Use g_unix_signal_add for ACAPs with GMainLoop

Author: isak-jakobsson

axoverlay/app/axoverlay.c

@@ -31,12 +31,12 @@
 #include <axoverlay.h>
 #include <cairo/cairo.h>
 #include <errno.h>
+#include <glib-unix.h>
 #include <glib.h>
 #include <syslog.h>
 
 #define PALETTE_VALUE_RANGE 255.0
 
-static GMainLoop* main_loop = NULL;
 static gint animation_timer = -1;
 static gint overlay_id      = -1;
 static gint overlay_id_text = -1;
@@ -327,47 +327,12 @@ static gboolean update_overlay_cb(gpointer user_data) {
 /**
  * brief Handles the signals.
  *
- * This function handles the signals when it is time to
- * quit the main loop.
- *
- * param signal_num Signal number.
- */
-static void signal_handler(gint signal_num) {
-    switch (signal_num) {
-        case SIGTERM:
-        case SIGABRT:
-        case SIGINT:
-            g_main_loop_quit(main_loop);
-            break;
-        default:
-            break;
-    }
-}
-
-/**
- * brief Initialize the signal handler.
- *
- * This function handles the initialization of signals.
- *
- * return result as boolean.
+ * param loop Loop to quit
  */
-static gboolean signal_handler_init(void) {
-    struct sigaction sa = {0};
-
-    if (sigemptyset(&sa.sa_mask) == -1) {
-        syslog(LOG_ERR, "Failed to initialize signal handler: %s", strerror(errno));
-        return FALSE;
-    }
-
-    sa.sa_handler = signal_handler;
-
-    if ((sigaction(SIGTERM, &sa, NULL) < 0) || (sigaction(SIGABRT, &sa, NULL) < 0) ||
-        (sigaction(SIGINT, &sa, NULL) < 0)) {
-        syslog(LOG_ERR, "Failed to install signal handler: %s", strerror(errno));
-        return FALSE;
-    }
-
-    return TRUE;
+static gboolean signal_handler(gpointer loop) {
+    g_main_loop_quit((GMainLoop*)loop);
+    syslog(LOG_INFO, "Application was stopped by SIGTERM or SIGINT.");
+    return G_SOURCE_REMOVE;
 }
 
 /***** Main function *********************************************************/
@@ -386,20 +351,18 @@ int main(int argc, char** argv) {
     (void)argc;
     (void)argv;
 
+    GMainLoop* loop    = NULL;
     GError* error      = NULL;
     GError* error_text = NULL;
     gint camera_height = 0;
     gint camera_width  = 0;
 
     openlog(NULL, LOG_PID, LOG_USER);
 
-    if (!signal_handler_init()) {
-        syslog(LOG_ERR, "Could not set up signal handler");
-        return 1;
-    }
-
     //  Create a glib main loop
-    main_loop = g_main_loop_new(NULL, FALSE);
+    loop = g_main_loop_new(NULL, FALSE);
+    g_unix_signal_add(SIGTERM, signal_handler, loop);
+    g_unix_signal_add(SIGINT, signal_handler, loop);
 
     if (!axoverlay_is_backend_supported(AXOVERLAY_CAIRO_IMAGE_BACKEND)) {
         syslog(LOG_ERR, "AXOVERLAY_CAIRO_IMAGE_BACKEND is not supported");
@@ -486,7 +449,7 @@ int main(int argc, char** argv) {
     animation_timer = g_timeout_add_seconds(1, update_overlay_cb, NULL);
 
     // Enter main loop
-    g_main_loop_run(main_loop);
+    g_main_loop_run(loop);
 
     // Destroy the overlay
     axoverlay_destroy_overlay(overlay_id, &error);
@@ -509,7 +472,7 @@ int main(int argc, char** argv) {
     g_source_remove(animation_timer);
 
     // Release main loop
-    g_main_loop_unref(main_loop);
+    g_main_loop_unref(loop);
 
     return 0;
 }

axparameter/app/axparameter.c

@@ -22,6 +22,7 @@
  * limitations they impose.
  */
 #include <axsdk/axparameter.h>
+#include <glib-unix.h>
 #include <stdbool.h>
 #include <syslog.h>
 
@@ -34,19 +35,10 @@ struct message {
     char* value;
 };
 
-static GMainLoop* loop = NULL;  // Must be global, so quit_main_loop() can use it
-
-static void quit_main_loop(__attribute__((unused)) int signal_num) {
-    g_main_loop_quit(loop);
-}
-
-static void set_sigterm_and_sigint_handler(void (*handler)(int)) {
-    struct sigaction sa = {0};
-
-    sigemptyset(&sa.sa_mask);
-    sa.sa_handler = handler;
-    sigaction(SIGTERM, &sa, NULL);
-    sigaction(SIGINT, &sa, NULL);
+static gboolean signal_handler(gpointer loop) {
+    g_main_loop_quit((GMainLoop*)loop);
+    syslog(LOG_INFO, "Application was stopped by SIGTERM or SIGINT.");
+    return G_SOURCE_REMOVE;
 }
 
 // Print an error to syslog and exit the application if a fatal error occurs.
@@ -182,7 +174,8 @@ static void parameter_changed(const gchar* name, const gchar* value, gpointer ha
 }
 
 int main(void) {
-    GError* error = NULL;
+    GError* error   = NULL;
+    GMainLoop* loop = NULL;
 
     openlog(APP_NAME, LOG_PID, LOG_USER);
 
@@ -209,9 +202,9 @@ int main(void) {
 
     // Start listening to callbacks by launching a GLib main loop.
     loop = g_main_loop_new(NULL, FALSE);
-    set_sigterm_and_sigint_handler(quit_main_loop);
+    g_unix_signal_add(SIGTERM, signal_handler, loop);
+    g_unix_signal_add(SIGINT, signal_handler, loop);
     g_main_loop_run(loop);
-    syslog(LOG_INFO, "Application was stopped by SIGTERM or SIGINT.");
 
     g_main_loop_unref(loop);
     ax_parameter_free(handle);

axserialport/app/axserialport.c

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <glib-unix.h>
 #include <glib.h>
 #include <stdlib.h>
 #include <syslog.h>
@@ -34,36 +35,15 @@ typedef struct MyConfigAndData {
     gpointer data;
 } MyConfigAndData;
 
-static GMainLoop* loop = NULL;
-
-/**
- * @brief Signals handling
- *
- * @param signal_num Signal number
- */
-static void handle_sigterm(int signo) {
-    (void)signo;
-    if (loop != NULL) {
-        g_main_loop_quit(loop);
-    } else {
-        exit(EXIT_FAILURE);
-    }
-}
-
 /**
- * @brief Initialize signals
+ * @brief Handles the signals.
  *
- * @param signo Signal id (not used)
+ * @param loop Loop to quit
  */
-static void init_signals(void) {
-    struct sigaction sa;
-
-    sa.sa_flags = 0;
-
-    sigemptyset(&sa.sa_mask);
-    sa.sa_handler = handle_sigterm;
-    sigaction(SIGTERM, &sa, NULL);
-    sigaction(SIGINT, &sa, NULL);
+static gboolean signal_handler(gpointer loop) {
+    g_main_loop_quit((GMainLoop*)loop);
+    syslog(LOG_INFO, "Application was stopped by SIGTERM or SIGINT.");
+    return G_SOURCE_REMOVE;
 }
 
 /**
@@ -187,12 +167,14 @@ int main(void) {
     guint port0            = 0;
     AXSerialConfig* config = NULL;
     GIOChannel* iochannel  = NULL;
+    GMainLoop* loop        = NULL;
     GError* error          = NULL;
     MyConfigAndData conf_data;
 
     /* Initialization */
-    init_signals();
     loop = g_main_loop_new(NULL, FALSE);
+    g_unix_signal_add(SIGTERM, signal_handler, loop);
+    g_unix_signal_add(SIGINT, signal_handler, loop);
 
     /* Print some startup messages */
     openlog(APP_NAME, LOG_PID, LOG_LOCAL4);

axstorage/app/axstorage.c

@@ -15,6 +15,7 @@
  */
 
 #include <errno.h>
+#include <glib-unix.h>
 #include <glib.h>
 #include <glib/gstdio.h>
 #include <signal.h>
@@ -45,36 +46,16 @@ typedef struct {
 } disk_item_t;
 
 static GList* disks_list = NULL;
-static GMainLoop* loop   = NULL;
 
 /**
- * @brief Signals handling
+ * @brief Handles the signals.
  *
- * @param signal_num Signal number
+ * @param loop Loop to quit
  */
-static void handle_sigterm(int signo) {
-    (void)signo;
-    if (loop != NULL) {
-        g_main_loop_quit(loop);
-    } else {
-        exit(EXIT_FAILURE);
-    }
-}
-
-/**
- * @brief Initialize signals
- *
- * @param signo Signal id (not used)
- */
-static void init_signals(void) {
-    struct sigaction sa;
-
-    sa.sa_flags = 0;
-
-    sigemptyset(&sa.sa_mask);
-    sa.sa_handler = handle_sigterm;
-    sigaction(SIGTERM, &sa, NULL);
-    sigaction(SIGINT, &sa, NULL);
+static gboolean signal_handler(gpointer loop) {
+    g_main_loop_quit((GMainLoop*)loop);
+    syslog(LOG_INFO, "Application was stopped by SIGTERM or SIGINT.");
+    return G_SOURCE_REMOVE;
 }
 
 /**
@@ -393,12 +374,12 @@ static disk_item_t* new_disk_item_t(gchar* storage_id) {
  * @return Result
  */
 gint main(void) {
-    GList* disks  = NULL;
-    GList* node   = NULL;
-    GError* error = NULL;
-    gint ret      = EXIT_SUCCESS;
+    GList* disks    = NULL;
+    GList* node     = NULL;
+    GError* error   = NULL;
+    GMainLoop* loop = NULL;
+    gint ret        = EXIT_SUCCESS;
 
-    init_signals();
     openlog(APP_NAME, LOG_PID, LOG_USER);
     syslog(LOG_INFO, "Start AXStorage application");
 
@@ -412,6 +393,8 @@ gint main(void) {
     }
 
     loop = g_main_loop_new(NULL, FALSE);
+    g_unix_signal_add(SIGTERM, signal_handler, loop);
+    g_unix_signal_add(SIGINT, signal_handler, loop);
 
     /* Loop through the retrieved disks and subscribe to their events. */
     for (node = g_list_first(disks); node != NULL; node = g_list_next(node)) {