[core] Removed libuv dependency from HTTPCurl*

Moved the fd watcher to the RunLoop. So far only needs to
be implemented by platforms using HTTPCurlRequest et al.

3 files changed, 139 insertions, 68 deletions

diff --git a/include/mbgl/util/run_loop.hpp b/include/mbgl/util/run_loop.hpp
index 122f90c3d7..85b8b8d665 100644
--- a/include/mbgl/util/run_loop.hpp
+++ b/include/mbgl/util/run_loop.hpp
@@ -2,6 +2,7 @@
 #define MBGL_UTIL_RUN_LOOP
 
 #include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/util.hpp>
 #include <mbgl/util/work_task.hpp>
 #include <mbgl/util/work_request.hpp>
 
@@ -23,6 +24,13 @@ public:
         New,
     };
 
+    enum class Event : uint8_t {
+        None      = 0,
+        Read      = 1,
+        Write     = 2,
+        ReadWrite = Read | Write,
+    };
+
     RunLoop(Type type = Type::Default);
     ~RunLoop();
 
@@ -33,6 +41,10 @@ public:
     void runOnce();
     void stop();
 
+    // So far only needed by the libcurl backend.
+    void addWatch(int fd, Event, std::function<void(int, Event)>&& callback);
+    void removeWatch(int fd);
+
     // Invoke fn(args...) on this RunLoop.
     template <class Fn, class... Args>
     void invoke(Fn&& fn, Args&&... args) {
@@ -96,6 +108,8 @@ public:
     }
 
 private:
+    MBGL_STORE_THREAD(tid)
+
     template <class F, class P>
     class Invoker : public WorkTask {
     public:
diff --git a/platform/default/http_request_curl.cpp b/platform/default/http_request_curl.cpp
index 18d6d9d62a..065b90501b 100644
--- a/platform/default/http_request_curl.cpp
+++ b/platform/default/http_request_curl.cpp
@@ -9,7 +9,6 @@
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/util/timer.hpp>
-#include <mbgl/util/uv.hpp>
 
 #include <curl/curl.h>
 
@@ -25,12 +24,6 @@
 #include <cstring>
 #include <cstdio>
 
-#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
-#define UV_TIMER_PARAMS(timer) uv_timer_t *timer, int
-#else
-#define UV_TIMER_PARAMS(timer) uv_timer_t *timer
-#endif
-
 void handleError(CURLMcode code) {
     if (code != CURLM_OK) {
         throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(code));
@@ -59,10 +52,10 @@ public:
                                std::shared_ptr<const Response>) final;
 
     static int handleSocket(CURL *handle, curl_socket_t s, int action, void *userp, void *socketp);
-    static void perform(uv_poll_t *req, int status, int events);
     static int startTimeout(CURLM *multi, long timeout_ms, void *userp);
     static void onTimeout(HTTPCURLContext *context);
 
+    void perform(curl_socket_t s, util::RunLoop::Event event);
     CURL *getHandle();
     void returnHandle(CURL *handle);
     void checkMultiInfo();
@@ -115,42 +108,6 @@ private:
     char error[CURL_ERROR_SIZE];
 };
 
-
-
-struct Socket {
-private:
-    uv_poll_t poll;
-
-public:
-    HTTPCURLContext *context = nullptr;
-    const curl_socket_t sockfd = 0;
-
-public:
-    Socket(HTTPCURLContext *context_, curl_socket_t sockfd_) : context(context_), sockfd(sockfd_) {
-        assert(context);
-        uv_poll_init_socket(reinterpret_cast<uv_loop_t*>(util::RunLoop::getLoopHandle()), &poll, sockfd);
-        poll.data = this;
-    }
-
-    void start(int events, uv_poll_cb cb) {
-        uv_poll_start(&poll, events, cb);
-    }
-
-    void stop() {
-        assert(poll.data);
-        uv_poll_stop(&poll);
-        uv_close((uv_handle_t *)&poll, [](uv_handle_t *handle) {
-            assert(handle->data);
-            delete reinterpret_cast<Socket *>(handle->data);
-        });
-    }
-
-private:
-    // Make the destructor private to ensure that we can only close the Socket
-    // with stop(), and disallow manual deletion.
-    ~Socket() = default;
-};
-
 // -------------------------------------------------------------------------------------------------
 
 HTTPCURLContext::HTTPCURLContext() {
@@ -224,51 +181,45 @@ void HTTPCURLContext::checkMultiInfo() {
     }
 }
 
-void HTTPCURLContext::perform(uv_poll_t *req, int /* status */, int events) {
-    assert(req->data);
-    auto socket = reinterpret_cast<Socket *>(req->data);
-    auto context = socket->context;
-    MBGL_VERIFY_THREAD(context->tid);
+void HTTPCURLContext::perform(curl_socket_t s, util::RunLoop::Event events) {
+    MBGL_VERIFY_THREAD(tid);
 
     int flags = 0;
 
-    if (events & UV_READABLE) {
+    if (events == util::RunLoop::Event::Read) {
         flags |= CURL_CSELECT_IN;
     }
-    if (events & UV_WRITABLE) {
+    if (events == util::RunLoop::Event::Write) {
         flags |= CURL_CSELECT_OUT;
     }
 
 
     int running_handles = 0;
-    curl_multi_socket_action(context->multi, socket->sockfd, flags, &running_handles);
-    context->checkMultiInfo();
+    curl_multi_socket_action(multi, s, flags, &running_handles);
+    checkMultiInfo();
 }
 
 int HTTPCURLContext::handleSocket(CURL * /* handle */, curl_socket_t s, int action, void *userp,
-                              void *socketp) {
-    auto socket = reinterpret_cast<Socket *>(socketp);
+                              void * /* socketp */) {
     assert(userp);
     auto context = reinterpret_cast<HTTPCURLContext *>(userp);
     MBGL_VERIFY_THREAD(context->tid);
 
-    if (!socket && action != CURL_POLL_REMOVE) {
-        socket = new Socket(context, s);
-        curl_multi_assign(context->multi, s, (void *)socket);
-    }
-
     switch (action) {
-    case CURL_POLL_IN:
-        socket->start(UV_READABLE, perform);
+    case CURL_POLL_IN: {
+        using namespace std::placeholders;
+        util::RunLoop::Get()->addWatch(s, util::RunLoop::Event::Read,
+                std::bind(&HTTPCURLContext::perform, context, _1, _2));
         break;
-    case CURL_POLL_OUT:
-        socket->start(UV_WRITABLE, perform);
+    }
+    case CURL_POLL_OUT: {
+        using namespace std::placeholders;
+        util::RunLoop::Get()->addWatch(s, util::RunLoop::Event::Write,
+                std::bind(&HTTPCURLContext::perform, context, _1, _2));
         break;
+    }
     case CURL_POLL_REMOVE:
-        if (socket) {
-            socket->stop();
-            curl_multi_assign(context->multi, s, nullptr);
-        }
+        util::RunLoop::Get()->removeWatch(s);
         break;
     default:
         throw std::runtime_error("Unhandled CURL socket action");
diff --git a/platform/default/run_loop.cpp b/platform/default/run_loop.cpp
index 845ee1b2ab..9ca7cc9207 100644
--- a/platform/default/run_loop.cpp
+++ b/platform/default/run_loop.cpp
@@ -3,6 +3,9 @@
 #include <mbgl/util/uv.hpp>
 #include <mbgl/util/thread_local.hpp>
 
+#include <functional>
+#include <unordered_map>
+
 namespace {
 
 using namespace mbgl::util;
@@ -13,6 +16,38 @@ static ThreadLocal<RunLoop>& current = *new ThreadLocal<RunLoop>;
 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() {
     return current.get();
 }
@@ -24,6 +59,8 @@ public:
     uv_loop_t *loop;
     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>()) {
@@ -84,10 +121,14 @@ void RunLoop::push(std::shared_ptr<WorkTask> task) {
 }
 
 void RunLoop::run() {
+    MBGL_VERIFY_THREAD(tid);
+
     uv_run(impl->loop, UV_RUN_DEFAULT);
 }
 
 void RunLoop::runOnce() {
+    MBGL_VERIFY_THREAD(tid);
+
     uv_run(impl->loop, UV_RUN_ONCE);
 }
 
@@ -95,5 +136,70 @@ void RunLoop::stop() {
     invoke([&] { impl->async->unref(); });
 }
 
+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);
+}
+
 }
 }