
}
CArchThreadImpl*
CArchMultithreadWindows::findNoRefOrCreate(DWORD id)
{
// linear search
for (CThreadList::const_iterator index = m_threadList.begin();
index != m_threadList.end(); ++index) {
if ((*index)->m_id == id) {
return *index;
}
}
return NULL;
}
void
CArchMultithreadWindows::insert(CArchThreadImpl* thread)
{
assert(thread != NULL);
// thread shouldn't already be on the list
assert(findNoRefOrCreate(thread->m_id) == NULL);
// append to list
m_threadList.push_back(thread);
}
void
CArchMultithreadWindows::erase(CArchThreadImpl* thread)
{
for (CThreadList::iterator index = m_threadList.begin();
index != m_threadList.end(); ++index) {
if (*index == thread) {
m_threadList.erase(index);
break;
}
}
}
void
CArchMultithreadWindows::refThread(CArchThreadImpl* thread)
{
assert(thread != NULL);
assert(findNoRefOrCreate(thread->m_id) != NULL);
++thread->m_refCount;
}
void
CArchMultithreadWindows::testCancelThreadImpl(CArchThreadImpl* thread)
{
assert(thread != NULL);
// poll cancel event. return if not set.
const DWORD result = WaitForSingleObject(thread->m_cancel, 0);
if (result != WAIT_OBJECT_0) {
return;
}
// update cancel state
lockMutex(m_threadMutex);
bool cancel = !thread->m_cancelling;
thread->m_cancelling = true;
ResetEvent(thread->m_cancel);
unlockMutex(m_threadMutex);
// unwind thread's stack if cancelling
if (cancel) {
throw XThreadCancel();
}
}
unsigned int __stdcall
CArchMultithreadWindows::threadFunc(void* vrep)
{
// get the thread
CArchThreadImpl* thread = reinterpret_cast<CArchThreadImpl*>(vrep);
// run thread
s_instance->doThreadFunc(thread);
// terminate the thread
return 0;
}
void
CArchMultithreadWindows::doThreadFunc(CArchThread thread)
{
// 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
SetEvent(thread->m_exit);
closeThread(thread);
throw;
}
// thread has exited
lockMutex(m_threadMutex);
thread->m_result = result;
unlockMutex(m_threadMutex);
SetEvent(thread->m_exit);
// done with thread
closeThread(thread);
}