1 /** @file the_Foundation/threadpool.h Thread pool.
2
3 @authors Copyright (c) 2017 Jaakko Keränen <jaakko.keranen@iki.fi>
4
5 @par License
6
7 Redistribution and use in source and binary forms, with or without
8 modification, are permitted provided that the following conditions are met:
9
10 1. Redistributions of source code must retain the above copyright notice, this
11 list of conditions and the following disclaimer.
12 2. Redistributions in binary form must reproduce the above copyright notice,
13 this list of conditions and the following disclaimer in the documentation
14 and/or other materials provided with the distribution.
15
16 <small>THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
20 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</small>
26 */
27
28 #include "the_Foundation/threadpool.h"
29
30 void finish_Thread_(iThread *); // thread.c
31
32 iDeclareClass(PooledThread)
33
34 struct Impl_PooledThread {
35 iThread thread;
36 iThreadPool *pool;
37 };
38
run_PooledThread_(iThread * thread)39 static iThreadResult run_PooledThread_(iThread *thread) {
40 iPooledThread *d = (iAny *) thread;
41 while (yield_ThreadPool(d->pool, 0.0)) { /* Keep going. */ }
42 return 0;
43 }
44
init_PooledThread(iPooledThread * d,iThreadPool * pool)45 static void init_PooledThread(iPooledThread *d, iThreadPool *pool) {
46 init_Thread(&d->thread, run_PooledThread_);
47 setName_Thread(&d->thread, "PooledThread");
48 d->pool = pool;
49 }
50
deinit_PooledThread(iPooledThread * d)51 static void deinit_PooledThread(iPooledThread *d) {
52 iUnused(d);
53 }
54
iDefineSubclass(PooledThread,Thread)55 iDefineSubclass(PooledThread, Thread)
56 iDefineObjectConstructionArgs(PooledThread, (iThreadPool *pool), pool)
57
58 iLocalDef void start_PooledThread(iPooledThread *d) { start_Thread(&d->thread); }
join_PooledThread(iPooledThread * d)59 iLocalDef void join_PooledThread (iPooledThread *d) { join_Thread(&d->thread); }
60
61 /*-------------------------------------------------------------------------------------*/
62
63 iDefineClass(ThreadPool)
iDefineObjectConstruction(ThreadPool)64 iDefineObjectConstruction(ThreadPool)
65
66 static void startThreads_ThreadPool_(iThreadPool *d, int minThreads, int reservedCores) {
67 const int count = iMaxi(iMaxi(1, minThreads), idealConcurrentCount_Thread() - reservedCores);
68 for (int i = 0; i < count; ++i) {
69 iPooledThread *pt = new_PooledThread(d);
70 pushBack_ObjectList(d->threads, pt);
71 start_PooledThread(pt);
72 iRelease(pt);
73 }
74 }
75
stopThreads_ThreadPool_(iThreadPool * d)76 static void stopThreads_ThreadPool_(iThreadPool *d) {
77 for (size_t count = size_ObjectList(d->threads); count; count--) {
78 put_Queue(&d->queue, d);
79 }
80 iForEach(ObjectList, i, d->threads) {
81 join_PooledThread((iPooledThread *) i.value->object);
82 remove_ObjectListIterator(&i);
83 }
84 }
85
newLimits_ThreadPool(int minThreads,int reservedCores)86 iThreadPool *newLimits_ThreadPool(int minThreads, int reservedCores) {
87 iThreadPool *d = iNew(ThreadPool);
88 initLimits_ThreadPool(d, minThreads, reservedCores);
89 return d;
90 }
91
init_ThreadPool(iThreadPool * d)92 void init_ThreadPool(iThreadPool *d) {
93 initLimits_ThreadPool(d, 0, 0);
94 }
95
initLimits_ThreadPool(iThreadPool * d,int minThreads,int reservedCores)96 void initLimits_ThreadPool(iThreadPool *d, int minThreads, int reservedCores) {
97 init_Queue(&d->queue);
98 d->threads = new_ObjectList();
99 startThreads_ThreadPool_(d, minThreads, reservedCores);
100 }
101
deinit_ThreadPool(iThreadPool * d)102 void deinit_ThreadPool(iThreadPool *d) {
103 stopThreads_ThreadPool_(d);
104 iRelease(d->threads);
105 deinit_Queue(&d->queue);
106 }
107
run_ThreadPool(iThreadPool * d,iThread * thread)108 iThread *run_ThreadPool(iThreadPool *d, iThread *thread) {
109 if (thread) {
110 put_Queue(&d->queue, thread);
111 }
112 return thread;
113 }
114
yield_ThreadPool(iThreadPool * d,double timeoutSeconds)115 iBool yield_ThreadPool(iThreadPool *d, double timeoutSeconds) {
116 iThread *job = NULL;
117 if (timeoutSeconds <= 0.0) {
118 job = (iAny *) take_Queue(&d->queue);
119 }
120 else {
121 job = (iAny *) takeTimeout_Queue(&d->queue, timeoutSeconds);
122 }
123 if (job == NULL || job == (void *) d) {
124 /* Terminated. */
125 return iFalse;
126 }
127 /* Run in the calling thread. */
128 iAssert(job->state == created_ThreadState);
129 iGuardMutex(&job->mutex, job->state = running_ThreadState);
130 job->result = job->run(job);
131 finish_Thread_(job);
132 iRelease(job);
133 return iTrue;
134 }
135