Revert suspending inside handle_exec_sql

src/conn.c

@@ -127,7 +127,6 @@ static void raft_connect(struct conn *c)
 	/* Close the connection without actually closing the transport, since
 	 * the stream will be used by raft */
 	c->closed = true;
-	gateway__close(&c->gateway);
 	closeCb(&c->transport);
 }
 
@@ -312,7 +311,7 @@ int conn__start(struct conn *c,
 	c->transport.data = c;
 	c->uv_transport = uv_transport;
 	c->close_cb = close_cb;
-	gateway__init(&c->gateway, config, loop, registry, raft, seed);
+	gateway__init(&c->gateway, config, registry, raft, seed);
 	rv = buffer__init(&c->read);
 	if (rv != 0) {
 		goto err_after_transport_init;

src/gateway.c

@@ -16,7 +16,6 @@
 
 void gateway__init(struct gateway *g,
 		   struct config *config,
-		   uv_loop_t *loop,
 		   struct registry *registry,
 		   struct raft *raft,
 		   struct id_state seed)
@@ -35,10 +34,6 @@ void gateway__init(struct gateway *g,
 	g->protocol = DQLITE_PROTOCOL_VERSION;
 	g->client_id = 0;
 	g->random_state = seed;
-	g->defer = (uv_timer_t){};
-	if (loop != NULL) {
-		uv_timer_init(loop, &g->defer);
-	}
 }
 
 void gateway__leader_close(struct gateway *g, int reason)
@@ -101,11 +96,6 @@ void gateway__leader_close(struct gateway *g, int reason)
 void gateway__close(struct gateway *g)
 {
 	tracef("gateway close");
-
-	if (g->defer.loop != NULL) {
-		uv_close((uv_handle_t *)&g->defer, NULL);
-	}
-
 	if (g->leader == NULL) {
 		stmt__registry_close(&g->stmts);
 		return;
@@ -728,14 +718,6 @@ static void handle_exec_sql_next(struct gateway *g,
 				 struct handle *req,
 				 bool done);
 
-static void handle_exec_sql_next_defer_cb(uv_timer_t *t)
-{
-	struct gateway *g = t->data;
-	PRE(g != NULL && g->req != NULL);
-	PRE(g->req->type == DQLITE_REQUEST_EXEC_SQL);
-	handle_exec_sql_next(g, g->req, true);
-}
-
 static void handle_exec_sql_cb(struct exec *exec, int status)
 {
 	tracef("handle exec sql cb status %d", status);
@@ -745,27 +727,12 @@ static void handle_exec_sql_cb(struct exec *exec, int status)
 	req->exec_count += 1;
 	sqlite3_finalize(exec->stmt);
 
-	if (status != SQLITE_DONE) {
+	if (status == SQLITE_DONE) {
+		handle_exec_sql_next(g, req, true);
+	} else {
 		assert(g->leader != NULL);
 		failure(req, status, error_message(g->leader->conn, status));
 		g->req = NULL;
-		return;
-	}
-
-	/* It would be valid to always invoke handle_exec_sql_next directly
-	 * here. But that can lead to bounded recursion when we have several
-	 * `;`-separated statements in a row that do not generate rows. To make
-	 * sure the stack depth stays under control, we defer have the event
-	 * loop invoke handle_exec_sql_next itself on the next iteration, but
-	 * only if there is a prior call to handle_exec_sql_next above us on
-	 * the stack. We also invoke handle_exec_sql_next directly if the
-	 * gateway doesn't have access to an event loop (this is only the case
-	 * in the unit tests). */
-	if (exec->async || g->defer.loop == NULL) {
-		handle_exec_sql_next(g, req, true);
-	} else {
-		g->defer.data = g;
-		uv_timer_start(&g->defer, handle_exec_sql_next_defer_cb, 0, 0);
 	}
 }
 

src/gateway.h

@@ -35,22 +35,10 @@ struct gateway {
 	uint64_t protocol;           /* Protocol format version */
 	uint64_t client_id;
 	struct id_state random_state; /* For generating IDs */
-	/* The EXEC_SQL request handler uses this to defer work to the next
-	 * loop iteration, to avoid recursion when processing multi-statement
-	 * SQL strings. */
-	uv_timer_t defer;
 };
 
-/**
- * Initialize a gateway.
- *
- * Passing NULL for the `loop` is permitted. Currently the loop is only used
- * optionally to break potential recursion when handling an EXEC_SQL request
- * that containss multiple `;`-separated statements.
- */
 void gateway__init(struct gateway *g,
 		   struct config *config,
-		   uv_loop_t *loop,
 		   struct registry *registry,
 		   struct raft *raft,
 		   struct id_state seed);

src/leader.c

@@ -295,7 +295,6 @@ static void leaderApplyFramesCb(struct raft_apply *req,
 finish:
 	l->inflight = NULL;
 	l->db->tx_id = 0;
-	l->exec->async = true;
 	leaderExecDone(l->exec);
 }
 
@@ -440,8 +439,6 @@ static void execBarrierCb(struct barrier *barrier, int status)
 	struct exec *req = barrier->data;
 	struct leader *l = req->leader;
 
-	req->async = req->barrier.async;
-
 	if (status != 0) {
 		l->exec->status = status;
 		leaderExecDone(l->exec);
@@ -508,7 +505,6 @@ static void raftBarrierCb(struct raft_barrier *req, int status)
 		return;
 	}
 	barrier->cb = NULL;
-	barrier->async = true;
 	cb(barrier, rv);
 }
 
@@ -518,7 +514,6 @@ int leader__barrier(struct leader *l, struct barrier *barrier, barrier_cb cb)
 	int rv;
 	if (!needsBarrier(l)) {
 		tracef("not needed");
-		barrier->async = false;
 		cb(barrier, 0);
 		return 0;
 	}

src/leader.h

@@ -49,9 +49,6 @@ struct barrier {
 	void *data;
 	struct leader *leader;
 	struct raft_barrier req;
-	/* When the callback is invoked, this field is `true` if raft_barrier
-	 * was called and `false` if the callback was invoked immediately. */
-	bool async;
 	barrier_cb cb;
 };
 
@@ -66,12 +63,8 @@ struct exec {
 	uint64_t id;
 	int status;
 	queue queue;
-	pool_work_t work;
-	/* When the callback is invoked, this field is `true` if raft_barrier
-	 * or raft_apply was called and `false` if the callback was invoked
-	 * immediately. */
-	bool async;
 	exec_cb cb;
+	pool_work_t work;
 };
 
 /**

test/integration/test_client.c

@@ -145,29 +145,3 @@ TEST(client, querySql, setUp, tearDown, 0, client_params)
 
 	return MUNIT_OK;
 }
-
-/* Stress test of an EXEC_SQL with many ';'-separated statements. */
-TEST(client, semicolons, setUp, tearDown, 0, NULL)
-{
-	struct fixture *f = data;
-	(void)params;
-
-	static const char trivial_stmt[] = "CREATE TABLE IF NOT EXISTS foo (n INT);";
-
-	size_t n = 1000;
-	size_t unit = sizeof(trivial_stmt) - 1;
-	char *sql = munit_malloc(n * unit);
-	char *p = sql;
-	for (size_t i = 0; i < n; i++) {
-		memcpy(p, trivial_stmt, unit);
-		p += unit;
-	}
-	sql[n * unit - 1] = '\0';
-
-	uint64_t last_insert_id;
-	uint64_t rows_affected;
-	EXEC_SQL(sql, &last_insert_id, &rows_affected);
-
-	free(sql);
-	return MUNIT_OK;
-}

test/unit/test_concurrency.c

@@ -49,12 +49,8 @@ struct connection {
 		struct request_open open;                                  \
 		struct response_db db;                                     \
 		struct id_state seed = { { 1 } };                          \
-		gateway__init(&c->gateway, \
-			      CLUSTER_CONFIG(0), \
-			      NULL, \
-			      CLUSTER_REGISTRY(0), \
-			      CLUSTER_RAFT(0), \
-			      seed); \
+		gateway__init(&c->gateway, CLUSTER_CONFIG(0),              \
+			      CLUSTER_REGISTRY(0), CLUSTER_RAFT(0), seed); \
 		c->handle.data = &c->context;                              \
 		rc = buffer__init(&c->request);                            \
 		munit_assert_int(rc, ==, 0);                               \

test/unit/test_gateway.c

@@ -55,12 +55,8 @@ struct connection {
 		struct id_state seed = { { 1 } };                       \
 		config = CLUSTER_CONFIG(i);                             \
 		config->page_size = 512;                                \
-		gateway__init(&c->gateway, \
-			      config, \
-			      NULL, \
-			      CLUSTER_REGISTRY(i), \
-			      CLUSTER_RAFT(i), \
-			      seed); \
+		gateway__init(&c->gateway, config, CLUSTER_REGISTRY(i), \
+			      CLUSTER_RAFT(i), seed);                   \
 		c->handle.data = &c->context;                           \
 		rc = buffer__init(&c->buf1);                            \
 		munit_assert_int(rc, ==, 0);                            \