job.c

   1 /* job.c - a job in the queue */
   2
   3 /* Copyright (C) 2007 Keith Rarick and Philotic Inc.
   4
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 #include "tube.h"
  23 #include "job.h"
  24 #include "primes.h"
  25 #include "util.h"
  26
  27 static uint64_t next_id = 1;
  28
  29 static int cur_prime = 0;
  30
  31 static job *all_jobs = NULL;
  32 static size_t all_jobs_cap = 12289; /* == primes[0] */
  33 static size_t all_jobs_used = 0;
  34
  35 static int hash_table_was_oom = 0;
  36
  37 static void rehash();
  38
  39 static int
  40 _get_job_hash_index(uint64_t job_id)
  41 {
  42     return job_id % all_jobs_cap;
  43 }
  44
  45 static void
  46 store_job(job j)
  47 {
  48     int index = 0;
  49
  50     index = _get_job_hash_index(j->id);
  51
  52     j->ht_next = all_jobs[index];
  53     all_jobs[index] = j;
  54     all_jobs_used++;
  55
  56     /* accept a load factor of 4 */
  57     if (all_jobs_used > (all_jobs_cap << 2)) rehash();
  58 }
  59
  60 static void
  61 rehash()
  62 {
  63     job *old = all_jobs;
  64     size_t old_cap = all_jobs_cap, old_used = all_jobs_used, i;
  65
  66     if (cur_prime >= NUM_PRIMES) return;
  67     if (hash_table_was_oom) return;
  68
  69     all_jobs_cap = primes[++cur_prime];
  70     all_jobs = calloc(all_jobs_cap, sizeof(job));
  71     if (!all_jobs) {
  72         twarnx("Failed to allocate %d new hash buckets", all_jobs_cap);
  73         hash_table_was_oom = 1;
  74         --cur_prime;
  75         all_jobs = old;
  76         all_jobs_cap = old_cap;
  77         all_jobs_used = old_used;
  78         return;
  79     }
  80     all_jobs_used = 0;
  81
  82     for (i = 0; i < old_cap; i++) {
  83         while (old[i]) {
  84             job j = old[i];
  85             old[i] = j->ht_next;
  86             j->ht_next = NULL;
  87             store_job(j);
  88         }
  89     }
  90     free(old);
  91 }
  92
  93 job
  94 job_find(uint64_t job_id)
  95 {
  96     job jh = NULL;
  97     int index = _get_job_hash_index(job_id);
  98
  99     for (jh = all_jobs[index]; jh && jh->id != job_id; jh = jh->ht_next);
 100
 101     return jh;
 102 }
 103
 104 job
 105 allocate_job(int body_size)
 106 {
 107     job j;
 108
 109     j = malloc(sizeof(struct job) + body_size);
 110     if (!j) return twarnx("OOM"), (job) 0;
 111
 112     j->id = 0;
 113     j->state = JOB_STATE_INVALID;
 114     j->created_at = now_usec();
 115     j->reserve_ct = j->timeout_ct = j->release_ct = j->bury_ct = j->kick_ct = 0;
 116     j->body_size = body_size;
 117     j->next = j->prev = j; /* not in a linked list */
 118     j->ht_next = NULL;
 119     j->tube = NULL;
 120     j->binlog = NULL;
 121     j->heap_index = 0;
 122     j->reserved_binlog_space = 0;
 123
 124     return j;
 125 }
 126
 127 job
 128 make_job_with_id(unsigned int pri, usec delay, usec ttr,
 129                  int body_size, tube tube, uint64_t id)
 130 {
 131     job j;
 132
 133     j = allocate_job(body_size);
 134     if (!j) return twarnx("OOM"), (job) 0;
 135
 136     if (id) {
 137         j->id = id;
 138         if (id >= next_id) next_id = id + 1;
 139     } else {
 140         j->id = next_id++;
 141     }
 142     j->pri = pri;
 143     j->delay = delay;
 144     j->ttr = ttr;
 145
 146     store_job(j);
 147
 148     TUBE_ASSIGN(j->tube, tube);
 149
 150     return j;
 151 }
 152
 153 static void
 154 job_hash_free(job j)
 155 {
 156     job *slot;
 157
 158     slot = &all_jobs[_get_job_hash_index(j->id)];
 159     while (*slot && *slot != j) slot = &(*slot)->ht_next;
 160     if (*slot) {
 161         *slot = (*slot)->ht_next;
 162         --all_jobs_used;
 163     }
 164 }
 165
 166 void
 167 job_free(job j)
 168 {
 169     if (j) {
 170         TUBE_ASSIGN(j->tube, NULL);
 171         if (j->state != JOB_STATE_COPY) job_hash_free(j);
 172     }
 173
 174     free(j);
 175 }
 176
 177 /* We can't substrct any of these values because there are too many bits */
 178 int
 179 job_pri_cmp(job a, job b)
 180 {
 181     if (a->pri > b->pri) return 1;
 182     if (a->pri < b->pri) return -1;
 183     if (a->id > b->id) return 1;
 184     if (a->id < b->id) return -1;
 185     return 0;
 186 }
 187
 188 /* We can't substrct any of these values because there are too many bits */
 189 int
 190 job_delay_cmp(job a, job b)
 191 {
 192     if (a->deadline_at > b->deadline_at) return 1;
 193     if (a->deadline_at < b->deadline_at) return -1;
 194     if (a->id > b->id) return 1;
 195     if (a->id < b->id) return -1;
 196     return 0;
 197 }
 198
 199 job
 200 job_copy(job j)
 201 {
 202     job n;
 203
 204     if (!j) return NULL;
 205
 206     n = malloc(sizeof(struct job) + j->body_size);
 207     if (!n) return twarnx("OOM"), (job) 0;
 208
 209     memcpy(n, j, sizeof(struct job) + j->body_size);
 210     n->next = n->prev = n; /* not in a linked list */
 211
 212     n->binlog = NULL; /* copies do not have refcnt on the binlog */
 213
 214     n->tube = 0; /* Don't use memcpy for the tube, which we must refcount. */
 215     TUBE_ASSIGN(n->tube, j->tube);
 216
 217     /* Mark this job as a copy so it can be appropriately freed later on */
 218     n->state = JOB_STATE_COPY;
 219
 220     return n;
 221 }
 222
 223 const char *
 224 job_state(job j)
 225 {
 226     if (j->state == JOB_STATE_READY) return "ready";
 227     if (j->state == JOB_STATE_RESERVED) return "reserved";
 228     if (j->state == JOB_STATE_BURIED) return "buried";
 229     if (j->state == JOB_STATE_DELAYED) return "delayed";
 230     return "invalid";
 231 }
 232
 233 int
 234 job_list_any_p(job head)
 235 {
 236     return head->next != head || head->prev != head;
 237 }
 238
 239 job
 240 job_remove(job j)
 241 {
 242     if (!j) return NULL;
 243     if (!job_list_any_p(j)) return NULL; /* not in a doubly-linked list */
 244
 245     j->next->prev = j->prev;
 246     j->prev->next = j->next;
 247
 248     j->prev = j->next = j;
 249
 250     return j;
 251 }
 252
 253 void
 254 job_insert(job head, job j)
 255 {
 256     if (job_list_any_p(j)) return; /* already in a linked list */
 257
 258     j->prev = head->prev;
 259     j->next = head;
 260     head->prev->next = j;
 261     head->prev = j;
 262 }
 263
 264 uint64_t
 265 total_jobs()
 266 {
 267     return next_id - 1;
 268 }
 269
 270 /* for unit tests */
 271 size_t
 272 get_all_jobs_used()
 273 {
 274     return all_jobs_used;
 275 }
 276
 277 void
 278 job_init()
 279 {
 280     all_jobs = calloc(all_jobs_cap, sizeof(job));
 281     if (!all_jobs) {
 282         twarnx("Failed to allocate %d hash buckets", all_jobs_cap);
 283     }
 284 }