refactor(server): change conn->closed to atomic, try to fix possible data race

Author: matyhtf

include/swoole_server.h

@@ -87,7 +87,6 @@ struct Connection {
     uint8_t websocket_compression;
     // If it is equal to 1, it means server actively closed the connection
     uint8_t close_actively;
-    uint8_t closed;
     uint8_t close_queued;
     uint8_t closing;
     uint8_t close_reset;
@@ -99,6 +98,7 @@ struct Connection {
     ReactorId reactor_id;
     uint16_t close_errno;
     int server_fd;
+    sw_atomic_t closed;
     sw_atomic_t recv_queued_bytes;
     uint32_t send_queued_bytes;
     uint16_t waiting_time;
@@ -1308,6 +1308,10 @@ class Server {
         return session->reactor_id != swoole_get_worker_id();
     }
 
+    bool if_do_close_callback(Connection *conn) const {
+        return onClose != nullptr && sw_atomic_cmp_set(&conn->closed, 0, 1);
+    }
+
     Worker *get_worker(uint16_t worker_id) const;
     bool kill_worker(int worker_id);
     void stop_async_worker(Worker *worker);

src/server/base.cc

@@ -170,7 +170,7 @@ bool BaseFactory::end(SessionId session_id, int flags) {
     }
 
     conn->closing = 1;
-    if (server_->onClose != nullptr && !conn->closed) {
+    if (server_->if_do_close_callback(conn)) {
         DataHead info{};
         info.fd = session_id;
         if (conn->close_actively) {
@@ -182,7 +182,6 @@ bool BaseFactory::end(SessionId session_id, int flags) {
         server_->onClose(server_, &info);
     }
     conn->closing = 0;
-    conn->closed = 1;
     conn->close_errno = 0;
     network::Socket *_socket = conn->socket;
 

src/server/process.cc

@@ -415,7 +415,7 @@ bool ProcessFactory::end(SessionId session_id, int flags) {
         return false;
     }
 
-    if (server_->onClose != nullptr && !conn->closed) {
+    if (server_->if_do_close_callback(conn)) {
         info.fd = session_id;
         if (conn->close_actively) {
             info.reactor_id = -1;
@@ -427,7 +427,6 @@ bool ProcessFactory::end(SessionId session_id, int flags) {
         server_->onClose(server_, &info);
         conn->closing = 0;
     }
-    conn->closed = 1;
     conn->close_errno = 0;
     return finish(&_send);
 }