pjproject: Add cache_pools debugging option.

The pool cache gets in the way of finding use after free errors of memory
pool contents.  Tools like valgrind and MALLOC_DEBUG don't know when a
pool is released because it gets put into the cache instead of being
freed.

* Added the "cache_pools" option to pjproject.conf.  Disabling the option
helps track down pool content mismanagement when using valgrind or
MALLOC_DEBUG.  The cache gets in the way of determining if the pool
contents are used after free and who freed it.

To disable the pool caching simply disable the cache_pools option in
pjproject.conf and restart Asterisk.

Sample pjproject.conf setting:
[startup]
cache_pools=no

* Made current users of the caching pool factory initialization and
destruction calls call common routines to create and destroy cached pools.

ASTERISK-27704

Change-Id: I64d5befbaeed2532f93aa027a51eb52347d2b828

include/asterisk/options.h

@@ -173,6 +173,11 @@ enum ast_option_flags {
 /*! Current linked pjproject maximum logging level */
 extern int ast_pjproject_max_log_level;
 
+#define DEFAULT_PJPROJECT_CACHE_POOLS	1
+
+/*! Current pjproject pool caching enable */
+extern int ast_option_pjproject_cache_pools;
+
 /*! Current pjproject logging level */
 extern int ast_option_pjproject_log_level;
 

include/asterisk/res_pjproject.h

@@ -19,6 +19,9 @@
 #ifndef _RES_PJPROJECT_H
 #define _RES_PJPROJECT_H
 
+#include <pj/types.h>
+#include <pj/pool.h>
+
 /*! \brief Determines whether the res_pjproject module is loaded */
 #define CHECK_PJPROJECT_MODULE_LOADED()                 \
 	do {                                                \
@@ -93,4 +96,27 @@ void ast_pjproject_ref(void);
  */
 void ast_pjproject_unref(void);
 
+/*!
+ * \brief Initialize the caching pool factory.
+ * \since 13.21.0
+ *
+ * \param cp Caching pool factory to initialize
+ * \param policy Pool factory policy
+ * \param max_capacity Total capacity to be retained in the cache.  Zero disables caching.
+ *
+ * \return Nothing
+ */
+void ast_pjproject_caching_pool_init(pj_caching_pool *cp,
+	const pj_pool_factory_policy *policy, pj_size_t max_capacity);
+
+/*!
+ * \brief Destroy caching pool factory and all cached pools.
+ * \since 13.21.0
+ *
+ * \param cp Caching pool factory to destroy
+ *
+ * \return Nothing
+ */
+void ast_pjproject_caching_pool_destroy(pj_caching_pool *cp);
+
 #endif /* _RES_PJPROJECT_H */