Files
foobar2000-sdk/foobar2000/helpers/CmdThread.h
2021-12-14 00:28:25 -07:00

133 lines
4.2 KiB
C++

#pragma once
#include <pfc/wait_queue.h>
#include <pfc/pool.h>
#include <pfc/threads.h>
#include <functional>
#include "rethrow.h"
#include <pfc/timers.h>
namespace ThreadUtils {
// Serialize access to some resource to a single thread
// Execute blocking/nonabortable methods in with proper abortability (detach on abort and move on)
class cmdThread {
public:
typedef std::function<void () > func_t;
typedef pfc::waitQueue<func_t> queue_t;
typedef std::function<void (abort_callback&) > funcAbortable_t;
protected:
std::function<void () > makeWorker() {
auto q = m_queue;
auto x = m_atExit;
return [q, x] {
for ( ;; ) {
func_t f;
if (!q->get(f)) break;
try { f(); } catch(...) {}
}
// No guard for atExit access, as nobody is supposed to be still able to call host object methods by the time we get here
for( auto i = x->begin(); i != x->end(); ++ i ) {
auto f = *i;
try { f(); } catch(...) {}
}
};
};
std::function<void () > makeWorker2( std::function<void()> updater, double interval) {
auto q = m_queue;
auto x = m_atExit;
return [=] {
pfc::lores_timer t; t.start();
for ( ;; ) {
{
bool bWorkReady = false;
double left = interval - t.query();
if ( left > 0 ) {
if (q->wait_read( left )) bWorkReady = true;
}
if (!bWorkReady) {
updater();
t.start();
continue;
}
}
func_t f;
if (!q->get(f)) break;
try { f(); } catch(...) {}
}
// No guard for atExit access, as nobody is supposed to be still able to call host object methods by the time we get here
for( auto i = x->begin(); i != x->end(); ++ i ) {
auto f = *i;
try { f(); } catch(...) {}
}
};
};
// For derived classes: create new instance without starting thread, supply thread using by yourself
class noCreate {};
cmdThread( noCreate ) {}
public:
cmdThread() {
pfc::splitThread( makeWorker() );
}
void atExit( func_t f ) {
m_atExit->push_back(f);
}
~cmdThread() {
m_queue->set_eof();
}
void runSynchronously( func_t f ) { runSynchronously_(f, nullptr); }
void runSynchronously_( func_t f, abort_callback * abortOrNull ) {
auto evt = m_eventPool.make();
evt->set_state(false);
auto rethrow = std::make_shared<ThreadUtils::CRethrow>();
auto worker2 = [f, rethrow, evt] {
rethrow->exec(f);
evt->set_state( true );
};
add ( worker2 );
if ( abortOrNull != nullptr ) {
abortOrNull->waitForEvent( * evt, -1 );
} else {
evt->wait_for(-1);
}
m_eventPool.put( evt );
rethrow->rethrow();
}
void runSynchronously( func_t f, abort_callback & abort ) {
runSynchronously_(f, &abort);
}
void runSynchronously2( funcAbortable_t f, abort_callback & abort ) {
auto subAbort = m_abortPool.make();
subAbort->reset();
auto worker = [subAbort, f] {
f(*subAbort);
};
try {
runSynchronously( worker, abort );
} catch(...) {
subAbort->set(); throw;
}
m_abortPool.put( subAbort );
}
void add( func_t f ) { m_queue->put( f ); }
private:
pfc::objPool<pfc::event> m_eventPool;
pfc::objPool<abort_callback_impl> m_abortPool;
std::shared_ptr<queue_t> m_queue = std::make_shared<queue_t>();
typedef std::list<func_t> atExit_t;
std::shared_ptr<atExit_t> m_atExit = std::make_shared< atExit_t >();
};
}