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Diffstat (limited to 'sql/threadpool.h')
| -rw-r--r-- | sql/threadpool.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/sql/threadpool.h b/sql/threadpool.h new file mode 100644 index 00000000..d815d538 --- /dev/null +++ b/sql/threadpool.h @@ -0,0 +1,166 @@ +/* Copyright (C) 2012, 2020, MariaDB + + 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 Street, Fifth Floor, Boston, MA 02110-1335 USA */ + +#pragma once +#ifdef HAVE_POOL_OF_THREADS +#define MAX_THREAD_GROUPS 100000 + +/* Threadpool parameters */ +extern uint threadpool_min_threads; /* Minimum threads in pool */ +extern uint threadpool_idle_timeout; /* Shutdown idle worker threads after this timeout */ +extern uint threadpool_size; /* Number of parallel executing threads */ +extern uint threadpool_max_size; +extern uint threadpool_stall_limit; /* time interval in milliseconds for stall checks*/ +extern uint threadpool_max_threads; /* Maximum threads in pool */ +extern uint threadpool_oversubscribe; /* Maximum active threads in group */ +extern uint threadpool_prio_kickup_timer; /* Time before low prio item gets prio boost */ +extern my_bool threadpool_exact_stats; /* Better queueing time stats for information_schema, at small performance cost */ +extern my_bool threadpool_dedicated_listener; /* Listener thread does not pick up work items. */ +#ifdef _WIN32 +extern uint threadpool_mode; /* Thread pool implementation , windows or generic */ +#define TP_MODE_WINDOWS 0 +#define TP_MODE_GENERIC 1 +#endif + +#define DEFAULT_THREADPOOL_STALL_LIMIT 500U + +struct TP_connection; +struct st_vio; + +extern void tp_callback(TP_connection *c); +extern void tp_timeout_handler(TP_connection *c); + + + +/* + Threadpool statistics +*/ +struct TP_STATISTICS +{ + /* Current number of worker thread. */ + Atomic_counter<uint32_t> num_worker_threads; +}; + +extern TP_STATISTICS tp_stats; + + +/* Functions to set threadpool parameters */ +extern void tp_set_min_threads(uint val); +extern void tp_set_max_threads(uint val); +extern void tp_set_threadpool_size(uint val); +extern void tp_set_threadpool_stall_limit(uint val); +extern int tp_get_idle_thread_count(); +extern int tp_get_thread_count(); + + +enum TP_PRIORITY { + TP_PRIORITY_HIGH, + TP_PRIORITY_LOW, + TP_PRIORITY_AUTO +}; + + +enum TP_STATE +{ + TP_STATE_IDLE, + TP_STATE_RUNNING, + TP_STATE_PENDING +}; + +/* + Connection structure, encapsulates THD + structures for asynchronous + IO and pool. + + Platform specific parts are specified in subclasses called connection_t, + inside threadpool_win.cc and threadpool_unix.cc +*/ + +class CONNECT; + +struct TP_connection +{ + THD* thd; + CONNECT* connect; + TP_STATE state; + TP_PRIORITY priority; + TP_connection(CONNECT *c) : + thd(0), + connect(c), + state(TP_STATE_IDLE), + priority(TP_PRIORITY_HIGH) + {} + + virtual ~TP_connection() = default; + + /* Initialize io structures windows threadpool, epoll etc */ + virtual int init() = 0; + + virtual void set_io_timeout(int sec) = 0; + + /* Read for the next client command (async) with specified timeout */ + virtual int start_io() = 0; + + virtual void wait_begin(int type)= 0; + virtual void wait_end() = 0; + IF_WIN(virtual,) void init_vio(st_vio *){}; +}; + + +struct TP_pool +{ + virtual ~TP_pool() = default; + virtual int init()= 0; + virtual TP_connection *new_connection(CONNECT *)= 0; + virtual void add(TP_connection *c)= 0; + virtual int set_max_threads(uint){ return 0; } + virtual int set_min_threads(uint){ return 0; } + virtual int set_pool_size(uint){ return 0; } + virtual int set_idle_timeout(uint){ return 0; } + virtual int set_oversubscribe(uint){ return 0; } + virtual int set_stall_limit(uint){ return 0; } + virtual int get_thread_count() { return tp_stats.num_worker_threads; } + virtual int get_idle_thread_count(){ return 0; } + virtual void resume(TP_connection* c)=0; +}; + +#ifdef _WIN32 + +struct TP_pool_win:TP_pool +{ + TP_pool_win(); + virtual int init(); + virtual ~TP_pool_win(); + virtual TP_connection *new_connection(CONNECT *c); + virtual void add(TP_connection *); + virtual int set_max_threads(uint); + virtual int set_min_threads(uint); + void resume(TP_connection *c); +}; +#endif + +struct TP_pool_generic :TP_pool +{ + TP_pool_generic(); + ~TP_pool_generic(); + virtual int init(); + virtual TP_connection *new_connection(CONNECT *c); + virtual void add(TP_connection *); + virtual int set_pool_size(uint); + virtual int set_stall_limit(uint); + virtual int get_idle_thread_count(); + void resume(TP_connection* c); +}; + +#endif /* HAVE_POOL_OF_THREADS */ |