This class defines an abstract interface for thread resources.
More...
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abstract nothing | cleanup () |
| This method is called by Qore itself when the thread resource is still allocated and requires cleanup. More...
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| constructor () |
| Creates the internal thread resource object.
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| destructor () |
| removes the thread resource if set; if so then the cleanup() method is called
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This class defines an abstract interface for thread resources.
- Overview
- Thread resources can be considered properties of a thread that need to be cleaned up when the thread exits or one of the thread cleanup functions is run:
The following functions allow classes of this type to be set or removed as thread resources:
If the thread resource is still set when the destructor is run, then the destructor frees the thread resource and calls cleanup().
- Example
class ThreadResourceExample inherits AbstractThreadResource {
public {}
private {
Qore::Thread::Mutex m();
Qore::Thread::Condition cond();
Qore::Thread::Counter cnt();
bool exit;
}
constructor() {
start();
}
synchronized private start() {
cnt.inc();
on_error {
cnt.dec();
}
background waiter();
}
stop() {
{
m.lock();
on_exit m.unlock();
exit = True;
cond.signal();
}
cnt.waitForZero();
}
cleanup() {
m.lock();
on_exit m.unlock();
if (!exit) {
stop();
throw
"THREAD-RESOURCE-ERROR",
sprintf(
"the background thread was stopped during thread resource cleanup; call %s::stop() before exiting the thread to avoid this exception", self.className());
}
}
private waiter() {
on_exit cnt.dec();
m.lock();
on_exit m.unlock();
while (!exit)
cond.wait(m);
}
}
- See also
- Thread Resources
- Since
- Qore 0.8.12
◆ cleanup()
abstract nothing Qore::Thread::AbstractThreadResource::cleanup |
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pure virtual |
This method is called by Qore itself when the thread resource is still allocated and requires cleanup.
This method should clean up the resource and normally should throw an appropriate exception explaining:
- what the programming error was (ex: failing to unlock a lock before the thread exited)
- what happened (ex: the lock was automatically released)
- how to prevent it from happening in the future (ex: make sure and release the lock before exiting the thread)
This method is called in the following situations:
- Note
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- See also
- Thread Resources