| Bug #80961 | mysql_stmt_execute() will block if table empty | ||
|---|---|---|---|
| Submitted: | 5 Apr 2016 14:45 | Modified: | 6 Apr 2016 18:06 |
| Reporter: | chen taosheng | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Server: C API (client library) | Severity: | S3 (Non-critical) |
| Version: | 5.7.11 | OS: | Windows (windows 7) |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | CURSOR_TYPE_READ_ONLY, mysql_stmt_execute | ||
[6 Apr 2016 18:06]
MySQL Verification Team
Thank you for the bug report. It hangs only with server 5.7.XX and not repeatable with server 5.6.XX even with the client compiled against 5.7 client library. c:\tmp>c:\dbs\5.6\bin\mysql -uroot -p testdb Enter password: ****** Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 10 Server version: 5.6.29-log MySQL Community Server (GPL) Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> select * from test_table; Empty set (0.00 sec) mysql> exit Bye c:\tmp>bug80961.exe Connected to the server: 5.6.29-log Client Info: 5.7.13 prepare, SELECT successful Done!! c:\tmp>c:\dbs\5.7\bin\mysql -uroot --port=3307 -p testdb Enter password: ****** Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 18 Server version: 5.7.11-log MySQL Community Server (GPL) Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> select * from test_table; Empty set (0.00 sec) mysql> exit Bye c:\tmp>bug80961.exe Connected to the server: 5.7.11-log Client Info: 5.7.13 prepare, SELECT successful ^C
[6 Apr 2016 18:12]
MySQL Verification Team
c:\tmp>c:\dbs\5.7\bin\mysql -uroot --port=3307 -p testdb -e "insert into test_table values (1,'a',1,NULL)" Enter password: ****** c:\tmp>bug80961.exe Connected to the server: 5.7.11-log Client Info: 5.7.13 prepare, SELECT successful Done!!
Description: mysql_stmt_execute() will block: #include <string.h> #include <mysql.h> int main(int argc, char **argv) { #define STRING_SIZE 50 #define SELECT_SAMPLE "call SP_TEST()" /* CREATE TABLE `test_table` ( `col1` int(10) UNSIGNED NOT NULL AUTO_INCREMENT , `col2` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL , `col3` smallint(6) NULL DEFAULT NULL , `col4` timestamp(6) NULL DEFAULT NULL , PRIMARY KEY (`col1`) ) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci AUTO_INCREMENT=2 ROW_FORMAT=DYNAMIC ; */ /* CREATE DEFINER = `root`@`%` PROCEDURE `SP_TEST`() BEGIN SELECT col1, col2, col3, col4 FROM test_table; END; */ MYSQL *mysql; mysql = mysql_init(NULL); if (mysql == NULL) { fprintf(stderr, " mysql_init() error.\n"); exit(0); } if (!mysql_real_connect(mysql, "127.0.0.1", "root", "root", "testdb", 3306, NULL, 0)) { fprintf(stderr, " mysql_real_connect() error.\n"); exit(0); } MYSQL_STMT *stmt; MYSQL_BIND bind[4]; MYSQL_RES *prepare_meta_result; MYSQL_TIME ts; unsigned long length[4]; int param_count, column_count, row_count; short small_data; int int_data; char str_data[STRING_SIZE]; my_bool is_null[4]; my_bool error[4]; /* Prepare a SELECT query to fetch data from test_table */ stmt = mysql_stmt_init(mysql); if (!stmt) { fprintf(stderr, " mysql_stmt_init(), out of memory\n"); exit(0); } unsigned long type = (unsigned long)CURSOR_TYPE_READ_ONLY; unsigned long prefetch_rows = 50; mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, (void*)&type); if (mysql_stmt_attr_set(stmt, STMT_ATTR_PREFETCH_ROWS, (void*)&prefetch_rows)) { fprintf(stderr, " %s\n", mysql_stmt_error(stmt)); exit(0); } if (mysql_stmt_prepare(stmt, SELECT_SAMPLE, strlen(SELECT_SAMPLE))) { fprintf(stderr, " mysql_stmt_prepare(), SELECT failed\n"); fprintf(stderr, " %s\n", mysql_stmt_error(stmt)); exit(0); } fprintf(stdout, " prepare, SELECT successful\n"); /* Execute the SELECT query */ if (mysql_stmt_execute(stmt)) { fprintf(stderr, " mysql_stmt_execute(), failed\n"); fprintf(stderr, " %s\n", mysql_stmt_error(stmt)); exit(0); } /* .... */ /* Close the statement */ if (mysql_stmt_close(stmt)) { fprintf(stderr, " failed while closing the statement\n"); fprintf(stderr, " %s\n", mysql_stmt_error(stmt)); exit(0); } mysql_close(mysql); return 0; } How to repeat: 1) use procedure to query data 2) table empty 3) set CURSOR_TYPE_READ_ONLY