[SR-Dev] git:master: timers: helpers for forking separate timer procs
Andrei Pelinescu-Onciul
andrei at iptel.org
Tue Mar 10 22:48:23 CET 2009
Module: sip-router
Branch: master
Commit: 45df9f7e49450e27507977fa71a67dd98d381d9e
URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=45df9f7e49450e27507977fa71a67dd98d381d9e
Author: Andrei Pelinescu-Onciul <andrei at iptel.org>
Committer: Andrei Pelinescu-Onciul <andrei at iptel.org>
Date: Tue Mar 10 22:35:33 2009 +0100
timers: helpers for forking separate timer procs
Helper functions for forking simple separate timer processes:
fork_dummy_timer(...) - forks a process that will just sleep()
for the required interval and then will call the provided
timer function, all that in a loop.
Care must be taken to use it only when fork_process() is
allowed (e.g.: module child_init function, when
rank==PROC_MAIN; see doc/modules_init.txt for more details)
It can be used to replace kamailio register_timer_process()
(but note that it's not a "drop-in" replacement).
fork_local_timer_process() - forks a process, initializes a
local_timer for it, and returns the local_timer handler both
to the parent and to the child process, so both of them can
add/del timers (if appropriate locking is used).
Example usage:
struct local_timer* lt_h;
pid=fork_local_timer_process(...., <_h);
if (pid==0){
timer_init(&my_timer1, my_timer_f1, 0, 0);
...
local_timer_add(<_h, &my_timer, S_TO_TICKS(10), get_ticks_raw());
...
while(1) { sleep(1); local_timer_run(lt, get_ticks_raw()); }
}
(note that instead of sleep()-ing the process can do some useful work,
like polling some fds a.s.o.)
---
timer_proc.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
timer_proc.h | 43 +++++++++++++++++++++
2 files changed, 159 insertions(+), 0 deletions(-)
diff --git a/timer_proc.c b/timer_proc.c
new file mode 100644
index 0000000..7d0abb7
--- /dev/null
+++ b/timer_proc.c
@@ -0,0 +1,116 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2009 iptelorg GmbH
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * timer_proc.c - separate process timers
+ * (unrelated to the main fast and slow timers)
+ */
+/*
+ * History:
+ * --------
+ * 2009-03-10 initial version (andrei)
+*/
+
+#include "timer_proc.h"
+#include "pt.h"
+#include "mem/shm_mem.h"
+
+#include <unistd.h>
+
+
+/** forks a separate simple sleep() periodic timer.
+ * Forks a very basic periodic timer process, that just sleep()s for
+ * the specified interval and then calls the timer function.
+ * The new "dummy timer" process execution start immediately, the sleep()
+ * is called first (so the first call to the timer function will happen
+ * <interval> seconds after the call to fork_dummy_timer)
+ * @param child_id - @see fork_process()
+ * @param desc - @see fork_process()
+ * @param make_sock - @see fork_process()
+ * @param f - timer function/callback
+ * @param param - parameter passed to the timer function
+ * @param interval - interval in seconds.
+ * @return - pid of the new process on success, -1 on error
+ * (doesn't return anything in the child process)
+ */
+int fork_dummy_timer(int child_id, char* desc, int make_sock,
+ timer_function* f, void* param, int interval)
+{
+ int pid;
+
+ pid=fork_process(child_id, desc, make_sock);
+ if (pid<0) return -1;
+ if (pid==0){
+ /* child */
+ for(;;){
+ sleep(interval);
+ f(get_ticks(), param); /* ticks in s for compatibility with old
+ timers */
+ }
+ }
+ /* parent */
+ return pid;
+}
+
+
+
+/** forks a timer process based on the local timer.
+ * Forks a separate timer process running a local_timer.h type of timer
+ * A pointer to the local_timer handle (allocated in shared memory) is
+ * returned in lt_h. It can be used to add/delete more timers at runtime
+ * (via local_timer_add()/local_timer_del() a.s.o).
+ * If timers are added from separate processes, some form of locking must be
+ * used (all the calls to local_timer* must be enclosed by locks if it
+ * cannot be guaranteed that they cannot execute in the same time)
+ * The timer "engine" must be run manually from the child process. For
+ * example a very simple local timer process that just runs a single
+ * periodic timer can be started in the following way:
+ * struct local_timer* lt_h;
+ *
+ * pid=fork_local_timer_process(...., <_h);
+ * if (pid==0){
+ * timer_init(&my_timer, my_timer_f, 0, 0);
+ * local_timer_add(<_h, &my_timer, S_TO_TICKS(10), get_ticks_raw());
+ * while(1) { sleep(1); local_timer_run(lt, get_ticks_raw()); }
+ * }
+ *
+ * @param child_id - @see fork_process()
+ * @param desc - @see fork_process()
+ * @param make_sock - @see fork_process()
+ * @param lt_h - local_timer handler
+ * @return - pid to the parent, 0 to the child, -1 if error.
+ */
+int fork_local_timer_process(int child_id, char* desc, int make_sock,
+ struct local_timer** lt_h)
+{
+ int pid;
+ struct local_timer* lt;
+
+ lt=shm_malloc(sizeof(*lt));
+ if (lt==0) goto error;
+ if (init_local_timer(lt, get_ticks_raw())<0) goto error;
+ pid=fork_process(child_id, desc, make_sock);
+ if (pid<0) goto error;
+ *lt_h=lt;
+ return pid;
+error:
+ if (lt) shm_free(lt);
+ return -1;
+}
+
+
+/* vi: set ts=4 sw=4 tw=79:ai:cindent: */
diff --git a/timer_proc.h b/timer_proc.h
new file mode 100644
index 0000000..e68e146
--- /dev/null
+++ b/timer_proc.h
@@ -0,0 +1,43 @@
+/*
+ * $Id$
+ *
+ * Copyright (C) 2009 iptelorg GmbH
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * timer_proc.h - separate process timers
+ * (unrelated to the main fast and slow timers)
+ */
+/*
+ * History:
+ * --------
+ * 2009-03-10 initial version (andrei)
+*/
+
+#ifndef __timer_proc_h
+#define __timer_proc_h
+
+#include "local_timer.h"
+
+/* forks a separate simple sleep() periodic timer */
+int fork_dummy_timer(int child_id, char* desc, int make_sock,
+ timer_function* f, void* param, int interval);
+
+/* forks a timer process based on the local timer */
+int fork_local_timer_process(int child_id, char* desc, int make_sock,
+ struct local_timer** lt_h);
+
+#endif /*__timer_proc_h*/
+
+/* vi: set ts=4 sw=4 tw=79:ai:cindent: */
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