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#include <mbgl/util/run_loop.hpp>
#include <mbgl/util/async_task.hpp>
#include <mbgl/util/thread_local.hpp>
#include <mbgl/actor/scheduler.hpp>
#include <uv.h>
#include <cassert>
#include <functional>
#include <unordered_map>
namespace {
void dummyCallback(uv_async_t*) {}
} // namespace
namespace mbgl {
namespace util {
struct Watch {
static void onEvent(uv_poll_t* poll, int, int event) {
auto watch = reinterpret_cast<Watch*>(poll->data);
RunLoop::Event watchEvent = RunLoop::Event::None;
switch (event) {
case UV_READABLE:
watchEvent = RunLoop::Event::Read;
break;
case UV_WRITABLE:
watchEvent = RunLoop::Event::Write;
break;
case UV_READABLE | UV_WRITABLE:
watchEvent = RunLoop::Event::ReadWrite;
break;
}
watch->eventCallback(watch->fd, watchEvent);
};
static void onClose(uv_handle_t *poll) {
auto watch = reinterpret_cast<Watch*>(poll->data);
watch->closeCallback();
};
uv_poll_t poll;
int fd;
std::function<void(int, RunLoop::Event)> eventCallback;
std::function<void()> closeCallback;
};
RunLoop* RunLoop::Get() {
assert(static_cast<RunLoop*>(Scheduler::GetCurrent()));
return static_cast<RunLoop*>(Scheduler::GetCurrent());
}
class RunLoop::Impl {
public:
void closeHolder() {
uv_close(holderHandle(), [](uv_handle_t* h) {
delete reinterpret_cast<uv_async_t*>(h);
});
}
uv_handle_t* holderHandle() {
return reinterpret_cast<uv_handle_t*>(holder);
}
uv_loop_t *loop = nullptr;
uv_async_t* holder = new uv_async_t;
RunLoop::Type type;
std::unique_ptr<AsyncTask> async;
std::unordered_map<int, std::unique_ptr<Watch>> watchPoll;
};
RunLoop::RunLoop(Type type) : impl(std::make_unique<Impl>()) {
switch (type) {
case Type::New:
impl->loop = new uv_loop_t;
if (uv_loop_init(impl->loop) != 0) {
throw std::runtime_error("Failed to initialize loop.");
}
break;
case Type::Default:
impl->loop = uv_default_loop();
break;
}
// Just for holding a ref to the main loop and keep
// it alive as required by libuv.
if (uv_async_init(impl->loop, impl->holder, dummyCallback) != 0) {
throw std::runtime_error("Failed to initialize async.");
}
impl->type = type;
Scheduler::SetCurrent(this);
impl->async = std::make_unique<AsyncTask>(std::bind(&RunLoop::process, this));
}
RunLoop::~RunLoop() {
Scheduler::SetCurrent(nullptr);
// Close the dummy handle that we have
// just to keep the main loop alive.
impl->closeHolder();
if (impl->type == Type::Default) {
return;
}
// Run the loop again to ensure that async
// close callbacks have been called. Not needed
// for the default main loop because it is only
// closed when the application exits.
impl->async.reset();
runOnce();
if (uv_loop_close(impl->loop) == UV_EBUSY) {
assert(false && "Failed to close loop.");
}
delete impl->loop;
}
LOOP_HANDLE RunLoop::getLoopHandle() {
return Get()->impl->loop;
}
void RunLoop::push(std::shared_ptr<WorkTask> task) {
withMutex([&] {
queue.push(std::move(task));
impl->async->send();
});
}
void RunLoop::run() {
MBGL_VERIFY_THREAD(tid);
uv_ref(impl->holderHandle());
uv_run(impl->loop, UV_RUN_DEFAULT);
}
void RunLoop::runOnce() {
MBGL_VERIFY_THREAD(tid);
uv_run(impl->loop, UV_RUN_NOWAIT);
}
void RunLoop::stop() {
invoke([&] { uv_unref(impl->holderHandle()); });
}
void RunLoop::addWatch(int fd, Event event, std::function<void(int, Event)>&& callback) {
MBGL_VERIFY_THREAD(tid);
Watch *watch = nullptr;
auto watchPollIter = impl->watchPoll.find(fd);
if (watchPollIter == impl->watchPoll.end()) {
std::unique_ptr<Watch> watchPtr = std::make_unique<Watch>();
watch = watchPtr.get();
impl->watchPoll[fd] = std::move(watchPtr);
if (uv_poll_init(impl->loop, &watch->poll, fd)) {
throw std::runtime_error("Failed to init poll on file descriptor.");
}
} else {
watch = watchPollIter->second.get();
}
watch->poll.data = watch;
watch->fd = fd;
watch->eventCallback = std::move(callback);
int pollEvent = 0;
switch (event) {
case Event::Read:
pollEvent = UV_READABLE;
break;
case Event::Write:
pollEvent = UV_WRITABLE;
break;
case Event::ReadWrite:
pollEvent = UV_READABLE | UV_WRITABLE;
break;
default:
throw std::runtime_error("Unhandled event.");
}
if (uv_poll_start(&watch->poll, pollEvent, &Watch::onEvent)) {
throw std::runtime_error("Failed to start poll on file descriptor.");
}
}
void RunLoop::removeWatch(int fd) {
MBGL_VERIFY_THREAD(tid);
auto watchPollIter = impl->watchPoll.find(fd);
if (watchPollIter == impl->watchPoll.end()) {
return;
}
Watch* watch = watchPollIter->second.release();
impl->watchPoll.erase(watchPollIter);
watch->closeCallback = [watch] {
delete watch;
};
if (uv_poll_stop(&watch->poll)) {
throw std::runtime_error("Failed to stop poll on file descriptor.");
}
uv_close(reinterpret_cast<uv_handle_t*>(&watch->poll), &Watch::onClose);
}
} // namespace util
} // namespace mbgl
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