From 7c4f14f941b361e97dd87afd215735c1cee1d81f Mon Sep 17 00:00:00 2001
From: Benjamin Sergeant <bsergean@gmail.com>
Date: Tue, 1 Jan 2019 16:11:27 -0800
Subject: [PATCH] thread accepting connections can be cancelled/stopped
 externally

---
 examples/echo_server/echo_server.cpp |  1 +
 ixwebsocket/IXWebSocketServer.cpp    | 34 +++++++++++++++++++++++-----
 ixwebsocket/IXWebSocketServer.h      |  5 ++++
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/examples/echo_server/echo_server.cpp b/examples/echo_server/echo_server.cpp
index 16eb979d..7b5f5f4e 100644
--- a/examples/echo_server/echo_server.cpp
+++ b/examples/echo_server/echo_server.cpp
@@ -67,6 +67,7 @@ int main(int argc, char** argv)
     }
 
     server.start();
+    server.wait();
 
     return 0;
 }
diff --git a/ixwebsocket/IXWebSocketServer.cpp b/ixwebsocket/IXWebSocketServer.cpp
index 3aa5cfc0..996fa497 100644
--- a/ixwebsocket/IXWebSocketServer.cpp
+++ b/ixwebsocket/IXWebSocketServer.cpp
@@ -7,6 +7,7 @@
 #include "IXWebSocketServer.h"
 #include "IXWebSocketTransport.h"
 #include "IXWebSocket.h"
+#include "IXSocketConnect.h"
 
 #include <sstream>
 #include <future>
@@ -120,32 +121,53 @@ namespace ix
         _thread = std::thread(&WebSocketServer::run, this);
     }
 
+    void WebSocketServer::wait()
+    {
+        std::unique_lock<std::mutex> lock(_conditionVariableMutex);
+        _conditionVariable.wait(lock);
+    }
+
     // FIXME: we should cancel all the async per connections tasks
     void WebSocketServer::stop()
     {
         _stop = true;
         _thread.join();
         _stop = false;
+
+        _conditionVariable.notify_one();
     }
 
     void WebSocketServer::run()
     {
+        // Set the socket to non blocking mode, so that accept calls are not blocking
+        SocketConnect::configure(_serverFd);
+
         std::future<void> f;
 
         for (;;)
         {
+            if (_stop) return;
+
             // Accept a connection.
             struct sockaddr_in client; // client address information
             int clientFd;              // socket connected to client
             socklen_t addressLen = sizeof(socklen_t);
 
-            if ((clientFd = accept(_serverFd, (struct sockaddr *)&client, &addressLen)) == -1)
+            if ((clientFd = accept(_serverFd, (struct sockaddr *)&client, &addressLen)) < 0)
             {
-                // FIXME: that error should be propagated
-                std::stringstream ss;
-                ss << "WebSocketServer::run() error accepting connection: "
-                   << strerror(errno);
-                logError(ss.str());
+                if (errno == EWOULDBLOCK)
+                {
+                    std::chrono::duration<double, std::milli> wait(10);
+                    std::this_thread::sleep_for(wait);
+                }
+                else
+                {
+                    // FIXME: that error should be propagated
+                    std::stringstream ss;
+                    ss << "WebSocketServer::run() error accepting connection: "
+                       << strerror(errno);
+                    logError(ss.str());
+                }
                 continue;
             }
 
diff --git a/ixwebsocket/IXWebSocketServer.h b/ixwebsocket/IXWebSocketServer.h
index 3750eb4e..74f9e644 100644
--- a/ixwebsocket/IXWebSocketServer.h
+++ b/ixwebsocket/IXWebSocketServer.h
@@ -13,6 +13,7 @@
 #include <mutex>
 #include <functional>
 #include <memory>
+#include <condition_variable>
 
 #include "IXWebSocket.h"
 
@@ -29,6 +30,7 @@ namespace ix
 
         void setOnConnectionCallback(const OnConnectionCallback& callback);
         void start();
+        void wait();
 
         std::pair<bool, std::string> listen();
 
@@ -54,6 +56,9 @@ namespace ix
         std::atomic<bool> _stop;
         std::thread _thread;
 
+        std::condition_variable _conditionVariable;
+        std::mutex _conditionVariableMutex;
+
         const static std::string kDefaultHost;
 
         // Methods