EventLoop.h¶

Detailed description

Run the SDK’s event loop.

The following functions are used for using the VNC SDK’s event loop as the the application’s event loop. In this case, the event loop will respond to the events as they occur inside the SDK, invoking callbacks as appropriate, until vnc_EventLoop_stop() is called inside one of the callbacks, at which point vnc_EventLoop_run() exits on the next turn of the event loop.

The other way of using the SDK is to use an event loop external to the SDK. On some platforms such as Android, OS X and iOS, the SDK is able to directly register its timers and sockets with the thread’s Android or Core Foundation run loop, so simply using the platform’s normal event loop will allow the SDK to process I/O automatically. On other platforms, the SDK’s timers and sockets must instead be manually added to the application’s event loop; use the functions in vnc/EventLoopFd.h and vnc/EventLoopWin.h to do this.

If another thread needs to schedule work for the SDK thread to perform, it should push an object representing the necessary work to a thread-safe queue and then call vnc_EventLoop_stop(). This should cause the SDK thread to complete its call to vnc_EventLoop_run(). The SDK thread should then pop and execute any queued work before looping back to call vnc_EventLoop_run() again, as in the following pseudocode:

var queue = [];
var queueMutex = mutex();

// On non-SDK thread:
function runOnSdkThread(var runnable) {
    try {
        lock(queueMutex);
        queue.push(runnable);
    } finally { unlock(queueMutex); }
    vnc_EventLoop_stop();
}

// On SDK thread:
function runSdk() {
    var task;
    while (true) {
        vnc_EventLoop_run();
        try {
            lock(queueMutex);
            while (!queue.empty()) {
                task = queue.pop();
                task();
            }
        } finally { unlock(queueMutex); }
    }
}

vnc_EventLoop_run() and vnc_EventLoop_stop() are not available on the HTML5 platform.