timer: add optional support for rust event loop (#48130)

src/core/eventlooptest.cpp

@@ -26,6 +26,7 @@
 #include "defercall.h"
 #include "eventloop.h"
 #include "socketnotifier.h"
+#include "timer.h"
 
 class EventLoopTest : public QObject
 {
@@ -62,6 +63,37 @@ private slots:
 		close(fds[1]);
 		close(fds[0]);
 	}
+
+	void timer()
+	{
+		EventLoop loop(2);
+
+		Timer *t1 = new Timer;
+		Timer *t2 = new Timer;
+
+		int timeoutCount = 0;
+
+		t1->timeout.connect([&] {
+			++timeoutCount;
+		});
+
+		t2->timeout.connect([&] {
+			++timeoutCount;
+			loop.exit(123);
+		});
+
+		t1->setSingleShot(true);
+		t1->start(0);
+
+		t2->setSingleShot(true);
+		t2->start(0);
+
+		QCOMPARE(loop.exec(), 123);
+		QCOMPARE(timeoutCount, 2);
+
+		delete t2;
+		delete t1;
+	}
 };
 
 namespace {

src/core/timer.cpp

@@ -27,6 +27,7 @@
 #include <QDateTime>
 #include <QTimer>
 #include "timerwheel.h"
+#include "eventloop.h"
 
 #define TICK_DURATION_MS 10
 #define UPDATE_TICKS_MAX 1000
@@ -174,6 +175,7 @@ void TimerManager::updateTimeout(qint64 currentTime)
 static thread_local TimerManager *g_manager = 0;
 
 Timer::Timer() :
+	loop_(EventLoop::instance()),
 	singleShot_(false),
 	interval_(0),
 	timerId_(-1)
@@ -208,29 +210,57 @@ void Timer::start(int msec)
 
 void Timer::start()
 {
-	// must call Timer::init first
-	assert(g_manager);
-
 	stop();
 
-	int id = g_manager->add(interval_, this);
-	assert(id >= 0);
+	if(loop_)
+	{
+		// if the rust-based eventloop is available, use it
+
+		int id = loop_->registerTimer(interval_, Timer::cb_timer_activated, this);
+		assert(id >= 0);
+
+		timerId_ = id;
+	}
+	else
+	{
+		// else fall back to qt eventloop
+
+		// must call Timer::init first
+		assert(g_manager);
+
+		int id = g_manager->add(interval_, this);
+		assert(id >= 0);
 
-	timerId_ = id;
+		timerId_ = id;
+	}
 }
 
 void Timer::stop()
 {
 	if(timerId_ >= 0)
 	{
-		assert(g_manager);
+		if(loop_)
+		{
+			loop_->deregister(timerId_);
+		}
+		else
+		{
+			assert(g_manager);
 
-		g_manager->remove(timerId_);
+			g_manager->remove(timerId_);
+		}
 
 		timerId_ = -1;
 	}
 }
 
+void Timer::cb_timer_activated(void *ctx)
+{
+	Timer *self = (Timer *)ctx;
+
+	self->timerReady();
+}
+
 void Timer::timerReady()
 {
 	timerId_ = -1;

src/core/timer.h

@@ -29,6 +29,7 @@
 
 using Signal = boost::signals2::signal<void()>;
 
+class EventLoop;
 class TimerManager;
 
 class Timer : public QObject
@@ -58,10 +59,12 @@ class Timer : public QObject
 private:
 	friend class TimerManager;
 
+	EventLoop *loop_;
 	bool singleShot_;
 	int interval_;
 	int timerId_;
 
+	static void cb_timer_activated(void *ctx);
 	void timerReady();
 };