gui: Do not decode the pressed key multiple times.

[paraslash.git] / daemon.c

diff --git a/daemon.c b/daemon.c
index ddfe680cebc63dc1c7af89fde333c665873765eb..a4e2f3193730d456ce9908eb55888cdb759154e0 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -31,6 +31,12 @@ struct daemon {
        /** Used for colored log messages. */
        char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
        char *old_cwd;
+       /*
+        * If these pointers are non-NULL, the functions are called from
+        * daemon_log() before and after writing each log message.
+        */
+       void (*pre_log_hook)(void);
+       void (*post_log_hook)(void);
 };
 
 static struct daemon the_daemon, *me = &the_daemon;
@@ -140,6 +146,28 @@ void daemon_set_loglevel(const char *loglevel)
        me->loglevel = ret;
 }
 
+/**
+ * Register functions to be called before and after a message is logged.
+ *
+ * \param pre_log_hook Called before the message is logged.
+ * \param post_log_hook Called after the message is logged.
+ *
+ * The purpose of this function is to provide a primitive for multi-threaded
+ * applications to serialize the access to the log facility, preventing
+ * interleaving log messages. This can be achieved by having the pre-log hook
+ * acquire a lock which blocks the other threads on the attempt to log a
+ * message at the same time.  The post-log hook is responsible for releasing
+ * the lock.
+ *
+ * If these hooks are unnecessary, for example because the application is
+ * single-threaded, this function does not need to be called.
+ */
+void daemon_set_hooks(void (*pre_log_hook)(void), void (*post_log_hook)(void))
+{
+       me->pre_log_hook = pre_log_hook;
+       me->post_log_hook = post_log_hook;
+}
+
 /**
  * Set one of the daemon config flags.
  *
@@ -409,6 +437,8 @@ __printf_2_3 void daemon_log(int ll, const char* fmt,...)
                return;
 
        fp = me->logfile? me->logfile : stderr;
+       if (me->pre_log_hook)
+               me->pre_log_hook();
        color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
        if (color)
                fprintf(fp, "%s", color);
@@ -441,4 +471,6 @@ __printf_2_3 void daemon_log(int ll, const char* fmt,...)
        va_end(argp);
        if (color)
                fprintf(fp, "%s", COLOR_RESET);
+       if (me->post_log_hook)
+               me->post_log_hook();
 }