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mirror of https://github.com/moparisthebest/minetest synced 2024-12-23 16:08:51 -05:00

jthread remove locks that aren't absolutely required

add c++11 atomic support (optional)
This commit is contained in:
sapier 2014-01-31 22:16:47 +01:00
parent c00ed9dac3
commit ea0df3e4cb
3 changed files with 39 additions and 109 deletions

View File

@ -26,9 +26,12 @@
*/
#ifndef JTHREAD_H
#define JTHREAD_H
#if __cplusplus >= 201103L
#include <atomic>
#endif
#include "jthread/jmutex.h"
#define ERR_JTHREAD_CANTINITMUTEX -1
@ -43,11 +46,14 @@ public:
JThread();
virtual ~JThread();
int Start();
void Stop();
inline void Stop()
{ requeststop = true; }
int Kill();
virtual void *Thread() = 0;
bool IsRunning();
bool StopRequested();
inline bool IsRunning()
{ return running; }
inline bool StopRequested()
{ return requeststop; }
void *GetReturnValue();
bool IsSameThread();
@ -75,13 +81,35 @@ private:
pthread_t threadid;
/*
* reading and writing bool values is atomic on all relevant architectures
* ( x86 + arm ). No need to waste time for locking here.
* once C++11 is supported we can tell compiler to handle cpu caches correct
* too. This should cause additional improvement (and silence thread
* concurrency check tools.
*/
#if __cplusplus >= 201103L
std::atomic_bool started;
#else
bool started;
#endif
#endif // WIN32
void *retval;
/*
* reading and writing bool values is atomic on all relevant architectures
* ( x86 + arm ). No need to waste time for locking here.
* once C++11 is supported we can tell compiler to handle cpu caches correct
* too. This should cause additional improvement (and silence thread
* concurrency check tools.
*/
#if __cplusplus >= 201103L
std::atomic_bool running;
std::atomic_bool requeststop;
#else
bool running;
bool requeststop;
#endif
JMutex runningmutex;
JMutex continuemutex,continuemutex2;
};

View File

@ -46,38 +46,25 @@ JThread::~JThread()
Kill();
}
void JThread::Stop() {
runningmutex.Lock();
requeststop = true;
runningmutex.Unlock();
}
void JThread::Wait() {
void* status;
runningmutex.Lock();
if (started) {
runningmutex.Unlock();
int pthread_join_retval = pthread_join(threadid,&status);
assert(pthread_join_retval == 0);
UNUSED(pthread_join_retval);
runningmutex.Lock();
started = false;
}
runningmutex.Unlock();
}
int JThread::Start()
{
int status;
runningmutex.Lock();
if (running)
{
runningmutex.Unlock();
return ERR_JTHREAD_ALREADYRUNNING;
}
requeststop = false;
runningmutex.Unlock();
pthread_attr_t attr;
pthread_attr_init(&attr);
@ -94,21 +81,15 @@ int JThread::Start()
/* Wait until 'running' is set */
runningmutex.Lock();
while (!running)
{
runningmutex.Unlock();
struct timespec req,rem;
req.tv_sec = 0;
req.tv_nsec = 1000000;
nanosleep(&req,&rem);
runningmutex.Lock();
}
started = true;
runningmutex.Unlock();
continuemutex.Unlock();
@ -120,63 +101,37 @@ int JThread::Start()
int JThread::Kill()
{
void* status;
runningmutex.Lock();
if (!running)
{
if (started) {
runningmutex.Unlock();
int pthread_join_retval = pthread_join(threadid,&status);
assert(pthread_join_retval == 0);
UNUSED(pthread_join_retval);
runningmutex.Lock();
started = false;
}
runningmutex.Unlock();
return ERR_JTHREAD_NOTRUNNING;
}
pthread_cancel(threadid);
if (started) {
runningmutex.Unlock();
int pthread_join_retval = pthread_join(threadid,&status);
assert(pthread_join_retval == 0);
UNUSED(pthread_join_retval);
runningmutex.Lock();
started = false;
}
running = false;
runningmutex.Unlock();
return 0;
}
bool JThread::IsRunning()
{
bool r;
runningmutex.Lock();
r = running;
runningmutex.Unlock();
return r;
}
bool JThread::StopRequested() {
bool r;
runningmutex.Lock();
r = requeststop;
runningmutex.Unlock();
return r;
}
void *JThread::GetReturnValue()
{
void *val;
runningmutex.Lock();
if (running)
if (running) {
val = NULL;
else
} else {
val = retval;
runningmutex.Unlock();
}
return val;
}
@ -193,19 +148,14 @@ void *JThread::TheThread(void *param)
jthread = (JThread *)param;
jthread->continuemutex2.Lock();
jthread->runningmutex.Lock();
jthread->running = true;
jthread->runningmutex.Unlock();
jthread->continuemutex.Lock();
jthread->continuemutex.Unlock();
ret = jthread->Thread();
jthread->runningmutex.Lock();
jthread->running = false;
jthread->retval = ret;
jthread->runningmutex.Unlock();
return NULL;
}

View File

@ -44,35 +44,20 @@ JThread::~JThread()
Kill();
}
void JThread::Stop() {
runningmutex.Lock();
requeststop = true;
runningmutex.Unlock();
}
void JThread::Wait() {
runningmutex.Lock();
if (running)
{
runningmutex.Unlock();
WaitForSingleObject(threadhandle, INFINITE);
}
else
{
runningmutex.Unlock();
}
}
int JThread::Start()
{
runningmutex.Lock();
if (running)
{
runningmutex.Unlock();
return ERR_JTHREAD_ALREADYRUNNING;
}
requeststop = false;
runningmutex.Unlock();
continuemutex.Lock();
#ifndef _WIN32_WCE
@ -87,15 +72,10 @@ int JThread::Start()
}
/* Wait until 'running' is set */
runningmutex.Lock();
while (!running)
{
runningmutex.Unlock();
Sleep(1);
runningmutex.Lock();
}
runningmutex.Unlock();
continuemutex.Unlock();
@ -107,48 +87,24 @@ int JThread::Start()
int JThread::Kill()
{
runningmutex.Lock();
if (!running)
{
runningmutex.Unlock();
return ERR_JTHREAD_NOTRUNNING;
}
TerminateThread(threadhandle,0);
CloseHandle(threadhandle);
running = false;
runningmutex.Unlock();
return 0;
}
bool JThread::IsRunning()
{
bool r;
runningmutex.Lock();
r = running;
runningmutex.Unlock();
return r;
}
bool JThread::StopRequested() {
bool r;
runningmutex.Lock();
r = requeststop;
runningmutex.Unlock();
return r;
}
void *JThread::GetReturnValue()
{
void *val;
runningmutex.Lock();
if (running)
if (running) {
val = NULL;
else
} else {
val = retval;
runningmutex.Unlock();
return val;
}
@ -169,20 +125,16 @@ DWORD WINAPI JThread::TheThread(void *param)
jthread = (JThread *)param;
jthread->continuemutex2.Lock();
jthread->runningmutex.Lock();
jthread->running = true;
jthread->runningmutex.Unlock();
jthread->continuemutex.Lock();
jthread->continuemutex.Unlock();
ret = jthread->Thread();
jthread->runningmutex.Lock();
jthread->running = false;
jthread->retval = ret;
CloseHandle(jthread->threadhandle);
jthread->runningmutex.Unlock();
return 0;
}