(closes issue #6002)

Reported by: rizzo
Tested by: murf

Proposal of the changes to be made, and then an announcement of how they were accomplished:

http://lists.digium.com/pipermail/asterisk-dev/2008-February/032065.html

and:

http://lists.digium.com/pipermail/asterisk-dev/2008-March/032124.html

Here is a recap, file by file, of what I have done:

pbx/pbx_config.c
pbx/pbx_ael.c

All funcs that were passed a ptr to the context list, now will ALSO be passed a hashtab ptr to the same set.
Why? because (for the time being), the dialplan is stored in both, to facilitate a quick, low-cost move to
hash-tables to speed up dialplan processing. If it was deemed necessary to pass the context LIST, well, it
is just as necessary to have the TABLE available. This is because the list/table in question might not be
the global one, but temporary ones we would use to stage the dialplan on, and then swap into the global
position when things are ready.

We now have one external function for apps to use, "ast_context_find_or_create()" instead of the pre-existing
"find" and "create", as all existing usages used both in tandem anyway.

pbx_config, and pbx_ael, will stage the reloaded dialplan into local lists and tables, and 
then call merge_contexts_and_delete, which will merge (now) existing contexts and 
priorities from other registrars into this local set by copying them. Then, merge_contexts_and_delete will
lock down the contexts, swap the lists and tables, and unlock (real quick), and then 
destroy the old dialplan.



chan_sip.c
chan_iax.c
chan_skinny.c

All the channel drivers that would add regcontexts now use the ast_context_find_or_create now.

chan_sip also includes a small fix to get rid of warnings about removing priorities that never got entered.


apps/app_meetme.c
apps/app_dial.c
apps/app_queue.c

All the apps that added a context/exten/priority were also modified to use ast_context_find_or_create instead.


include/asterisk/pbx.h

ast_context_create() is removed. Find_or_create_ is the new method.
ast_context_find_or_create()  interface gets the hashtab added.
ast_merge_contexts_and_delete() gets the local hashtab arg added.
ast_wrlock_contexts_version() is added so you can detect if someone else got a writelock between your readlocking and writelocking.
ast_hashtab_compare_contexts was made public for use in pbx_config/pbx_ael
ast_hashtab_hash_contexts was in like fashion make public.


include/asterisk/pval.h

ast_compile_ael2() interface changed to include the local hashtab table ptr.


main/features.c

For the sake of the parking context, we use ast_context_find_or_create().



main/pbx.c

I changed all the "tree" names to "table" instead. That's because the original
implementation was based on binary trees. (had a free library). Then I moved
to hashtabs. Now, the names move forward too.

refcount field added to contexts, so you can keep track of how many modules
wanted this context to exist.

Some log messages that are warnings were inflated from LOG_NOTICE to LOG_WARNING.

Added some calls to ast_verb(3,...) for debug messages

Lots of little mods to ast_context_remove_extension2, which is now excersized in ways
it was not previously; one definite bug fixed.

find_or_create was upgraded to handle both local lists/tables as well as the globals.

context_merge() was added to do the per-context merging of the old/present contexts/extens/prios into the new/proposed local list/tables

ast_merge_contexts_and_delete() was heavily modified.

ast_add_extension2() was also upgraded to handle changes. 

the context_destroy() code was re-engineered to handle the new way of doing things,
by exten/prio instead of by context.



res/ael/pval.c
res/ael/ael.tab.c
res/ael/ael.tab.h
res/ael/ael.y
res/ael/ael_lex.c
res/ael/ael.flex
utils/ael_main.c
utils/extconf.c
utils/conf2ael.c
utils/Makefile

Had to change the interface to ast_compile_ael2(), to include the hashtab ptr.
This ended up involving several external apps.  The main gotcha was I had to 
include lock.h and hashtab.h in several places.


As a side note, I tested this stuff pretty thoroughly, I replicated the problems
originally reported by Luigi, and made triply sure that reloads worked, and everything
worked thru "stop gracefully". I found a and fixed a few bugs as I was merging into
trunk, that did not appear in my tests of bug6002.

How's this for verbose commit messages?




git-svn-id: http://svn.digium.com/svn/asterisk/trunk@106757 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 20 insertions, 18 deletions

diff --git a/include/asterisk/pbx.h b/include/asterisk/pbx.h
index 1ba9b0d70..14e7af4b2 100644
--- a/include/asterisk/pbx.h
+++ b/include/asterisk/pbx.h
@@ -25,6 +25,7 @@
 
 #include "asterisk/sched.h"
 #include "asterisk/chanvars.h"
+#include "asterisk/hashtab.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
@@ -167,45 +168,36 @@ struct ast_app *pbx_findapp(const char *app);
 int pbx_exec(struct ast_channel *c, struct ast_app *app, void *data);
 
 /*!
- * \brief Register a new context
- *
- * \param extcontexts pointer to the ast_context structure pointer
- * \param name name of the new context
- * \param registrar registrar of the context
- *
- * This will first search for a context with your name.  If it exists already, it will not
- * create a new one.  If it does not exist, it will create a new one with the given name
- * and registrar.
- *
- * \return NULL on failure, and an ast_context structure on success
- */
-struct ast_context *ast_context_create(struct ast_context **extcontexts, const char *name, const char *registrar);
-
-/*!
  * \brief Register a new context or find an existing one
  *
  * \param extcontexts pointer to the ast_context structure pointer
+ * \param exttable pointer to the hashtable that contains all the elements in extcontexts
  * \param name name of the new context
  * \param registrar registrar of the context
  *
+ * This function allows you to play in two environments: the global contexts (active dialplan)
+ * or an external context set of your choosing. To act on the external set, make sure extcontexts
+ * and exttable are set; for the globals, make sure both extcontexts and exttable are NULL.
+ *
  * This will first search for a context with your name.  If it exists already, it will not
  * create a new one.  If it does not exist, it will create a new one with the given name
  * and registrar.
  *
  * \return NULL on failure, and an ast_context structure on success
  */
-struct ast_context *ast_context_find_or_create(struct ast_context **extcontexts, const char *name, const char *registrar);
+struct ast_context *ast_context_find_or_create(struct ast_context **extcontexts, struct ast_hashtab *exttable, const char *name, const char *registrar);
 
 /*!
  * \brief Merge the temporary contexts into a global contexts list and delete from the 
  *        global list the ones that are being added
  *
- * \param extcontexts pointer to the ast_context structure pointer
+ * \param extcontexts pointer to the ast_context structure
+ * \param exttable pointer to the ast_hashtab structure that contains all the elements in extcontexts
  * \param registrar of the context; if it's set the routine will delete all contexts 
  *        that belong to that registrar; if NULL only the contexts that are specified 
  *        in extcontexts
  */
-void ast_merge_contexts_and_delete(struct ast_context **extcontexts, const char *registrar);
+void ast_merge_contexts_and_delete(struct ast_context **extcontexts, struct ast_hashtab *exttable, const char *registrar);
 
 /*!
  * \brief Destroy a context (matches the specified context (or ANY context if NULL)
@@ -973,8 +965,18 @@ struct ast_exten *pbx_find_extension(struct ast_channel *chan,
 									 struct ast_context *bypass, struct pbx_find_info *q,
 									 const char *context, const char *exten, int priority,
 									 const char *label, const char *callerid, enum ext_match_t action);
+
+
+/* every time a write lock is obtained for contexts,
+   a counter is incremented. You can check this via the
+   following func */
+
+int ast_wrlock_contexts_version(void);
 	
 
+/* hashtable functions for contexts */
+int ast_hashtab_compare_contexts(const void *ah_a, const void *ah_b);
+unsigned int ast_hashtab_hash_contexts(const void *obj);
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }