alpine/after.c

   1 /* ========================================================================
   2  * Copyright 2013-2021 Eduardo Chappa
   3  * Copyright 2006-2007 University of Washington
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * ========================================================================
  12  */
  13
  14 /*======================================================================
  15      Implement asynchronous start_after() call
  16  ====*/
  17
  18
  19 #include <system.h>
  20 #include <general.h>
  21
  22 #include "../pith/debug.h"
  23 #include "../pith/osdep/err_desc.h"
  24
  25 #include "../pico/utf8stub.h"
  26
  27 #include "after.h"
  28
  29
  30 /* internal state */
  31 int      after_active;
  32
  33 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
  34 static pthread_t after_thread;
  35 static pthread_mutex_t status_message_mutex;
  36 #endif
  37
  38
  39 /* internal prototypes */
  40 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
  41 void    *do_after(void *);
  42 #else
  43 void    *cleanup_data;
  44 #endif
  45
  46 void     cleanup_after(void *);
  47
  48
  49 /*
  50  * start_after - pause and/or loop calling passed function
  51  *               without getting in the way of main thread
  52  *
  53  */
  54 void
  55 start_after(AFTER_S *a)
  56 {
  57     if(a){
  58 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
  59         pthread_attr_t attr;
  60         int rc;
  61         size_t stack;
  62
  63         if(after_active)
  64           stop_after(1);
  65
  66         /* Initialize and set thread detached attribute */
  67         pthread_attr_init(&attr);
  68         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
  69 #if     defined(PTHREAD_STACK_MIN)
  70         stack = PTHREAD_STACK_MIN + 0x10000;
  71         pthread_attr_setstacksize(&attr, stack);
  72 #endif
  73
  74         if((rc = pthread_create(&after_thread, &attr, do_after, (void *) a)) != 0){
  75             after_active = 0;
  76             dprint((1, "start_after: pthread_create failed %d (%d)", rc, errno));
  77         }
  78         else
  79           after_active = 1;
  80
  81         pthread_attr_destroy(&attr);
  82         dprint((9, "start_after() created %x: done", after_thread));
  83 #else /* !(defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)) */
  84         /*
  85          * Just call the first function
  86          */
  87         if(!a->delay)
  88           (void) (*a->f)(a->data);              /* do the thing */
  89
  90         cleanup_data = (void *) a;
  91         after_active = 1;
  92 #endif
  93     }
  94 }
  95
  96
  97 /*
  98  * stop_after - stop the thread
  99  */
 100 void
 101 stop_after(int join)
 102 {
 103 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 104     int rv;
 105
 106     dprint((9, "stop_after(join=%d) tid=%x", join, pthread_self()));
 107
 108     if(after_active){
 109         if((rv = pthread_cancel(after_thread)) != 0){   /* tell thread to end */
 110             dprint((1, "pthread_cancel: %d (%s)\n", rv, error_description(errno)));
 111         }
 112
 113         if(join){
 114             if((rv = pthread_join(after_thread, NULL)) != 0){ /* wait for it to end */
 115                 dprint((1, "pthread_join: %d (%s)\n", rv, error_description(errno)));
 116             }
 117         }
 118         else if((rv = pthread_detach(after_thread)) != 0){ /* mark thread for deletion */
 119             dprint((1, "pthread_detach: %d (%s)\n", rv, error_description(errno)));
 120         }
 121     }
 122
 123     /* not literally true unless "join" set */
 124     after_active = 0;
 125
 126 #else   /* !(defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)) */
 127
 128     cleanup_after((void *) cleanup_data);
 129     cleanup_data = NULL;
 130     after_active = 0;
 131
 132 #endif
 133 }
 134
 135
 136 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 137 /*
 138  * do_after - loop thru list of pause/loop functions
 139  */
 140 void *
 141 do_after(void *data)
 142 {
 143     AFTER_S         *a;
 144     struct timespec  ts;
 145     int              loop;
 146     sigset_t         sigs;
 147
 148 #if defined(SIGCHLD) || defined(SIGWINCH)
 149     sigemptyset(&sigs);
 150 #if defined(SIGCHLD)
 151     /* make sure we don't end up with SIGCHLD */
 152     sigaddset(&sigs, SIGCHLD);
 153 #endif  /* SIGCHLD */
 154 #if defined(SIGCHLD)
 155     /* or with SIGWINCH */
 156     sigaddset(&sigs, SIGWINCH);
 157 #endif  /* SIGWINCH */
 158     pthread_sigmask(SIG_BLOCK, &sigs, NULL);
 159 #endif
 160
 161     /* prepare for the finish */
 162     pthread_cleanup_push(cleanup_after, data);
 163     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 164     pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
 165
 166     /* and jump in */
 167     for(a  = (AFTER_S *) data; a != NULL && a->f != NULL; a = a->next){
 168         if(a->delay){
 169             ts.tv_sec  = a->delay / 100;        /* seconds */
 170             ts.tv_nsec = (a->delay % 100) * 10000000;
 171
 172             if(nanosleep(&ts, NULL))
 173               pthread_exit(NULL);               /* interrupted */
 174         }
 175
 176         while(1){
 177             /* after waking, make sure we're still wanted */
 178             pthread_testcancel();
 179
 180             loop = (*a->f)(a->data);            /* do the thing */
 181
 182             if(loop > 0){
 183                 ts.tv_sec  = loop / 100;
 184                 ts.tv_nsec = (loop % 100) * 10000000;
 185
 186                 if(nanosleep(&ts, NULL))
 187                   pthread_exit(NULL);           /* interrupted */
 188             }
 189             else
 190               break;
 191         }
 192     }
 193
 194     pthread_cleanup_pop(1);
 195     pthread_exit(NULL);
 196 }
 197
 198 #endif  /* defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP) */
 199
 200
 201 /*
 202  * cleanup_after - give start_after caller opportunity to clean up
 203  *                 their data, then free up AFTER_S list
 204  */
 205 void
 206 cleanup_after(void *data)
 207 {
 208     AFTER_S *a, *an;
 209
 210 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 211     dprint((9, "cleanup_after() tid=%x", pthread_self()));
 212 #endif
 213
 214     /* free linked list of AFTER_S's */
 215     a = (AFTER_S *) data;
 216     while(a != NULL){
 217         an = a->next;
 218
 219         if(a->cf)
 220           (*a->cf)(a->data);
 221
 222         free((void *) a);
 223
 224         a = an;
 225     }
 226 }
 227
 228
 229 AFTER_S *
 230 new_afterstruct(void)
 231 {
 232     AFTER_S *a;
 233
 234     if((a = (AFTER_S *)malloc(sizeof(AFTER_S))) == NULL){
 235         fatal("Out of memory");
 236     }
 237
 238     memset((void *) a, 0, sizeof(AFTER_S));
 239
 240     return(a);
 241 }
 242
 243
 244 void
 245 status_message_lock_init(void)
 246 {
 247 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 248     pthread_mutex_init(&status_message_mutex, NULL);
 249 #endif
 250 }
 251
 252
 253 int
 254 status_message_lock(void)
 255 {
 256 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 257     return(pthread_mutex_lock(&status_message_mutex));
 258 #else
 259     return(0);
 260 #endif
 261 }
 262
 263
 264 int
 265 status_message_unlock(void)
 266 {
 267 #if     defined(HAVE_PTHREAD) && defined(HAVE_NANOSLEEP)
 268     return(pthread_mutex_unlock(&status_message_mutex));
 269 #else
 270     return(0);
 271 #endif
 272 }