Fix Bug #58653 - Sporadic crash due to assertion failure 0 == space->n_pending_flushes

      
Check whether the master and purge thread are active after creating them. Do
not proceed until both threads have started. We do this by checking whether a
slot has been reserved by both the respective threads.
      
Add srv_thread_has_reserved_slot() returns slot no or ULINT_UNDEFINED.
      
rb://536 Approved by Jimmy

storage/innobase/include/srv0srv.h

@@ -476,6 +476,14 @@ enum srv_thread_type
 srv_get_thread_type(void);
 /*=====================*/
 /*********************************************************************//**
+Check whether thread type has reserved a slot.
+@return	slot number or UNDEFINED if not found*/
+UNIV_INTERN
+ulint
+srv_thread_has_reserved_slot(
+/*=========================*/
+	enum srv_thread_type	type);	/*!< in: thread type to check */
+/*********************************************************************//**
 Sets the info describing an i/o thread current state. */
 UNIV_INTERN
 void

storage/innobase/srv/srv0srv.c

@@ -982,6 +982,37 @@ srv_get_thread_type(void)
 	return(type);
 }
 
+/*********************************************************************//**
+Check whether thread type has reserved a slot. Return the first slot that
+is found. This works because we currently have only 1 thread of each type.
+@return	slot number or ULINT_UNDEFINED if not found*/
+UNIV_INTERN
+ulint
+srv_thread_has_reserved_slot(
+/*=========================*/
+	enum srv_thread_type	type)	/*!< in: thread type to check */
+{
+	ulint			i;
+	ulint			slot_no = ULINT_UNDEFINED;
+
+	mutex_enter(&kernel_mutex);
+
+	for (i = 0; i < OS_THREAD_MAX_N; i++) {
+		srv_slot_t*	slot;
+
+		slot = srv_table_get_nth_slot(i);
+
+		if (slot->in_use && slot->type == type) {
+			slot_no = i;
+			break;
+		}
+	}
+
+	mutex_exit(&kernel_mutex);
+
+	return(slot_no);
+}
+
 /*********************************************************************//**
 Initializes the server. */
 UNIV_INTERN

storage/innobase/srv/srv0start.c

@@ -1833,6 +1833,24 @@ innobase_start_or_create_for_mysql(void)
 		os_thread_create(&srv_purge_thread, NULL, NULL);
 	}
 
+	/* Wait for the purge and master thread to startup. */
+
+	while (srv_shutdown_state == SRV_SHUTDOWN_NONE) {
+		if (srv_thread_has_reserved_slot(SRV_MASTER) == ULINT_UNDEFINED
+		    || (srv_n_purge_threads == 1
+			&& srv_thread_has_reserved_slot(SRV_WORKER)
+			== ULINT_UNDEFINED)) {
+
+			ut_print_timestamp(stderr);
+			fprintf(stderr, "  InnoDB: "
+				"Waiting for the background threads to "
+				"start\n");
+			os_thread_sleep(1000000);
+		} else {
+			break;
+		}
+	}
+
 #ifdef UNIV_DEBUG
 	/* buf_debug_prints = TRUE; */
 #endif /* UNIV_DEBUG */