libmainloop/signal.c

   1 /*
   2  * ion/libmainloop/signal.c
   3  *
   4  * Copyright (c) Tuomo Valkonen 1999-2009.
   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 static sigset_t special_sigs;
  40
  41
  42 /*{{{ Timers */
  43
  44
  45 static WTimer *queue=NULL;
  46
  47
  48 int mainloop_gettime(struct timeval *val)
  49 {
  50 #if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK>=0)
  51     struct timespec spec;
  52     int ret;
  53     static int checked=0;
  54
  55     if(checked>=0){
  56         ret=clock_gettime(CLOCK_MONOTONIC, &spec);
  57
  58         if(ret==-1 && errno==EINVAL && checked==0){
  59             checked=-1;
  60         }else{
  61             checked=1;
  62
  63             val->tv_sec=spec.tv_sec;
  64             val->tv_usec=spec.tv_nsec/1000;
  65
  66             return ret;
  67         }
  68     }
  69 #else
  70     #warning "Monotonic clock unavailable; please fix your operating system."
  71 #endif
  72     return gettimeofday(val, NULL);
  73 }
  74
  75
  76 #define TIMEVAL_LATER(a, b) \
  77     ((a.tv_sec > b.tv_sec) || \
  78     ((a.tv_sec == b.tv_sec) && \
  79      (a.tv_usec > b.tv_usec)))
  80
  81 #define USECS_IN_SEC 1000000
  82
  83
  84 bool libmainloop_get_timeout(struct timeval *tv)
  85 {
  86     if(queue==NULL)
  87         return FALSE;
  88
  89     /* Subtract queue time from current time, don't go below zero */
  90     mainloop_gettime(tv);
  91     if(TIMEVAL_LATER((queue)->when, (*tv))){
  92         if(queue->when.tv_usec<tv->tv_usec){
  93             tv->tv_usec=(queue->when.tv_usec+USECS_IN_SEC)-tv->tv_usec;
  94             /* TIMEVAL_LATER ensures >= 0 */
  95             tv->tv_sec=(queue->when.tv_sec-1)-tv->tv_sec;
  96         }else{
  97             tv->tv_usec=queue->when.tv_usec-tv->tv_usec;
  98             tv->tv_sec=queue->when.tv_sec-tv->tv_sec;
  99         }
 100         /* POSIX and some kernels have been designed by absolute morons and
 101          * contain idiotic artificial restrictions on the value of tv_usec,
 102          * that will only cause more code being run and clock cycles being
 103          * spent to do the same thing, as the kernel will in any case convert
 104          * the seconds to some other units.
 105          */
 106          tv->tv_sec+=tv->tv_usec/USECS_IN_SEC;
 107          tv->tv_usec%=USECS_IN_SEC;
 108     }else{
 109         had_tmr=TRUE;
 110         return FALSE;
 111     }
 112
 113     return TRUE;
 114 }
 115
 116
 117 static void do_timer_set()
 118 {
 119     struct itimerval val={{0, 0}, {0, 0}};
 120
 121     if(libmainloop_get_timeout(&val.it_value)){
 122         val.it_interval.tv_usec=0;
 123         val.it_interval.tv_sec=0;
 124
 125         if((setitimer(ITIMER_REAL, &val, NULL)))
 126             had_tmr=TRUE;
 127     }else if(!had_tmr){
 128         setitimer(ITIMER_REAL, &val, NULL);
 129     }
 130 }
 131
 132
 133 typedef struct{
 134     pid_t pid;
 135     int code;
 136 } ChldParams;
 137
 138
 139 static bool mrsh_chld(void (*fn)(pid_t, int), ChldParams *p)
 140 {
 141     fn(p->pid, p->code);
 142     return TRUE;
 143 }
 144
 145
 146 static bool mrsh_chld_extl(ExtlFn fn, ChldParams *p)
 147 {
 148     ExtlTab t=extl_create_table();
 149     bool ret;
 150
 151     extl_table_sets_i(t, "pid", (int)p->pid);
 152
 153     if(WIFEXITED(p->code)){
 154         extl_table_sets_b(t, "exited", TRUE);
 155         extl_table_sets_i(t, "exitstatus", WEXITSTATUS(p->code));
 156     }
 157     if(WIFSIGNALED(p->code)){
 158         extl_table_sets_b(t, "signaled", TRUE);
 159         extl_table_sets_i(t, "termsig", WTERMSIG(p->code));
 160 #ifdef WCOREDUMP
 161         extl_table_sets_i(t, "coredump", WCOREDUMP(p->code));
 162 #endif
 163     }
 164     if(WIFSTOPPED(p->code)){
 165         extl_table_sets_b(t, "stopped", TRUE);
 166         extl_table_sets_i(t, "stopsig", WSTOPSIG(p->code));
 167     }
 168     /*if(WIFCONTINUED(p->code)){
 169         extl_table_sets_b(t, "continued", TRUE);
 170     }*/
 171
 172     ret=extl_call(fn, "t", NULL, t);
 173
 174     extl_unref_table(t);
 175
 176     return ret;
 177 }
 178
 179 static bool mrsh_usr2(void (*fn)(void), void *UNUSED(p))
 180 {
 181     fn();
 182     return TRUE;
 183 }
 184
 185 static bool mrsh_usr2_extl(ExtlFn fn, void *UNUSED(p))
 186 {
 187     bool ret;
 188     ExtlTab t=extl_create_table();
 189     ret=extl_call(fn, "t", NULL, t);
 190     extl_unref_table(t);
 191     return ret;
 192 }
 193
 194
 195 bool mainloop_check_signals()
 196 {
 197     struct timeval current_time;
 198     WTimer *q;
 199     int ret=0;
 200
 201     if(usr2_sig!=0){
 202         usr2_sig=0;
 203         if(mainloop_sigusr2_hook!=NULL){
 204             hook_call(mainloop_sigusr2_hook, NULL,
 205                       (WHookMarshall*)mrsh_usr2,
 206                       (WHookMarshallExtl*)mrsh_usr2_extl);
 207         }
 208     }
 209
 210 #if 1
 211     if(wait_sig!=0){
 212         ChldParams p;
 213         wait_sig=0;
 214         while((p.pid=waitpid(-1, &p.code, WNOHANG|WUNTRACED))>0){
 215             if(mainloop_sigchld_hook!=NULL &&
 216                (WIFEXITED(p.code) || WIFSIGNALED(p.code))){
 217                 hook_call(mainloop_sigchld_hook, &p,
 218                           (WHookMarshall*)mrsh_chld,
 219                           (WHookMarshallExtl*)mrsh_chld_extl);
 220             }
 221         }
 222     }
 223 #endif
 224
 225     if(kill_sig!=0)
 226         return kill_sig;
 227
 228     /* Check for timer events in the queue */
 229     while(had_tmr){
 230         had_tmr=FALSE;
 231         if(queue==NULL)
 232             break;
 233         mainloop_gettime(&current_time);
 234         while(queue!=NULL){
 235             if(TIMEVAL_LATER(current_time, queue->when)){
 236                 q=queue;
 237                 queue=q->next;
 238                 q->next=NULL;
 239                 if(q->handler!=NULL){
 240                     WTimerHandler *handler=q->handler;
 241                     Obj *obj=q->objwatch.obj;
 242                     q->handler=NULL;
 243                     watch_reset(&(q->objwatch));
 244                     handler(q, obj);
 245                 }else if(q->extl_handler!=extl_fn_none()){
 246                     ExtlFn fn=q->extl_handler;
 247                     Obj *obj=q->objwatch.obj;
 248                     watch_reset(&(q->objwatch));
 249                     q->extl_handler=extl_fn_none();
 250                     extl_call(fn, "o", NULL, obj);
 251                     extl_unref_fn(fn);
 252                 }
 253             }else{
 254                 break;
 255             }
 256         }
 257         do_timer_set();
 258     }
 259
 260     return ret;
 261 }
 262
 263
 264 void mainloop_block_signals(sigset_t *oldmask)
 265 {
 266     sigprocmask(SIG_BLOCK, &special_sigs, oldmask);
 267 }
 268
 269
 270 bool mainloop_unhandled_signals()
 271 {
 272     return (usr2_sig || wait_sig || kill_sig || had_tmr);
 273 }
 274
 275
 276 static void add_to_current_time(struct timeval *when, uint msecs)
 277 {
 278     long tmp_usec;
 279
 280     mainloop_gettime(when);
 281     tmp_usec=when->tv_usec + (msecs * 1000);
 282     when->tv_usec=tmp_usec % 1000000;
 283     when->tv_sec+=tmp_usec / 1000000;
 284 }
 285
 286
 287 /*EXTL_DOC
 288  * Is timer set?
 289  */
 290 EXTL_EXPORT_MEMBER
 291 bool timer_is_set(WTimer *timer)
 292 {
 293     WTimer *tmr;
 294     for(tmr=queue; tmr!=NULL; tmr=tmr->next){
 295         if(tmr==timer)
 296             return TRUE;
 297     }
 298     return FALSE;
 299 }
 300
 301
 302 void timer_do_set(WTimer *timer, uint msecs, WTimerHandler *handler,
 303                   Obj *obj, ExtlFn fn)
 304 {
 305     WTimer *q, **qptr;
 306
 307     timer_reset(timer);
 308
 309     /* Initialize the new queue timer event */
 310     add_to_current_time(&(timer->when), msecs);
 311     timer->next=NULL;
 312     timer->handler=handler;
 313     timer->extl_handler=fn;
 314     if(obj!=NULL)
 315         watch_setup(&(timer->objwatch), obj, NULL);
 316     else
 317         watch_reset(&(timer->objwatch));
 318
 319     /* Add timerevent in place to queue */
 320     q=queue;
 321     qptr=&queue;
 322
 323     while(q!=NULL){
 324         if(TIMEVAL_LATER(q->when, timer->when))
 325             break;
 326         qptr=&(q->next);
 327         q=q->next;
 328     }
 329
 330     timer->next=q;
 331     *qptr=timer;
 332
 333     do_timer_set();
 334 }
 335
 336
 337 void timer_set(WTimer *timer, uint msecs, WTimerHandler *handler,
 338                Obj *obj)
 339 {
 340     timer_do_set(timer, msecs, handler, obj, extl_fn_none());
 341 }
 342
 343
 344 /*EXTL_DOC
 345  * Set \var{timer} to call \var{fn} in \var{msecs} milliseconds.
 346  */
 347 EXTL_EXPORT_AS(WTimer, set)
 348 void timer_set_extl(WTimer *timer, uint msecs, ExtlFn fn)
 349 {
 350     timer_do_set(timer, msecs, NULL, NULL, extl_ref_fn(fn));
 351 }
 352
 353
 354 /*EXTL_DOC
 355  * Reset timer.
 356  */
 357 EXTL_EXPORT_MEMBER
 358 void timer_reset(WTimer *timer)
 359 {
 360     WTimer *q=queue, **qptr=&queue;
 361
 362     while(q!=NULL){
 363         if(q==timer){
 364             *qptr=timer->next;
 365             do_timer_set();
 366             break;
 367         }
 368         qptr=&(q->next);
 369         q=q->next;
 370
 371     }
 372
 373     timer->handler=NULL;
 374     extl_unref_fn(timer->extl_handler);
 375     timer->extl_handler=extl_fn_none();
 376     watch_reset(&(timer->objwatch));
 377 }
 378
 379
 380 bool timer_init(WTimer *timer)
 381 {
 382     timer->when.tv_sec=0;
 383     timer->when.tv_usec=0;
 384     timer->next=NULL;
 385     timer->handler=NULL;
 386     timer->extl_handler=extl_fn_none();
 387     watch_init(&(timer->objwatch));
 388     return TRUE;
 389 }
 390
 391 void timer_deinit(WTimer *timer)
 392 {
 393     timer_reset(timer);
 394 }
 395
 396
 397 WTimer *create_timer()
 398 {
 399     CREATEOBJ_IMPL(WTimer, timer, (p));
 400 }
 401
 402 /*EXTL_DOC
 403  * Create a new timer.
 404  */
 405 EXTL_EXPORT_AS(mainloop, create_timer)
 406 WTimer *create_timer_extl_owned()
 407 {
 408     WTimer *timer=create_timer();
 409     if(timer!=NULL)
 410         ((Obj*)timer)->flags|=OBJ_EXTL_OWNED;
 411     return timer;
 412 }
 413
 414
 415 EXTL_EXPORT
 416 IMPLCLASS(WTimer, Obj, timer_deinit, NULL);
 417
 418
 419 /*}}}*/
 420
 421
 422 /*{{{ Signal handling */
 423
 424 static void deadly_signal_handler(int signal_num)
 425 {
 426     set_warn_handler(NULL);
 427     warn(TR("Caught signal %d. Dying."), signal_num);
 428     signal(signal_num, SIG_DFL);
 429     /*if(ioncore_g.opmode==IONCORE_OPMODE_INIT)
 430         kill(getpid(), signal_num);
 431     else*/
 432         kill_sig=signal_num;
 433 }
 434
 435
 436 static void chld_handler(int UNUSED(signal_num))
 437 {
 438 #if 0
 439     pid_t pid;
 440
 441     while((pid=waitpid(-1, NULL, WNOHANG|WUNTRACED))>0){
 442         /* nothing */
 443     }
 444 #else
 445     wait_sig=1;
 446 #endif
 447 }
 448
 449 static void usr2_handler(int UNUSED(signal_num))
 450 {
 451     usr2_sig=1;
 452 }
 453
 454
 455 static void exit_handler(int signal_num)
 456 {
 457     if(kill_sig>0){
 458         warn(TR("Got signal %d while %d is still to be handled."),
 459              signal_num, kill_sig);
 460     }
 461     kill_sig=signal_num;
 462 }
 463
 464
 465 static void timer_handler(int UNUSED(signal_num))
 466 {
 467     had_tmr=TRUE;
 468 }
 469
 470
 471 static void ignore_handler(int UNUSED(signal_num))
 472 {
 473
 474 }
 475
 476
 477 #ifndef SA_RESTART
 478  /* glibc is broken (?) and does not define SA_RESTART with
 479   * '-ansi -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED', so just try to live
 480   * without it.
 481   */
 482 #define SA_RESTART 0
 483 #endif
 484
 485 #define IFTRAP(X) if(sigismember(which, X))
 486 #define DEADLY(X) IFTRAP(X) signal(X, deadly_signal_handler);
 487 #define IGNORE(X) IFTRAP(X) signal(X, SIG_IGN)
 488
 489
 490 void mainloop_trap_signals(const sigset_t *which)
 491 {
 492     struct sigaction sa;
 493     sigset_t set, oldset;
 494     sigset_t dummy;
 495
 496     if(which==NULL){
 497         sigfillset(&dummy);
 498         which=&dummy;
 499     }
 500
 501     sigemptyset(&special_sigs);
 502     sigemptyset(&set);
 503     sigemptyset(&oldset);
 504     sigprocmask(SIG_SETMASK, &set, &oldset);
 505
 506     /* I do not handle SIG{ILL,SEGV,FPE,BUS} since there's not much I can do in
 507      * response */
 508
 509     DEADLY(SIGHUP);
 510     DEADLY(SIGQUIT);
 511     DEADLY(SIGINT);
 512     DEADLY(SIGABRT);
 513
 514     IGNORE(SIGTRAP);
 515     /*IGNORE(SIGWINCH);*/
 516
 517     sigemptyset(&(sa.sa_mask));
 518
 519     IFTRAP(SIGALRM){
 520         sa.sa_handler=timer_handler;
 521         sa.sa_flags=SA_RESTART;
 522         sigaction(SIGALRM, &sa, NULL);
 523         sigaddset(&special_sigs, SIGALRM);
 524     }
 525
 526     IFTRAP(SIGCHLD){
 527         sa.sa_handler=chld_handler;
 528         sa.sa_flags=SA_NOCLDSTOP|SA_RESTART;
 529         sigaction(SIGCHLD, &sa, NULL);
 530         sigaddset(&special_sigs, SIGCHLD);
 531     }
 532
 533     IFTRAP(SIGUSR2){
 534         sa.sa_handler=usr2_handler;
 535         sa.sa_flags=SA_RESTART;
 536         sigaction(SIGUSR2, &sa, NULL);
 537         sigaddset(&special_sigs, SIGUSR2);
 538     }
 539
 540     IFTRAP(SIGTERM){
 541         sa.sa_handler=exit_handler;
 542         sa.sa_flags=SA_RESTART;
 543         sigaction(SIGTERM, &sa, NULL);
 544         sigaddset(&special_sigs, SIGTERM);
 545     }
 546
 547     IFTRAP(SIGUSR1){
 548         sa.sa_handler=exit_handler;
 549         sa.sa_flags=SA_RESTART;
 550         sigaction(SIGUSR1, &sa, NULL);
 551     }
 552
 553     /* SIG_IGN is preserved over execve and since the the default action
 554      * for SIGPIPE is not to ignore it, some programs may get upset if
 555      * the behaviour is not the default.
 556      */
 557     IFTRAP(SIGPIPE){
 558         sa.sa_handler=ignore_handler;
 559         sigaction(SIGPIPE, &sa, NULL);
 560     }
 561
 562 }
 563
 564 #undef IGNORE
 565 #undef DEADLY
 566
 567
 568 /*}}}*/
 569