[MEDIUM] signals: add support for registering functions and tasks

The two new functions below make it possible to register any number
of functions or tasks to a system signal. They will be called in the
registration order when the signal is received.

    struct sig_handler *signal_register_fct(int sig, void (*fct)(struct sig_handler *), int arg);
    struct sig_handler *signal_register_task(int sig, struct task *task, int reason);
diff --git a/include/proto/signal.h b/include/proto/signal.h
index 2734827..5b5a64a 100644
--- a/include/proto/signal.h
+++ b/include/proto/signal.h
@@ -1,7 +1,8 @@
 /*
+ * include/proto/signal.h
  * Asynchronous signal delivery functions.
  *
- * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -16,14 +17,25 @@
 
 extern int signal_queue_len;
 extern struct signal_descriptor signal_state[];
+extern struct pool_head *pool2_sig_handlers;
 
-void signal_init();
-void signal_handler(int sig);
-void signal_register(int sig, void (*handler)(int));
 void __signal_process_queue();
+int signal_init();
+void deinit_signals();
+struct sig_handler *signal_register_fct(int sig, void (*fct)(struct sig_handler *), int arg);
+struct sig_handler *signal_register_task(int sig, struct task *task, int reason);
+void signal_unregister_handler(struct sig_handler *handler);
+void signal_unregister_target(int sig, void *target);
 
 static inline void signal_process_queue()
 {
 	if (unlikely(signal_queue_len > 0))
 		__signal_process_queue();
 }
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/include/proto/task.h b/include/proto/task.h
index 0cfe28f..2c02ca6 100644
--- a/include/proto/task.h
+++ b/include/proto/task.h
@@ -1,23 +1,23 @@
 /*
-  include/proto/task.h
-  Functions for task management.
-
-  Copyright (C) 2000-2009 Willy Tarreau - w@1wt.eu
-  
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-*/
+ * include/proto/task.h
+ * Functions for task management.
+ *
+ * Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 
 #ifndef _PROTO_TASK_H
 #define _PROTO_TASK_H
diff --git a/include/types/signal.h b/include/types/signal.h
index b863d23..598001e 100644
--- a/include/types/signal.h
+++ b/include/types/signal.h
@@ -1,7 +1,8 @@
 /*
+ * include/types/signal.h
  * Asynchronous signal delivery functions descriptors.
  *
- * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -10,11 +11,39 @@
  *
  */
 
+#ifndef _TYPES_SIGNAL_H
+#define _TYPES_SIGNAL_H
+
+
 #include <signal.h>
 #include <common/config.h>
+#include <common/mini-clist.h>
 #include <common/standard.h>
 
+/* flags for -> flags */
+#define SIG_F_ONE_SHOOT         0x0001  /* unregister handler before calling it */
+#define SIG_F_TYPE_FCT          0x0002  /* handler is a function + arg */
+#define SIG_F_TYPE_TASK         0x0004  /* handler is a task + reason */
+
+/* those are highly dynamic and stored in pools */
+struct sig_handler {
+	struct list list;
+	void *handler;                  /* function to call or task to wake up */
+	int arg;                        /* arg to pass to function, or signals*/
+	int flags;                      /* SIG_F_* */
+};
+
+/* one per signal */
 struct signal_descriptor {
-	int count;  /* number of times raised */
-	void (*handler)(int sig);
+	int count;                      /* number of times raised */
+	struct list handlers;           /* sig_handler */
 };
+
+#endif /* _TYPES_SIGNAL_H */
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/include/types/task.h b/include/types/task.h
index 41f889c..405404b 100644
--- a/include/types/task.h
+++ b/include/types/task.h
@@ -1,23 +1,23 @@
 /*
-  include/types/task.h
-  Macros, variables and structures for task management.
-
-  Copyright (C) 2000-2009 Willy Tarreau - w@1wt.eu
-  
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-*/
+ * include/types/task.h
+ * Macros, variables and structures for task management.
+ *
+ * Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 
 #ifndef _TYPES_TASK_H
 #define _TYPES_TASK_H
@@ -44,6 +44,12 @@
                            TASK_WOKEN_IO|TASK_WOKEN_SIGNAL|TASK_WOKEN_MSG| \
                            TASK_WOKEN_RES)
 
+/* Additional wakeup info may be passed in the state by lef-shifting the value
+ * by this number of bits. Not more than 8 bits are guaranteed to be delivered.
+ * System signals may use that too.
+ */
+#define TASK_REASON_SHIFT 8
+
 /* The base for all tasks */
 struct task {
 	struct eb32_node wq;		/* ebtree node used to hold the task in the wait queue */