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Diffstat (limited to '')
-rw-r--r-- | sql/scheduler.cc | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/sql/scheduler.cc b/sql/scheduler.cc new file mode 100644 index 00000000..7380b134 --- /dev/null +++ b/sql/scheduler.cc @@ -0,0 +1,141 @@ +/* Copyright (c) 2007, 2013, Oracle and/or its affiliates. + Copyright (c) 2012, 2014, SkySQL Ab. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* + Implementation for the thread scheduler +*/ + +#ifdef USE_PRAGMA_INTERFACE +#pragma implementation +#endif + +#include "mariadb.h" +#include "mysqld.h" +#include "scheduler.h" +#include "sql_class.h" +#include "sql_callback.h" +#include <violite.h> + +/** @internal + Helper functions to allow mysys to call the thread scheduler when + waiting for locks. +*/ + +/**@{*/ +extern "C" +{ +static void scheduler_wait_lock_begin(void) { + thd_wait_begin(NULL, THD_WAIT_TABLE_LOCK); +} + +static void scheduler_wait_lock_end(void) { + thd_wait_end(NULL); +} + +static void scheduler_wait_sync_begin(void) { + thd_wait_begin(NULL, THD_WAIT_SYNC); +} + +static void scheduler_wait_sync_end(void) { + thd_wait_end(NULL); +} + +static void scheduler_wait_net_begin(void) { + thd_wait_begin(NULL, THD_WAIT_NET); +} + +static void scheduler_wait_net_end(void) { + thd_wait_end(NULL); +} + +}; +/**@}*/ + +/** + Common scheduler init function. + + The scheduler is either initialized by calling + one_thread_scheduler() or one_thread_per_connection_scheduler() in + mysqld.cc, so this init function will always be called. + */ + +void scheduler_init() +{ + thr_set_lock_wait_callback(scheduler_wait_lock_begin, + scheduler_wait_lock_end); + thr_set_sync_wait_callback(scheduler_wait_sync_begin, + scheduler_wait_sync_end); + + vio_set_wait_callback(scheduler_wait_net_begin, + scheduler_wait_net_end); +} + + +/** + Kill notification callback, used by one-thread-per-connection + and threadpool scheduler. + + Wakes up a thread that is stuck in read/poll/epoll/event-poll + routines used by threadpool, such that subsequent attempt to + read from client connection will result in IO error. +*/ + +void post_kill_notification(THD *thd) +{ + DBUG_ENTER("post_kill_notification"); + if (current_thd == thd || thd->system_thread) + DBUG_VOID_RETURN; + + if (thd->net.vio) + vio_shutdown(thd->net.vio, SHUT_RD); + DBUG_VOID_RETURN; +} + +/* + Initialize scheduler for --thread-handling=one-thread-per-connection +*/ + +#ifndef EMBEDDED_LIBRARY + +void one_thread_per_connection_scheduler(scheduler_functions *func, + ulong *arg_max_connections, + Atomic_counter<uint> *arg_connection_count) +{ + scheduler_init(); + func->max_threads= *arg_max_connections + 1; + func->max_connections= arg_max_connections; + func->connection_count= arg_connection_count; + func->add_connection= create_thread_to_handle_connection; + func->post_kill_notification= post_kill_notification; +} +#else +void handle_connection_in_main_thread(CONNECT *connect) +{ +} +#endif + +/* + Initialize scheduler for --thread-handling=no-threads +*/ + +void one_thread_scheduler(scheduler_functions *func) +{ + scheduler_init(); + func->max_threads= 1; + func->max_connections= &max_connections; + func->connection_count= &connection_count; + func->add_connection= handle_connection_in_main_thread; +} |