fix malloc/free deadlock in signal handler by implementing a signaling pipe for sigco...

diff --git a/src/main.c b/src/main.c
index 8536cb67c77d8e7fa8258f9ccab837b46d4bb75d..fa16de1f46dc0e196059f217b12e725fff6689a5 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -48,6 +48,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <signal.h>
 #include <string.h>
 
@@ -63,6 +64,7 @@ static const guint update_interval = 500;
 static struct mpdclient *mpd = NULL;
 static GMainLoop *main_loop;
 static guint reconnect_source_id, update_source_id;
+static int sigwinch_pipes[2];
 
 #ifndef NCMPC_MINI
 static guint check_key_bindings_source_id;
@@ -120,7 +122,9 @@ catch_sigint(G_GNUC_UNUSED int sig)
 static void
 catch_sigcont(G_GNUC_UNUSED int sig)
 {
-       screen_resize(mpd);
+       char irrelevant = 'a';
+       if (1 != write(sigwinch_pipes[1], &irrelevant, 1))
+               exit(EXIT_FAILURE);
 }
 
 void
@@ -131,29 +135,27 @@ sigstop(void)
        kill(0, SIGSTOP); /* issue SIGSTOP */
 }
 
-static guint timer_sigwinch_id;
-
 static gboolean
-timer_sigwinch(G_GNUC_UNUSED gpointer data)
+sigwinch_event(G_GNUC_UNUSED GIOChannel *source,
+               G_GNUC_UNUSED GIOCondition condition, G_GNUC_UNUSED gpointer data)
 {
-       /* the following causes the screen to flicker.  There might be
-          better solutions, but I believe it isn't all that
-          important. */
+       char ignoreme[64];
+       if (1 > read(sigwinch_pipes[0], ignoreme, 64))
+               exit(EXIT_FAILURE);
 
        endwin();
        refresh();
        screen_resize(mpd);
 
-       return FALSE;
+       return TRUE;
 }
 
 static void
 catch_sigwinch(G_GNUC_UNUSED int sig)
 {
-       if (timer_sigwinch_id != 0)
-               g_source_remove(timer_sigwinch_id);
-
-       timer_sigwinch_id = g_timeout_add(100, timer_sigwinch, NULL);
+       char irrelevant = 'a';
+       if (1 != write(sigwinch_pipes[1], &irrelevant, 1))
+               exit(EXIT_FAILURE);
 }
 
 static void
@@ -545,6 +547,7 @@ main(int argc, const char *argv[])
        int lirc_socket;
        GIOChannel *lirc_channel = NULL;
 #endif
+       GIOChannel *sigwinch_channel = NULL;
 
 #ifdef ENABLE_LOCALE
        /* time and date formatting */
@@ -663,6 +666,16 @@ main(int argc, const char *argv[])
        }
 #endif
 
+       if (!pipe(sigwinch_pipes) &&
+               !fcntl(sigwinch_pipes[1], F_SETFL, O_NONBLOCK)) {
+               sigwinch_channel = g_io_channel_unix_new(sigwinch_pipes[0]);
+               g_io_add_watch(sigwinch_channel, G_IO_IN, sigwinch_event, NULL);
+       }
+       else {
+               perror("sigwinch pipe creation failed");
+               exit(EXIT_FAILURE);
+       }
+
        /* attempt to connect */
        reconnect_source_id = g_timeout_add(1, timer_reconnect, NULL);
 
@@ -692,6 +705,9 @@ main(int argc, const char *argv[])
 
        g_main_loop_unref(main_loop);
        g_io_channel_unref(keyboard_channel);
+       g_io_channel_unref(sigwinch_channel);
+       close(sigwinch_pipes[0]);
+       close(sigwinch_pipes[1]);
 
 #ifdef ENABLE_LIRC
        if (lirc_socket >= 0)