add an example that shows the integration of the server in an external mainloop

CMakeLists.txt

@@ -464,6 +464,9 @@ if(UA_BUILD_EXAMPLES)
     add_executable(server_variable ${PROJECT_SOURCE_DIR}/examples/server_variable.c $<TARGET_OBJECTS:open62541-object>)
 	target_link_libraries(server_variable ${LIBS})
 
+    add_executable(server_mainloop ${PROJECT_SOURCE_DIR}/examples/server_mainloop.c $<TARGET_OBJECTS:open62541-object>)
+	target_link_libraries(server_mainloop ${LIBS})
+
 	add_executable(server_datasource ${PROJECT_SOURCE_DIR}/examples/server_datasource.c $<TARGET_OBJECTS:open62541-object>)
 	target_link_libraries(server_datasource ${LIBS})
 

examples/CMakeLists.txt

@@ -20,6 +20,9 @@ endif()
 add_executable(server_variable server_variable.c)
 target_link_libraries(server_variable ${LIBS})
 
+add_executable(server_mainloop server_mainloop.c)
+target_link_libraries(server_mainloop ${LIBS})
+
 add_executable(server_datasource server_datasource.c)
 target_link_libraries(server_datasource ${LIBS})
 

examples/server_mainloop.c

@@ -0,0 +1,63 @@
+/*
+ * This work is licensed under a Creative Commons CCZero 1.0 Universal License.
+ * See http://creativecommons.org/publicdomain/zero/1.0/ for more information.
+ */
+
+#define _BSD_SOURCE
+#include <signal.h>
+#include <unistd.h>
+
+#ifdef UA_NO_AMALGAMATION
+# include "ua_types.h"
+# include "ua_server.h"
+# include "logger_stdout.h"
+# include "networklayer_tcp.h"
+#else
+# include "open62541.h"
+#endif
+
+UA_Boolean running = true;
+UA_Logger logger = Logger_Stdout;
+
+static void stopHandler(int sign) {
+    UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "received ctrl-c");
+    running = false;
+}
+
+/* In this example, we integrate the server into an external "mainloop". This
+   can be for example the event-loop used in GUI toolkits, such as Qt or GTK. */
+
+int main(int argc, char** argv) {
+    signal(SIGINT, stopHandler); /* catches ctrl-c */
+
+    UA_ServerConfig config = UA_ServerConfig_standard;
+    UA_ServerNetworkLayer nl = UA_ServerNetworkLayerTCP(UA_ConnectionConfig_standard, 16664);
+    config.logger = Logger_Stdout;
+    config.networkLayers = &nl;
+    config.networkLayersSize = 1;
+    UA_Server *server = UA_Server_new(config);
+
+    UA_StatusCode retval = UA_Server_run_startup(server);
+    if(retval != UA_STATUSCODE_GOOD)
+        goto cleanup;
+
+    /* Should the server networklayer block (with a timeout) until a message
+       arrives or should it return immediately? */
+    UA_Boolean waitInternal = false;
+
+    while(running) {
+        /* timeout is the maximum possible delay (in millisec) until the next
+           _iterate call. Otherwise, the server might miss an internal timeout
+           or cannot react to messages with the promised responsiveness. */
+        UA_UInt16 timeout = UA_Server_run_iterate(server, waitInternal);
+
+        /* now we can use the max timeout to do something else */
+        usleep((__useconds_t)(timeout * 1000));
+    }
+    retval = UA_Server_run_shutdown(server);
+
+ cleanup:
+    UA_Server_delete(server);
+    nl.deleteMembers(&nl);
+    return (int)retval;
+}