signal.h: Add documentation of signal_pre_select().

[paraslash.git] / signal.h

diff --git a/signal.h b/signal.h
index 822b73d8be896d2ceab63ed1b63cf089070f9f50..742f677a2568cad3001ae9cc2220344ebf7f8b1b 100644 (file)
--- a/signal.h
+++ b/signal.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -13,14 +13,36 @@ struct signal_task {
        /** The signal pipe. */
        int fd;
        /** The associated task structure. */
-       struct task task;
+       struct task *task;
 };
 
-int para_signal_init(void);
+/**
+ * A generic pre-select method for signal tasks.
+ *
+ * \param s Passed to para_fd_set().
+ * \param context Signal task pointer.
+ *
+ * This convenience helper is called from several programs which need to handle
+ * signals, including para_server and para_audiod. These programs define a
+ * signal task structure and set its ->pre_select method to this function which
+ * adds the file descriptor of the signal task to the set of descriptors to be
+ * watched in the next select() call.
+ *
+ * Although the second parameter must be in fact a pointer to a signal_task
+ * structure, the parameter is specified as void * here to match the
+ * ->pre_select method of struct task.
+ */
+_static_inline_ void signal_pre_select(struct sched *s, void *context)
+{
+       struct signal_task *st = context;
+       para_fd_set(st->fd, &s->rfds, &s->max_fileno);
+}
+
+struct signal_task *signal_init_or_die(void);
 void para_sigaction(int sig, void (*handler)(int));
 void para_install_sighandler(int);
 int para_reap_child(pid_t *pid);
 int para_next_signal(fd_set *rfds);
-void para_signal_shutdown(void);
+void signal_shutdown(struct signal_task *st);
 void para_block_signal(int sig);
 void para_unblock_signal(int sig);