A taskprocessor is an object that has a name, a task queue, and an event processing...
authorDwayne M. Hubbard <dwayne.hubbard@gmail.com>
Sat, 3 May 2008 03:40:32 +0000 (03:40 +0000)
committerDwayne M. Hubbard <dwayne.hubbard@gmail.com>
Sat, 3 May 2008 03:40:32 +0000 (03:40 +0000)
A task wraps a callback function pointer and a data pointer and is managed internal to the taskprocessor subsystem.  The callback function is responsible for releasing task data.

Taskprocessor API
 * ast_taskprocessor_get(..) - returns a reference to a taskprocessor
 * ast_taskprocessor_unreference(..) - releases reference to a taskprocessor
 * ast_taskprocessor_push(..) - push a task into a taskprocessor queue

Check doxygen for more details

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@115268 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/_private.h
include/asterisk/taskprocessor.h [new file with mode: 0644]
main/Makefile
main/asterisk.c
main/taskprocessor.c [new file with mode: 0644]

index 52b7e22..215a561 100644 (file)
@@ -36,6 +36,7 @@ int ast_features_init(void);            /*!< Provided by features.c */
 void ast_autoservice_init(void);       /*!< Provided by autoservice.c */
 int ast_http_init(void);               /*!< Provided by http.c */
 int ast_http_reload(void);             /*!< Provided by http.c */
+int ast_tps_init(void);                /*!< Provided by taskprocessor.c */
 
 /*!
  * \brief Reload asterisk modules.
diff --git a/include/asterisk/taskprocessor.h b/include/asterisk/taskprocessor.h
new file mode 100644 (file)
index 0000000..72d810c
--- /dev/null
@@ -0,0 +1,94 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007-2008, Dwayne M. Hubbard 
+ *
+ * Dwayne M. Hubbard <dhubbard@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+#include "asterisk.h"
+#include "asterisk/lock.h"
+#include "asterisk/linkedlists.h"
+#include "asterisk/utils.h"
+#include "asterisk/options.h"
+
+#ifndef __taskprocessor_h__
+#define __taskprocessor_h__
+
+/*!
+ * \file taskprocessor.h
+ * \brief An API for managing task processing threads that can be shared across modules
+ *
+ * \author Dwayne M. Hubbard <dhubbard@digium.com>
+ *
+ * \note A taskprocessor is a named singleton containing a processing thread and
+ * a task queue that serializes tasks pushed into it by [a] module(s) that reference the taskprocessor.  
+ * A taskprocessor is created the first time its name is requested via the ast_taskprocessor_get()
+ * function and destroyed when the taskprocessor reference count reaches zero.
+ *
+ * Modules that obtain a reference to a taskprocessor can queue tasks into the taskprocessor
+ * to be processed by the singleton processing thread when the task is popped off the front 
+ * of the queue.  A task is a wrapper around a task-handling function pointer and a data
+ * pointer.  It is the responsibility of the task handling function to free memory allocated for
+ * the task data pointer.  A task is pushed into a taskprocessor queue using the 
+ * ast_taskprocessor_push(taskprocessor, taskhandler, taskdata) function and freed by the
+ * taskprocessor after the task handling function returns.  A module releases its reference to a
+ * taskprocessor using the ast_taskprocessor_unreference() function which may result in the
+ * destruction of the taskprocessor if the taskprocessor's reference count reaches zero.  Tasks waiting
+ * to be processed in the taskprocessor queue when the taskprocessor reference count reaches zero
+ * will be purged and released from the taskprocessor queue without being processed.
+ */
+struct ast_taskprocessor;
+
+/*! \brief ast_tps_options for specification of taskprocessor options
+ *
+ * Specify whether a taskprocessor should be created via ast_taskprocessor_get() if the taskprocessor 
+ * does not already exist.  The default behavior is to create a taskprocessor if it does not already exist 
+ * and provide its reference to the calling function.  To only return a reference to a taskprocessor if 
+ * and only if it exists, use the TPS_REF_IF_EXISTS option in ast_taskprocessor_get(). */
+enum ast_tps_options {
+       /*! \brief return a reference to a taskprocessor, create one if it does not exist */
+       TPS_REF_DEFAULT = 0,
+       /*! \brief return a reference to a taskprocessor ONLY if it already exists */
+       TPS_REF_IF_EXISTS = (1 << 0),
+};
+
+/*! \brief Get a reference to a taskprocessor with the specified name and create the taskprocessor if necessary
+ *
+ * The default behavior of instantiating a taskprocessor if one does not already exist can be
+ * disabled by specifying the TPS_REF_IF_EXISTS ast_tps_options as the second argument to ast_taskprocessor_get().
+ * \param name The name of the taskprocessor
+ * \param create Use 0 by default or specify TPS_REF_IF_EXISTS to return NULL if the taskprocessor does 
+ * not already exist
+ * return A pointer to a reference counted taskprocessor under normal conditions, or NULL if the
+ * TPS_REF_IF_EXISTS reference type is specified and the taskprocessor does not exist */
+struct ast_taskprocessor *ast_taskprocessor_get(char *name, enum ast_tps_options create);
+
+/*! \brief Unreference the specified taskprocessor and its reference count will decrement.
+ *
+ * Taskprocessors use astobj2 and will unlink from the taskprocessor singleton container and destroy
+ * themself when the taskprocessor reference count reaches zero.
+ * \param tps taskprocessor to unreference
+ * \return NULL */
+void *ast_taskprocessor_unreference(struct ast_taskprocessor *tps);
+
+/*! \brief Push a task into the specified taskprocessor queue and signal the taskprocessor thread
+ * \param tps The taskprocessor structure
+ * \param task_exe The task handling function to push into the taskprocessor queue
+ * \param datap The data to be used by the task handling function
+ * \return zero on success, -1 on failure */
+int ast_taskprocessor_push(struct ast_taskprocessor *tps, int (*task_exe)(void *datap), void *datap);
+
+/*! \brief Return the name of the taskprocessor singleton */
+const char *ast_taskprocessor_name(struct ast_taskprocessor *tps);
+#endif
+
index 976c37b..51fe901 100644 (file)
@@ -30,7 +30,7 @@ OBJS= tcptls.o io.o sched.o logger.o frame.o loader.o config.o channel.o \
        cryptostub.o sha1.o http.o fixedjitterbuf.o abstract_jb.o \
        strcompat.o threadstorage.o dial.o event.o adsistub.o audiohook.o \
        astobj2.o hashtab.o global_datastores.o $(RESAMPLE_OBJS) version.o \
-       features.o
+       features.o taskprocessor.o
 
 # we need to link in the objects statically, not as a library, because
 # otherwise modules will not have them available if none of the static
index b6ba7d3..05a3230 100644 (file)
@@ -2815,6 +2815,7 @@ int main(int argc, char *argv[])
        ast_builtins_init();
        ast_utils_init();
        tdd_init();
+       ast_tps_init();
 
        if (getenv("HOME")) 
                snprintf(filename, sizeof(filename), "%s/.asterisk_history", getenv("HOME"));
diff --git a/main/taskprocessor.c b/main/taskprocessor.c
new file mode 100644 (file)
index 0000000..cf88bb2
--- /dev/null
@@ -0,0 +1,490 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007-2008, Dwayne M. Hubbard 
+ *
+ * Dwayne M. Hubbard <dhubbard@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+/*! \file
+ *
+ * \brief Maintain a container of uniquely-named taskprocessor threads that can be shared across modules.
+ *
+ * \author Dwayne Hubbard <dhubbard@digium.com>
+ */
+
+#include "asterisk.h"
+#include "asterisk/_private.h"
+#include "asterisk/module.h"
+#include "asterisk/time.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/cli.h"
+#include "asterisk/taskprocessor.h"
+#include "signal.h"
+#include "sys/time.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+/*! \brief tps_task structure is queued to a taskprocessor
+ *
+ * tps_tasks are processed in FIFO order and freed by the taskprocessing
+ * thread after the task handler returns.  The callback function that is assigned
+ * to the execute() function pointer is responsible for releasing datap resources if necessary. */
+struct tps_task {
+       /*! \brief The execute() task callback function pointer */
+       int (*execute)(void *datap);
+       /*! \brief The data pointer for the task execute() function */
+       void *datap;
+       /*! \brief AST_LIST_ENTRY overhead */
+       AST_LIST_ENTRY(tps_task) list;
+};
+
+/*! \brief tps_taskprocessor_stats maintain statistics for a taskprocessor. */
+struct tps_taskprocessor_stats {
+       /*! \brief This is the maximum number of tasks queued at any one time */
+       unsigned long max_qsize;
+       /*! \brief This is the current number of tasks processed */
+       unsigned long _tasks_processed_count;
+};
+
+/*! \brief A ast_taskprocessor structure is a singleton by name */
+struct ast_taskprocessor {
+       /*! \brief Friendly name of the taskprocessor */
+       char *name;
+       /*! \brief Thread poll condition */
+       ast_cond_t poll_cond;
+       /*! \brief Taskprocessor thread */
+       pthread_t poll_thread;
+       /*! \brief Taskprocessor lock */
+       ast_mutex_t taskprocessor_lock;
+       /*! \brief Taskprocesor thread run flag */
+       unsigned char poll_thread_run;
+       /*! \brief Taskprocessor statistics */
+       struct tps_taskprocessor_stats *stats;
+       /*! \brief Taskprocessor current queue size */
+       long queue_size;
+       /*! \brief Taskprocessor queue */
+       AST_LIST_HEAD_NOLOCK(queue, tps_task) queue;
+       /*! \brief Taskprocessor singleton list entry */
+       AST_LIST_ENTRY(ast_taskprocessor) list;
+};
+#define TPS_MAX_BUCKETS 7
+/*! \brief tps_singletons is the astobj2 container for taskprocessor singletons */
+static struct ao2_container *tps_singletons;
+
+/*! \brief CLI 'taskprocessor ping <blah>' operation requires a ping condition */
+static ast_cond_t cli_ping_cond;
+/*! \brief CLI 'taskprocessor ping <blah>' operation requires a ping condition lock */
+static ast_mutex_t cli_ping_cond_lock;
+
+/*! \brief The astobj2 hash callback for taskprocessors */
+static int tps_hash_cb(const void *obj, const int flags);
+/*! \brief The astobj2 compare callback for taskprocessors */
+static int tps_cmp_cb(void *obj, void *arg, int flags);
+
+/*! \brief The task processing function executed by a taskprocessor */
+static void *tps_processing_function(void *data);
+
+/*! \brief Destroy the taskprocessor when its refcount reaches zero */
+static void tps_taskprocessor_destroy(void *tps);
+
+/*! \brief CLI 'taskprocessor ping <blah>' handler function */
+static int tps_ping_handler(void *datap);
+
+/*! \brief Remove the front task off the taskprocessor queue */
+static struct tps_task *tps_taskprocessor_pop(struct ast_taskprocessor *tps);
+
+/*! \brief Return the size of the taskprocessor queue */
+static int tps_taskprocessor_depth(struct ast_taskprocessor *tps);
+
+static char *cli_tps_ping(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
+static char *cli_tps_report(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
+
+static struct ast_cli_entry taskprocessor_clis[] = {
+       AST_CLI_DEFINE(cli_tps_ping, "Ping a named task processors"),
+       AST_CLI_DEFINE(cli_tps_report, "List instantiated task processors and statistics"),
+};
+
+/* initialize the taskprocessor container and register CLI operations */
+int ast_tps_init(void)
+{
+       if (!(tps_singletons = ao2_container_alloc(TPS_MAX_BUCKETS, tps_hash_cb, tps_cmp_cb))) {
+               ast_log(LOG_ERROR, "taskprocessor container failed to initialize!\n");
+               return -1;
+       }
+       ast_cli_register_multiple(taskprocessor_clis, ARRAY_LEN(taskprocessor_clis));
+       return 0;
+}
+
+/* allocate resources for the task */
+static struct tps_task *tps_task_alloc(int (*task_exe)(void *datap), void *datap)
+{
+       struct tps_task *t;
+       if ((t = ast_calloc(1, sizeof(*t)))) {
+               t->execute = task_exe;
+               t->datap = datap;
+       }
+       return t;
+}
+
+/* release task resources */   
+static void *tps_task_free(struct tps_task *task)
+{
+       if (task) {
+               ast_free(task);
+       }
+       return NULL;
+}
+
+/* taskprocessor tab completion */
+static char *tps_taskprocessor_tab_complete(struct ast_taskprocessor *p, struct ast_cli_args *a) 
+{
+       int tklen;
+       int wordnum = 0;
+       char *name = NULL;
+       struct ao2_iterator i;
+
+       if (a->pos != 2)
+               return NULL;
+
+       tklen = strlen(a->word);
+       i = ao2_iterator_init(tps_singletons, 0);
+       while ((p = ao2_iterator_next(&i))) {
+               if (!strncasecmp(a->word, p->name, tklen) && ++wordnum > a->n) {
+                       name = ast_strdup(p->name);
+                       ao2_ref(p, -1);
+                       break;
+               }
+               ao2_ref(p, -1);
+       }
+       return name;
+}
+
+/* ping task handling function */
+static int tps_ping_handler(void *datap)
+{
+       ast_mutex_lock(&cli_ping_cond_lock);
+       ast_cond_signal(&cli_ping_cond);
+       ast_mutex_unlock(&cli_ping_cond_lock);
+       return 0;
+}
+
+/* ping the specified taskprocessor and display the ping time on the CLI */
+static char *cli_tps_ping(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+       struct timeval begin, end, delta;
+       char *name;
+       struct timeval tv;
+       struct timespec ts;
+       struct ast_taskprocessor *tps = NULL;
+
+       switch (cmd) {
+       case CLI_INIT:
+               e->command = "taskprocessor ping";
+               e->usage = 
+                       "Usage: taskprocessor ping <taskprocessor>\n"
+                       "       Displays the time required for a processor to deliver a task\n";
+               return NULL;
+       case CLI_GENERATE:
+               return tps_taskprocessor_tab_complete(tps, a);
+       }
+
+       if (a->argc != 3)
+               return CLI_SHOWUSAGE;
+
+       name = a->argv[2];
+       if (!(tps = ast_taskprocessor_get(name, TPS_REF_IF_EXISTS))) {
+               ast_cli(a->fd, "\nping failed: %s not found\n\n", name);
+               return CLI_SUCCESS;
+       }
+       ast_cli(a->fd, "\npinging %s ...", name);
+       tv = ast_tvadd((begin = ast_tvnow()), ast_samp2tv(1000, 1000));
+       ts.tv_sec = tv.tv_sec;
+       ts.tv_nsec = tv.tv_usec * 1000;
+       ast_mutex_lock(&cli_ping_cond_lock);
+       if (ast_taskprocessor_push(tps, tps_ping_handler, 0) < 0) {
+               ast_cli(a->fd, "\nping failed: could not push task to %s\n\n", name);
+               ao2_ref(tps, -1);
+               return CLI_FAILURE;
+       }
+       ast_cond_timedwait(&cli_ping_cond, &cli_ping_cond_lock, &ts);
+       ast_mutex_unlock(&cli_ping_cond_lock);
+       end = ast_tvnow();
+       delta = ast_tvsub(end, begin);
+       ast_cli(a->fd, "\n\t%24s ping time: %.1ld.%.6ld sec\n\n", name, delta.tv_sec, (long int)delta.tv_usec);
+       ao2_ref(tps, -1);
+       return CLI_SUCCESS;     
+}
+
+/* TPS reports are cool */
+static char *cli_tps_report(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+       char name[256];
+       int tcount;
+       unsigned long qsize;
+       unsigned long maxqsize;
+       unsigned long processed;
+       struct ast_taskprocessor *p;
+       struct ao2_iterator i;
+
+       switch (cmd) {
+       case CLI_INIT:
+               e->command = "taskprocessor show stats";
+               e->usage = 
+                       "Usage: taskprocessor show stats\n"
+                       "       Shows a list of instantiated task processors and their statistics\n";
+               return NULL;
+       case CLI_GENERATE:
+               return NULL;    
+       }
+
+       if (a->argc != e->args)
+               return CLI_SHOWUSAGE;
+
+       ast_cli(a->fd, "\n\t+----- Processor -----+--- Processed ---+- In Queue -+- Max Depth -+");
+       i = ao2_iterator_init(tps_singletons, 0);
+       while ((p = ao2_iterator_next(&i))) {
+               ast_copy_string(name, p->name, sizeof(name));
+               qsize = p->queue_size;
+               maxqsize = p->stats->max_qsize;
+               processed = p->stats->_tasks_processed_count;
+               ast_cli(a->fd, "\n%24s   %17ld %12ld %12ld", name, processed, qsize, maxqsize);
+               ao2_ref(p, -1);
+       }
+       tcount = ao2_container_count(tps_singletons); 
+       ast_cli(a->fd, "\n\t+---------------------+-----------------+------------+-------------+\n\t%d taskprocessors\n\n", tcount);
+       return CLI_SUCCESS;     
+}
+
+/* this is the task processing worker function */
+static void *tps_processing_function(void *data)
+{
+       struct ast_taskprocessor *i = data;
+       struct tps_task *t;
+       int size;
+
+       if (!i) {
+               ast_log(LOG_ERROR, "cannot start thread_function loop without a ast_taskprocessor structure.\n");
+               return NULL;
+       }
+
+       while (i->poll_thread_run) {
+               ast_mutex_lock(&i->taskprocessor_lock);
+               if (!i->poll_thread_run) {
+                       ast_mutex_unlock(&i->taskprocessor_lock);
+                       break;
+               }
+               if (!(size = tps_taskprocessor_depth(i))) {
+                       ast_cond_wait(&i->poll_cond, &i->taskprocessor_lock);
+                       if (!i->poll_thread_run) {
+                               ast_mutex_unlock(&i->taskprocessor_lock);
+                               break;
+                       }
+               }
+               ast_mutex_unlock(&i->taskprocessor_lock);
+               /* stuff is in the queue */
+               if (!(t = tps_taskprocessor_pop(i))) {
+                       ast_log(LOG_ERROR, "Wtf?? %d tasks in the queue, but we're popping blanks!\n", size);
+                       continue;
+               }
+               if (!t->execute) {
+                       ast_log(LOG_WARNING, "Task is missing a function to execute!\n");
+                       tps_task_free(t);
+                       continue;
+               }
+               t->execute(t->datap);
+               ast_mutex_lock(&i->taskprocessor_lock);
+               if (i->stats) {
+                       i->stats->_tasks_processed_count++;
+                       if (size > i->stats->max_qsize) {
+                               i->stats->max_qsize = size;
+                       }
+               }
+               ast_mutex_unlock(&i->taskprocessor_lock);
+               tps_task_free(t);
+       }
+       while ((t = tps_taskprocessor_pop(i))) {
+               tps_task_free(t);
+       }
+       return NULL;
+}
+
+/* hash callback for astobj2 */
+static int tps_hash_cb(const void *obj, const int flags)
+{
+       const struct ast_taskprocessor *tps = obj;
+
+       return ast_str_hash(tps->name);
+}
+
+/* compare callback for astobj2 */
+static int tps_cmp_cb(void *obj, void *arg, int flags)
+{
+       struct ast_taskprocessor *lhs = obj, *rhs = arg;
+
+       return !strcasecmp(lhs->name, rhs->name) ? CMP_MATCH : 0;
+}
+
+/* destroy the taskprocessor */
+static void tps_taskprocessor_destroy(void *tps)
+{
+       struct ast_taskprocessor *t = tps;
+       
+       if (!tps) {
+               ast_log(LOG_ERROR, "missing taskprocessor\n");
+               return;
+       }
+       ast_log(LOG_DEBUG, "destroying taskprocessor '%s'\n", t->name);
+       /* kill it */   
+       ast_mutex_lock(&t->taskprocessor_lock);
+       t->poll_thread_run = 0;
+       ast_cond_signal(&t->poll_cond);
+       ast_mutex_unlock(&t->taskprocessor_lock);
+       pthread_join(t->poll_thread, NULL);
+       t->poll_thread = AST_PTHREADT_NULL;
+       /* free it */
+       if (t->stats) {
+               ast_free(t->stats);
+               t->stats = NULL;
+       }
+       ast_free(t->name);
+}
+
+/* pop the front task and return it */
+static struct tps_task *tps_taskprocessor_pop(struct ast_taskprocessor *tps)
+{
+       struct tps_task *task;
+
+       if (!tps) {
+               ast_log(LOG_ERROR, "missing taskprocessor\n");
+               return NULL;
+       }
+       ast_mutex_lock(&tps->taskprocessor_lock);
+       if ((task = AST_LIST_REMOVE_HEAD(&tps->queue, list))) {
+               tps->queue_size--;
+       }
+       ast_mutex_unlock(&tps->taskprocessor_lock);
+       return task;
+}
+
+static int tps_taskprocessor_depth(struct ast_taskprocessor *tps)
+{
+       return (tps) ? tps->queue_size : -1;
+}
+
+/* taskprocessor name accessor */
+const char *ast_taskprocessor_name(struct ast_taskprocessor *tps)
+{
+       if (!tps) {
+               ast_log(LOG_ERROR, "no taskprocessor specified!\n");
+               return NULL;
+       }
+       return tps->name;
+}
+
+/* Provide a reference to a taskprocessor.  Create the taskprocessor if necessary, but don't
+ * create the taskprocessor if we were told via ast_tps_options to return a reference only 
+ * if it already exists */
+struct ast_taskprocessor *ast_taskprocessor_get(char *name, enum ast_tps_options create)
+{
+       struct ast_taskprocessor *p, tmp_tps = {
+               .name = name,
+       };
+               
+       if (ast_strlen_zero(name)) {
+               ast_log(LOG_ERROR, "requesting a nameless taskprocessor!!!\n");
+               return NULL;
+       }
+       ao2_lock(tps_singletons);
+       p = ao2_find(tps_singletons, &tmp_tps, OBJ_POINTER);
+       if (p) {
+               ao2_unlock(tps_singletons);
+               return p;
+       }
+       if (create & TPS_REF_IF_EXISTS) {
+               /* calling function does not want a new taskprocessor to be created if it doesn't already exist */
+               ao2_unlock(tps_singletons);
+               return NULL;
+       }
+       /* create a new taskprocessor */
+       if (!(p = ao2_alloc(sizeof(*p), tps_taskprocessor_destroy))) {
+               ao2_unlock(tps_singletons);
+               ast_log(LOG_WARNING, "failed to create taskprocessor '%s'\n", name);
+               return NULL;
+       }
+       if (!(p->stats = ast_calloc(1, sizeof(*p->stats)))) {
+               ao2_unlock(tps_singletons);
+               ast_log(LOG_WARNING, "failed to create taskprocessor stats for '%s'\n", name);
+               ao2_ref(p, -1);
+               return NULL;
+       }
+       if (!(p->name = ast_strdup(name))) {
+               ao2_unlock(tps_singletons);
+               ao2_ref(p, -1);
+               return NULL;
+       }
+       p->poll_thread_run = 1;
+       ast_cond_init(&p->poll_cond, NULL);
+       p->poll_thread = AST_PTHREADT_NULL;
+       if (ast_pthread_create(&p->poll_thread, NULL, tps_processing_function, p) < 0) {
+               ao2_unlock(tps_singletons);
+               ast_log(LOG_ERROR, "Taskprocessor '%s' failed to create the processing thread.\n", p->name);
+               ao2_ref(p, -1);
+               return NULL;
+       }
+       if (!(ao2_link(tps_singletons, p))) {
+               ao2_unlock(tps_singletons);
+               ast_log(LOG_ERROR, "Failed to add taskprocessor '%s' to container\n", p->name);
+               ao2_ref(p, -1);
+               return NULL;
+       }
+       ao2_unlock(tps_singletons);
+       return p;
+}
+
+/* decrement the taskprocessor reference count and unlink from the container if necessary */
+void *ast_taskprocessor_unreference(struct ast_taskprocessor *tps)
+{
+       if (tps) {
+               ao2_lock(tps_singletons);
+               ao2_unlink(tps_singletons, tps);
+               if (ao2_ref(tps, -1) > 1) {
+                       ao2_link(tps_singletons, tps);
+               }
+               ao2_unlock(tps_singletons);
+       }
+       return NULL;
+}
+
+/* push the task into the taskprocessor queue */       
+int ast_taskprocessor_push(struct ast_taskprocessor *tps, int (*task_exe)(void *datap), void *datap)
+{
+       struct tps_task *t;
+
+       if (!tps || !task_exe) {
+               ast_log(LOG_ERROR, "%s is missing!!\n", (tps) ? "task callback" : "taskprocessor");
+               return -1;
+       }
+       if (!(t = tps_task_alloc(task_exe, datap))) {
+               ast_log(LOG_ERROR, "failed to allocate task!  Can't push to '%s'\n", tps->name);
+               return -1;
+       }
+       ast_mutex_lock(&tps->taskprocessor_lock);
+       AST_LIST_INSERT_TAIL(&tps->queue, t, list);
+       tps->queue_size++;
+       ast_cond_signal(&tps->poll_cond);
+       ast_mutex_unlock(&tps->taskprocessor_lock);
+       return 0;
+}
+