libmainloop/signal.c

   1 /*
   2  * ion/libmainloop/signal.c
   3  *
   4  * Copyright (c) Tuomo Valkonen 1999-2008.
   5  *
   6  * See the included file LICENSE for details.
   7  */
   8
   9 #include <unistd.h>
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <sys/time.h>
  13 #include <time.h>
  14 #include <signal.h>
  15 #include <string.h>
  16 #include <stdlib.h>
  17 #include <errno.h>
  18
  19 #include <libtu/objp.h>
  20 #include <libtu/types.h>
  21 #include <libtu/misc.h>
  22 #include <libtu/locale.h>
  23 #include <libtu/output.h>
  24
  25 #include "signal.h"
  26 #include "hooks.h"
  27
  28 static int kill_sig=0;
  29 #if 1
  30 static int wait_sig=0;
  31 #endif
  32
  33 static int usr2_sig=0;
  34 static bool had_tmr=FALSE;
  35
  36 WHook *mainloop_sigchld_hook=NULL;
  37 WHook *mainloop_sigusr2_hook=NULL;
  38
  39
  40 /*{{{ Timers */
  41
  42
  43 static WTimer *queue=NULL;
  44
  45
  46 int mainloop_gettime(struct timeval *val)
  47 {
  48 #if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK>=0)
  49     struct timespec spec;
  50     int ret;
  51     static int checked=0;
  52
  53     if(checked>=0){
  54         ret=clock_gettime(CLOCK_MONOTONIC, &spec);
  55
  56         if(ret==-1 && errno==EINVAL && checked==0){
  57             checked=-1;
  58         }else{
  59             checked=1;
  60
  61             val->tv_sec=spec.tv_sec;
  62             val->tv_usec=spec.tv_nsec/1000;
  63
  64             return ret;
  65         }
  66     }
  67 #else
  68     #warning "Monotonic clock unavailable; please fix your operating system."
  69 #endif
  70     return gettimeofday(val, NULL);
  71 }
  72
  73
  74 #define TIMEVAL_LATER(a, b) \
  75     ((a.tv_sec > b.tv_sec) || \
  76     ((a.tv_sec == b.tv_sec) && \
  77      (a.tv_usec > b.tv_usec)))
  78
  79 #define USECS_IN_SEC 1000000
  80
  81
  82 static void do_timer_set()
  83 {
  84     struct itimerval val={{0, 0}, {0, 0}};
  85
  86     if(queue==NULL){
  87         setitimer(ITIMER_REAL, &val, NULL);
  88         return;
  89     }
  90
  91     /* Subtract queue time from current time, don't go below zero */
  92     mainloop_gettime(&(val.it_value));
  93     if(TIMEVAL_LATER((queue)->when, val.it_value)){
  94         if(queue->when.tv_usec<val.it_value.tv_usec){
  95             queue->when.tv_usec+=USECS_IN_SEC;
  96             queue->when.tv_sec--;
  97         }
  98         val.it_value.tv_usec=queue->when.tv_usec-val.it_value.tv_usec;
  99         val.it_value.tv_sec=queue->when.tv_sec-val.it_value.tv_sec;
 100         if(val.it_value.tv_usec<0)
 101             val.it_value.tv_usec=0;
 102         /* POSIX and some kernels have been designed by absolute morons and
 103          * contain idiotic artificial restrictions on the value of tv_usec,
 104          * that will only cause more code being run and clock cycles being
 105          * spent to do the same thing, as the kernel will in any case convert
 106          * the seconds to some other units.
 107          */
 108          val.it_value.tv_sec+=val.it_value.tv_usec/USECS_IN_SEC;
 109          val.it_value.tv_usec%=USECS_IN_SEC;
 110     }else{
 111         had_tmr=TRUE;
 112         return;
 113     }
 114
 115     val.it_interval.tv_usec=val.it_value.tv_usec;
 116     val.it_interval.tv_sec=val.it_value.tv_sec;
 117
 118     if((setitimer(ITIMER_REAL, &val, NULL))){
 119         had_tmr=TRUE;
 120     }
 121 }
 122
 123
 124 typedef struct{
 125     pid_t pid;
 126     int code;
 127 } ChldParams;
 128
 129
 130 static bool mrsh_chld(void (*fn)(pid_t, int), ChldParams *p)
 131 {
 132     fn(p->pid, p->code);
 133     return TRUE;
 134 }
 135
 136
 137 static bool mrsh_chld_extl(ExtlFn fn, ChldParams *p)
 138 {
 139     ExtlTab t=extl_create_table();
 140     bool ret;
 141
 142     extl_table_sets_i(t, "pid", (int)p->pid);
 143
 144     if(WIFEXITED(p->code)){
 145         extl_table_sets_b(t, "exited", TRUE);
 146         extl_table_sets_i(t, "exitstatus", WEXITSTATUS(p->code));
 147     }
 148     if(WIFSIGNALED(p->code)){
 149         extl_table_sets_b(t, "signaled", TRUE);
 150         extl_table_sets_i(t, "termsig", WTERMSIG(p->code));
 151 #ifdef WCOREDUMP
 152         extl_table_sets_i(t, "coredump", WCOREDUMP(p->code));
 153 #endif
 154     }
 155     if(WIFSTOPPED(p->code)){
 156         extl_table_sets_b(t, "stopped", TRUE);
 157         extl_table_sets_i(t, "stopsig", WSTOPSIG(p->code));
 158     }
 159     /*if(WIFCONTINUED(p->code)){
 160         extl_table_sets_b(t, "continued", TRUE);
 161     }*/
 162
 163     ret=extl_call(fn, "t", NULL, t);
 164
 165     extl_unref_table(t);
 166
 167     return ret;
 168 }
 169
 170 static bool mrsh_usr2(void (*fn)(void), void *p)
 171 {
 172     fn();
 173     return TRUE;
 174 }
 175
 176 static bool mrsh_usr2_extl(ExtlFn fn, void *p)
 177 {
 178     bool ret;
 179     ExtlTab t=extl_create_table();
 180     ret=extl_call(fn, "t", NULL, t);
 181     extl_unref_table(t);
 182     return ret;
 183 }
 184
 185
 186 bool mainloop_check_signals()
 187 {
 188     struct timeval current_time;
 189     WTimer *q;
 190     int ret=0;
 191
 192     if(usr2_sig!=0){
 193         usr2_sig=0;
 194         if(mainloop_sigusr2_hook!=NULL){
 195             hook_call(mainloop_sigusr2_hook, NULL,
 196                       (WHookMarshall*)mrsh_usr2,
 197                       (WHookMarshallExtl*)mrsh_usr2_extl);
 198         }
 199     }
 200
 201 #if 1
 202     if(wait_sig!=0){
 203         ChldParams p;
 204         wait_sig=0;
 205         while((p.pid=waitpid(-1, &p.code, WNOHANG|WUNTRACED))>0){
 206             if(mainloop_sigchld_hook!=NULL &&
 207                (WIFEXITED(p.code) || WIFSIGNALED(p.code))){
 208                 hook_call(mainloop_sigchld_hook, &p,
 209                           (WHookMarshall*)mrsh_chld,
 210                           (WHookMarshallExtl*)mrsh_chld_extl);
 211             }
 212         }
 213     }
 214 #endif
 215
 216     if(kill_sig!=0)
 217         return kill_sig;
 218
 219     /* Check for timer events in the queue */
 220     while(had_tmr && queue!=NULL){
 221         had_tmr=FALSE;
 222         mainloop_gettime(&current_time);
 223         while(queue!=NULL){
 224             if(TIMEVAL_LATER(current_time, queue->when)){
 225                 q=queue;
 226                 queue=q->next;
 227                 q->next=NULL;
 228                 if(q->handler!=NULL){
 229                     WTimerHandler *handler=q->handler;
 230                     Obj *obj=q->objwatch.obj;
 231                     q->handler=NULL;
 232                     watch_reset(&(q->objwatch));
 233                     handler(q, obj);
 234                 }else if(q->extl_handler!=extl_fn_none()){
 235                     ExtlFn fn=q->extl_handler;
 236                     Obj *obj=q->objwatch.obj;
 237                     watch_reset(&(q->objwatch));
 238                     q->extl_handler=extl_fn_none();
 239                     extl_call(fn, "o", NULL, obj);
 240                     extl_unref_fn(fn);
 241                 }
 242             }else{
 243                 break;
 244             }
 245         }
 246         do_timer_set();
 247     }
 248
 249     return ret;
 250 }
 251
 252
 253 static void add_to_current_time(struct timeval *when, uint msecs)
 254 {
 255     long tmp_usec;
 256
 257     mainloop_gettime(when);
 258     tmp_usec=when->tv_usec + (msecs * 1000);
 259     when->tv_usec=tmp_usec % 1000000;
 260     when->tv_sec+=tmp_usec / 1000000;
 261 }
 262
 263
 264 /*EXTL_DOC
 265  * Is timer set?
 266  */
 267 EXTL_EXPORT_MEMBER
 268 bool timer_is_set(WTimer *timer)
 269 {
 270     WTimer *tmr;
 271     for(tmr=queue; tmr!=NULL; tmr=tmr->next){
 272         if(tmr==timer)
 273             return TRUE;
 274     }
 275     return FALSE;
 276 }
 277
 278
 279 void timer_do_set(WTimer *timer, uint msecs, WTimerHandler *handler,
 280                   Obj *obj, ExtlFn fn)
 281 {
 282     WTimer *q, **qptr;
 283     bool set=FALSE;
 284
 285     timer_reset(timer);
 286
 287     /* Initialize the new queue timer event */
 288     add_to_current_time(&(timer->when), msecs);
 289     timer->next=NULL;
 290     timer->handler=handler;
 291     timer->extl_handler=fn;
 292     if(obj!=NULL)
 293         watch_setup(&(timer->objwatch), obj, NULL);
 294     else
 295         watch_reset(&(timer->objwatch));
 296
 297     /* Add timerevent in place to queue */
 298     q=queue;
 299     qptr=&queue;
 300
 301     while(q!=NULL){
 302         if(TIMEVAL_LATER(q->when, timer->when))
 303             break;
 304         qptr=&(q->next);
 305         q=q->next;
 306     }
 307
 308     timer->next=q;
 309     *qptr=timer;
 310
 311     do_timer_set();
 312 }
 313
 314
 315 void timer_set(WTimer *timer, uint msecs, WTimerHandler *handler,
 316                Obj *obj)
 317 {
 318     timer_do_set(timer, msecs, handler, obj, extl_fn_none());
 319 }
 320
 321
 322 /*EXTL_DOC
 323  * Set \var{timer} to call \var{fn} in \var{msecs} milliseconds.
 324  */
 325 EXTL_EXPORT_AS(WTimer, set)
 326 void timer_set_extl(WTimer *timer, uint msecs, ExtlFn fn)
 327 {
 328     timer_do_set(timer, msecs, NULL, NULL, extl_ref_fn(fn));
 329 }
 330
 331
 332 /*EXTL_DOC
 333  * Reset timer.
 334  */
 335 EXTL_EXPORT_MEMBER
 336 void timer_reset(WTimer *timer)
 337 {
 338     WTimer *q=queue, **qptr=&queue;
 339
 340     while(q!=NULL){
 341         if(q==timer){
 342             *qptr=timer->next;
 343             do_timer_set();
 344             break;
 345         }
 346         qptr=&(q->next);
 347         q=q->next;
 348
 349     }
 350
 351     timer->handler=NULL;
 352     extl_unref_fn(timer->extl_handler);
 353     timer->extl_handler=extl_fn_none();
 354     watch_reset(&(timer->objwatch));
 355 }
 356
 357
 358 bool timer_init(WTimer *timer)
 359 {
 360     timer->when.tv_sec=0;
 361     timer->when.tv_usec=0;
 362     timer->next=NULL;
 363     timer->handler=NULL;
 364     timer->extl_handler=extl_fn_none();
 365     watch_init(&(timer->objwatch));
 366     return TRUE;
 367 }
 368
 369 void timer_deinit(WTimer *timer)
 370 {
 371     timer_reset(timer);
 372 }
 373
 374
 375 WTimer *create_timer()
 376 {
 377     CREATEOBJ_IMPL(WTimer, timer, (p));
 378 }
 379
 380 /*EXTL_DOC
 381  * Create a new timer.
 382  */
 383 EXTL_EXPORT_AS(mainloop, create_timer)
 384 WTimer *create_timer_extl_owned()
 385 {
 386     WTimer *timer=create_timer();
 387     if(timer!=NULL)
 388         ((Obj*)timer)->flags|=OBJ_EXTL_OWNED;
 389     return timer;
 390 }
 391
 392
 393 EXTL_EXPORT
 394 IMPLCLASS(WTimer, Obj, timer_deinit, NULL);
 395
 396
 397 /*}}}*/
 398
 399
 400 /*{{{ Signal handling */
 401
 402
 403 static void fatal_signal_handler(int signal_num)
 404 {
 405     set_warn_handler(NULL);
 406     warn(TR("Caught fatal signal %d. Dying without deinit."), signal_num);
 407     signal(signal_num, SIG_DFL);
 408     kill(getpid(), signal_num);
 409 }
 410
 411
 412 static void deadly_signal_handler(int signal_num)
 413 {
 414     set_warn_handler(NULL);
 415     warn(TR("Caught signal %d. Dying."), signal_num);
 416     signal(signal_num, SIG_DFL);
 417     /*if(ioncore_g.opmode==IONCORE_OPMODE_INIT)
 418         kill(getpid(), signal_num);
 419     else*/
 420         kill_sig=signal_num;
 421 }
 422
 423
 424 static void chld_handler(int signal_num)
 425 {
 426 #if 0
 427     pid_t pid;
 428
 429     while((pid=waitpid(-1, NULL, WNOHANG|WUNTRACED))>0){
 430         /* nothing */
 431     }
 432 #else
 433     wait_sig=1;
 434 #endif
 435 }
 436
 437 static void usr2_handler(int signal_num)
 438 {
 439     usr2_sig=1;
 440 }
 441
 442
 443 static void exit_handler(int signal_num)
 444 {
 445     if(kill_sig>0){
 446         warn(TR("Got signal %d while %d is still to be handled."),
 447              signal_num, kill_sig);
 448     }
 449     kill_sig=signal_num;
 450 }
 451
 452
 453 static void timer_handler(int signal_num)
 454 {
 455     had_tmr=TRUE;
 456 }
 457
 458
 459 static void ignore_handler(int signal_num)
 460 {
 461
 462 }
 463
 464
 465 #ifndef SA_RESTART
 466  /* glibc is broken (?) and does not define SA_RESTART with
 467   * '-ansi -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED', so just try to live
 468   * without it.
 469   */
 470 #define SA_RESTART 0
 471 #endif
 472
 473 #define IFTRAP(X) if(sigismember(which, X))
 474 #define DEADLY(X) IFTRAP(X) signal(X, deadly_signal_handler);
 475 #define FATAL(X) IFTRAP(X) signal(X, fatal_signal_handler);
 476 #define IGNORE(X) IFTRAP(X) signal(X, SIG_IGN)
 477
 478 void mainloop_trap_signals(const sigset_t *which)
 479 {
 480     struct sigaction sa;
 481     sigset_t set, oldset;
 482     sigset_t dummy;
 483
 484     if(which==NULL){
 485         sigfillset(&dummy);
 486         which=&dummy;
 487     }
 488
 489     sigemptyset(&set);
 490     sigemptyset(&oldset);
 491     sigprocmask(SIG_SETMASK, &set, &oldset);
 492
 493     DEADLY(SIGHUP);
 494     DEADLY(SIGQUIT);
 495     DEADLY(SIGINT);
 496     DEADLY(SIGABRT);
 497
 498     FATAL(SIGILL);
 499     FATAL(SIGSEGV);
 500     FATAL(SIGFPE);
 501     FATAL(SIGBUS);
 502
 503     IGNORE(SIGTRAP);
 504     /*IGNORE(SIGWINCH);*/
 505
 506     sigemptyset(&(sa.sa_mask));
 507
 508     IFTRAP(SIGALRM){
 509         sa.sa_handler=timer_handler;
 510         sa.sa_flags=SA_RESTART;
 511         sigaction(SIGALRM, &sa, NULL);
 512     }
 513
 514     IFTRAP(SIGCHLD){
 515         sa.sa_handler=chld_handler;
 516         sa.sa_flags=SA_NOCLDSTOP|SA_RESTART;
 517         sigaction(SIGCHLD, &sa, NULL);
 518     }
 519
 520     IFTRAP(SIGUSR2){
 521         sa.sa_handler=usr2_handler;
 522         sa.sa_flags=SA_RESTART;
 523         sigaction(SIGUSR2, &sa, NULL);
 524     }
 525
 526     IFTRAP(SIGTERM){
 527         sa.sa_handler=exit_handler;
 528         sa.sa_flags=SA_RESTART;
 529         sigaction(SIGTERM, &sa, NULL);
 530     }
 531
 532     IFTRAP(SIGUSR1){
 533         sa.sa_handler=exit_handler;
 534         sa.sa_flags=SA_RESTART;
 535         sigaction(SIGUSR1, &sa, NULL);
 536     }
 537
 538     /* SIG_IGN is preserved over execve and since the the default action
 539      * for SIGPIPE is not to ignore it, some programs may get upset if
 540      * the behaviour is not the default.
 541      */
 542     IFTRAP(SIGPIPE){
 543         sa.sa_handler=ignore_handler;
 544         sigaction(SIGPIPE, &sa, NULL);
 545     }
 546
 547 }
 548
 549 #undef IGNORE
 550 #undef FATAL
 551 #undef DEADLY
 552
 553
 554 /*}}}*/
 555