[tarantool-patches] [PATCH v2 2/8] Get rid of autocommit from a txn structure

Georgy Kirichenko georgy at tarantool.org
Thu May 23 11:19:34 MSK 2019


Move transaction auto start and auto commit behavior to the box level.
>From now a transaction won't start and commit automatically without
txn_begin/txn_commit invocations. This is a part of a bigger transaction
refactoring in order to implement detachable transactions and a parallel
applier.

Prerequisites: #1254
---
 src/box/applier.cc     | 31 +++++++++++---
 src/box/box.cc         | 91 ++++++++++++++++++++++++++++++++----------
 src/box/index.cc       | 10 ++---
 src/box/journal.h      |  1 +
 src/box/memtx_engine.c | 10 ++++-
 src/box/memtx_space.c  |  8 ++--
 src/box/sql.c          |  2 +-
 src/box/txn.c          | 47 ++++++++--------------
 src/box/txn.h          | 16 +++-----
 src/box/vinyl.c        | 12 ++----
 src/box/vy_scheduler.c |  6 +--
 src/box/wal.c          |  1 -
 12 files changed, 142 insertions(+), 93 deletions(-)

diff --git a/src/box/applier.cc b/src/box/applier.cc
index 373e1feb9..9d2989094 100644
--- a/src/box/applier.cc
+++ b/src/box/applier.cc
@@ -172,11 +172,22 @@ applier_writer_f(va_list ap)
 static int
 apply_initial_join_row(struct xrow_header *row)
 {
+	struct txn *txn = txn_begin();
+	if (txn == NULL)
+		return -1;
 	struct request request;
 	xrow_decode_dml(row, &request, dml_request_key_map(row->type));
-	struct space *space = space_cache_find_xc(request.space_id);
+	struct space *space = space_cache_find(request.space_id);
+	if (space == NULL)
+		return -1;
 	/* no access checks here - applier always works with admin privs */
-	return space_apply_initial_join_row(space, &request);
+	if (space_apply_initial_join_row(space, &request)) {
+		txn_rollback();
+		return -1;
+	}
+	int rc = txn_commit(txn);
+	fiber_gc();
+	return rc;
 }
 
 /**
@@ -189,8 +200,8 @@ static int
 process_nop(struct request *request)
 {
 	assert(request->type == IPROTO_NOP);
-	struct txn *txn = txn_begin_stmt(NULL);
-	if (txn == NULL)
+	struct txn *txn = in_txn();
+	if (txn_begin_stmt(txn, NULL) == NULL)
 		return -1;
 	return txn_commit_stmt(txn, request);
 }
@@ -403,8 +414,16 @@ applier_join(struct applier *applier)
 		applier->last_row_time = ev_monotonic_now(loop());
 		if (iproto_type_is_dml(row.type)) {
 			vclock_follow_xrow(&replicaset.vclock, &row);
-			if (apply_row(&row) != 0)
+			struct txn *txn = txn_begin();
+			if (txn == NULL)
+				diag_raise();
+			if (apply_row(&row) != 0) {
+				txn_rollback();
+				diag_raise();
+			}
+			if (txn_commit(txn) != 0)
 				diag_raise();
+			fiber_gc();
 			if (++row_count % 100000 == 0)
 				say_info("%.1fM rows received", row_count / 1e6);
 		} else if (row.type == IPROTO_OK) {
@@ -555,7 +574,7 @@ applier_apply_tx(struct stailq *rows)
 	 * conflict safely access failed xrow object and allocate
 	 * IPROTO_NOP on gc.
 	 */
-	struct txn *txn = txn_begin(false);
+	struct txn *txn = txn_begin();
 	struct applier_tx_row *item;
 	if (txn == NULL)
 		diag_raise();
diff --git a/src/box/box.cc b/src/box/box.cc
index 57419ee01..2a738fa36 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -169,34 +169,65 @@ int
 box_process_rw(struct request *request, struct space *space,
 	       struct tuple **result)
 {
+	struct tuple *tuple = NULL;
+	struct txn *txn = in_txn();
+	bool is_autocommit = txn == NULL;
+	if (is_autocommit && (txn = txn_begin()) == NULL)
+		return -1;
 	assert(iproto_type_is_dml(request->type));
 	rmean_collect(rmean_box, request->type, 1);
 	if (access_check_space(space, PRIV_W) != 0)
-		return -1;
-	struct txn *txn = txn_begin_stmt(space);
-	if (txn == NULL)
-		return -1;
-	struct tuple *tuple;
+		goto fail;
+	if (txn_begin_stmt(txn, space) == NULL)
+		goto fail;
 	if (space_execute_dml(space, txn, request, &tuple) != 0) {
-		txn_rollback_stmt();
-		return -1;
+		txn_rollback_stmt(txn);
+		goto fail;
 	}
-	if (result == NULL)
-		return txn_commit_stmt(txn, request);
-	*result = tuple;
-	if (tuple == NULL)
-		return txn_commit_stmt(txn, request);
 	/*
 	 * Pin the tuple locally before the commit,
 	 * otherwise it may go away during yield in
 	 * when WAL is written in autocommit mode.
 	 */
+	if (result != NULL)
+		*result = tuple;
+
+	if (result == NULL || tuple == NULL) {
+		if (!is_autocommit)
+			return txn_commit_stmt(txn, request);
+		/* Autocommit mode. */
+		if (txn_commit_stmt(txn, request) != 0) {
+			txn_rollback();
+			return -1;
+		}
+		if (txn_commit(txn) != 0)
+			return -1;
+		fiber_gc();
+		return 0;
+	}
 	tuple_ref(tuple);
-	int rc = txn_commit_stmt(txn, request);
-	if (rc == 0)
-		tuple_bless(tuple);
+
+	if (txn_commit_stmt(txn, request)) {
+		/* Unref tuple and rollback if autocommit. */
+		tuple_unref(tuple);
+		goto fail;
+	}
+	if (is_autocommit) {
+		if (txn_commit(txn) != 0) {
+			/* Unref tuple and exit. */
+			tuple_unref(tuple);
+			return -1;
+		}
+	        fiber_gc();
+	}
+	tuple_bless(tuple);
 	tuple_unref(tuple);
-	return rc;
+	return 0;
+
+fail:
+	if (is_autocommit)
+		txn_rollback();
+	return -1;
 }
 
 void
@@ -299,8 +330,12 @@ apply_wal_row(struct xstream *stream, struct xrow_header *row)
 	xrow_decode_dml_xc(row, &request, dml_request_key_map(row->type));
 	if (request.type != IPROTO_NOP) {
 		struct space *space = space_cache_find_xc(request.space_id);
-		if (box_process_rw(&request, space, NULL) != 0) {
+		struct txn *txn = txn_begin();
+		if (txn == NULL || box_process_rw(&request, space, NULL) != 0 ||
+		    txn_commit(txn) != 0) {
 			say_error("error applying row: %s", request_str(&request));
+			if (txn != NULL)
+				txn_rollback();
 			diag_raise();
 		}
 	}
@@ -1055,7 +1090,7 @@ box_select(uint32_t space_id, uint32_t index_id,
 	struct iterator *it = index_create_iterator(index, type,
 						    key, part_count);
 	if (it == NULL) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 
@@ -1080,7 +1115,7 @@ box_select(uint32_t space_id, uint32_t index_id,
 
 	if (rc != 0) {
 		port_destroy(port);
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	txn_commit_ro_stmt(txn);
@@ -1313,8 +1348,15 @@ box_sequence_reset(uint32_t seq_id)
 static inline void
 box_register_replica(uint32_t id, const struct tt_uuid *uuid)
 {
+	struct txn *txn = txn_begin();
+	if (txn == NULL)
+		diag_raise();
 	if (boxk(IPROTO_INSERT, BOX_CLUSTER_ID, "[%u%s]",
-		 (unsigned) id, tt_uuid_str(uuid)) != 0)
+		 (unsigned) id, tt_uuid_str(uuid)) != 0) {
+		txn_rollback();
+		diag_raise();
+	}
+	if (txn_commit(txn) != 0)
 		diag_raise();
 	assert(replica_by_uuid(uuid)->id == id);
 }
@@ -1636,9 +1678,16 @@ box_set_replicaset_uuid(const struct tt_uuid *replicaset_uuid)
 		uu = *replicaset_uuid;
 	else
 		tt_uuid_create(&uu);
+	struct txn *txn = txn_begin();
+	if (txn == NULL)
+		diag_raise();
 	/* Save replica set UUID in _schema */
 	if (boxk(IPROTO_INSERT, BOX_SCHEMA_ID, "[%s%s]", "cluster",
-		 tt_uuid_str(&uu)))
+		 tt_uuid_str(&uu))) {
+		txn_rollback();
+		diag_raise();
+	}
+	if (txn_commit(txn) != 0)
 		diag_raise();
 }
 
diff --git a/src/box/index.cc b/src/box/index.cc
index 4a444e5d0..7f26c9bc2 100644
--- a/src/box/index.cc
+++ b/src/box/index.cc
@@ -240,7 +240,7 @@ box_index_get(uint32_t space_id, uint32_t index_id, const char *key,
 	if (txn_begin_ro_stmt(space, &txn) != 0)
 		return -1;
 	if (index_get(index, key, part_count, result) != 0) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	txn_commit_ro_stmt(txn);
@@ -274,7 +274,7 @@ box_index_min(uint32_t space_id, uint32_t index_id, const char *key,
 	if (txn_begin_ro_stmt(space, &txn) != 0)
 		return -1;
 	if (index_min(index, key, part_count, result) != 0) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	txn_commit_ro_stmt(txn);
@@ -306,7 +306,7 @@ box_index_max(uint32_t space_id, uint32_t index_id, const char *key,
 	if (txn_begin_ro_stmt(space, &txn) != 0)
 		return -1;
 	if (index_max(index, key, part_count, result) != 0) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	txn_commit_ro_stmt(txn);
@@ -340,7 +340,7 @@ box_index_count(uint32_t space_id, uint32_t index_id, int type,
 		return -1;
 	ssize_t count = index_count(index, itype, key, part_count);
 	if (count < 0) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	txn_commit_ro_stmt(txn);
@@ -377,7 +377,7 @@ box_index_iterator(uint32_t space_id, uint32_t index_id, int type,
 	struct iterator *it = index_create_iterator(index, itype,
 						    key, part_count);
 	if (it == NULL) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return NULL;
 	}
 	txn_commit_ro_stmt(txn);
diff --git a/src/box/journal.h b/src/box/journal.h
index 8ac32ee5e..77d3073c8 100644
--- a/src/box/journal.h
+++ b/src/box/journal.h
@@ -32,6 +32,7 @@
  */
 #include <stdint.h>
 #include <stdbool.h>
+#include "trigger.h"
 #include "salad/stailq.h"
 
 #if defined(__cplusplus)
diff --git a/src/box/memtx_engine.c b/src/box/memtx_engine.c
index f4312484a..149215b87 100644
--- a/src/box/memtx_engine.c
+++ b/src/box/memtx_engine.c
@@ -272,16 +272,22 @@ memtx_engine_recover_snapshot_row(struct memtx_engine *memtx,
 		diag_set(ClientError, ER_CROSS_ENGINE_TRANSACTION);
 		return -1;
 	}
+	struct txn *txn = txn_begin();
+	if (txn == NULL)
+		return -1;
 	/* no access checks here - applier always works with admin privs */
-	if (space_apply_initial_join_row(space, &request) != 0)
+	if (space_apply_initial_join_row(space, &request) != 0) {
+		txn_rollback();
 		return -1;
+	}
+	int rc = txn_commit(txn);
 	/*
 	 * Don't let gc pool grow too much. Yet to
 	 * it before reading the next row, to make
 	 * sure it's not freed along here.
 	 */
 	fiber_gc();
-	return 0;
+	return rc;
 }
 
 /** Called at start to tell memtx to recover to a given LSN. */
diff --git a/src/box/memtx_space.c b/src/box/memtx_space.c
index 5ddb4f7ee..829ab7f4c 100644
--- a/src/box/memtx_space.c
+++ b/src/box/memtx_space.c
@@ -310,10 +310,10 @@ memtx_space_apply_initial_join_row(struct space *space, struct request *request)
 		return -1;
 	}
 	request->header->replica_id = 0;
-	struct txn *txn = txn_begin_stmt(space);
-	if (txn == NULL)
+	struct txn *txn = in_txn();
+	struct txn_stmt *stmt = txn_begin_stmt(txn, space);
+	if (stmt == NULL)
 		return -1;
-	struct txn_stmt *stmt = txn_current_stmt(txn);
 	stmt->new_tuple = memtx_tuple_new(space->format, request->tuple,
 					  request->tuple_end);
 	if (stmt->new_tuple == NULL)
@@ -326,7 +326,7 @@ memtx_space_apply_initial_join_row(struct space *space, struct request *request)
 
 rollback:
 	say_error("rollback: %s", diag_last_error(diag_get())->errmsg);
-	txn_rollback_stmt();
+	txn_rollback_stmt(txn);
 	return -1;
 }
 
diff --git a/src/box/sql.c b/src/box/sql.c
index fbfa59992..1bdbdb815 100644
--- a/src/box/sql.c
+++ b/src/box/sql.c
@@ -915,7 +915,7 @@ cursor_seek(BtCursor *pCur, int *pRes)
 				      part_count);
 	if (it == NULL) {
 		if (txn != NULL)
-			txn_rollback_stmt();
+			txn_rollback_stmt(txn);
 		pCur->eState = CURSOR_INVALID;
 		return SQL_TARANTOOL_ITERATOR_FAIL;
 	}
diff --git a/src/box/txn.c b/src/box/txn.c
index da749d7cc..87fd8b3bc 100644
--- a/src/box/txn.c
+++ b/src/box/txn.c
@@ -174,7 +174,7 @@ txn_free(struct txn *txn)
 }
 
 struct txn *
-txn_begin(bool is_autocommit)
+txn_begin()
 {
 	static int64_t tsn = 0;
 	assert(! in_txn());
@@ -187,7 +187,6 @@ txn_begin(bool is_autocommit)
 	txn->n_new_rows = 0;
 	txn->n_local_rows = 0;
 	txn->n_applier_rows = 0;
-	txn->is_autocommit = is_autocommit;
 	txn->has_triggers  = false;
 	txn->is_aborted = false;
 	txn->in_sub_stmt = 0;
@@ -220,26 +219,20 @@ txn_begin_in_engine(struct engine *engine, struct txn *txn)
 	return 0;
 }
 
-struct txn *
-txn_begin_stmt(struct space *space)
+struct txn_stmt *
+txn_begin_stmt(struct txn *txn, struct space *space)
 {
-	struct txn *txn = in_txn();
-	if (txn == NULL) {
-		txn = txn_begin(true);
-		if (txn == NULL)
-			return NULL;
-	} else if (txn->in_sub_stmt > TXN_SUB_STMT_MAX) {
+	assert(txn == in_txn());
+	assert(txn != NULL);
+	if (txn->in_sub_stmt > TXN_SUB_STMT_MAX) {
 		diag_set(ClientError, ER_SUB_STMT_MAX);
 		return NULL;
 	}
 	struct txn_stmt *stmt = txn_stmt_new(txn);
-	if (stmt == NULL) {
-		if (txn->is_autocommit && txn->in_sub_stmt == 0)
-			txn_rollback();
+	if (stmt == NULL)
 		return NULL;
-	}
 	if (space == NULL)
-		return txn;
+		return stmt;
 
 	if (trigger_run(&space->on_stmt_begin, txn) != 0)
 		goto fail;
@@ -252,9 +245,9 @@ txn_begin_stmt(struct space *space)
 	if (engine_begin_statement(engine, txn) != 0)
 		goto fail;
 
-	return txn;
+	return stmt;
 fail:
-	txn_rollback_stmt();
+	txn_rollback_stmt(txn);
 	return NULL;
 }
 
@@ -272,8 +265,7 @@ txn_is_distributed(struct txn *txn)
 }
 
 /**
- * End a statement. In autocommit mode, end
- * the current transaction as well.
+ * End a statement.
  */
 int
 txn_commit_stmt(struct txn *txn, struct request *request)
@@ -316,14 +308,9 @@ txn_commit_stmt(struct txn *txn, struct request *request)
 			goto fail;
 	}
 	--txn->in_sub_stmt;
-	if (txn->is_autocommit && txn->in_sub_stmt == 0) {
-		int rc = txn_commit(txn);
-		fiber_gc();
-		return rc;
-	}
 	return 0;
 fail:
-	txn_rollback_stmt();
+	txn_rollback_stmt(txn);
 	return -1;
 }
 
@@ -359,7 +346,7 @@ txn_write_to_wal(struct txn *txn)
 
 	if (res < 0) {
 		/* Cascading rollback. */
-		txn_rollback(); /* Perform our part of cascading rollback. */
+		txn_rollback(txn); /* Perform our part of cascading rollback. */
 		/*
 		 * Move fiber to end of event loop to avoid
 		 * execution of any new requests before all
@@ -441,14 +428,11 @@ fail:
 }
 
 void
-txn_rollback_stmt()
+txn_rollback_stmt(struct txn *txn)
 {
-	struct txn *txn = in_txn();
 	if (txn == NULL || txn->in_sub_stmt == 0)
 		return;
 	txn->in_sub_stmt--;
-	if (txn->is_autocommit && txn->in_sub_stmt == 0)
-		return txn_rollback();
 	txn_rollback_to_svp(txn, txn->sub_stmt_begin[txn->in_sub_stmt]);
 }
 
@@ -465,6 +449,7 @@ txn_rollback()
 		unreachable();
 		panic("rollback trigger failed");
 	}
+
 	if (txn->engine)
 		engine_rollback(txn->engine, txn);
 
@@ -519,7 +504,7 @@ box_txn_begin()
 		diag_set(ClientError, ER_ACTIVE_TRANSACTION);
 		return -1;
 	}
-	if (txn_begin(false) == NULL)
+	if (txn_begin() == NULL)
 		return -1;
 	return 0;
 }
diff --git a/src/box/txn.h b/src/box/txn.h
index f4d861824..5a66f8e53 100644
--- a/src/box/txn.h
+++ b/src/box/txn.h
@@ -162,11 +162,6 @@ struct txn {
 	 * already assigned LSN.
 	 */
 	int n_applier_rows;
-	/**
-	 * True if this transaction is running in autocommit mode
-	 * (statement end causes an automatic transaction commit).
-	 */
-	bool is_autocommit;
 	/**
 	 * True if the transaction was aborted so should be
 	 * rolled back at commit.
@@ -214,7 +209,7 @@ in_txn()
  * @pre no transaction is active
  */
 struct txn *
-txn_begin(bool is_autocommit);
+txn_begin();
 
 /**
  * Commit a transaction.
@@ -271,11 +266,10 @@ txn_on_rollback(struct txn *txn, struct trigger *trigger)
 }
 
 /**
- * Start a new statement. If no current transaction,
- * start a new transaction with autocommit = true.
+ * Start a new statement.
  */
-struct txn *
-txn_begin_stmt(struct space *space);
+struct txn_stmt *
+txn_begin_stmt(struct txn *txn, struct space *space);
 
 int
 txn_begin_in_engine(struct engine *engine, struct txn *txn);
@@ -334,7 +328,7 @@ txn_commit_stmt(struct txn *txn, struct request *request);
  * rolls back the entire transaction.
  */
 void
-txn_rollback_stmt();
+txn_rollback_stmt(struct txn *txn);
 
 /**
  * Raise an error if this is a multi-statement transaction: DDL
diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index 9372e5f7f..2abfab366 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -2415,10 +2415,8 @@ vinyl_engine_begin(struct engine *engine, struct txn *txn)
 	txn->engine_tx = vy_tx_begin(env->xm);
 	if (txn->engine_tx == NULL)
 		return -1;
-	if (!txn->is_autocommit) {
-		trigger_create(&txn->fiber_on_stop, txn_on_stop, NULL, NULL);
-		trigger_add(&fiber()->on_stop, &txn->fiber_on_stop);
-	}
+	trigger_create(&txn->fiber_on_stop, txn_on_stop, NULL, NULL);
+	trigger_add(&fiber()->on_stop, &txn->fiber_on_stop);
 	return 0;
 }
 
@@ -2488,8 +2486,7 @@ vinyl_engine_commit(struct engine *engine, struct txn *txn)
 	vy_regulator_check_dump_watermark(&env->regulator);
 
 	txn->engine_tx = NULL;
-	if (!txn->is_autocommit)
-		trigger_clear(&txn->fiber_on_stop);
+	trigger_clear(&txn->fiber_on_stop);
 }
 
 static void
@@ -2503,8 +2500,7 @@ vinyl_engine_rollback(struct engine *engine, struct txn *txn)
 	vy_tx_rollback(tx);
 
 	txn->engine_tx = NULL;
-	if (!txn->is_autocommit)
-		trigger_clear(&txn->fiber_on_stop);
+	trigger_clear(&txn->fiber_on_stop);
 }
 
 static int
diff --git a/src/box/vy_scheduler.c b/src/box/vy_scheduler.c
index fabb4bb48..9d5f18e32 100644
--- a/src/box/vy_scheduler.c
+++ b/src/box/vy_scheduler.c
@@ -840,14 +840,14 @@ vy_deferred_delete_process_one(struct space *deferred_delete_space,
 
 	tuple_unref(delete);
 
-	struct txn *txn = txn_begin_stmt(deferred_delete_space);
-	if (txn == NULL)
+	struct txn *txn = in_txn();
+	if (txn_begin_stmt(txn, deferred_delete_space) == NULL)
 		return -1;
 
 	struct tuple *unused;
 	if (space_execute_dml(deferred_delete_space, txn,
 			      &request, &unused) != 0) {
-		txn_rollback_stmt();
+		txn_rollback_stmt(txn);
 		return -1;
 	}
 	return txn_commit_stmt(txn, &request);
diff --git a/src/box/wal.c b/src/box/wal.c
index 0ea15a432..628e7529a 100644
--- a/src/box/wal.c
+++ b/src/box/wal.c
@@ -303,7 +303,6 @@ tx_schedule_rollback(struct cmsg *msg)
 	 * in-memory database state.
 	 */
 	stailq_reverse(&writer->rollback);
-	/* Must not yield. */
 	tx_schedule_queue(&writer->rollback);
 	stailq_create(&writer->rollback);
 	if (msg != &writer->in_rollback)
-- 
2.21.0





More information about the Tarantool-patches mailing list