[Qt] Implement the AsyncTask, Timer and RunLoop using Qt

Now Mapbox GL will handle events using Qt as backend
instead of libuv.

1 files changed, 144 insertions, 0 deletions

diff --git a/platform/qt/src/run_loop.cpp b/platform/qt/src/run_loop.cpp
new file mode 100644
index 0000000000..d33eb9cda6
--- /dev/null
+++ b/platform/qt/src/run_loop.cpp
@@ -0,0 +1,144 @@
+#include "run_loop_impl.hpp"
+
+#include <mbgl/util/thread_local.hpp>
+
+#include <QCoreApplication>
+
+#include <functional>
+#include <utility>
+
+#include <cassert>
+
+namespace {
+
+using namespace mbgl::util;
+static ThreadLocal<RunLoop>& current = *new ThreadLocal<RunLoop>;
+
+}
+
+namespace mbgl {
+namespace util {
+
+void RunLoop::Impl::onReadEvent(int fd) {
+    readPoll[fd].second(fd, Event::Read);
+}
+
+void RunLoop::Impl::onWriteEvent(int fd) {
+    writePoll[fd].second(fd, Event::Write);
+}
+
+RunLoop* RunLoop::Get() {
+    return current.get();
+}
+
+RunLoop::RunLoop(Type type) : impl(std::make_unique<Impl>()) {
+    // XXX: We should probably throw an runtime exception
+    // here instead of creating a QCoreApplication which is
+    // way too intrusive. This is a hack mostly for the unit
+    // tests to work, as you always need a QCoreApplication
+    // prior to run a Qt app.
+    if (!QCoreApplication::instance()) {
+        static const char* argv[] = { "mbgl" };
+        static int argc = 1;
+
+        // We need to keep this around because it would otherwise crash
+        // on Qt4 due to a bug on QNetworkConfigurationManager when recreating
+        // a QCoreApplication: https://bugreports.qt.io/browse/QTBUG-36897
+        static auto* app = new QCoreApplication(argc, const_cast<char**>(argv));
+        Q_UNUSED(app);
+    }
+
+    switch (type) {
+    case Type::New:
+        impl->loop = std::make_unique<QEventLoop>();
+        break;
+    case Type::Default:
+        // Use QCoreApplication::instance().
+        break;
+    }
+
+    impl->type = type;
+
+    current.set(this);
+    impl->async = std::make_unique<AsyncTask>(std::bind(&RunLoop::process, this));
+}
+
+RunLoop::~RunLoop() {
+    MBGL_VERIFY_THREAD(tid);
+
+    current.set(nullptr);
+}
+
+LOOP_HANDLE RunLoop::getLoopHandle() {
+    throw std::runtime_error("Should not be used in Qt.");
+
+    return nullptr;
+}
+
+void RunLoop::push(std::shared_ptr<WorkTask> task) {
+    withMutex([&] { queue.push(task); });
+    impl->async->send();
+}
+
+void RunLoop::run() {
+    MBGL_VERIFY_THREAD(tid);
+
+    if (impl->type == Type::Default) {
+        QCoreApplication::instance()->exec();
+    } else {
+        impl->loop->exec();
+    }
+}
+
+void RunLoop::stop() {
+    invoke([&] {
+        if (impl->type == Type::Default) {
+            QCoreApplication::instance()->exit();
+        } else {
+            impl->loop->exit();
+        }
+    });
+}
+
+void RunLoop::runOnce() {
+    MBGL_VERIFY_THREAD(tid);
+
+    if (impl->type == Type::Default) {
+        QCoreApplication::instance()->processEvents();
+    } else {
+        impl->loop->processEvents();
+    }
+}
+
+void RunLoop::addWatch(int fd, Event event, std::function<void(int, Event)>&& cb) {
+    MBGL_VERIFY_THREAD(tid);
+
+    if (event == Event::Read || event == Event::ReadWrite) {
+        auto notifier = std::make_unique<QSocketNotifier>(fd, QSocketNotifier::Read);
+        QObject::connect(notifier.get(), SIGNAL(activated(int)), impl.get(), SLOT(onReadEvent(int)));
+        impl->readPoll[fd] = WatchPair(std::move(notifier), std::move(cb));
+    }
+
+    if (event == Event::Write || event == Event::ReadWrite) {
+        auto notifier = std::make_unique<QSocketNotifier>(fd, QSocketNotifier::Write);
+        QObject::connect(notifier.get(), SIGNAL(activated(int)), impl.get(), SLOT(onWriteEvent(int)));
+        impl->writePoll[fd] = WatchPair(std::move(notifier), std::move(cb));
+    }
+}
+
+void RunLoop::removeWatch(int fd) {
+    MBGL_VERIFY_THREAD(tid);
+
+    auto writePollIter = impl->writePoll.find(fd);
+    if (writePollIter != impl->writePoll.end()) {
+        impl->writePoll.erase(writePollIter);
+    }
+
+    auto readPollIter = impl->readPoll.find(fd);
+    if (readPollIter != impl->readPoll.end()) {
+        impl->readPoll.erase(readPollIter);
+    }
+}
+
+}
+}