src/scheduler.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
   2
   3 /*  Monkey HTTP Daemon
   4  *  ------------------
   5  *  Copyright (C) 2008, Eduardo Silva P.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <errno.h>
  25 #include <pthread.h>
  26 #include <sys/epoll.h>
  27 #include <unistd.h>
  28 #include <sys/syscall.h>
  29 #include <string.h>
  30
  31 #include "monkey.h"
  32 #include "conn_switch.h"
  33 #include "signal.h"
  34 #include "scheduler.h"
  35 #include "memory.h"
  36 #include "epoll.h"
  37 #include "request.h"
  38 #include "cache.h"
  39 #include "config.h"
  40 #include "clock.h"
  41
  42 /* Register thread information */
  43 int mk_sched_register_thread(pthread_t tid, int efd)
  44 {
  45         int i;
  46         struct sched_list_node *sr, *aux;
  47
  48         sr = mk_mem_malloc_z(sizeof(struct sched_list_node));
  49         sr->tid = tid;
  50         sr->pid = -1;
  51         sr->epoll_fd = efd;
  52         sr->queue = mk_mem_malloc_z(sizeof(struct sched_connection)*
  53                                     config->worker_capacity);
  54         sr->request_handler = NULL;
  55         sr->next = NULL;
  56
  57         for(i=0; i<config->worker_capacity; i++){
  58                 sr->queue[i].status = MK_SCHEDULER_CONN_AVAILABLE;
  59         }
  60
  61         if(!sched_list)
  62         {
  63                 sr->idx = 1;
  64                 sched_list = sr;
  65                 return 0;
  66         }
  67
  68         aux = sched_list;
  69         while(aux->next)
  70         {
  71                 aux = aux->next;
  72         }
  73         sr->idx = aux->idx + 1;
  74         aux->next = sr;
  75
  76         return 0;
  77 }
  78
  79 /*
  80  * Create thread which will be listening
  81  * for incomings file descriptors
  82  */
  83 int mk_sched_launch_thread(int max_events)
  84 {
  85         int efd;
  86         pthread_t tid;
  87         pthread_attr_t attr;
  88         sched_thread_conf *thconf;
  89         pthread_mutex_t mutex_wait_register;
  90
  91         /* Creating epoll file descriptor */
  92         efd = mk_epoll_create(max_events);
  93         if(efd < 1)
  94         {
  95                 return -1;
  96         }
  97
  98         /* Thread stuff */
  99         pthread_mutex_init(&mutex_wait_register,(pthread_mutexattr_t *) NULL);
 100         pthread_mutex_lock(&mutex_wait_register);
 101
 102         thconf = mk_mem_malloc(sizeof(sched_thread_conf));
 103         thconf->epoll_fd = efd;
 104         thconf->max_events = max_events;
 105
 106         pthread_attr_init(&attr);
 107         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 108         if(pthread_create(&tid, &attr, mk_sched_launch_epoll_loop,
 109                                 (void *) thconf)!=0)
 110         {
 111                 perror("pthread_create");
 112                 return -1;
 113         }
 114
 115         /* Register working thread */
 116         mk_sched_register_thread(tid, efd);
 117         pthread_mutex_unlock(&mutex_wait_register);
 118         return 0;
 119 }
 120
 121 /* created thread, all this calls are in the thread context */
 122 void *mk_sched_launch_epoll_loop(void *thread_conf)
 123 {
 124         sched_thread_conf *thconf;
 125         struct sched_list_node *thinfo;
 126
 127         /* Avoid SIGPIPE signals */
 128         mk_signal_thread_sigpipe_safe();
 129
 130         thconf = thread_conf;
 131
 132         /* Init specific thread cache */
 133         mk_cache_thread_init();
 134
 135         mk_epoll_calls *callers;
 136         callers = mk_epoll_set_callers((void *)mk_conn_switch,
 137                         MK_CONN_SWITCH_READ,
 138                         MK_CONN_SWITCH_WRITE);
 139
 140         /* Nasty way to export task id */
 141         usleep(1000);
 142         thinfo = mk_sched_get_thread_conf();
 143         while(!thinfo){
 144                 thinfo = mk_sched_get_thread_conf();
 145         }
 146
 147         /* Glibc doesn't export to user space the gettid() syscall */
 148         thinfo->pid = syscall(__NR_gettid);
 149
 150         mk_sched_set_thread_poll(thconf->epoll_fd);
 151         mk_epoll_init(thconf->epoll_fd, callers, thconf->max_events);
 152
 153         return 0;
 154 }
 155
 156 struct request_idx *mk_sched_get_request_index()
 157 {
 158         return (struct request_idx *) pthread_getspecific(request_index);
 159 }
 160
 161 void mk_sched_set_request_index(struct request_idx *ri)
 162 {
 163         pthread_setspecific(request_index, (void *)ri);
 164 }
 165
 166 void mk_sched_set_thread_poll(int epoll)
 167 {
 168         pthread_setspecific(epoll_fd, (void *) epoll);
 169 }
 170
 171 int mk_sched_get_thread_poll()
 172 {
 173         return (int) pthread_getspecific(epoll_fd);
 174 }
 175
 176 struct sched_list_node *mk_sched_get_thread_conf()
 177 {
 178         struct sched_list_node *node;
 179         pthread_t current;
 180
 181         current = pthread_self();
 182         node = sched_list;
 183         while(node){
 184                 if(pthread_equal(node->tid, current) != 0){
 185                         return node;
 186                 }
 187                 node = node->next;
 188         }
 189
 190         return NULL;
 191 }
 192
 193
 194 void mk_sched_update_thread_status(int active, int closed)
 195 {
 196         struct sched_list_node *thnode;
 197
 198         thnode = mk_sched_get_thread_conf();
 199
 200         switch(active){
 201                 case MK_SCHEDULER_ACTIVE_UP:
 202                         thnode->active_requests++;
 203                         break;
 204                 case MK_SCHEDULER_ACTIVE_DOWN:
 205                         thnode->active_requests--;
 206                         break;
 207         }
 208
 209         switch(closed){
 210                 case MK_SCHEDULER_CLOSED_UP:
 211                         thnode->closed_requests++;
 212                         break;
 213                 case MK_SCHEDULER_CLOSED_DOWN:
 214                         thnode->closed_requests--;
 215                         break;
 216         }
 217 }
 218
 219 int mk_sched_add_client(struct sched_list_node **sched, int remote_fd)
 220 {
 221         int i;
 222         struct sched_list_node *l;
 223
 224         l = (struct sched_list_node *) *sched;
 225
 226         /* Look for an available slot */
 227         for(i=0; i<config->worker_capacity; i++){
 228                 if(l->queue[i].status == MK_SCHEDULER_CONN_AVAILABLE){
 229                         l->queue[i].socket = remote_fd;
 230                         l->queue[i].status = MK_SCHEDULER_CONN_PENDING;
 231                         l->queue[i].arrive_time = log_current_utime;
 232
 233                         mk_epoll_add_client(l->epoll_fd, remote_fd,
 234                                             MK_EPOLL_BEHAVIOR_TRIGGERED);
 235                         return 0;
 236                 }
 237         }
 238
 239         return -1;
 240 }
 241
 242 int mk_sched_remove_client(struct sched_list_node **sched, int remote_fd)
 243 {
 244         struct sched_connection *sc;
 245
 246         sc = mk_sched_get_connection(sched, remote_fd);
 247         if(sc){
 248                 close(remote_fd);
 249                 sc->status = MK_SCHEDULER_CONN_AVAILABLE;
 250                 return 0;
 251         }
 252
 253         return -1;
 254 }
 255
 256 struct sched_connection *mk_sched_get_connection(struct sched_list_node **sched,
 257                                                  int remote_fd)
 258 {
 259         int i;
 260         struct sched_list_node *l;
 261
 262         if(!sched){
 263                 l = mk_sched_get_thread_conf();
 264         }
 265         else{
 266                 l = (struct sched_list_node *) *sched;
 267         }
 268
 269         for(i=0; i<config->worker_capacity; i++){
 270                 if(l->queue[i].socket == remote_fd){
 271                         return &l->queue[i];
 272                 }
 273         }
 274
 275         return NULL;
 276 }
 277
 278 int mk_sched_check_timeouts(struct sched_list_node **sched)
 279 {
 280         int i;
 281         struct request_idx *req_idx;
 282         struct client_request *req_cl;
 283         struct sched_list_node *l;
 284
 285         l = (struct sched_list_node *) *sched;
 286
 287         /* PENDING CONN TIMEOUT */
 288         for(i=0; i<config->worker_capacity; i++){
 289                 if(l->queue[i].status == MK_SCHEDULER_CONN_PENDING){
 290                         if(l->queue[i].arrive_time + config->timeout <= log_current_utime){
 291                                 mk_sched_remove_client(&l, l->queue[i].socket);
 292                         }
 293                 }
 294         }
 295
 296         /* PROCESSING CONN TIMEOUT */
 297         req_idx = mk_sched_get_request_index();
 298         req_cl = req_idx->first;
 299
 300         while(req_cl){
 301                 if(req_cl->status == MK_REQUEST_STATUS_INCOMPLETE){
 302                         if((req_cl->init_time + config->timeout) >=
 303                            log_current_utime){
 304                                 close(req_cl->socket);
 305                         }
 306                 }
 307                 req_cl = req_cl->next;
 308         }
 309
 310         return 0;
 311 }