libresman

annotate src/threadpool.c @ 15:2b8281a146af

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added debugging crap in the threadpool
author John Tsiombikas <nuclear@member.fsf.org>
date Tue, 11 Feb 2014 18:47:00 +0200
parents 84f55eab27cb
children 711698580eb0
rev   line source
nuclear@6 1 #include <stdio.h>
nuclear@6 2 #include <stdlib.h>
nuclear@6 3 #include <string.h>
nuclear@6 4 #include <pthread.h>
nuclear@6 5 #include "threadpool.h"
nuclear@6 6
nuclear@6 7 struct work_item {
nuclear@15 8 int id; /* just for debugging messages */
nuclear@6 9 void *data;
nuclear@6 10 struct work_item *next;
nuclear@6 11 };
nuclear@6 12
nuclear@6 13 struct thread_pool {
nuclear@6 14 pthread_t *workers;
nuclear@6 15 int num_workers;
nuclear@6 16
nuclear@6 17 pthread_mutex_t work_lock;
nuclear@6 18 pthread_cond_t work_cond;
nuclear@6 19
nuclear@6 20 tpool_work_func work_func;
nuclear@6 21 void *cls;
nuclear@6 22
nuclear@6 23 struct work_item *work_list, *work_list_tail;
nuclear@6 24 int work_count;
nuclear@6 25 };
nuclear@6 26
nuclear@6 27
nuclear@6 28 static void *thread_func(void *tp);
nuclear@6 29 static struct work_item *alloc_node(void);
nuclear@6 30 static void free_node(struct work_item *node);
nuclear@6 31 static int get_processor_count(void);
nuclear@6 32
nuclear@6 33
nuclear@6 34
nuclear@6 35 int tpool_init(struct thread_pool *tpool, int num_threads)
nuclear@6 36 {
nuclear@6 37 int i;
nuclear@6 38
nuclear@6 39 memset(tpool, 0, sizeof *tpool);
nuclear@6 40
nuclear@11 41
nuclear@11 42 pthread_mutex_init(&tpool->work_lock, 0);
nuclear@11 43 pthread_cond_init(&tpool->work_cond, 0);
nuclear@11 44
nuclear@11 45
nuclear@6 46 if(num_threads <= 0) {
nuclear@6 47 num_threads = get_processor_count();
nuclear@6 48 }
nuclear@6 49 tpool->num_workers = num_threads;
nuclear@6 50
nuclear@6 51 printf("initializing thread pool with %d worker threads\n", num_threads);
nuclear@6 52
nuclear@11 53 if(!(tpool->workers = malloc(num_threads * sizeof *tpool->workers))) {
nuclear@11 54 fprintf(stderr, "failed to create array of %d threads\n", num_threads);
nuclear@11 55 return -1;
nuclear@11 56 }
nuclear@11 57
nuclear@6 58 for(i=0; i<num_threads; i++) {
nuclear@6 59 if(pthread_create(tpool->workers + i, 0, thread_func, tpool) == -1) {
nuclear@6 60 fprintf(stderr, "%s: failed to create thread %d\n", __FUNCTION__, i);
nuclear@6 61 tpool_destroy(tpool);
nuclear@6 62 return -1;
nuclear@6 63 }
nuclear@6 64 }
nuclear@6 65 return 0;
nuclear@6 66 }
nuclear@6 67
nuclear@6 68 void tpool_destroy(struct thread_pool *tpool)
nuclear@6 69 {
nuclear@6 70 int i;
nuclear@6 71 for(i=0; i<tpool->num_workers; i++) {
nuclear@6 72 void *ret;
nuclear@6 73 pthread_join(tpool->workers[i], &ret);
nuclear@6 74 }
nuclear@6 75
nuclear@6 76 pthread_mutex_destroy(&tpool->work_lock);
nuclear@6 77 pthread_cond_destroy(&tpool->work_cond);
nuclear@6 78 }
nuclear@6 79
nuclear@10 80 struct thread_pool *tpool_create(int num_threads)
nuclear@10 81 {
nuclear@10 82 struct thread_pool *tpool = malloc(sizeof *tpool);
nuclear@10 83 if(!tpool) {
nuclear@10 84 return 0;
nuclear@10 85 }
nuclear@10 86 if(tpool_init(tpool, num_threads) == -1) {
nuclear@10 87 free(tpool);
nuclear@10 88 return 0;
nuclear@10 89 }
nuclear@10 90 return tpool;
nuclear@10 91 }
nuclear@10 92
nuclear@10 93 void tpool_free(struct thread_pool *tpool)
nuclear@10 94 {
nuclear@10 95 if(tpool) {
nuclear@10 96 tpool_destroy(tpool);
nuclear@10 97 free(tpool);
nuclear@10 98 }
nuclear@10 99 }
nuclear@10 100
nuclear@6 101 void tpool_set_work_func(struct thread_pool *tpool, tpool_work_func func, void *cls)
nuclear@6 102 {
nuclear@6 103 tpool->work_func = func;
nuclear@6 104 tpool->cls = cls;
nuclear@6 105 }
nuclear@6 106
nuclear@6 107 int tpool_add_work(struct thread_pool *tpool, void *data)
nuclear@6 108 {
nuclear@6 109 struct work_item *node;
nuclear@15 110 static int jcounter;
nuclear@6 111
nuclear@6 112 if(!(node = alloc_node())) {
nuclear@6 113 fprintf(stderr, "%s: failed to allocate new work item node\n", __FUNCTION__);
nuclear@6 114 return -1;
nuclear@6 115 }
nuclear@6 116 node->data = data;
nuclear@6 117 node->next = 0;
nuclear@6 118
nuclear@6 119 pthread_mutex_lock(&tpool->work_lock);
nuclear@15 120 node->id = jcounter++;
nuclear@15 121
nuclear@15 122 printf("TPOOL: adding work item: %d\n", node->id);
nuclear@6 123
nuclear@6 124 if(!tpool->work_list) {
nuclear@6 125 tpool->work_list = tpool->work_list_tail = node;
nuclear@6 126 } else {
nuclear@6 127 tpool->work_list_tail->next = node;
nuclear@6 128 tpool->work_list_tail = node;
nuclear@6 129 }
nuclear@12 130 pthread_mutex_unlock(&tpool->work_lock);
nuclear@6 131
nuclear@12 132 /* wakeup all threads, there's work to do */
nuclear@12 133 pthread_cond_broadcast(&tpool->work_cond);
nuclear@6 134 return 0;
nuclear@6 135 }
nuclear@6 136
nuclear@6 137
nuclear@6 138 static void *thread_func(void *tp)
nuclear@6 139 {
nuclear@15 140 int i, tidx = -1;
nuclear@6 141 struct work_item *job;
nuclear@6 142 struct thread_pool *tpool = tp;
nuclear@15 143 pthread_t tid = pthread_self();
nuclear@15 144
nuclear@15 145 for(i=0; i<tpool->num_workers; i++) {
nuclear@15 146 if(tpool[i].workers[i] == tid) {
nuclear@15 147 tidx = i;
nuclear@15 148 break;
nuclear@15 149 }
nuclear@15 150 }
nuclear@6 151
nuclear@6 152 pthread_mutex_lock(&tpool->work_lock);
nuclear@6 153 for(;;) {
nuclear@6 154 /* while there aren't any work items to do go to sleep on the condvar */
nuclear@6 155 pthread_cond_wait(&tpool->work_cond, &tpool->work_lock);
nuclear@6 156 if(!tpool->work_list) {
nuclear@6 157 continue; /* spurious wakeup, go back to sleep */
nuclear@6 158 }
nuclear@6 159
nuclear@15 160 printf("TPOOL: worker %d start job: %d\n", tidx, job->id);
nuclear@15 161
nuclear@6 162 job = tpool->work_list;
nuclear@6 163 tpool->work_list = tpool->work_list->next;
nuclear@6 164
nuclear@6 165 tpool->work_func(job->data, tpool->cls);
nuclear@9 166
nuclear@15 167 printf("TPOOL: worker %d completed job: %d\n", tidx, job->id);
nuclear@9 168 free_node(job);
nuclear@6 169 }
nuclear@6 170 pthread_mutex_unlock(&tpool->work_lock);
nuclear@6 171 return 0;
nuclear@6 172 }
nuclear@6 173
nuclear@6 174 /* TODO: custom allocator */
nuclear@6 175 static struct work_item *alloc_node(void)
nuclear@6 176 {
nuclear@6 177 return malloc(sizeof(struct work_item));
nuclear@6 178 }
nuclear@6 179
nuclear@6 180 static void free_node(struct work_item *node)
nuclear@6 181 {
nuclear@6 182 free(node);
nuclear@6 183 }
nuclear@6 184
nuclear@6 185 /* The following highly platform-specific code detects the number
nuclear@6 186 * of processors available in the system. It's used by the thread pool
nuclear@6 187 * to autodetect how many threads to spawn.
nuclear@6 188 * Currently works on: Linux, BSD, Darwin, and Windows.
nuclear@6 189 */
nuclear@6 190
nuclear@6 191 #if defined(__APPLE__) && defined(__MACH__)
nuclear@6 192 # ifndef __unix__
nuclear@6 193 # define __unix__ 1
nuclear@6 194 # endif /* unix */
nuclear@6 195 # ifndef __bsd__
nuclear@6 196 # define __bsd__ 1
nuclear@6 197 # endif /* bsd */
nuclear@6 198 #endif /* apple */
nuclear@6 199
nuclear@6 200 #if defined(unix) || defined(__unix__)
nuclear@6 201 #include <unistd.h>
nuclear@6 202
nuclear@6 203 # ifdef __bsd__
nuclear@6 204 # include <sys/sysctl.h>
nuclear@6 205 # endif
nuclear@6 206 #endif
nuclear@6 207
nuclear@6 208 #if defined(WIN32) || defined(__WIN32__)
nuclear@6 209 #include <windows.h>
nuclear@6 210 #endif
nuclear@6 211
nuclear@6 212
nuclear@6 213 static int get_processor_count(void)
nuclear@6 214 {
nuclear@6 215 #if defined(unix) || defined(__unix__)
nuclear@6 216 # if defined(__bsd__)
nuclear@6 217 /* BSD systems provide the num.processors through sysctl */
nuclear@6 218 int num, mib[] = {CTL_HW, HW_NCPU};
nuclear@6 219 size_t len = sizeof num;
nuclear@6 220
nuclear@6 221 sysctl(mib, 2, &num, &len, 0, 0);
nuclear@6 222 return num;
nuclear@6 223
nuclear@6 224 # elif defined(__sgi)
nuclear@6 225 /* SGI IRIX flavour of the _SC_NPROC_ONLN sysconf */
nuclear@6 226 return sysconf(_SC_NPROC_ONLN);
nuclear@6 227 # else
nuclear@6 228 /* Linux (and others?) have the _SC_NPROCESSORS_ONLN sysconf */
nuclear@6 229 return sysconf(_SC_NPROCESSORS_ONLN);
nuclear@6 230 # endif /* bsd/sgi/other */
nuclear@6 231
nuclear@6 232 #elif defined(WIN32) || defined(__WIN32__)
nuclear@6 233 /* under windows we need to call GetSystemInfo */
nuclear@6 234 SYSTEM_INFO info;
nuclear@6 235 GetSystemInfo(&info);
nuclear@6 236 return info.dwNumberOfProcessors;
nuclear@6 237 #endif
nuclear@6 238 }