obj: introduce pmemobj_tx_set_abort_on_failure

This function can be used to disable or enable aborting tx
in case of an error (for example when allocation fails).

This patch also introduces pmemobj_tx_is_abort_on_failure
which allows to query current setting of a transaction.

doc/libpmemobj/pmemobj_tx_begin.3.md

@@ -37,7 +37,10 @@ date: pmemobj API version 2.3
 **pmemobj_tx_log_intents_max_size**(),
 
 **pmemobj_tx_set_user_data**(),
-**pmemobj_tx_get_user_data**()
+**pmemobj_tx_get_user_data**(),
+
+**pmemobj_tx_set_abort_on_failure**(),
+**pmemobj_tx_get_abort_on_failure**()
 - transactional object manipulation
 
 # SYNOPSIS #
@@ -72,6 +75,9 @@ size_t pmemobj_tx_log_intents_max_size(size_t nintents);
 
 void pmemobj_tx_set_user_data(void *data);
 void *pmemobj_tx_get_user_data(void);
+
+void pmemobj_tx_set_abort_on_failure(int enable);
+int pmemobj_tx_get_abort_on_failure(void);
 ```
 
 # DESCRIPTION #
@@ -412,6 +418,19 @@ If **pmemobj_tx_set_user_data**() was not called for a current transaction,
 during **TX_STAGE_WORK** or **TX_STAGE_ONABORT** or **TX_STAGE_ONCOMMIT** or
 **TX_STAGE_FINALLY**.
 
+**pmemobj_tx_set_abort_on_failure**() enables or disables automatic transaction
+abort in case **pmemobj_tx_add_rage**, **pmemobj_tx_add_rage_direct**, **pmemobj_tx_alloc**,
+**pmemobj_tx_free**, **pmemobj_tx_wcsdup**,  **pmemobj_tx_lock**, **pmemobj_tx_strdup**,
+**pmemobj_tx_xpublish** or **pmemobj_tx_log_append_buffer** fails. If called with
+**enable** == 0 *_NO_ABORT flag will be implicitly passed to all of those functions. If
+**pmemobj_tx_set_abort_on_failure** is not called (or called with **enable** == 1),
+the transaction will abort if any of the previously listed functions fails (unless
+*_NO_ABORT flag was passed expliciltly). This functions affects the current transaction
+and all inner transactions. It does not affect any outer transactions.
+**pmemobj_tx_get_abort_on_failure**() function returns 1 if transaction automatically
+aborts on failure, 0 otherwise. Both **pmemobj_tx_set_abort_on_failure**() and
+**pmemobj_tx_get_abort_on_failure**() must be called during **TX_STAGE_WORK**.
+
 # RETURN VALUE #
 
 The **pmemobj_tx_stage**() function returns the stage of the current transaction

src/include/libpmemobj/tx_base.h

@@ -424,6 +424,25 @@ void pmemobj_tx_set_user_data(void *data);
  */
 void *pmemobj_tx_get_user_data(void);
 
+/*
+ * Enables or disables automatic transaction abort in case of an error.
+ * If called with enable == 0 _NO_ABORT flag will be implicitly passed to
+ * functions which accept such flag.
+ *
+ * This setting is inherited by inner transactions. Aborting on failure is
+ * the default behaviour.
+ *
+ * This function must be called during TX_STAGE_WORK.
+ */
+void pmemobj_tx_set_abort_on_failure(int enable);
+
+/*
+ * Returns 1 if transaction automatically aborts on failure, 0 otherwise.
+ *
+ * This function must be called during TX_STAGE_WORK.
+ */
+int pmemobj_tx_get_abort_on_failure(void);
+
 #ifdef __cplusplus
 }
 #endif

src/libpmemobj/libpmemobj.def

@@ -96,6 +96,8 @@ EXPORTS
 	pmemobj_tx_log_intents_max_size
 	pmemobj_tx_set_user_data
 	pmemobj_tx_get_user_data
+	pmemobj_tx_set_abort_on_failure
+	pmemobj_tx_get_abort_on_failure
 	pmemobj_memcpy
 	pmemobj_memcpy_persist
 	pmemobj_memmove

src/libpmemobj/libpmemobj.link.in

@@ -87,6 +87,8 @@ LIBPMEMOBJ_1.0 {
 		pmemobj_tx_log_intents_max_size;
 		pmemobj_tx_set_user_data;
 		pmemobj_tx_get_user_data;
+		pmemobj_tx_set_abort_on_failure;
+		pmemobj_tx_get_abort_on_failure;
 		pmemobj_memcpy;
 		pmemobj_memcpy_persist;
 		pmemobj_memmove;