[sr-dev] git:master: db_mysql: fixes FS#434, Kamailio will eat sometimes 100% CPU due a bug in db_mysql

Module: sip-router Branch: master Commit: 0d7d5dc4d7219c5beb9a150cc56e74edac9dc4d5 URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=0d7d5dc… Author: Henning Westerholt <hw(a)kamailio.org> Committer: Henning Westerholt <hw(a)kamailio.org> Date: Tue May 27 12:14:24 2014 +0200 db_mysql: fixes FS#434, Kamailio will eat sometimes 100% CPU due a bug in db_mysql * Fixes FS#434 reported from Maxim, incorrect mysql API usage for mysql_next_result(..) * According MySQL doc, return values for mysql_next_result(..) can be the following: 0 - Successful and there are more results -1 - Successful and there are no more results * Thus, if there will be an error when reading a next result, the code will be infinitely looped in “while” cycle and current process will eat 100% CPU (The mysql_more_results will not help here because it just checks a local flag that will be set to TRUE in cases when there will be more than one result). * The solution is to replace " > 0” with " == 0”: --- modules/db_mysql/km_dbase.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/modules/db_mysql/km_dbase.c b/modules/db_mysql/km_dbase.c index cf22e4c..d2ef5c5 100644 --- a/modules/db_mysql/km_dbase.c +++ b/modules/db_mysql/km_dbase.c @@ -258,7 +258,7 @@ static int db_mysql_store_result(const db1_con_t* _h, db1_res_t** _r) db_mysql_free_result(_h, *_r); *_r = 0; #if (MYSQL_VERSION_ID >= 40100) - while( mysql_more_results(CON_CONNECTION(_h)) && mysql_next_result(CON_CONNECTION(_h)) > 0 ) { + while( mysql_more_results(CON_CONNECTION(_h)) && mysql_next_result(CON_CONNECTION(_h)) == 0 ) { MYSQL_RES *res = mysql_store_result( CON_CONNECTION(_h) ); mysql_free_result(res); } @@ -268,7 +268,7 @@ static int db_mysql_store_result(const db1_con_t* _h, db1_res_t** _r) done: #if (MYSQL_VERSION_ID >= 40100) - while( mysql_more_results(CON_CONNECTION(_h)) && mysql_next_result(CON_CONNECTION(_h)) > 0 ) { + while( mysql_more_results(CON_CONNECTION(_h)) && mysql_next_result(CON_CONNECTION(_h)) == 0 ) { MYSQL_RES *res = mysql_store_result( CON_CONNECTION(_h) ); mysql_free_result(res); }