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 *p)
 180 {
 181     fn();
 182     return TRUE;
 183 }
 184
 185 static bool mrsh_usr2_extl(ExtlFn fn, void *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     bool set=FALSE;
 307
 308     timer_reset(timer);
 309
 310     /* Initialize the new queue timer event */
 311     add_to_current_time(&(timer->when), msecs);
 312     timer->next=NULL;
 313     timer->handler=handler;
 314     timer->extl_handler=fn;
 315     if(obj!=NULL)
 316         watch_setup(&(timer->objwatch), obj, NULL);
 317     else
 318         watch_reset(&(timer->objwatch));
 319
 320     /* Add timerevent in place to queue */
 321     q=queue;
 322     qptr=&queue;
 323
 324     while(q!=NULL){
 325         if(TIMEVAL_LATER(q->when, timer->when))
 326             break;
 327         qptr=&(q->next);
 328         q=q->next;
 329     }
 330
 331     timer->next=q;
 332     *qptr=timer;
 333
 334     do_timer_set();
 335 }
 336
 337
 338 void timer_set(WTimer *timer, uint msecs, WTimerHandler *handler,
 339                Obj *obj)
 340 {
 341     timer_do_set(timer, msecs, handler, obj, extl_fn_none());
 342 }
 343
 344
 345 /*EXTL_DOC
 346  * Set \var{timer} to call \var{fn} in \var{msecs} milliseconds.
 347  */
 348 EXTL_EXPORT_AS(WTimer, set)
 349 void timer_set_extl(WTimer *timer, uint msecs, ExtlFn fn)
 350 {
 351     timer_do_set(timer, msecs, NULL, NULL, extl_ref_fn(fn));
 352 }
 353
 354
 355 /*EXTL_DOC
 356  * Reset timer.
 357  */
 358 EXTL_EXPORT_MEMBER
 359 void timer_reset(WTimer *timer)
 360 {
 361     WTimer *q=queue, **qptr=&queue;
 362
 363     while(q!=NULL){
 364         if(q==timer){
 365             *qptr=timer->next;
 366             do_timer_set();
 367             break;
 368         }
 369         qptr=&(q->next);
 370         q=q->next;
 371
 372     }
 373
 374     timer->handler=NULL;
 375     extl_unref_fn(timer->extl_handler);
 376     timer->extl_handler=extl_fn_none();
 377     watch_reset(&(timer->objwatch));
 378 }
 379
 380
 381 bool timer_init(WTimer *timer)
 382 {
 383     timer->when.tv_sec=0;
 384     timer->when.tv_usec=0;
 385     timer->next=NULL;
 386     timer->handler=NULL;
 387     timer->extl_handler=extl_fn_none();
 388     watch_init(&(timer->objwatch));
 389     return TRUE;
 390 }
 391
 392 void timer_deinit(WTimer *timer)
 393 {
 394     timer_reset(timer);
 395 }
 396
 397
 398 WTimer *create_timer()
 399 {
 400     CREATEOBJ_IMPL(WTimer, timer, (p));
 401 }
 402
 403 /*EXTL_DOC
 404  * Create a new timer.
 405  */
 406 EXTL_EXPORT_AS(mainloop, create_timer)
 407 WTimer *create_timer_extl_owned()
 408 {
 409     WTimer *timer=create_timer();
 410     if(timer!=NULL)
 411         ((Obj*)timer)->flags|=OBJ_EXTL_OWNED;
 412     return timer;
 413 }
 414
 415
 416 EXTL_EXPORT
 417 IMPLCLASS(WTimer, Obj, timer_deinit, NULL);
 418
 419
 420 /*}}}*/
 421
 422
 423 /*{{{ Signal handling */
 424
 425 static void deadly_signal_handler(int signal_num)
 426 {
 427     set_warn_handler(NULL);
 428     warn(TR("Caught signal %d. Dying."), signal_num);
 429     signal(signal_num, SIG_DFL);
 430     /*if(ioncore_g.opmode==IONCORE_OPMODE_INIT)
 431         kill(getpid(), signal_num);
 432     else*/
 433         kill_sig=signal_num;
 434 }
 435
 436
 437 static void chld_handler(int signal_num)
 438 {
 439 #if 0
 440     pid_t pid;
 441
 442     while((pid=waitpid(-1, NULL, WNOHANG|WUNTRACED))>0){
 443         /* nothing */
 444     }
 445 #else
 446     wait_sig=1;
 447 #endif
 448 }
 449
 450 static void usr2_handler(int signal_num)
 451 {
 452     usr2_sig=1;
 453 }
 454
 455
 456 static void exit_handler(int signal_num)
 457 {
 458     if(kill_sig>0){
 459         warn(TR("Got signal %d while %d is still to be handled."),
 460              signal_num, kill_sig);
 461     }
 462     kill_sig=signal_num;
 463 }
 464
 465
 466 static void timer_handler(int signal_num)
 467 {
 468     had_tmr=TRUE;
 469 }
 470
 471
 472 static void ignore_handler(int signal_num)
 473 {
 474
 475 }
 476
 477
 478 #ifndef SA_RESTART
 479  /* glibc is broken (?) and does not define SA_RESTART with
 480   * '-ansi -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED', so just try to live
 481   * without it.
 482   */
 483 #define SA_RESTART 0
 484 #endif
 485
 486 #define IFTRAP(X) if(sigismember(which, X))
 487 #define DEADLY(X) IFTRAP(X) signal(X, deadly_signal_handler);
 488 #define IGNORE(X) IFTRAP(X) signal(X, SIG_IGN)
 489
 490
 491 void mainloop_trap_signals(const sigset_t *which)
 492 {
 493     struct sigaction sa;
 494     sigset_t set, oldset;
 495     sigset_t dummy;
 496
 497     if(which==NULL){
 498         sigfillset(&dummy);
 499         which=&dummy;
 500     }
 501
 502     sigemptyset(&special_sigs);
 503     sigemptyset(&set);
 504     sigemptyset(&oldset);
 505     sigprocmask(SIG_SETMASK, &set, &oldset);
 506
 507     // I do not handle SIG{ILL,SEGV,FPE,BUS} since there's not much I can do in
 508     // response
 509
 510     DEADLY(SIGHUP);
 511     DEADLY(SIGQUIT);
 512     DEADLY(SIGINT);
 513     DEADLY(SIGABRT);
 514
 515     IGNORE(SIGTRAP);
 516     /*IGNORE(SIGWINCH);*/
 517
 518     sigemptyset(&(sa.sa_mask));
 519
 520     IFTRAP(SIGALRM){
 521         sa.sa_handler=timer_handler;
 522         sa.sa_flags=SA_RESTART;
 523         sigaction(SIGALRM, &sa, NULL);
 524         sigaddset(&special_sigs, SIGALRM);
 525     }
 526
 527     IFTRAP(SIGCHLD){
 528         sa.sa_handler=chld_handler;
 529         sa.sa_flags=SA_NOCLDSTOP|SA_RESTART;
 530         sigaction(SIGCHLD, &sa, NULL);
 531         sigaddset(&special_sigs, SIGCHLD);
 532     }
 533
 534     IFTRAP(SIGUSR2){
 535         sa.sa_handler=usr2_handler;
 536         sa.sa_flags=SA_RESTART;
 537         sigaction(SIGUSR2, &sa, NULL);
 538         sigaddset(&special_sigs, SIGUSR2);
 539     }
 540
 541     IFTRAP(SIGTERM){
 542         sa.sa_handler=exit_handler;
 543         sa.sa_flags=SA_RESTART;
 544         sigaction(SIGTERM, &sa, NULL);
 545         sigaddset(&special_sigs, SIGTERM);
 546     }
 547
 548     IFTRAP(SIGUSR1){
 549         sa.sa_handler=exit_handler;
 550         sa.sa_flags=SA_RESTART;
 551         sigaction(SIGUSR1, &sa, NULL);
 552     }
 553
 554     /* SIG_IGN is preserved over execve and since the the default action
 555      * for SIGPIPE is not to ignore it, some programs may get upset if
 556      * the behaviour is not the default.
 557      */
 558     IFTRAP(SIGPIPE){
 559         sa.sa_handler=ignore_handler;
 560         sigaction(SIGPIPE, &sa, NULL);
 561     }
 562
 563 }
 564
 565 #undef IGNORE
 566 #undef DEADLY
 567
 568
 569 /*}}}*/
 570