Fix

programs/client/Client.cpp

@@ -417,7 +417,13 @@ try
 {
     UseSSL use_ssl;
     MainThreadStatus::getInstance();
-    signal(SIGINT, signalHandler);
+
+    struct sigaction new_act;
+    struct sigaction old_act;
+    new_act.sa_handler = interruptSignalHandler;
+    sigemptyset(&new_act.sa_mask);
+    new_act.sa_flags = 0;
+    sigaction(SIGINT, &new_act, &old_act);
 
     std::cout << std::fixed << std::setprecision(3);
     std::cerr << std::fixed << std::setprecision(3);

programs/local/LocalServer.cpp

@@ -414,7 +414,13 @@ try
 {
     UseSSL use_ssl;
     ThreadStatus thread_status;
-    signal(SIGINT, signalHandler);
+
+    struct sigaction new_act;
+    struct sigaction old_act;
+    new_act.sa_handler = interruptSignalHandler;
+    sigemptyset(&new_act.sa_mask);
+    new_act.sa_flags = 0;
+    sigaction(SIGINT, &new_act, &old_act);
 
     std::cout << std::fixed << std::setprecision(3);
     std::cerr << std::fixed << std::setprecision(3);

src/Client/ClientBase.cpp

@@ -74,18 +74,13 @@ namespace ErrorCodes
 namespace DB
 {
 
-volatile sig_atomic_t need_cancel_query = false;
-volatile sig_atomic_t query_cancelled = true;
+std::atomic<bool> catch_signal = false;
 
 /// This signal handler is set only for sigint.
-void signalHandler(int signum)
+void interruptSignalHandler(int signum)
 {
-    if (query_cancelled)
-        return;
-    /// Exit if it is a second sigint and query is not cancelled yet.
-    if (need_cancel_query && !query_cancelled)
-        exit(signum);
-    need_cancel_query = true;
+    if (!catch_signal.exchange(false))
+        _exit(signum);
 }
 
 
@@ -469,7 +464,8 @@ void ClientBase::processOrdinaryQuery(const String & query_to_execute, ASTPtr pa
 /// Also checks if query execution should be cancelled.
 void ClientBase::receiveResult(ASTPtr parsed_query)
 {
-    query_cancelled = false;
+    bool cancelled = false;
+    catch_signal.store(true);
 
     // TODO: get the poll_interval from commandline.
     const auto receive_timeout = connection_parameters.timeouts.receive_timeout;
@@ -487,21 +483,21 @@ void ClientBase::receiveResult(ASTPtr parsed_query)
             /// Has the Ctrl+C been pressed and thus the query should be cancelled?
             /// If this is the case, inform the server about it and receive the remaining packets
             /// to avoid losing sync.
-            if (!query_cancelled)
+            if (!cancelled)
             {
                 auto cancel_query = [&] {
                     connection->sendCancel();
-                    query_cancelled = true;
                     if (is_interactive)
                     {
                         progress_indication.clearProgressOutput();
                         std::cout << "Cancelling query." << std::endl;
                     }
-
-                    need_cancel_query = false;
+                    cancelled = true;
+                    catch_signal.store(true);
                 };
 
-                if (need_cancel_query)
+                /// handler received sigint
+                if (!catch_signal.load())
                 {
                     cancel_query();
                 }
@@ -526,15 +522,14 @@ void ClientBase::receiveResult(ASTPtr parsed_query)
                 break;
         }
 
-        if (!receiveAndProcessPacket(parsed_query, query_cancelled))
+        if (!receiveAndProcessPacket(parsed_query, cancelled))
             break;
     }
 
-    if (query_cancelled && is_interactive)
+    if (cancelled && is_interactive)
         std::cout << "Query was cancelled." << std::endl;
 
-    /// Mark that there is no query in execution.
-    query_cancelled = true;
+    catch_signal.store(false);
 }
 
 

src/Client/ClientBase.h

@@ -30,7 +30,7 @@ enum MultiQueryProcessingStage
     PARSING_FAILED,
 };
 
-void signalHandler(int signum);
+void interruptSignalHandler(int signum);
 
 class ClientBase : public Poco::Util::Application
 {