Addition of scheduler engine and a few applications to use it.

This patch adds a scheduler thread to the core and moves the heartbeat
event to use the new scheduler as an example.

Also The following features are implemented that use this scheduler:

sched_hangup dialplan application:

<action application="sched_hangup" data="+10 normal_clearing bleg"/>

** The cause code is optional and the optional bleg keyword will only hangup the
   channel the current channel is bridged to if the call is in a bridge.

sched_transfer dialplan application:

<action application="sched_transfer" data="+10 1000 XML default"/>

** The last 2 args (dialplan and context) are optional

sched_broadcast dialplan application:

<action application="sched_broadcast" data="+10 playback:/tmp/foo.wav"/>
<action application="sched_broadcast" data="+10 playback!normal_clearing:/tmp/foo.wav"/>

** The optional !<cause_code> can be added to make the channel hangup after broadcasting the file.


sched_hangup api function:

sched_hangup +10 <uuid_string> normal_clearing

** The cause code is optional

sched_transfer api function:

sched_transfer +10 <uuid_string> 1000 XML default

** The last 2 args (dialplan and context) are optional

sched_broadcast api function:

sched_broadcast +10 <uuid_str> playback:/tmp/foo.wav
sched_broadcast +10 <uuid_str> playback!normal_clearing:/tmp/foo.wav

** The optional !<cause_code> can be added to make the channel hangup after broadcasting the file.

The new C functions in the core are documented in the doxeygen.

*NOTE* This commit should satisfy at least 2 bounties on the wiki



git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4785 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch_core.h

@@ -104,17 +104,68 @@ struct switch_core_session;
 struct switch_core_runtime;
 struct switch_core_port_allocator;
 
+struct switch_core_scheduler_task {
+	time_t created;
+	time_t runtime;
+	uint32_t cmd_id;
+	char *group;
+	void *cmd_arg;
+	uint32_t task_id;
+};
+
+
 /*!
   \defgroup core1 Core Library 
   \ingroup FREESWITCH
   \{ 
 */
 
-
 ///\defgroup mb1 Media Bugs
 ///\ingroup core1
 ///\{
 
+
+///\defgroup sched1 Scheduler
+///\ingroup core1
+///\{
+
+
+/*!
+  \brief Schedule a task in the future
+  \param runtime the time in epoch seconds to execute the task.
+  \param func the callback function to execute when the task is executed.
+  \param desc an arbitrary description of the task.
+  \param group a group id tag to link multiple tasks to a single entity.
+  \param cmd_id an arbitrary index number be used in the callback.
+  \param cmd_arg user data to be passed to the callback.
+  \param flags flags to alter behaviour 
+  \return the id of the task
+*/
+SWITCH_DECLARE(uint32_t) switch_core_scheduler_add_task(time_t task_runtime,
+														switch_core_scheduler_func_t func,
+														char *desc,
+														char *group,
+														uint32_t cmd_id,
+														void *cmd_arg,
+														switch_scheduler_flag_t flags);
+
+/*!
+  \brief Delete a scheduled task
+  \param task_id the id of the task
+  \return SWITCH_STATUS_SUCCESS if the task was deleted.
+*/
+SWITCH_DECLARE(switch_status_t) switch_core_scheduler_del_task_id(uint32_t task_id);
+
+/*!
+  \brief Delete a scheduled task based on the group name
+  \param group the group name
+  \return SWITCH_STATUS_SUCCESS if any tasks were deleted
+*/
+SWITCH_DECLARE(switch_status_t) switch_core_scheduler_del_task_group(char *group);
+
+
+///\}
+
 /*!
   \brief Add a media bug to the session
   \param session the session to add the bug to