httpserver: use a future rather than relying on boost's try_join_for

src/httpserver.cpp

@@ -19,6 +19,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <signal.h>
+#include <future>
 
 #include <event2/event.h>
 #include <event2/http.h>
@@ -302,13 +303,14 @@ static void http_reject_request_cb(struct evhttp_request* req, void*)
 }
 
 /** Event dispatcher thread */
-static void ThreadHTTP(struct event_base* base, struct evhttp* http)
+static bool ThreadHTTP(struct event_base* base, struct evhttp* http)
 {
     RenameThread("bitcoin-http");
     LogPrint("http", "Entering http event loop\n");
     event_base_dispatch(base);
     // Event loop will be interrupted by InterruptHTTPServer()
     LogPrint("http", "Exited http event loop\n");
+    return event_base_got_break(base) == 0;
 }
 
 /** Bind HTTP server to specified addresses */
@@ -438,13 +440,16 @@ bool InitHTTPServer()
 }
 
 boost::thread threadHTTP;
+std::future<bool> threadResult;
 
 bool StartHTTPServer()
 {
     LogPrint("http", "Starting HTTP server\n");
     int rpcThreads = std::max((long)GetArg("-rpcthreads", DEFAULT_HTTP_THREADS), 1L);
     LogPrintf("HTTP: starting %d worker threads\n", rpcThreads);
-    threadHTTP = boost::thread(boost::bind(&ThreadHTTP, eventBase, eventHTTP));
+    std::packaged_task<bool(event_base*, evhttp*)> task(ThreadHTTP);
+    threadResult = task.get_future();
+    threadHTTP = boost::thread(std::bind(std::move(task), eventBase, eventHTTP));
 
     for (int i = 0; i < rpcThreads; i++)
         boost::thread(boost::bind(&HTTPWorkQueueRun, workQueue));
@@ -482,15 +487,11 @@ void StopHTTPServer()
         // master that appears to be solved, so in the future that solution
         // could be used again (if desirable).
         // (see discussion in https://github.com/bitcoin/bitcoin/pull/6990)
-#if BOOST_VERSION >= 105000
-        if (!threadHTTP.try_join_for(boost::chrono::milliseconds(2000))) {
-#else
-        if (!threadHTTP.timed_join(boost::posix_time::milliseconds(2000))) {
-#endif
+        if (threadResult.valid() && threadResult.wait_for(std::chrono::milliseconds(2000)) == std::future_status::timeout) {
             LogPrintf("HTTP event loop did not exit within allotted time, sending loopbreak\n");
             event_base_loopbreak(eventBase);
-            threadHTTP.join();
         }
+        threadHTTP.join();
     }
     if (eventHTTP) {
         evhttp_free(eventHTTP);