Add option sendPingsAutomatically

examples/EchoServer.cpp

@@ -21,8 +21,11 @@ int main() {
         /* Settings */
         .compression = uWS::SHARED_COMPRESSOR,
         .maxPayloadLength = 16 * 1024,
-        .idleTimeout = 10,
+        .idleTimeout = 16,
         .maxBackpressure = 1 * 1024 * 1024,
+        .closeOnBackpressureLimit = false,
+        .resetIdleTimeoutOnSend = false,
+        .sendPingsAutomatically = true,
         /* Handlers */
         .upgrade = nullptr,
         .open = [](auto */*ws*/) {

src/App.h

@@ -139,8 +139,10 @@ public:
         unsigned int maxPayloadLength = 16 * 1024;
         unsigned int idleTimeout = 120;
         unsigned int maxBackpressure = 1 * 1024 * 1024;
+        // change these before release
         bool closeOnBackpressureLimit = false;
         bool resetIdleTimeoutOnSend = true;
+        bool sendPingsAutomatically = false;
         fu2::unique_function<void(HttpResponse<SSL> *, HttpRequest *, struct us_socket_context_t *)> upgrade = nullptr;
         fu2::unique_function<void(uWS::WebSocket<SSL, true> *)> open = nullptr;
         fu2::unique_function<void(uWS::WebSocket<SSL, true> *, std::string_view, uWS::OpCode)> message = nullptr;
@@ -204,8 +206,12 @@ public:
         webSocketContext->getExt()->maxBackpressure = behavior.maxBackpressure;
         webSocketContext->getExt()->closeOnBackpressureLimit = behavior.closeOnBackpressureLimit;
         webSocketContext->getExt()->resetIdleTimeoutOnSend = behavior.resetIdleTimeoutOnSend;
+        webSocketContext->getExt()->sendPingsAutomatically = behavior.sendPingsAutomatically;
         webSocketContext->getExt()->compression = behavior.compression;
 
+        /* Calculate idleTimeoutCompnents */
+        webSocketContext->getExt()->calculateIdleTimeoutCompnents();
+
         httpContext->onHttp("get", pattern, [webSocketContext, behavior = std::move(behavior)](auto *res, auto *req) mutable {
 
             /* If we have this header set, it's a websocket */

src/WebSocket.h

@@ -123,7 +123,9 @@ public:
 
         /* Every successful send resets the timeout */
         if (webSocketContextData->resetIdleTimeoutOnSend) {
-            Super::timeout(webSocketContextData->idleTimeout);
+            Super::timeout(webSocketContextData->idleTimeoutComponents.first);
+            WebSocketData *webSocketData = (WebSocketData *) Super::getAsyncSocketData();
+            webSocketData->hasTimedOut = false;
         }
 
         /* Return success */

src/WebSocketContext.h

@@ -276,7 +276,8 @@ private:
             auto *asyncSocket = (AsyncSocket<SSL> *) s;
 
             /* Every time we get data and not in shutdown state we simply reset the timeout */
-            asyncSocket->timeout(webSocketContextData->idleTimeout);
+            asyncSocket->timeout(webSocketContextData->idleTimeoutComponents.first);
+            webSocketData->hasTimedOut = false;
 
             /* We always cork on data */
             asyncSocket->cork();
@@ -325,7 +326,8 @@ private:
             /* Also reset timeout if we came here with 0 backpressure */
             if (!backpressure || backpressure > asyncSocket->getBufferedAmount()) {
                 auto *webSocketContextData = (WebSocketContextData<SSL> *) us_socket_context_ext(SSL, us_socket_context(SSL, (us_socket_t *) s));
-                asyncSocket->timeout(webSocketContextData->idleTimeout);
+                asyncSocket->timeout(webSocketContextData->idleTimeoutComponents.first);
+                webSocketData->hasTimedOut = false;
             }
 
             /* Are we in (WebSocket) shutdown mode? */
@@ -359,6 +361,17 @@ private:
         /* Handle socket timeouts, simply close them so to not confuse client with FIN */
         us_socket_context_on_timeout(SSL, getSocketContext(), [](auto *s) {
 
+            auto *webSocketData = (WebSocketData *)(us_socket_ext(SSL, s));
+            auto *webSocketContextData = (WebSocketContextData<SSL> *) us_socket_context_ext(SSL, us_socket_context(SSL, (us_socket_t *) s));
+
+            if (webSocketContextData->sendPingsAutomatically && !webSocketData->hasTimedOut) {
+                webSocketData->hasTimedOut = true;
+                us_socket_timeout(SSL, s, webSocketContextData->idleTimeoutComponents.second);
+                /* Send ping without being corked */
+                ((AsyncSocket<SSL> *) s)->write("\x89\x00", 2);
+                return s;
+            }
+
             /* Timeout is very simple; we just close it */
             /* Warning: we happen to know forceClose will not use first parameter so pass nullptr here */
             forceClose(nullptr, s, ERR_WEBSOCKET_TIMEOUT);

src/WebSocketContextData.h

@@ -66,10 +66,31 @@ public:
     size_t maxBackpressure = 0;
     bool closeOnBackpressureLimit;
     bool resetIdleTimeoutOnSend;
+    bool sendPingsAutomatically;
+
+    /* These are calculated on creation */
+    std::pair<unsigned short, unsigned short> idleTimeoutComponents;
 
     /* Each websocket context has a topic tree for pub/sub */
     TopicTree topicTree;
 
+    /* This is run once on start-up */
+    void calculateIdleTimeoutCompnents() {
+        unsigned short margin = 4;
+        /* 4, 8 or 16 seconds margin based on idleTimeout */
+        while ((int) idleTimeout - margin * 2 >= margin * 2 && margin < 16) {
+            margin *= 2;
+        }
+        /* We should have no margin if not using sendPingsAutomatically */
+        if (!sendPingsAutomatically) {
+            margin = 0;
+        }
+        idleTimeoutComponents = {
+            idleTimeout - margin,
+            margin
+        };
+    }
+
     ~WebSocketContextData() {
         /* We must unregister any loop post handler here */
         Loop::get()->removePostHandler(this);
@@ -157,7 +178,9 @@ public:
                  * ENTIRE SUCCESS - we need minor API changes to support correct checks */
                 if (!failed) {
                     if (this->resetIdleTimeoutOnSend) {
-                        asyncSocket->timeout(this->idleTimeout);
+                        auto *webSocketData = (WebSocketData *) us_socket_ext(SSL, (us_socket_t *) asyncSocket);
+                        webSocketData->hasTimedOut = false;
+                        asyncSocket->timeout(this->idleTimeoutComponents.first);
                     }
                 }
             });
@@ -171,7 +194,9 @@ public:
             /* Again, this check should be more like DID WE PROGRESS rather than DID WE SUCCEED ENTIRELY */
             if (!failed) {
                 if (this->resetIdleTimeoutOnSend) {
-                    asyncSocket->timeout(this->idleTimeout);
+                    auto *webSocketData = (WebSocketData *) us_socket_ext(SSL, (us_socket_t *) asyncSocket);
+                    webSocketData->hasTimedOut = false;
+                    asyncSocket->timeout(this->idleTimeoutComponents.first);
                 }
             }
         }

src/WebSocketData.h

@@ -37,6 +37,7 @@ private:
     std::string fragmentBuffer;
     unsigned int controlTipLength = 0;
     bool isShuttingDown = 0;
+    bool hasTimedOut = false;
     enum CompressionStatus : char {
         DISABLED,
         ENABLED,