Use QThreadPool inside a worker task
2
I have QThreadPool which run some tasks.
I need also create new tasks in other tasks.
To do that i think implement something like following:
class Task : public QRunnable
{
QThreadPool *pool;
public:
Task (QThreadPool *p) : pool(p){}
void run()
{
static std::atomic<int> counter = ATOMIC_FLAG_INIT;
qDebug() << QThread::currentThreadId();
int c;
if ((c = counter.load(std::memory_order_acquire)) < 10) {
pool->start(new Task(pool));
counter.store(c + 1, std::memory_order_release);
}
}
};
int main(int argc, char *argv)
{
//...
QThreadPool threadPool;
threadPool.start(new Task(&threadPool));
//...
}
But I'm not sure that this is the right approach.
multithreading qt c++11
asked Nov 24 '18 at 10:11
KriKri
3116
add a comment |
2
I have QThreadPool which run some tasks.
I need also create new tasks in other tasks.
To do that i think implement something like following:
class Task : public QRunnable
{
QThreadPool *pool;
public:
Task (QThreadPool *p) : pool(p){}
void run()
{
static std::atomic<int> counter = ATOMIC_FLAG_INIT;
qDebug() << QThread::currentThreadId();
int c;
if ((c = counter.load(std::memory_order_acquire)) < 10) {
pool->start(new Task(pool));
counter.store(c + 1, std::memory_order_release);
}
}
};
int main(int argc, char *argv)
{
//...
QThreadPool threadPool;
threadPool.start(new Task(&threadPool));
//...
}
But I'm not sure that this is the right approach.
multithreading qt c++11
asked Nov 24 '18 at 10:11
KriKri
3116
2
The general approach looks fine, but the seperateload/storeof counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it.QThreadPool::setMaxThreadCountshould be used to control this instead.
– Felix
Nov 24 '18 at 15:08
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49
add a comment |
2
2
2
I have QThreadPool which run some tasks.
I need also create new tasks in other tasks.
To do that i think implement something like following:
class Task : public QRunnable
{
QThreadPool *pool;
public:
Task (QThreadPool *p) : pool(p){}
void run()
{
static std::atomic<int> counter = ATOMIC_FLAG_INIT;
qDebug() << QThread::currentThreadId();
int c;
if ((c = counter.load(std::memory_order_acquire)) < 10) {
pool->start(new Task(pool));
counter.store(c + 1, std::memory_order_release);
}
}
};
int main(int argc, char *argv)
{
//...
QThreadPool threadPool;
threadPool.start(new Task(&threadPool));
//...
}
But I'm not sure that this is the right approach.
multithreading qt c++11
asked Nov 24 '18 at 10:11
KriKri
3116
I have QThreadPool which run some tasks.
I need also create new tasks in other tasks.
To do that i think implement something like following:
class Task : public QRunnable
{
QThreadPool *pool;
public:
Task (QThreadPool *p) : pool(p){}
void run()
{
static std::atomic<int> counter = ATOMIC_FLAG_INIT;
qDebug() << QThread::currentThreadId();
int c;
if ((c = counter.load(std::memory_order_acquire)) < 10) {
pool->start(new Task(pool));
counter.store(c + 1, std::memory_order_release);
}
}
};
int main(int argc, char *argv)
{
//...
QThreadPool threadPool;
threadPool.start(new Task(&threadPool));
//...
}
But I'm not sure that this is the right approach.
multithreading qt c++11
multithreading qt c++11
asked Nov 24 '18 at 10:11
KriKri
3116
asked Nov 24 '18 at 10:11
KriKri
3116
asked Nov 24 '18 at 10:11
KriKri
3116
asked Nov 24 '18 at 10:11
KriKri
3116
asked Nov 24 '18 at 10:11
KriKri
3116
3116
2
The general approach looks fine, but the seperateload/storeof counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it.QThreadPool::setMaxThreadCountshould be used to control this instead.
– Felix
Nov 24 '18 at 15:08
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49
add a comment |
2
The general approach looks fine, but the seperateload/storeof counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it.QThreadPool::setMaxThreadCountshould be used to control this instead.
– Felix
Nov 24 '18 at 15:08
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49
2
2
The general approach looks fine, but the seperate
load/store of counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it. QThreadPool::setMaxThreadCount should be used to control this instead.– Felix
Nov 24 '18 at 15:08
The general approach looks fine, but the seperate
load/store of counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it. QThreadPool::setMaxThreadCount should be used to control this instead.– Felix
Nov 24 '18 at 15:08
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49
add a comment |
0
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2
The general approach looks fine, but the seperate
load/storeof counter is unsafe (as it could be changed in between the calls). However, if you only use it to control the number of parallel task, you don't even need it.QThreadPool::setMaxThreadCountshould be used to control this instead.– Felix
Nov 24 '18 at 15:08
@Felix OK, thank you
– Kri
Nov 24 '18 at 17:49