ODBC transaction support
authorTilghman Lesher <tilghman@meg.abyt.es>
Thu, 19 Feb 2009 00:26:01 +0000 (00:26 +0000)
committerTilghman Lesher <tilghman@meg.abyt.es>
Thu, 19 Feb 2009 00:26:01 +0000 (00:26 +0000)
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@177320 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES
configs/res_odbc.conf.sample
funcs/func_odbc.c
include/asterisk/res_odbc.h
res/res_odbc.c

diff --git a/CHANGES b/CHANGES
index 215ec68..a3a2781 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -94,6 +94,7 @@ Dialplan Functions
    of "core show function AES_ENCRYPT" from the CLI
  * Added AES_DECRYPT. For information on its use, please see the output
    of "core show function AES_DECRYPT" from the CLI
+ * func_odbc now supports database transactions across multiple queries.
 
 Applications
 ------------
index c40b47e..217cd2f 100644 (file)
@@ -47,6 +47,13 @@ username => oscar
 password => thegrouch
 pre-connect => yes
 sanitysql => select count(*) from systables
+; forcecommit => no            ; Default to committing uncommitted transactions?
+; isolation => read_committed  ; Isolation level; supported levels are:
+                               ; read_uncommitted, read_committed, repeatable_read,
+                               ; serializable.  Note that not all databases support
+                               ; all isolation levels (e.g. Postgres only supports
+                               ; repeatable_read and serializable).  See database
+                               ; documentation for further information.
 ;
 ; Many databases have a default of '\' to escape special characters.  MS SQL
 ; Server does not.
index d56a1df..fb733a4 100644 (file)
@@ -2,6 +2,7 @@
  * Asterisk -- An open source telephony toolkit.
  *
  * Copyright (c) 2005, 2006 Tilghman Lesher
+ * Copyright (c) 2008 Digium, Inc.
  *
  * Tilghman Lesher <func_odbc__200508@the-tilghman.com>
  *
@@ -205,6 +206,7 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
        struct acf_odbc_query *query;
        char *t, varname[15];
        int i, dsn, bogus_chan = 0;
+       int transactional = 0;
        AST_DECLARE_APP_ARGS(values,
                AST_APP_ARG(field)[100];
        );
@@ -293,16 +295,32 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
        }
        pbx_builtin_setvar_helper(chan, "VALUE", NULL);
 
+       /*!\note
+        * Okay, this part is confusing.  Transactions belong to a single database
+        * handle.  Therefore, when working with transactions, we CANNOT failover
+        * to multiple DSNs.  We MUST have a single handle all the way through the
+        * transaction, or else we CANNOT enforce atomicity.
+        */
        for (dsn = 0; dsn < 5; dsn++) {
+               if (transactional) {
+                       /* This can only happen second time through or greater. */
+                       ast_log(LOG_WARNING, "Transactions do not work well with multiple DSNs for 'writehandle'\n");
+               }
+
                if (!ast_strlen_zero(query->writehandle[dsn])) {
-                       obj = ast_odbc_request_obj(query->writehandle[dsn], 0);
-                       if (obj)
-                               stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(buf));
+                       if ((obj = ast_odbc_retrieve_transaction_obj(chan, query->writehandle[dsn]))) {
+                               transactional = 1;
+                       } else {
+                               obj = ast_odbc_request_obj(query->writehandle[dsn], 0);
+                               transactional = 0;
+                       }
+                       if (obj && (stmt = ast_odbc_direct_execute(obj, generic_execute, ast_str_buffer(buf)))) {
+                               break;
+                       }
                }
-               if (stmt) {
-                       status = "SUCCESS";
-                       SQLRowCount(stmt, &rows);
-                       break;
+
+               if (obj && !transactional) {
+                       ast_odbc_release_obj(obj);
                }
        }
 
@@ -322,6 +340,9 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
                                break;
                        }
                }
+       } else if (stmt) {
+               status = "SUCCESS";
+               SQLRowCount(stmt, &rows);
        }
 
        AST_RWLIST_UNLOCK(&queries);
@@ -338,7 +359,7 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
                SQLCloseCursor(stmt);
                SQLFreeHandle(SQL_HANDLE_STMT, stmt);
        }
-       if (obj) {
+       if (obj && !transactional) {
                ast_odbc_release_obj(obj);
                obj = NULL;
        }
index 005cf29..ecd2fbb 100644 (file)
 
 typedef enum { ODBC_SUCCESS=0, ODBC_FAIL=-1} odbc_status;
 
+/*! \brief Flags for use with ast_odbc_request_obj2 */
+enum {
+       RES_ODBC_SANITY_CHECK = (1 << 0),
+       RES_ODBC_INDEPENDENT_CONNECTION = (1 << 1),
+};
+
 /*! \brief ODBC container */
 struct odbc_obj {
        ast_mutex_t lock;
-       SQLHDBC  con;                   /* ODBC Connection Handle */
-       struct odbc_class *parent;      /* Information about the connection is protected */
-       struct timeval last_used;
+       SQLHDBC  con;                   /*!< ODBC Connection Handle */
+       struct odbc_class *parent;      /*!< Information about the connection is protected */
+       struct timeval last_used;       /*!< Used by idlecheck to determine if the connection should be renegotiated */
 #ifdef DEBUG_THREADS
        char file[80];
        char function[80];
        int lineno;
 #endif
-       unsigned int used:1;
+       unsigned int used:1;            /*!< Is this connection currently in use? */
        unsigned int up:1;
+       unsigned int tx:1;              /*!< Should this connection be unshared, regardless of the class setting? */
+       struct odbc_txn_frame *txf;     /*!< Reference back to the transaction frame, if applicable */
        AST_LIST_ENTRY(odbc_obj) list;
 };
 
-/*!\brief These aren't used in any API calls, but they are kept in a common
- * location, simply for convenience and to avoid duplication.
- */
 struct odbc_cache_columns {
        char *name;
        SQLSMALLINT type;
@@ -107,12 +112,31 @@ int ast_odbc_smart_execute(struct odbc_obj *obj, SQLHSTMT stmt) __attribute__((d
  * when the thread is done by calling odbc_release_obj(), below.
  */
 #ifdef DEBUG_THREADS
+struct odbc_obj *_ast_odbc_request_obj2(const char *name, struct ast_flags flags, const char *file, const char *function, int lineno);
+#define ast_odbc_request_obj2(a, b)    _ast_odbc_request_obj2(a, b, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#else
+struct odbc_obj *ast_odbc_request_obj2(const char *name, struct ast_flags flags);
+#endif
+
+#ifdef DEBUG_THREADS
 struct odbc_obj *_ast_odbc_request_obj(const char *name, int check, const char *file, const char *function, int lineno);
 #define ast_odbc_request_obj(a, b)     _ast_odbc_request_obj(a, b, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #else
 struct odbc_obj *ast_odbc_request_obj(const char *name, int check);
 #endif
 
+/*!
+ * \brief Retrieve a stored ODBC object, if a transaction has been started.
+ * \param chan Channel associated with the transaction.
+ * \param objname Name of the database handle.  This name corresponds to the name passed
+ * to ast_odbc_request_obj2 (or formerly, to ast_odbc_request_obj).  Note that the
+ * existence of this parameter name explicitly allows for multiple transactions to be open
+ * at once, albeit to different databases.
+ * \retval A stored ODBC object, if a transaction was already started.
+ * \retval NULL, if no transaction yet exists.
+ */
+struct odbc_obj *ast_odbc_retrieve_transaction_obj(struct ast_channel *chan, const char *objname);
+
 /*! 
  * \brief Releases an ODBC object previously allocated by odbc_request_obj()
  * \param obj The ODBC object
index ee5cc30..8abdbc0 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2005, Digium, Inc.
+ * Copyright (C) 1999 - 2008, Digium, Inc.
  *
  * Mark Spencer <markster@digium.com>
  *
@@ -25,6 +25,7 @@
  * 
  * \author Mark Spencer <markster@digium.com>
  * \author Anthony Minessale II <anthmct@yahoo.com>
+ * \author Tilghman Lesher <tilghman@digium.com>
  *
  * \arg See also: \ref cdr_odbc
  */
@@ -48,7 +49,69 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/res_odbc.h"
 #include "asterisk/time.h"
 #include "asterisk/astobj2.h"
+#include "asterisk/app.h"
 #include "asterisk/strings.h"
+#include "asterisk/threadstorage.h"
+
+/*** DOCUMENTATION
+       <function name="ODBC" language="en_US">
+               <synopsis>
+                       Controls ODBC transaction properties.
+               </synopsis>
+               <syntax>
+                       <parameter name="property" required="true">
+                               <enumlist>
+                                       <enum name="transaction">
+                                               <para>Gets or sets the active transaction ID.  If set, and the transaction ID does not
+                                               exist and a <replaceable>database name</replaceable> is specified as an argument, it will be created.</para>
+                                       </enum>
+                                       <enum name="forcecommit">
+                                               <para>Controls whether a transaction will be automatically committed when the channel
+                                               hangs up.  Defaults to false.  If a <replaceable>transaction ID</replaceable> is specified in the optional argument,
+                                               the property will be applied to that ID, otherwise to the current active ID.</para>
+                                       </enum>
+                                       <enum name="isolation">
+                                               <para>Controls the data isolation on uncommitted transactions.  May be one of the
+                                               following: <literal>read_committed</literal>, <literal>read_uncommitted</literal>,
+                                               <literal>repeatable_read</literal>, or <literal>serializable</literal>.  Defaults to the
+                                               database setting in <filename>res_odbc.conf</filename> or <literal>read_committed</literal>
+                                               if not specified.  If a <replaceable>transaction ID</replaceable> is specified as an optional argument, it will be
+                                               applied to that ID, otherwise the current active ID.</para>
+                                       </enum>
+                               </enumlist>
+                       </parameter>
+                       <parameter name="argument" required="false" />
+               </syntax>
+               <description>
+                       <para>The ODBC() function allows setting several properties to influence how a connected
+                       database processes transactions.</para>
+               </description>
+       </function>
+       <application name="ODBC_Commit" language="en_US">
+               <synopsis>
+                       Commits a currently open database transaction.
+               </synopsis>
+               <syntax>
+                       <parameter name="transaction ID" required="no" />
+               </syntax>
+               <description>
+                       <para>Commits the database transaction specified by <replaceable>transaction ID</replaceable>
+                       or the current active transaction, if not specified.</para>
+               </description>
+       </application>
+       <application name="ODBC_Rollback" language="en_US">
+               <synopsis>
+                       Rollback a currently open database transaction.
+               </synopsis>
+               <syntax>
+                       <parameter name="transaction ID" required="no" />
+               </syntax>
+               <description>
+                       <para>Rolls back the database transaction specified by <replaceable>transaction ID</replaceable>
+                       or the current active transaction, if not specified.</para>
+               </description>
+       </application>
+ ***/
 
 struct odbc_class
 {
@@ -59,12 +122,14 @@ struct odbc_class
        char *password;
        char *sanitysql;
        SQLHENV env;
-       unsigned int haspool:1;              /* Boolean - TDS databases need this */
-       unsigned int delme:1;                /* Purge the class */
-       unsigned int backslash_is_escape:1;  /* On this database, the backslash is a native escape sequence */
-       unsigned int limit;                  /* 1023 wasn't enough for some people */
-       unsigned int count;                  /* Running count of pooled connections */
-       unsigned int idlecheck;              /* Recheck the connection if it is idle for this long */
+       unsigned int haspool:1;              /*!< Boolean - TDS databases need this */
+       unsigned int delme:1;                /*!< Purge the class */
+       unsigned int backslash_is_escape:1;  /*!< On this database, the backslash is a native escape sequence */
+       unsigned int forcecommit:1;          /*!< Should uncommitted transactions be auto-committed on handle release? */
+       unsigned int isolation;              /*!< Flags for how the DB should deal with data in other, uncommitted transactions */
+       unsigned int limit;                  /*!< Maximum number of database handles we will allow */
+       int count;                           /*!< Running count of pooled connections */
+       unsigned int idlecheck;              /*!< Recheck the connection if it is idle for this long (in seconds) */
        struct ao2_container *obj_container;
 };
 
@@ -75,6 +140,232 @@ static AST_RWLIST_HEAD_STATIC(odbc_tables, odbc_cache_tables);
 static odbc_status odbc_obj_connect(struct odbc_obj *obj);
 static odbc_status odbc_obj_disconnect(struct odbc_obj *obj);
 static int odbc_register_class(struct odbc_class *class, int connect);
+static void odbc_txn_free(void *data);
+static void odbc_release_obj2(struct odbc_obj *obj, struct odbc_txn_frame *tx);
+
+AST_THREADSTORAGE(errors_buf);
+
+static struct ast_datastore_info txn_info = {
+       .type = "ODBC_Transaction",
+       .destroy = odbc_txn_free,
+};
+
+struct odbc_txn_frame {
+       AST_LIST_ENTRY(odbc_txn_frame) list;
+       struct ast_channel *owner;
+       struct odbc_obj *obj;        /*!< Database handle within which transacted statements are run */
+       /*!\brief Is this record the current active transaction within the channel?
+        * Note that the active flag is really only necessary for statements which
+        * are triggered from the dialplan, as there isn't a direct correlation
+        * between multiple statements.  Applications wishing to use transactions
+        * may simply perform each statement on the same odbc_obj, which keeps the
+        * transaction persistent.
+        */
+       unsigned int active:1;
+       unsigned int forcecommit:1;     /*!< Should uncommitted transactions be auto-committed on handle release? */
+       unsigned int isolation;         /*!< Flags for how the DB should deal with data in other, uncommitted transactions */
+       char name[0];                   /*!< Name of this transaction ID */
+};
+
+static const char *isolation2text(int iso)
+{
+       if (iso == SQL_TXN_READ_COMMITTED) {
+               return "read_committed";
+       } else if (iso == SQL_TXN_READ_UNCOMMITTED) {
+               return "read_uncommitted";
+       } else if (iso == SQL_TXN_SERIALIZABLE) {
+               return "serializable";
+       } else if (iso == SQL_TXN_REPEATABLE_READ) {
+               return "repeatable_read";
+       } else {
+               return "unknown";
+       }
+}
+
+static int text2isolation(const char *txt)
+{
+       if (strncasecmp(txt, "read_", 5) == 0) {
+               if (strncasecmp(txt + 5, "c", 1) == 0) {
+                       return SQL_TXN_READ_COMMITTED;
+               } else if (strncasecmp(txt + 5, "u", 1) == 0) {
+                       return SQL_TXN_READ_UNCOMMITTED;
+               } else {
+                       return 0;
+               }
+       } else if (strncasecmp(txt, "ser", 3) == 0) {
+               return SQL_TXN_SERIALIZABLE;
+       } else if (strncasecmp(txt, "rep", 3) == 0) {
+               return SQL_TXN_REPEATABLE_READ;
+       } else {
+               return 0;
+       }
+}
+
+static struct odbc_txn_frame *find_transaction(struct ast_channel *chan, struct odbc_obj *obj, const char *name, int active)
+{
+       struct ast_datastore *txn_store;
+       AST_LIST_HEAD(, odbc_txn_frame) *oldlist;
+       struct odbc_txn_frame *txn = NULL;
+
+       if (!chan && obj && obj->txf && obj->txf->owner) {
+               chan = obj->txf->owner;
+       } else if (!chan) {
+               /* No channel == no transaction */
+               return NULL;
+       }
+
+       ast_channel_lock(chan);
+       if ((txn_store = ast_channel_datastore_find(chan, &txn_info, NULL))) {
+               oldlist = txn_store->data;
+       } else {
+               /* Need to create a new datastore */
+               if (!(txn_store = ast_datastore_alloc(&txn_info, NULL))) {
+                       ast_log(LOG_ERROR, "Unable to allocate a new datastore.  Cannot create a new transaction.\n");
+                       ast_channel_unlock(chan);
+                       return NULL;
+               }
+
+               if (!(oldlist = ast_calloc(1, sizeof(*oldlist)))) {
+                       ast_log(LOG_ERROR, "Unable to allocate datastore list head.  Cannot create a new transaction.\n");
+                       ast_datastore_free(txn_store);
+                       ast_channel_unlock(chan);
+                       return NULL;
+               }
+
+               txn_store->data = oldlist;
+               AST_LIST_HEAD_INIT(oldlist);
+               ast_channel_datastore_add(chan, txn_store);
+       }
+
+       AST_LIST_LOCK(oldlist);
+       ast_channel_unlock(chan);
+
+       /* Scanning for an object is *fast*.  Scanning for a name is much slower. */
+       if (obj != NULL || active == 1) {
+               AST_LIST_TRAVERSE(oldlist, txn, list) {
+                       if (txn->obj == obj || txn->active) {
+                               AST_LIST_UNLOCK(oldlist);
+                               return txn;
+                       }
+               }
+       }
+
+       if (name != NULL) {
+               AST_LIST_TRAVERSE(oldlist, txn, list) {
+                       if (!strcasecmp(txn->name, name)) {
+                               AST_LIST_UNLOCK(oldlist);
+                               return txn;
+                       }
+               }
+       }
+
+       /* Nothing found, create one */
+       if (name && obj && (txn = ast_calloc(1, sizeof(*txn) + strlen(name) + 1))) {
+               struct odbc_txn_frame *otxn;
+
+               strcpy(txn->name, name); /* SAFE */
+               txn->obj = obj;
+               txn->isolation = obj->parent->isolation;
+               txn->forcecommit = obj->parent->forcecommit;
+               txn->owner = chan;
+               txn->active = 1;
+
+               /* On creation, the txn becomes active, and all others inactive */
+               AST_LIST_TRAVERSE(oldlist, otxn, list) {
+                       otxn->active = 0;
+               }
+               AST_LIST_INSERT_TAIL(oldlist, txn, list);
+
+               obj->txf = txn;
+               obj->tx = 1;
+       }
+       AST_LIST_UNLOCK(oldlist);
+
+       return txn;
+}
+
+static struct odbc_txn_frame *release_transaction(struct odbc_txn_frame *tx)
+{
+       if (!tx) {
+               return NULL;
+       }
+
+       ast_debug(2, "release_transaction(%p) called (tx->obj = %p, tx->obj->txf = %p)\n", tx, tx->obj, tx->obj ? tx->obj->txf : NULL);
+
+       /* If we have an owner, disassociate */
+       if (tx->owner) {
+               struct ast_datastore *txn_store;
+               AST_LIST_HEAD(, odbc_txn_frame) *oldlist;
+
+               ast_channel_lock(tx->owner);
+               if ((txn_store = ast_channel_datastore_find(tx->owner, &txn_info, NULL))) {
+                       oldlist = txn_store->data;
+                       AST_LIST_LOCK(oldlist);
+                       AST_LIST_REMOVE(oldlist, tx, list);
+                       AST_LIST_UNLOCK(oldlist);
+               }
+               ast_channel_unlock(tx->owner);
+               tx->owner = NULL;
+       }
+
+       if (tx->obj) {
+               /* If we have any uncommitted transactions, they are handled when we release the object */
+               struct odbc_obj *obj = tx->obj;
+               /* Prevent recursion during destruction */
+               tx->obj->txf = NULL;
+               tx->obj = NULL;
+               odbc_release_obj2(obj, tx);
+       }
+       ast_free(tx);
+       return NULL;
+}
+
+static void odbc_txn_free(void *vdata)
+{
+       struct odbc_txn_frame *tx;
+       AST_LIST_HEAD(, odbc_txn_frame) *oldlist = vdata;
+
+       ast_debug(2, "odbc_txn_free(%p) called\n", vdata);
+
+       AST_LIST_LOCK(oldlist);
+       while ((tx = AST_LIST_REMOVE_HEAD(oldlist, list))) {
+               release_transaction(tx);
+       }
+       AST_LIST_UNLOCK(oldlist);
+       AST_LIST_HEAD_DESTROY(oldlist);
+       ast_free(oldlist);
+}
+
+static int mark_transaction_active(struct ast_channel *chan, struct odbc_txn_frame *tx)
+{
+       struct ast_datastore *txn_store;
+       AST_LIST_HEAD(, odbc_txn_frame) *oldlist;
+       struct odbc_txn_frame *active = NULL, *txn;
+
+       if (!chan && tx && tx->owner) {
+               chan = tx->owner;
+       }
+
+       ast_channel_lock(chan);
+       if (!(txn_store = ast_channel_datastore_find(chan, &txn_info, NULL))) {
+               ast_channel_unlock(chan);
+               return -1;
+       }
+
+       oldlist = txn_store->data;
+       AST_LIST_LOCK(oldlist);
+       AST_LIST_TRAVERSE(oldlist, txn, list) {
+               if (txn == tx) {
+                       txn->active = 1;
+                       active = txn;
+               } else {
+                       txn->active = 0;
+               }
+       }
+       AST_LIST_UNLOCK(oldlist);
+       ast_channel_unlock(chan);
+       return active ? 0 : -1;
+}
 
 static void odbc_class_destructor(void *data)
 {
@@ -82,12 +373,15 @@ static void odbc_class_destructor(void *data)
        /* Due to refcounts, we can safely assume that any objects with a reference
         * to us will prevent our destruction, so we don't need to worry about them.
         */
-       if (class->username)
+       if (class->username) {
                ast_free(class->username);
-       if (class->password)
+       }
+       if (class->password) {
                ast_free(class->password);
-       if (class->sanitysql)
+       }
+       if (class->sanitysql) {
                ast_free(class->sanitysql);
+       }
        ao2_ref(class->obj_container, -1);
        SQLFreeHandle(SQL_HANDLE_ENV, class->env);
 }
@@ -154,18 +448,18 @@ struct odbc_cache_tables *ast_odbc_find_table(const char *database, const char *
 
        if (!obj) {
                ast_log(LOG_WARNING, "Unable to retrieve database handle for table description '%s@%s'\n", tablename, database);
+               AST_RWLIST_UNLOCK(&odbc_tables);
                return NULL;
        }
 
        /* Table structure not already cached; build it now. */
        do {
-retry:
                res = SQLAllocHandle(SQL_HANDLE_STMT, obj->con, &stmt);
                if ((res != SQL_SUCCESS) && (res != SQL_SUCCESS_WITH_INFO)) {
                        if (try == 0) {
                                try = 1;
                                ast_odbc_sanity_check(obj);
-                               goto retry;
+                               continue;
                        }
                        ast_log(LOG_WARNING, "SQL Alloc Handle failed on connection '%s'!\n", database);
                        break;
@@ -177,7 +471,7 @@ retry:
                                try = 1;
                                SQLFreeHandle(SQL_HANDLE_STMT, stmt);
                                ast_odbc_sanity_check(obj);
-                               goto retry;
+                               continue;
                        }
                        ast_log(LOG_ERROR, "Unable to query database columns on connection '%s'.\n", database);
                        break;
@@ -227,7 +521,8 @@ retry:
 
                AST_RWLIST_INSERT_TAIL(&odbc_tables, tableptr, list);
                AST_RWLIST_RDLOCK(&(tableptr->columns));
-       } while (0);
+               break;
+       } while (1);
 
        AST_RWLIST_UNLOCK(&odbc_tables);
 
@@ -279,6 +574,9 @@ SQLHSTMT ast_odbc_direct_execute(struct odbc_obj *obj, SQLHSTMT (*exec_cb)(struc
 
                if (stmt) {
                        break;
+               } else if (obj->tx) {
+                       ast_log(LOG_WARNING, "Failed to execute, but unable to reconnect, as we're transactional.\n");
+                       break;
                } else {
                        obj->up = 0;
                        ast_log(LOG_WARNING, "SQL Exec Direct failed.  Attempting a reconnect...\n");
@@ -322,22 +620,29 @@ SQLHSTMT ast_odbc_prepare_and_execute(struct odbc_obj *obj, SQLHSTMT (*prepare_c
                                        }
                                }
 
-                               ast_log(LOG_WARNING, "SQL Execute error %d! Attempting a reconnect...\n", res);
-                               SQLFreeHandle(SQL_HANDLE_STMT, stmt);
-                               stmt = NULL;
+                               if (obj->tx) {
+                                       ast_log(LOG_WARNING, "SQL Execute error, but unable to reconnect, as we're transactional.\n");
+                                       break;
+                               } else {
+                                       ast_log(LOG_WARNING, "SQL Execute error %d! Attempting a reconnect...\n", res);
+                                       SQLFreeHandle(SQL_HANDLE_STMT, stmt);
+                                       stmt = NULL;
 
-                               obj->up = 0;
-                               /*
-                                * While this isn't the best way to try to correct an error, this won't automatically
-                                * fail when the statement handle invalidates.
-                                */
-                               ast_odbc_sanity_check(obj);
-                               continue;
-                       } else
+                                       obj->up = 0;
+                                       /*
+                                        * While this isn't the best way to try to correct an error, this won't automatically
+                                        * fail when the statement handle invalidates.
+                                        */
+                                       ast_odbc_sanity_check(obj);
+                                       continue;
+                               }
+                       } else {
                                obj->last_used = ast_tvnow();
+                       }
                        break;
-               } else if (attempt == 0)
+               } else if (attempt == 0) {
                        ast_odbc_sanity_check(obj);
+               }
        }
 
        return stmt;
@@ -413,7 +718,7 @@ int ast_odbc_sanity_check(struct odbc_obj *obj)
                SQLFreeHandle (SQL_HANDLE_STMT, stmt);
        }
 
-       if (!obj->up) { /* Try to reconnect! */
+       if (!obj->up && !obj->tx) { /* Try to reconnect! */
                ast_log(LOG_WARNING, "Connection is down attempting to reconnect...\n");
                odbc_obj_disconnect(obj);
                odbc_obj_connect(obj);
@@ -428,7 +733,7 @@ static int load_odbc_config(void)
        struct ast_variable *v;
        char *cat;
        const char *dsn, *username, *password, *sanitysql;
-       int enabled, pooling, limit, bse;
+       int enabled, pooling, limit, bse, forcecommit, isolation;
        unsigned int idlecheck;
        int preconnect = 0, res = 0;
        struct ast_flags config_flags = { 0 };
@@ -454,6 +759,8 @@ static int load_odbc_config(void)
                        pooling = 0;
                        limit = 0;
                        bse = 1;
+                       forcecommit = 0;
+                       isolation = SQL_TXN_READ_COMMITTED;
                        for (v = ast_variable_browse(config, cat); v; v = v->next) {
                                if (!strcasecmp(v->name, "pooling")) {
                                        if (ast_true(v->value))
@@ -488,6 +795,13 @@ static int load_odbc_config(void)
                                        sanitysql = v->value;
                                } else if (!strcasecmp(v->name, "backslash_is_escape")) {
                                        bse = ast_true(v->value);
+                               } else if (!strcasecmp(v->name, "forcecommit")) {
+                                       forcecommit = ast_true(v->value);
+                               } else if (!strcasecmp(v->name, "isolation")) {
+                                       if ((isolation = text2isolation(v->value)) == 0) {
+                                               ast_log(LOG_ERROR, "Unrecognized value for 'isolation': '%s' in section '%s'\n", v->value, cat);
+                                               isolation = SQL_TXN_READ_COMMITTED;
+                                       }
                                }
                        }
 
@@ -521,6 +835,8 @@ static int load_odbc_config(void)
                                }
 
                                new->backslash_is_escape = bse ? 1 : 0;
+                               new->forcecommit = forcecommit ? 1 : 0;
+                               new->isolation = isolation;
                                new->idlecheck = idlecheck;
 
                                if (cat)
@@ -616,10 +932,11 @@ static char *handle_cli_odbc_show(struct ast_cli_entry *e, int cmd, struct ast_c
                                        ao2_ref(current, -1);
                                }
                        } else {
-                               /* Should only ever be one of these */
+                               /* Should only ever be one of these (unless there are transactions) */
                                struct ao2_iterator aoi2 = ao2_iterator_init(class->obj_container, 0);
                                while ((current = ao2_iterator_next(&aoi2))) {
-                                       ast_cli(a->fd, "  Pooled: No\n  Connected: %s\n", current->up && ast_odbc_sanity_check(current) ? "Yes" : "No");
+                                       ast_cli(a->fd, "  Pooled: No\n  Connected: %s\n", current->used ? "In use" :
+                                               current->up && ast_odbc_sanity_check(current) ? "Yes" : "No");
                                        ao2_ref(current, -1);
                                }
                        }
@@ -645,8 +962,9 @@ static int odbc_register_class(struct odbc_class *class, int preconnect)
                if (preconnect) {
                        /* Request and release builds a connection */
                        obj = ast_odbc_request_obj(class->name, 0);
-                       if (obj)
+                       if (obj) {
                                ast_odbc_release_obj(obj);
+                       }
                }
 
                return 0;
@@ -656,65 +974,204 @@ static int odbc_register_class(struct odbc_class *class, int preconnect)
        }
 }
 
-void ast_odbc_release_obj(struct odbc_obj *obj)
+static void odbc_release_obj2(struct odbc_obj *obj, struct odbc_txn_frame *tx)
 {
-       /* For pooled connections, this frees the connection to be
-        * reused.  For non-pooled connections, it does nothing. */
-       obj->used = 0;
+       SQLINTEGER nativeerror=0, numfields=0;
+       SQLSMALLINT diagbytes=0, i;
+       unsigned char state[10], diagnostic[256];
+
+       ast_debug(2, "odbc_release_obj2(%p) called (obj->txf = %p)\n", obj, obj->txf);
+       if (tx) {
+               ast_debug(1, "called on a transactional handle with %s\n", tx->forcecommit ? "COMMIT" : "ROLLBACK");
+               if (SQLEndTran(SQL_HANDLE_DBC, obj->con, tx->forcecommit ? SQL_COMMIT : SQL_ROLLBACK) == SQL_ERROR) {
+                       /* Handle possible transaction commit failure */
+                       SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_log(LOG_WARNING, "SQLEndTran returned an error: %s: %s\n", state, diagnostic);
+                               if (!strcmp((char *)state, "25S02") || !strcmp((char *)state, "08007")) {
+                                       /* These codes mean that a commit failed and a transaction
+                                        * is still active. We must rollback, or things will get
+                                        * very, very weird for anybody using the handle next. */
+                                       SQLEndTran(SQL_HANDLE_DBC, obj->con, SQL_ROLLBACK);
+                               }
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+               }
+
+               /* Transaction is done, reset autocommit */
+               if (SQLSetConnectAttr(obj->con, SQL_ATTR_AUTOCOMMIT, (void *)SQL_AUTOCOMMIT_ON, 0) == SQL_ERROR) {
+                       SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_log(LOG_WARNING, "SetConnectAttr (Autocommit) returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+               }
+       }
+
 #ifdef DEBUG_THREADS
        obj->file[0] = '\0';
        obj->function[0] = '\0';
        obj->lineno = 0;
 #endif
+
+       /* For pooled connections, this frees the connection to be
+        * reused.  For non-pooled connections, it does nothing. */
+       obj->used = 0;
+       if (obj->txf) {
+               /* Prevent recursion -- transaction is already closed out. */
+               obj->txf->obj = NULL;
+               obj->txf = release_transaction(obj->txf);
+       }
        ao2_ref(obj, -1);
 }
 
+void ast_odbc_release_obj(struct odbc_obj *obj)
+{
+       struct odbc_txn_frame *tx = find_transaction(NULL, obj, NULL, 0);
+       odbc_release_obj2(obj, tx);
+}
+
 int ast_odbc_backslash_is_escape(struct odbc_obj *obj)
 {
        return obj->parent->backslash_is_escape;
 }
 
+static int commit_exec(struct ast_channel *chan, void *data)
+{
+       struct odbc_txn_frame *tx;
+       SQLINTEGER nativeerror=0, numfields=0;
+       SQLSMALLINT diagbytes=0, i;
+       unsigned char state[10], diagnostic[256];
+
+       if (ast_strlen_zero(data)) {
+               tx = find_transaction(chan, NULL, NULL, 1);
+       } else {
+               tx = find_transaction(chan, NULL, data, 0);
+       }
+
+       pbx_builtin_setvar_helper(chan, "COMMIT_RESULT", "OK");
+
+       if (tx) {
+               if (SQLEndTran(SQL_HANDLE_DBC, tx->obj->con, SQL_COMMIT) == SQL_ERROR) {
+                       struct ast_str *errors = ast_str_thread_get(&errors_buf, 16);
+                       ast_str_reset(errors);
+
+                       /* Handle possible transaction commit failure */
+                       SQLGetDiagField(SQL_HANDLE_DBC, tx->obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, tx->obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_str_append(&errors, 0, "%s%s", ast_str_strlen(errors) ? "," : "", state);
+                               ast_log(LOG_WARNING, "SQLEndTran returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+                       pbx_builtin_setvar_helper(chan, "COMMIT_RESULT", ast_str_buffer(errors));
+               }
+       }
+       return 0;
+}
+
+static int rollback_exec(struct ast_channel *chan, void *data)
+{
+       struct odbc_txn_frame *tx;
+       SQLINTEGER nativeerror=0, numfields=0;
+       SQLSMALLINT diagbytes=0, i;
+       unsigned char state[10], diagnostic[256];
+
+       if (ast_strlen_zero(data)) {
+               tx = find_transaction(chan, NULL, NULL, 1);
+       } else {
+               tx = find_transaction(chan, NULL, data, 0);
+       }
+
+       pbx_builtin_setvar_helper(chan, "ROLLBACK_RESULT", "OK");
+
+       if (tx) {
+               if (SQLEndTran(SQL_HANDLE_DBC, tx->obj->con, SQL_ROLLBACK) == SQL_ERROR) {
+                       struct ast_str *errors = ast_str_thread_get(&errors_buf, 16);
+                       ast_str_reset(errors);
+
+                       /* Handle possible transaction commit failure */
+                       SQLGetDiagField(SQL_HANDLE_DBC, tx->obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, tx->obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_str_append(&errors, 0, "%s%s", ast_str_strlen(errors) ? "," : "", state);
+                               ast_log(LOG_WARNING, "SQLEndTran returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+                       pbx_builtin_setvar_helper(chan, "ROLLBACK_RESULT", ast_str_buffer(errors));
+               }
+       }
+       return 0;
+}
+
+static int aoro2_class_cb(void *obj, void *arg, int flags)
+{
+       struct odbc_class *class = obj;
+       char *name = arg;
+       if (!strcmp(class->name, name) && !class->delme) {
+               return CMP_MATCH | CMP_STOP;
+       }
+       return 0;
+}
+
+#define USE_TX (void *)(long)1
+#define NO_TX  (void *)(long)2
+#define EOR_TX (void *)(long)3
+
+static int aoro2_obj_cb(void *vobj, void *arg, int flags)
+{
+       struct odbc_obj *obj = vobj;
+       ast_mutex_lock(&obj->lock);
+       if ((arg == NO_TX && !obj->tx) || (arg == EOR_TX && !obj->used) || (arg == USE_TX && obj->tx && !obj->used)) {
+               obj->used = 1;
+               ast_mutex_unlock(&obj->lock);
+               return CMP_MATCH | CMP_STOP;
+       }
+       ast_mutex_unlock(&obj->lock);
+       return 0;
+}
+
 #ifdef DEBUG_THREADS
-struct odbc_obj *_ast_odbc_request_obj(const char *name, int check, const char *file, const char *function, int lineno)
+struct odbc_obj *_ast_odbc_request_obj2(const char *name, struct ast_flags flags, const char *file, const char *function, int lineno)
 #else
-struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
+struct odbc_obj *ast_odbc_request_obj2(const char *name, struct ast_flags flags)
 #endif
 {
        struct odbc_obj *obj = NULL;
        struct odbc_class *class;
-       struct ao2_iterator aoi = ao2_iterator_init(class_container, 0);
-
-       while ((class = ao2_iterator_next(&aoi))) {
-               if (!strcmp(class->name, name) && !class->delme) {
-                       break;
-               }
-               ao2_ref(class, -1);
-       }
+       SQLINTEGER nativeerror=0, numfields=0;
+       SQLSMALLINT diagbytes=0, i;
+       unsigned char state[10], diagnostic[256];
 
-       if (!class)
+       if (!(class = ao2_callback(class_container, 0, aoro2_class_cb, (char *) name))) {
                return NULL;
+       }
 
        ast_assert(ao2_ref(class, 0) > 1);
 
        if (class->haspool) {
                /* Recycle connections before building another */
-               aoi = ao2_iterator_init(class->obj_container, 0);
-               while ((obj = ao2_iterator_next(&aoi))) {
-                       if (! obj->used) {
-                               ast_mutex_lock(&obj->lock);
-                               obj->used = 1;
-                               ast_mutex_unlock(&obj->lock);
-                               break;
-                       }
-                       ao2_ref(obj, -1);
-               }
+               obj = ao2_callback(class->obj_container, 0, aoro2_obj_cb, EOR_TX);
 
                if (obj) {
                        ast_assert(ao2_ref(obj, 0) > 1);
                }
 
                if (!obj && (class->count < class->limit)) {
-                       class->count++;
                        obj = ao2_alloc(sizeof(*obj), odbc_obj_destructor);
                        if (!obj) {
                                ao2_ref(class, -1);
@@ -724,6 +1181,7 @@ struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
                        ast_mutex_init(&obj->lock);
                        /* obj inherits the outstanding reference to class */
                        obj->parent = class;
+                       class = NULL;
                        if (odbc_obj_connect(obj) == ODBC_FAIL) {
                                ast_log(LOG_WARNING, "Failed to connect to %s\n", name);
                                ao2_ref(obj, -1);
@@ -731,31 +1189,73 @@ struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
                                obj = NULL;
                        } else {
                                obj->used = 1;
-                               ao2_link(class->obj_container, obj);
+                               ao2_link(obj->parent->obj_container, obj);
+                               ast_atomic_fetchadd_int(&obj->parent->count, +1);
                        }
-                       class = NULL;
                } else {
                        /* Object is not constructed, so delete outstanding reference to class. */
                        ao2_ref(class, -1);
                        class = NULL;
                }
-       } else {
-               /* Non-pooled connection: multiple modules can use the same connection. */
-               aoi = ao2_iterator_init(class->obj_container, 0);
-               while ((obj = ao2_iterator_next(&aoi))) {
-                       /* Non-pooled connection: if there is an entry, return it */
-                       break;
+
+               if (obj && ast_test_flag(&flags, RES_ODBC_INDEPENDENT_CONNECTION)) {
+                       /* Ensure this connection has autocommit turned off. */
+                       if (SQLSetConnectAttr(obj->con, SQL_ATTR_AUTOCOMMIT, (void *)SQL_AUTOCOMMIT_OFF, 0) == SQL_ERROR) {
+                               SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                               for (i = 0; i < numfields; i++) {
+                                       SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                                       ast_log(LOG_WARNING, "SQLSetConnectAttr (Autocommit) returned an error: %s: %s\n", state, diagnostic);
+                                       if (i > 10) {
+                                               ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                               break;
+                                       }
+                               }
+                       }
+               }
+       } else if (ast_test_flag(&flags, RES_ODBC_INDEPENDENT_CONNECTION)) {
+               /* Non-pooled connections -- but must use a separate connection handle */
+               if (!(obj = ao2_callback(class->obj_container, 0, aoro2_obj_cb, USE_TX))) {
+                       obj = ao2_alloc(sizeof(*obj), odbc_obj_destructor);
+                       if (!obj) {
+                               ao2_ref(class, -1);
+                               return NULL;
+                       }
+                       ast_mutex_init(&obj->lock);
+                       /* obj inherits the outstanding reference to class */
+                       obj->parent = class;
+                       class = NULL;
+                       if (odbc_obj_connect(obj) == ODBC_FAIL) {
+                               ast_log(LOG_WARNING, "Failed to connect to %s\n", name);
+                               ao2_ref(obj, -1);
+                               obj = NULL;
+                       } else {
+                               obj->used = 1;
+                               ao2_link(obj->parent->obj_container, obj);
+                               ast_atomic_fetchadd_int(&obj->parent->count, +1);
+                       }
                }
 
-               if (obj) {
+               if (obj && SQLSetConnectAttr(obj->con, SQL_ATTR_AUTOCOMMIT, (void *)SQL_AUTOCOMMIT_OFF, 0) == SQL_ERROR) {
+                       SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_log(LOG_WARNING, "SetConnectAttr (Autocommit) returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+               }
+       } else {
+               /* Non-pooled connection: multiple modules can use the same connection. */
+               if (!(obj = ao2_callback(class->obj_container, 0, aoro2_obj_cb, NO_TX))) {
                        /* Object is not constructed, so delete outstanding reference to class. */
                        ast_assert(ao2_ref(class, 0) > 1);
                        ao2_ref(class, -1);
                        class = NULL;
                } else {
                        /* No entry: build one */
-                       obj = ao2_alloc(sizeof(*obj), odbc_obj_destructor);
-                       if (!obj) {
+                       if (!(obj = ao2_alloc(sizeof(*obj), odbc_obj_destructor))) {
                                ast_assert(ao2_ref(class, 0) > 1);
                                ao2_ref(class, -1);
                                return NULL;
@@ -763,19 +1263,44 @@ struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
                        ast_mutex_init(&obj->lock);
                        /* obj inherits the outstanding reference to class */
                        obj->parent = class;
+                       class = NULL;
                        if (odbc_obj_connect(obj) == ODBC_FAIL) {
                                ast_log(LOG_WARNING, "Failed to connect to %s\n", name);
                                ao2_ref(obj, -1);
                                obj = NULL;
                        } else {
-                               ao2_link(class->obj_container, obj);
+                               ao2_link(obj->parent->obj_container, obj);
                                ast_assert(ao2_ref(obj, 0) > 1);
                        }
-                       class = NULL;
+               }
+
+               if (obj && SQLSetConnectAttr(obj->con, SQL_ATTR_AUTOCOMMIT, (void *)SQL_AUTOCOMMIT_ON, 0) == SQL_ERROR) {
+                       SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_log(LOG_WARNING, "SetConnectAttr (Autocommit) returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
                }
        }
 
-       if (obj && check) {
+       /* Set the isolation property */
+       if (obj && SQLSetConnectAttr(obj->con, SQL_ATTR_TXN_ISOLATION, (void *)(long)obj->parent->isolation, 0) == SQL_ERROR) {
+               SQLGetDiagField(SQL_HANDLE_DBC, obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+               for (i = 0; i < numfields; i++) {
+                       SQLGetDiagRec(SQL_HANDLE_DBC, obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                       ast_log(LOG_WARNING, "SetConnectAttr (Txn isolation) returned an error: %s: %s\n", state, diagnostic);
+                       if (i > 10) {
+                               ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                               break;
+                       }
+               }
+       }
+
+       if (obj && ast_test_flag(&flags, RES_ODBC_SANITY_CHECK)) {
                ast_odbc_sanity_check(obj);
        } else if (obj && obj->parent->idlecheck > 0 && ast_tvdiff_sec(ast_tvnow(), obj->last_used) > obj->parent->idlecheck)
                odbc_obj_connect(obj);
@@ -795,6 +1320,52 @@ struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
        return obj;
 }
 
+#ifdef DEBUG_THREADS
+struct odbc_obj *_ast_odbc_request_obj(const char *name, int check, const char *file, const char *function, int lineno)
+#else
+struct odbc_obj *ast_odbc_request_obj(const char *name, int check)
+#endif
+{
+       struct ast_flags flags = { check ? RES_ODBC_SANITY_CHECK : 0 };
+#ifdef DEBUG_THREADS
+       return _ast_odbc_request_obj2(name, flags, file, function, lineno);
+#else
+       return ast_odbc_request_obj2(name, flags);
+#endif
+}
+
+struct odbc_obj *ast_odbc_retrieve_transaction_obj(struct ast_channel *chan, const char *objname)
+{
+       struct ast_datastore *txn_store;
+       AST_LIST_HEAD(, odbc_txn_frame) *oldlist;
+       struct odbc_txn_frame *txn = NULL;
+
+       if (!chan) {
+               /* No channel == no transaction */
+               return NULL;
+       }
+
+       ast_channel_lock(chan);
+       if ((txn_store = ast_channel_datastore_find(chan, &txn_info, NULL))) {
+               oldlist = txn_store->data;
+       } else {
+               ast_channel_unlock(chan);
+               return NULL;
+       }
+
+       AST_LIST_LOCK(oldlist);
+       ast_channel_unlock(chan);
+
+       AST_LIST_TRAVERSE(oldlist, txn, list) {
+               if (txn->obj && txn->obj->parent && !strcmp(txn->obj->parent->name, objname)) {
+                       AST_LIST_UNLOCK(oldlist);
+                       return txn->obj;
+               }
+       }
+       AST_LIST_UNLOCK(oldlist);
+       return NULL;
+}
+
 static odbc_status odbc_obj_disconnect(struct odbc_obj *obj)
 {
        int res;
@@ -885,6 +1456,146 @@ static odbc_status odbc_obj_connect(struct odbc_obj *obj)
        return ODBC_SUCCESS;
 }
 
+static int acf_transaction_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
+{
+       AST_DECLARE_APP_ARGS(args,
+               AST_APP_ARG(property);
+               AST_APP_ARG(opt);
+       );
+       struct odbc_txn_frame *tx;
+
+       AST_STANDARD_APP_ARGS(args, data);
+       if (strcasecmp(args.property, "transaction") == 0) {
+               if ((tx = find_transaction(chan, NULL, NULL, 1))) {
+                       ast_copy_string(buf, tx->name, len);
+                       return 0;
+               }
+       } else if (strcasecmp(args.property, "isolation") == 0) {
+               if (!ast_strlen_zero(args.opt)) {
+                       tx = find_transaction(chan, NULL, args.opt, 0);
+               } else {
+                       tx = find_transaction(chan, NULL, NULL, 1);
+               }
+               if (tx) {
+                       ast_copy_string(buf, isolation2text(tx->isolation), len);
+                       return 0;
+               }
+       } else if (strcasecmp(args.property, "forcecommit") == 0) {
+               if (!ast_strlen_zero(args.opt)) {
+                       tx = find_transaction(chan, NULL, args.opt, 0);
+               } else {
+                       tx = find_transaction(chan, NULL, NULL, 1);
+               }
+               if (tx) {
+                       ast_copy_string(buf, tx->forcecommit ? "1" : "0", len);
+                       return 0;
+               }
+       }
+       return -1;
+}
+
+static int acf_transaction_write(struct ast_channel *chan, const char *cmd, char *s, const char *value)
+{
+       AST_DECLARE_APP_ARGS(args,
+               AST_APP_ARG(property);
+               AST_APP_ARG(opt);
+       );
+       struct odbc_txn_frame *tx;
+       SQLINTEGER nativeerror=0, numfields=0;
+       SQLSMALLINT diagbytes=0, i;
+       unsigned char state[10], diagnostic[256];
+
+       AST_STANDARD_APP_ARGS(args, s);
+       if (strcasecmp(args.property, "transaction") == 0) {
+               /* Set active transaction */
+               struct odbc_obj *obj;
+               if ((tx = find_transaction(chan, NULL, value, 0))) {
+                       mark_transaction_active(chan, tx);
+               } else {
+                       /* No such transaction, create one */
+                       struct ast_flags flags = { RES_ODBC_INDEPENDENT_CONNECTION };
+                       if (ast_strlen_zero(args.opt) || !(obj = ast_odbc_request_obj2(args.opt, flags))) {
+                               ast_log(LOG_ERROR, "Could not create transaction: invalid database specification '%s'\n", S_OR(args.opt, ""));
+                               pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "INVALID_DB");
+                               return -1;
+                       }
+                       if (!(tx = find_transaction(chan, obj, value, 0))) {
+                               pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "FAILED_TO_CREATE");
+                               return -1;
+                       }
+                       obj->tx = 1;
+               }
+               pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "OK");
+               return 0;
+       } else if (strcasecmp(args.property, "forcecommit") == 0) {
+               /* Set what happens when an uncommitted transaction ends without explicit Commit or Rollback */
+               if (ast_strlen_zero(args.opt)) {
+                       tx = find_transaction(chan, NULL, NULL, 1);
+               } else {
+                       tx = find_transaction(chan, NULL, args.opt, 0);
+               }
+               if (!tx) {
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "FAILED_TO_CREATE");
+                       return -1;
+               }
+               if (ast_true(value)) {
+                       tx->forcecommit = 1;
+               } else if (ast_false(value)) {
+                       tx->forcecommit = 0;
+               } else {
+                       ast_log(LOG_ERROR, "Invalid value for forcecommit: '%s'\n", S_OR(value, ""));
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "INVALID_VALUE");
+                       return -1;
+               }
+
+               pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "OK");
+               return 0;
+       } else if (strcasecmp(args.property, "isolation") == 0) {
+               /* How do uncommitted transactions affect reads? */
+               int isolation = text2isolation(value);
+               if (ast_strlen_zero(args.opt)) {
+                       tx = find_transaction(chan, NULL, NULL, 1);
+               } else {
+                       tx = find_transaction(chan, NULL, args.opt, 0);
+               }
+               if (!tx) {
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "FAILED_TO_CREATE");
+                       return -1;
+               }
+               if (isolation == 0) {
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "INVALID_VALUE");
+                       ast_log(LOG_ERROR, "Invalid isolation specification: '%s'\n", S_OR(value, ""));
+               } else if (SQLSetConnectAttr(tx->obj->con, SQL_ATTR_TXN_ISOLATION, (void *)(long)isolation, 0) == SQL_ERROR) {
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "SQL_ERROR");
+                       SQLGetDiagField(SQL_HANDLE_DBC, tx->obj->con, 1, SQL_DIAG_NUMBER, &numfields, SQL_IS_INTEGER, &diagbytes);
+                       for (i = 0; i < numfields; i++) {
+                               SQLGetDiagRec(SQL_HANDLE_DBC, tx->obj->con, i + 1, state, &nativeerror, diagnostic, sizeof(diagnostic), &diagbytes);
+                               ast_log(LOG_WARNING, "SetConnectAttr (Txn isolation) returned an error: %s: %s\n", state, diagnostic);
+                               if (i > 10) {
+                                       ast_log(LOG_WARNING, "Oh, that was good.  There are really %d diagnostics?\n", (int)numfields);
+                                       break;
+                               }
+                       }
+               } else {
+                       pbx_builtin_setvar_helper(chan, "ODBC_RESULT", "OK");
+                       tx->isolation = isolation;
+               }
+               return 0;
+       } else {
+               ast_log(LOG_ERROR, "Unknown property: '%s'\n", args.property);
+               return -1;
+       }
+}
+
+static struct ast_custom_function odbc_function = {
+       .name = "ODBC",
+       .read = acf_transaction_read,
+       .write = acf_transaction_write,
+};
+
+static const char *app_commit = "ODBC_Commit";
+static const char *app_rollback = "ODBC_Rollback";
+
 static int reload(void)
 {
        struct odbc_cache_tables *table;
@@ -969,6 +1680,9 @@ static int load_module(void)
        if (load_odbc_config() == -1)
                return AST_MODULE_LOAD_DECLINE;
        ast_cli_register_multiple(cli_odbc, ARRAY_LEN(cli_odbc));
+       ast_register_application_xml(app_commit, commit_exec);
+       ast_register_application_xml(app_rollback, rollback_exec);
+       ast_custom_function_register(&odbc_function);
        ast_log(LOG_NOTICE, "res_odbc loaded.\n");
        return 0;
 }