diff --git a/src/httpserver.cpp b/src/httpserver.cpp index e967d3a4a..9f079aedf 100644 --- a/src/httpserver.cpp +++ b/src/httpserver.cpp @@ -72,13 +72,35 @@ private: std::deque queue; bool running; size_t maxDepth; + int numThreads; + + /** RAII object to keep track of number of running worker threads */ + class ThreadCounter + { + public: + WorkQueue &wq; + ThreadCounter(WorkQueue &w): wq(w) + { + boost::lock_guard lock(wq.cs); + wq.numThreads += 1; + } + ~ThreadCounter() + { + boost::lock_guard lock(wq.cs); + wq.numThreads -= 1; + wq.cond.notify_all(); + } + }; public: WorkQueue(size_t maxDepth) : running(true), - maxDepth(maxDepth) + maxDepth(maxDepth), + numThreads(0) { } - /* Precondition: worker threads have all stopped */ + /*( Precondition: worker threads have all stopped + * (call WaitExit) + */ ~WorkQueue() { while (!queue.empty()) { @@ -100,6 +122,7 @@ public: /** Thread function */ void Run() { + ThreadCounter count(*this); while (running) { WorkItem* i = 0; { @@ -122,6 +145,13 @@ public: running = false; cond.notify_all(); } + /** Wait for worker threads to exit */ + void WaitExit() + { + boost::unique_lock lock(cs); + while (numThreads > 0) + cond.wait(lock); + } /** Return current depth of queue */ size_t Depth() @@ -434,7 +464,11 @@ void InterruptHTTPServer() void StopHTTPServer() { LogPrint("http", "Stopping HTTP server\n"); - delete workQueue; + if (workQueue) { + LogPrint("http", "Waiting for HTTP worker threads to exit\n"); + workQueue->WaitExit(); + delete workQueue; + } if (eventHTTP) { evhttp_free(eventHTTP); eventHTTP = 0;