lib/common/mainloop.c

/* */
This source file includes following definitions.
crm_trigger_prepare
crm_trigger_check
crm_trigger_dispatch
crm_trigger_finalize
mainloop_setup_trigger
mainloop_trigger_complete
mainloop_add_trigger
mainloop_set_trigger
mainloop_destroy_trigger
crm_signal_dispatch
mainloop_signal_handler
crm_signal_handler
mainloop_destroy_signal_entry
mainloop_add_signal
mainloop_destroy_signal
mainloop_cleanup
gio_read_socket
gio_poll_destroy
conv_prio_libqb2glib
conv_libqb_prio2ratelimit
gio_poll_dispatch_update
gio_poll_dispatch_add
gio_poll_dispatch_mod
gio_poll_dispatch_del
pick_ipc_type
mainloop_add_ipc_server
mainloop_add_ipc_server_with_prio
mainloop_del_ipc_server
mainloop_gio_callback
mainloop_gio_destroy
pcmk__add_mainloop_ipc
pcmk__mainloop_timer_get_period
mainloop_add_ipc_client
mainloop_del_ipc_client
mainloop_get_ipc_client
mainloop_add_fd
mainloop_del_fd
mainloop_child_pid
mainloop_child_name
mainloop_child_timeout
mainloop_child_userdata
mainloop_clear_child_userdata
child_free
child_kill_helper
child_timeout_callback
child_waitpid
child_death_dispatch
child_signal_init
mainloop_child_kill
mainloop_child_add_with_flags
mainloop_child_add
mainloop_timer_cb
mainloop_timer_running
mainloop_timer_start
mainloop_timer_stop
mainloop_timer_set_period
mainloop_timer_add
mainloop_timer_del
drain_timeout_cb
pcmk_quit_main_loop
pcmk_drain_main_loop
crm_signal
   1 /*
   2  * Copyright 2004-2022 the Pacemaker project contributors
   3  *
   4  * The version control history for this file may have further details.
   5  *
   6  * This source code is licensed under the GNU Lesser General Public License
   7  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
   8  */
   9 
  10 #include <crm_internal.h>
  11 
  12 #ifndef _GNU_SOURCE
  13 #  define _GNU_SOURCE
  14 #endif
  15 
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <signal.h>
  19 #include <errno.h>
  20 
  21 #include <sys/wait.h>
  22 
  23 #include <crm/crm.h>
  24 #include <crm/common/xml.h>
  25 #include <crm/common/mainloop.h>
  26 #include <crm/common/ipc_internal.h>
  27 
  28 #include <qb/qbarray.h>
  29 
  30 struct mainloop_child_s {
  31     pid_t pid;
  32     char *desc;
  33     unsigned timerid;
  34     gboolean timeout;
  35     void *privatedata;
  36 
  37     enum mainloop_child_flags flags;
  38 
  39     /* Called when a process dies */
  40     void (*callback) (mainloop_child_t * p, pid_t pid, int core, int signo, int exitcode);
  41 };
  42 
  43 struct trigger_s {
  44     GSource source;
  45     gboolean running;
  46     gboolean trigger;
  47     void *user_data;
  48     guint id;
  49 
  50 };
  51 
  52 struct mainloop_timer_s {
  53         guint id;
  54         guint period_ms;
  55         bool repeat;
  56         char *name;
  57         GSourceFunc cb;
  58         void *userdata;
  59 };
  60 
  61 static gboolean
  62 crm_trigger_prepare(GSource * source, gint * timeout)
     /*  */
  63 {
  64     crm_trigger_t *trig = (crm_trigger_t *) source;
  65 
  66     /* cluster-glue's FD and IPC related sources make use of
  67      * g_source_add_poll() but do not set a timeout in their prepare
  68      * functions
  69      *
  70      * This means mainloop's poll() will block until an event for one
  71      * of these sources occurs - any /other/ type of source, such as
  72      * this one or g_idle_*, that doesn't use g_source_add_poll() is
  73      * S-O-L and won't be processed until there is something fd-based
  74      * happens.
  75      *
  76      * Luckily the timeout we can set here affects all sources and
  77      * puts an upper limit on how long poll() can take.
  78      *
  79      * So unconditionally set a small-ish timeout, not too small that
  80      * we're in constant motion, which will act as an upper bound on
  81      * how long the signal handling might be delayed for.
  82      */
  83     *timeout = 500;             /* Timeout in ms */
  84 
  85     return trig->trigger;
  86 }
  87 
  88 static gboolean
  89 crm_trigger_check(GSource * source)
     /*  */
  90 {
  91     crm_trigger_t *trig = (crm_trigger_t *) source;
  92 
  93     return trig->trigger;
  94 }
  95 
  96 /*!
  97  * \internal
  98  * \brief GSource dispatch function for crm_trigger_t
  99  *
 100  * \param[in] source        crm_trigger_t being dispatched
 101  * \param[in] callback      Callback passed at source creation
 102  * \param[in,out] userdata  User data passed at source creation
 103  *
 104  * \return G_SOURCE_REMOVE to remove source, G_SOURCE_CONTINUE to keep it
 105  */
 106 static gboolean
 107 crm_trigger_dispatch(GSource *source, GSourceFunc callback, gpointer userdata)
     /*  */
 108 {
 109     gboolean rc = G_SOURCE_CONTINUE;
 110     crm_trigger_t *trig = (crm_trigger_t *) source;
 111 
 112     if (trig->running) {
 113         /* Wait until the existing job is complete before starting the next one */
 114         return G_SOURCE_CONTINUE;
 115     }
 116     trig->trigger = FALSE;
 117 
 118     if (callback) {
 119         int callback_rc = callback(trig->user_data);
 120 
 121         if (callback_rc < 0) {
 122             crm_trace("Trigger handler %p not yet complete", trig);
 123             trig->running = TRUE;
 124         } else if (callback_rc == 0) {
 125             rc = G_SOURCE_REMOVE;
 126         }
 127     }
 128     return rc;
 129 }
 130 
 131 static void
 132 crm_trigger_finalize(GSource * source)
     /*  */
 133 {
 134     crm_trace("Trigger %p destroyed", source);
 135 }
 136 
 137 static GSourceFuncs crm_trigger_funcs = {
 138     crm_trigger_prepare,
 139     crm_trigger_check,
 140     crm_trigger_dispatch,
 141     crm_trigger_finalize,
 142 };
 143 
 144 static crm_trigger_t *
 145 mainloop_setup_trigger(GSource * source, int priority, int (*dispatch) (gpointer user_data),
     /*  */
 146                        gpointer userdata)
 147 {
 148     crm_trigger_t *trigger = NULL;
 149 
 150     trigger = (crm_trigger_t *) source;
 151 
 152     trigger->id = 0;
 153     trigger->trigger = FALSE;
 154     trigger->user_data = userdata;
 155 
 156     if (dispatch) {
 157         g_source_set_callback(source, dispatch, trigger, NULL);
 158     }
 159 
 160     g_source_set_priority(source, priority);
 161     g_source_set_can_recurse(source, FALSE);
 162 
 163     trigger->id = g_source_attach(source, NULL);
 164     return trigger;
 165 }
 166 
 167 void
 168 mainloop_trigger_complete(crm_trigger_t * trig)
     /*  */
 169 {
 170     crm_trace("Trigger handler %p complete", trig);
 171     trig->running = FALSE;
 172 }
 173 
 174 /*!
 175  * \brief Create a trigger to be used as a mainloop source
 176  *
 177  * \param[in] priority  Relative priority of source (lower number is higher priority)
 178  * \param[in] dispatch  Trigger dispatch function (should return 0 to remove the
 179  *                      trigger from the mainloop, -1 if the trigger should be
 180  *                      kept but the job is still running and not complete, and
 181  *                      1 if the trigger should be kept and the job is complete)
 182  * \param[in] userdata  Pointer to pass to \p dispatch
 183  *
 184  * \return Newly allocated mainloop source for trigger
 185  */
 186 crm_trigger_t *
 187 mainloop_add_trigger(int priority, int (*dispatch) (gpointer user_data),
     /*  */
 188                      gpointer userdata)
 189 {
 190     GSource *source = NULL;
 191 
 192     CRM_ASSERT(sizeof(crm_trigger_t) > sizeof(GSource));
 193     source = g_source_new(&crm_trigger_funcs, sizeof(crm_trigger_t));
 194     CRM_ASSERT(source != NULL);
 195 
 196     return mainloop_setup_trigger(source, priority, dispatch, userdata);
 197 }
 198 
 199 void
 200 mainloop_set_trigger(crm_trigger_t * source)
     /*  */
 201 {
 202     if(source) {
 203         source->trigger = TRUE;
 204     }
 205 }
 206 
 207 gboolean
 208 mainloop_destroy_trigger(crm_trigger_t * source)
     /*  */
 209 {
 210     GSource *gs = NULL;
 211 
 212     if(source == NULL) {
 213         return TRUE;
 214     }
 215 
 216     gs = (GSource *)source;
 217 
 218     g_source_destroy(gs); /* Remove from mainloop, ref_count-- */
 219     g_source_unref(gs); /* The caller no longer carries a reference to source
 220                          *
 221                          * At this point the source should be free'd,
 222                          * unless we're currently processing said
 223                          * source, in which case mainloop holds an
 224                          * additional reference and it will be free'd
 225                          * once our processing completes
 226                          */
 227     return TRUE;
 228 }
 229 
 230 // Define a custom glib source for signal handling
 231 
 232 // Data structure for custom glib source
 233 typedef struct signal_s {
 234     crm_trigger_t trigger;      // trigger that invoked source (must be first)
 235     void (*handler) (int sig);  // signal handler
 236     int signal;                 // signal that was received
 237 } crm_signal_t;
 238 
 239 // Table to associate signal handlers with signal numbers
 240 static crm_signal_t *crm_signals[NSIG];
 241 
 242 /*!
 243  * \internal
 244  * \brief Dispatch an event from custom glib source for signals
 245  *
 246  * Given an signal event, clear the event trigger and call any registered
 247  * signal handler.
 248  *
 249  * \param[in] source    glib source that triggered this dispatch
 250  * \param[in] callback  (ignored)
 251  * \param[in] userdata  (ignored)
 252  */
 253 static gboolean
 254 crm_signal_dispatch(GSource *source, GSourceFunc callback, gpointer userdata)
     /*  */
 255 {
 256     crm_signal_t *sig = (crm_signal_t *) source;
 257 
 258     if(sig->signal != SIGCHLD) {
 259         crm_notice("Caught '%s' signal "CRM_XS" %d (%s handler)",
 260                    strsignal(sig->signal), sig->signal,
 261                    (sig->handler? "invoking" : "no"));
 262     }
 263 
 264     sig->trigger.trigger = FALSE;
 265     if (sig->handler) {
 266         sig->handler(sig->signal);
 267     }
 268     return TRUE;
 269 }
 270 
 271 /*!
 272  * \internal
 273  * \brief Handle a signal by setting a trigger for signal source
 274  *
 275  * \param[in] sig  Signal number that was received
 276  *
 277  * \note This is the true signal handler for the mainloop signal source, and
 278  *       must be async-safe.
 279  */
 280 static void
 281 mainloop_signal_handler(int sig)
     /*  */
 282 {
 283     if (sig > 0 && sig < NSIG && crm_signals[sig] != NULL) {
 284         mainloop_set_trigger((crm_trigger_t *) crm_signals[sig]);
 285     }
 286 }
 287 
 288 // Functions implementing our custom glib source for signal handling
 289 static GSourceFuncs crm_signal_funcs = {
 290     crm_trigger_prepare,
 291     crm_trigger_check,
 292     crm_signal_dispatch,
 293     crm_trigger_finalize,
 294 };
 295 
 296 /*!
 297  * \internal
 298  * \brief Set a true signal handler
 299  *
 300  * signal()-like interface to sigaction()
 301  *
 302  * \param[in] sig       Signal number to register handler for
 303  * \param[in] dispatch  Signal handler
 304  *
 305  * \return The previous value of the signal handler, or SIG_ERR on error
 306  * \note The dispatch function must be async-safe.
 307  */
 308 sighandler_t
 309 crm_signal_handler(int sig, sighandler_t dispatch)
     /*  */
 310 {
 311     sigset_t mask;
 312     struct sigaction sa;
 313     struct sigaction old;
 314 
 315     if (sigemptyset(&mask) < 0) {
 316         crm_err("Could not set handler for signal %d: %s",
 317                 sig, pcmk_rc_str(errno));
 318         return SIG_ERR;
 319     }
 320 
 321     memset(&sa, 0, sizeof(struct sigaction));
 322     sa.sa_handler = dispatch;
 323     sa.sa_flags = SA_RESTART;
 324     sa.sa_mask = mask;
 325 
 326     if (sigaction(sig, &sa, &old) < 0) {
 327         crm_err("Could not set handler for signal %d: %s",
 328                 sig, pcmk_rc_str(errno));
 329         return SIG_ERR;
 330     }
 331     return old.sa_handler;
 332 }
 333 
 334 static void
 335 mainloop_destroy_signal_entry(int sig)
     /*  */
 336 {
 337     crm_signal_t *tmp = crm_signals[sig];
 338 
 339     crm_signals[sig] = NULL;
 340 
 341     crm_trace("Destroying signal %d", sig);
 342     mainloop_destroy_trigger((crm_trigger_t *) tmp);
 343 }
 344 
 345 /*!
 346  * \internal
 347  * \brief Add a signal handler to a mainloop
 348  *
 349  * \param[in] sig       Signal number to handle
 350  * \param[in] dispatch  Signal handler function
 351  *
 352  * \note The true signal handler merely sets a mainloop trigger to call this
 353  *       dispatch function via the mainloop. Therefore, the dispatch function
 354  *       does not need to be async-safe.
 355  */
 356 gboolean
 357 mainloop_add_signal(int sig, void (*dispatch) (int sig))
     /*  */
 358 {
 359     GSource *source = NULL;
 360     int priority = G_PRIORITY_HIGH - 1;
 361 
 362     if (sig == SIGTERM) {
 363         /* TERM is higher priority than other signals,
 364          *   signals are higher priority than other ipc.
 365          * Yes, minus: smaller is "higher"
 366          */
 367         priority--;
 368     }
 369 
 370     if (sig >= NSIG || sig < 0) {
 371         crm_err("Signal %d is out of range", sig);
 372         return FALSE;
 373 
 374     } else if (crm_signals[sig] != NULL && crm_signals[sig]->handler == dispatch) {
 375         crm_trace("Signal handler for %d is already installed", sig);
 376         return TRUE;
 377 
 378     } else if (crm_signals[sig] != NULL) {
 379         crm_err("Different signal handler for %d is already installed", sig);
 380         return FALSE;
 381     }
 382 
 383     CRM_ASSERT(sizeof(crm_signal_t) > sizeof(GSource));
 384     source = g_source_new(&crm_signal_funcs, sizeof(crm_signal_t));
 385 
 386     crm_signals[sig] = (crm_signal_t *) mainloop_setup_trigger(source, priority, NULL, NULL);
 387     CRM_ASSERT(crm_signals[sig] != NULL);
 388 
 389     crm_signals[sig]->handler = dispatch;
 390     crm_signals[sig]->signal = sig;
 391 
 392     if (crm_signal_handler(sig, mainloop_signal_handler) == SIG_ERR) {
 393         mainloop_destroy_signal_entry(sig);
 394         return FALSE;
 395     }
 396 #if 0
 397     /* If we want signals to interrupt mainloop's poll(), instead of waiting for
 398      * the timeout, then we should call siginterrupt() below
 399      *
 400      * For now, just enforce a low timeout
 401      */
 402     if (siginterrupt(sig, 1) < 0) {
 403         crm_perror(LOG_INFO, "Could not enable system call interruptions for signal %d", sig);
 404     }
 405 #endif
 406 
 407     return TRUE;
 408 }
 409 
 410 gboolean
 411 mainloop_destroy_signal(int sig)
     /*  */
 412 {
 413     if (sig >= NSIG || sig < 0) {
 414         crm_err("Signal %d is out of range", sig);
 415         return FALSE;
 416 
 417     } else if (crm_signal_handler(sig, NULL) == SIG_ERR) {
 418         crm_perror(LOG_ERR, "Could not uninstall signal handler for signal %d", sig);
 419         return FALSE;
 420 
 421     } else if (crm_signals[sig] == NULL) {
 422         return TRUE;
 423     }
 424     mainloop_destroy_signal_entry(sig);
 425     return TRUE;
 426 }
 427 
 428 static qb_array_t *gio_map = NULL;
 429 
 430 void
 431 mainloop_cleanup(void) 
     /*  */
 432 {
 433     if (gio_map) {
 434         qb_array_free(gio_map);
 435     }
 436 
 437     for (int sig = 0; sig < NSIG; ++sig) {
 438         mainloop_destroy_signal_entry(sig);
 439     }
 440 }
 441 
 442 /*
 443  * libqb...
 444  */
 445 struct gio_to_qb_poll {
 446     int32_t is_used;
 447     guint source;
 448     int32_t events;
 449     void *data;
 450     qb_ipcs_dispatch_fn_t fn;
 451     enum qb_loop_priority p;
 452 };
 453 
 454 static gboolean
 455 gio_read_socket(GIOChannel * gio, GIOCondition condition, gpointer data)
     /*  */
 456 {
 457     struct gio_to_qb_poll *adaptor = (struct gio_to_qb_poll *)data;
 458     gint fd = g_io_channel_unix_get_fd(gio);
 459 
 460     crm_trace("%p.%d %d", data, fd, condition);
 461 
 462     /* if this assert get's hit, then there is a race condition between
 463      * when we destroy a fd and when mainloop actually gives it up */
 464     CRM_ASSERT(adaptor->is_used > 0);
 465 
 466     return (adaptor->fn(fd, condition, adaptor->data) == 0);
 467 }
 468 
 469 static void
 470 gio_poll_destroy(gpointer data)
     /*  */
 471 {
 472     struct gio_to_qb_poll *adaptor = (struct gio_to_qb_poll *)data;
 473 
 474     adaptor->is_used--;
 475     CRM_ASSERT(adaptor->is_used >= 0);
 476 
 477     if (adaptor->is_used == 0) {
 478         crm_trace("Marking adaptor %p unused", adaptor);
 479         adaptor->source = 0;
 480     }
 481 }
 482 
 483 /*!
 484  * \internal
 485  * \brief Convert libqb's poll priority into GLib's one
 486  *
 487  * \param[in] prio  libqb's poll priority (#QB_LOOP_MED assumed as fallback)
 488  *
 489  * \return  best matching GLib's priority
 490  */
 491 static gint
 492 conv_prio_libqb2glib(enum qb_loop_priority prio)
     /*  */
 493 {
 494     switch (prio) {
 495         case QB_LOOP_LOW:   return G_PRIORITY_LOW;
 496         case QB_LOOP_HIGH:  return G_PRIORITY_HIGH;
 497         default:            return G_PRIORITY_DEFAULT; // QB_LOOP_MED
 498     }
 499 }
 500 
 501 /*!
 502  * \internal
 503  * \brief Convert libqb's poll priority to rate limiting spec
 504  *
 505  * \param[in] prio  libqb's poll priority (#QB_LOOP_MED assumed as fallback)
 506  *
 507  * \return  best matching rate limiting spec
 508  * \note This is the inverse of libqb's qb_ipcs_request_rate_limit().
 509  */
 510 static enum qb_ipcs_rate_limit
 511 conv_libqb_prio2ratelimit(enum qb_loop_priority prio)
     /*  */
 512 {
 513     switch (prio) {
 514         case QB_LOOP_LOW:   return QB_IPCS_RATE_SLOW;
 515         case QB_LOOP_HIGH:  return QB_IPCS_RATE_FAST;
 516         default:            return QB_IPCS_RATE_NORMAL; // QB_LOOP_MED
 517     }
 518 }
 519 
 520 static int32_t
 521 gio_poll_dispatch_update(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 522                          void *data, qb_ipcs_dispatch_fn_t fn, int32_t add)
 523 {
 524     struct gio_to_qb_poll *adaptor;
 525     GIOChannel *channel;
 526     int32_t res = 0;
 527 
 528     res = qb_array_index(gio_map, fd, (void **)&adaptor);
 529     if (res < 0) {
 530         crm_err("Array lookup failed for fd=%d: %d", fd, res);
 531         return res;
 532     }
 533 
 534     crm_trace("Adding fd=%d to mainloop as adaptor %p", fd, adaptor);
 535 
 536     if (add && adaptor->source) {
 537         crm_err("Adaptor for descriptor %d is still in-use", fd);
 538         return -EEXIST;
 539     }
 540     if (!add && !adaptor->is_used) {
 541         crm_err("Adaptor for descriptor %d is not in-use", fd);
 542         return -ENOENT;
 543     }
 544 
 545     /* channel is created with ref_count = 1 */
 546     channel = g_io_channel_unix_new(fd);
 547     if (!channel) {
 548         crm_err("No memory left to add fd=%d", fd);
 549         return -ENOMEM;
 550     }
 551 
 552     if (adaptor->source) {
 553         g_source_remove(adaptor->source);
 554         adaptor->source = 0;
 555     }
 556 
 557     /* Because unlike the poll() API, glib doesn't tell us about HUPs by default */
 558     evts |= (G_IO_HUP | G_IO_NVAL | G_IO_ERR);
 559 
 560     adaptor->fn = fn;
 561     adaptor->events = evts;
 562     adaptor->data = data;
 563     adaptor->p = p;
 564     adaptor->is_used++;
 565     adaptor->source =
 566         g_io_add_watch_full(channel, conv_prio_libqb2glib(p), evts,
 567                             gio_read_socket, adaptor, gio_poll_destroy);
 568 
 569     /* Now that mainloop now holds a reference to channel,
 570      * thanks to g_io_add_watch_full(), drop ours from g_io_channel_unix_new().
 571      *
 572      * This means that channel will be free'd by:
 573      * g_main_context_dispatch()
 574      *  -> g_source_destroy_internal()
 575      *      -> g_source_callback_unref()
 576      * shortly after gio_poll_destroy() completes
 577      */
 578     g_io_channel_unref(channel);
 579 
 580     crm_trace("Added to mainloop with gsource id=%d", adaptor->source);
 581     if (adaptor->source > 0) {
 582         return 0;
 583     }
 584 
 585     return -EINVAL;
 586 }
 587 
 588 static int32_t
 589 gio_poll_dispatch_add(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 590                       void *data, qb_ipcs_dispatch_fn_t fn)
 591 {
 592     return gio_poll_dispatch_update(p, fd, evts, data, fn, QB_TRUE);
 593 }
 594 
 595 static int32_t
 596 gio_poll_dispatch_mod(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 597                       void *data, qb_ipcs_dispatch_fn_t fn)
 598 {
 599     return gio_poll_dispatch_update(p, fd, evts, data, fn, QB_FALSE);
 600 }
 601 
 602 static int32_t
 603 gio_poll_dispatch_del(int32_t fd)
     /*  */
 604 {
 605     struct gio_to_qb_poll *adaptor;
 606 
 607     crm_trace("Looking for fd=%d", fd);
 608     if (qb_array_index(gio_map, fd, (void **)&adaptor) == 0) {
 609         if (adaptor->source) {
 610             g_source_remove(adaptor->source);
 611             adaptor->source = 0;
 612         }
 613     }
 614     return 0;
 615 }
 616 
 617 struct qb_ipcs_poll_handlers gio_poll_funcs = {
 618     .job_add = NULL,
 619     .dispatch_add = gio_poll_dispatch_add,
 620     .dispatch_mod = gio_poll_dispatch_mod,
 621     .dispatch_del = gio_poll_dispatch_del,
 622 };
 623 
 624 static enum qb_ipc_type
 625 pick_ipc_type(enum qb_ipc_type requested)
     /*  */
 626 {
 627     const char *env = getenv("PCMK_ipc_type");
 628 
 629     if (env && strcmp("shared-mem", env) == 0) {
 630         return QB_IPC_SHM;
 631     } else if (env && strcmp("socket", env) == 0) {
 632         return QB_IPC_SOCKET;
 633     } else if (env && strcmp("posix", env) == 0) {
 634         return QB_IPC_POSIX_MQ;
 635     } else if (env && strcmp("sysv", env) == 0) {
 636         return QB_IPC_SYSV_MQ;
 637     } else if (requested == QB_IPC_NATIVE) {
 638         /* We prefer shared memory because the server never blocks on
 639          * send.  If part of a message fits into the socket, libqb
 640          * needs to block until the remainder can be sent also.
 641          * Otherwise the client will wait forever for the remaining
 642          * bytes.
 643          */
 644         return QB_IPC_SHM;
 645     }
 646     return requested;
 647 }
 648 
 649 qb_ipcs_service_t *
 650 mainloop_add_ipc_server(const char *name, enum qb_ipc_type type,
     /*  */
 651                         struct qb_ipcs_service_handlers *callbacks)
 652 {
 653     return mainloop_add_ipc_server_with_prio(name, type, callbacks, QB_LOOP_MED);
 654 }
 655 
 656 qb_ipcs_service_t *
 657 mainloop_add_ipc_server_with_prio(const char *name, enum qb_ipc_type type,
     /*  */
 658                                   struct qb_ipcs_service_handlers *callbacks,
 659                                   enum qb_loop_priority prio)
 660 {
 661     int rc = 0;
 662     qb_ipcs_service_t *server = NULL;
 663 
 664     if (gio_map == NULL) {
 665         gio_map = qb_array_create_2(64, sizeof(struct gio_to_qb_poll), 1);
 666     }
 667 
 668     server = qb_ipcs_create(name, 0, pick_ipc_type(type), callbacks);
 669 
 670     if (server == NULL) {
 671         crm_err("Could not create %s IPC server: %s (%d)", name, pcmk_strerror(rc), rc);
 672         return NULL;
 673     }
 674 
 675     if (prio != QB_LOOP_MED) {
 676         qb_ipcs_request_rate_limit(server, conv_libqb_prio2ratelimit(prio));
 677     }
 678 
 679     /* All clients should use at least ipc_buffer_max as their buffer size */
 680     qb_ipcs_enforce_buffer_size(server, crm_ipc_default_buffer_size());
 681     qb_ipcs_poll_handlers_set(server, &gio_poll_funcs);
 682 
 683     rc = qb_ipcs_run(server);
 684     if (rc < 0) {
 685         crm_err("Could not start %s IPC server: %s (%d)", name, pcmk_strerror(rc), rc);
 686         qb_ipcs_destroy(server);
 687         return NULL;
 688     }
 689 
 690     return server;
 691 }
 692 
 693 void
 694 mainloop_del_ipc_server(qb_ipcs_service_t * server)
     /*  */
 695 {
 696     if (server) {
 697         qb_ipcs_destroy(server);
 698     }
 699 }
 700 
 701 struct mainloop_io_s {
 702     char *name;
 703     void *userdata;
 704 
 705     int fd;
 706     guint source;
 707     crm_ipc_t *ipc;
 708     GIOChannel *channel;
 709 
 710     int (*dispatch_fn_ipc) (const char *buffer, ssize_t length, gpointer userdata);
 711     int (*dispatch_fn_io) (gpointer userdata);
 712     void (*destroy_fn) (gpointer userdata);
 713 
 714 };
 715 
 716 /*!
 717  * \internal
 718  * \brief I/O watch callback function (GIOFunc)
 719  *
 720  * \param[in] gio        I/O channel being watched
 721  * \param[in] condition  I/O condition satisfied
 722  * \param[in] data       User data passed when source was created
 723  *
 724  * \return G_SOURCE_REMOVE to remove source, G_SOURCE_CONTINUE to keep it
 725  */
 726 static gboolean
 727 mainloop_gio_callback(GIOChannel *gio, GIOCondition condition, gpointer data)
     /*  */
 728 {
 729     gboolean rc = G_SOURCE_CONTINUE;
 730     mainloop_io_t *client = data;
 731 
 732     CRM_ASSERT(client->fd == g_io_channel_unix_get_fd(gio));
 733 
 734     if (condition & G_IO_IN) {
 735         if (client->ipc) {
 736             long read_rc = 0L;
 737             int max = 10;
 738 
 739             do {
 740                 read_rc = crm_ipc_read(client->ipc);
 741                 if (read_rc <= 0) {
 742                     crm_trace("Could not read IPC message from %s: %s (%ld)",
 743                               client->name, pcmk_strerror(read_rc), read_rc);
 744 
 745                 } else if (client->dispatch_fn_ipc) {
 746                     const char *buffer = crm_ipc_buffer(client->ipc);
 747 
 748                     crm_trace("New %ld-byte IPC message from %s "
 749                               "after I/O condition %d",
 750                               read_rc, client->name, (int) condition);
 751                     if (client->dispatch_fn_ipc(buffer, read_rc, client->userdata) < 0) {
 752                         crm_trace("Connection to %s no longer required", client->name);
 753                         rc = G_SOURCE_REMOVE;
 754                     }
 755                 }
 756 
 757             } while ((rc == G_SOURCE_CONTINUE) && (read_rc > 0) && --max > 0);
 758 
 759         } else {
 760             crm_trace("New I/O event for %s after I/O condition %d",
 761                       client->name, (int) condition);
 762             if (client->dispatch_fn_io) {
 763                 if (client->dispatch_fn_io(client->userdata) < 0) {
 764                     crm_trace("Connection to %s no longer required", client->name);
 765                     rc = G_SOURCE_REMOVE;
 766                 }
 767             }
 768         }
 769     }
 770 
 771     if (client->ipc && crm_ipc_connected(client->ipc) == FALSE) {
 772         crm_err("Connection to %s closed " CRM_XS "client=%p condition=%d",
 773                 client->name, client, condition);
 774         rc = G_SOURCE_REMOVE;
 775 
 776     } else if (condition & (G_IO_HUP | G_IO_NVAL | G_IO_ERR)) {
 777         crm_trace("The connection %s[%p] has been closed (I/O condition=%d)",
 778                   client->name, client, condition);
 779         rc = G_SOURCE_REMOVE;
 780 
 781     } else if ((condition & G_IO_IN) == 0) {
 782         /*
 783            #define      GLIB_SYSDEF_POLLIN     =1
 784            #define      GLIB_SYSDEF_POLLPRI    =2
 785            #define      GLIB_SYSDEF_POLLOUT    =4
 786            #define      GLIB_SYSDEF_POLLERR    =8
 787            #define      GLIB_SYSDEF_POLLHUP    =16
 788            #define      GLIB_SYSDEF_POLLNVAL   =32
 789 
 790            typedef enum
 791            {
 792            G_IO_IN      GLIB_SYSDEF_POLLIN,
 793            G_IO_OUT     GLIB_SYSDEF_POLLOUT,
 794            G_IO_PRI     GLIB_SYSDEF_POLLPRI,
 795            G_IO_ERR     GLIB_SYSDEF_POLLERR,
 796            G_IO_HUP     GLIB_SYSDEF_POLLHUP,
 797            G_IO_NVAL    GLIB_SYSDEF_POLLNVAL
 798            } GIOCondition;
 799 
 800            A bitwise combination representing a condition to watch for on an event source.
 801 
 802            G_IO_IN      There is data to read.
 803            G_IO_OUT     Data can be written (without blocking).
 804            G_IO_PRI     There is urgent data to read.
 805            G_IO_ERR     Error condition.
 806            G_IO_HUP     Hung up (the connection has been broken, usually for pipes and sockets).
 807            G_IO_NVAL    Invalid request. The file descriptor is not open.
 808          */
 809         crm_err("Strange condition: %d", condition);
 810     }
 811 
 812     /* G_SOURCE_REMOVE results in mainloop_gio_destroy() being called
 813      * just before the source is removed from mainloop
 814      */
 815     return rc;
 816 }
 817 
 818 static void
 819 mainloop_gio_destroy(gpointer c)
     /*  */
 820 {
 821     mainloop_io_t *client = c;
 822     char *c_name = strdup(client->name);
 823 
 824     /* client->source is valid but about to be destroyed (ref_count == 0) in gmain.c
 825      * client->channel will still have ref_count > 0... should be == 1
 826      */
 827     crm_trace("Destroying client %s[%p]", c_name, c);
 828 
 829     if (client->ipc) {
 830         crm_ipc_close(client->ipc);
 831     }
 832 
 833     if (client->destroy_fn) {
 834         void (*destroy_fn) (gpointer userdata) = client->destroy_fn;
 835 
 836         client->destroy_fn = NULL;
 837         destroy_fn(client->userdata);
 838     }
 839 
 840     if (client->ipc) {
 841         crm_ipc_t *ipc = client->ipc;
 842 
 843         client->ipc = NULL;
 844         crm_ipc_destroy(ipc);
 845     }
 846 
 847     crm_trace("Destroyed client %s[%p]", c_name, c);
 848 
 849     free(client->name); client->name = NULL;
 850     free(client);
 851 
 852     free(c_name);
 853 }
 854 
 855 /*!
 856  * \brief Connect to IPC and add it as a main loop source
 857  *
 858  * \param[in,out] ipc        IPC connection to add
 859  * \param[in]     priority   Event source priority to use for connection
 860  * \param[in]     userdata   Data to register with callbacks
 861  * \param[in]     callbacks  Dispatch and destroy callbacks for connection
 862  * \param[out]    source     Newly allocated event source
 863  *
 864  * \return Standard Pacemaker return code
 865  *
 866  * \note On failure, the caller is still responsible for ipc. On success, the
 867  *       caller should call mainloop_del_ipc_client() when source is no longer
 868  *       needed, which will lead to the disconnection of the IPC later in the
 869  *       main loop if it is connected. However the IPC disconnects,
 870  *       mainloop_gio_destroy() will free ipc and source after calling the
 871  *       destroy callback.
 872  */
 873 int
 874 pcmk__add_mainloop_ipc(crm_ipc_t *ipc, int priority, void *userdata,
     /*  */
 875                        const struct ipc_client_callbacks *callbacks,
 876                        mainloop_io_t **source)
 877 {
 878     CRM_CHECK((ipc != NULL) && (callbacks != NULL), return EINVAL);
 879 
 880     if (!crm_ipc_connect(ipc)) {
 881         int rc = errno;
 882         crm_debug("Connection to %s failed: %d", crm_ipc_name(ipc), errno);
 883         return rc;
 884     }
 885     *source = mainloop_add_fd(crm_ipc_name(ipc), priority, crm_ipc_get_fd(ipc),
 886                               userdata, NULL);
 887     if (*source == NULL) {
 888         int rc = errno;
 889 
 890         crm_ipc_close(ipc);
 891         return rc;
 892     }
 893     (*source)->ipc = ipc;
 894     (*source)->destroy_fn = callbacks->destroy;
 895     (*source)->dispatch_fn_ipc = callbacks->dispatch;
 896     return pcmk_rc_ok;
 897 }
 898 
 899 /*!
 900  * \brief Get period for mainloop timer
 901  *
 902  * \param[in]  timer      Timer
 903  *
 904  * \return Period in ms
 905  */
 906 guint
 907 pcmk__mainloop_timer_get_period(const mainloop_timer_t *timer)
     /*  */
 908 {
 909     if (timer) {
 910         return timer->period_ms;
 911     }
 912     return 0;
 913 }
 914 
 915 mainloop_io_t *
 916 mainloop_add_ipc_client(const char *name, int priority, size_t max_size,
     /*  */
 917                         void *userdata, struct ipc_client_callbacks *callbacks)
 918 {
 919     crm_ipc_t *ipc = crm_ipc_new(name, max_size);
 920     mainloop_io_t *source = NULL;
 921     int rc = pcmk__add_mainloop_ipc(ipc, priority, userdata, callbacks,
 922                                     &source);
 923 
 924     if (rc != pcmk_rc_ok) {
 925         if (crm_log_level == LOG_STDOUT) {
 926             fprintf(stderr, "Connection to %s failed: %s",
 927                     name, pcmk_rc_str(rc));
 928         }
 929         crm_ipc_destroy(ipc);
 930         if (rc > 0) {
 931             errno = rc;
 932         } else {
 933             errno = ENOTCONN;
 934         }
 935         return NULL;
 936     }
 937     return source;
 938 }
 939 
 940 void
 941 mainloop_del_ipc_client(mainloop_io_t * client)
     /*  */
 942 {
 943     mainloop_del_fd(client);
 944 }
 945 
 946 crm_ipc_t *
 947 mainloop_get_ipc_client(mainloop_io_t * client)
     /*  */
 948 {
 949     if (client) {
 950         return client->ipc;
 951     }
 952     return NULL;
 953 }
 954 
 955 mainloop_io_t *
 956 mainloop_add_fd(const char *name, int priority, int fd, void *userdata,
     /*  */
 957                 struct mainloop_fd_callbacks * callbacks)
 958 {
 959     mainloop_io_t *client = NULL;
 960 
 961     if (fd >= 0) {
 962         client = calloc(1, sizeof(mainloop_io_t));
 963         if (client == NULL) {
 964             return NULL;
 965         }
 966         client->name = strdup(name);
 967         client->userdata = userdata;
 968 
 969         if (callbacks) {
 970             client->destroy_fn = callbacks->destroy;
 971             client->dispatch_fn_io = callbacks->dispatch;
 972         }
 973 
 974         client->fd = fd;
 975         client->channel = g_io_channel_unix_new(fd);
 976         client->source =
 977             g_io_add_watch_full(client->channel, priority,
 978                                 (G_IO_IN | G_IO_HUP | G_IO_NVAL | G_IO_ERR), mainloop_gio_callback,
 979                                 client, mainloop_gio_destroy);
 980 
 981         /* Now that mainloop now holds a reference to channel,
 982          * thanks to g_io_add_watch_full(), drop ours from g_io_channel_unix_new().
 983          *
 984          * This means that channel will be free'd by:
 985          * g_main_context_dispatch() or g_source_remove()
 986          *  -> g_source_destroy_internal()
 987          *      -> g_source_callback_unref()
 988          * shortly after mainloop_gio_destroy() completes
 989          */
 990         g_io_channel_unref(client->channel);
 991         crm_trace("Added connection %d for %s[%p].%d", client->source, client->name, client, fd);
 992     } else {
 993         errno = EINVAL;
 994     }
 995 
 996     return client;
 997 }
 998 
 999 void
1000 mainloop_del_fd(mainloop_io_t * client)
     /*  */
1001 {
1002     if (client != NULL) {
1003         crm_trace("Removing client %s[%p]", client->name, client);
1004         if (client->source) {
1005             /* Results in mainloop_gio_destroy() being called just
1006              * before the source is removed from mainloop
1007              */
1008             g_source_remove(client->source);
1009         }
1010     }
1011 }
1012 
1013 static GList *child_list = NULL;
1014 
1015 pid_t
1016 mainloop_child_pid(mainloop_child_t * child)
     /*  */
1017 {
1018     return child->pid;
1019 }
1020 
1021 const char *
1022 mainloop_child_name(mainloop_child_t * child)
     /*  */
1023 {
1024     return child->desc;
1025 }
1026 
1027 int
1028 mainloop_child_timeout(mainloop_child_t * child)
     /*  */
1029 {
1030     return child->timeout;
1031 }
1032 
1033 void *
1034 mainloop_child_userdata(mainloop_child_t * child)
     /*  */
1035 {
1036     return child->privatedata;
1037 }
1038 
1039 void
1040 mainloop_clear_child_userdata(mainloop_child_t * child)
     /*  */
1041 {
1042     child->privatedata = NULL;
1043 }
1044 
1045 /* good function name */
1046 static void
1047 child_free(mainloop_child_t *child)
     /*  */
1048 {
1049     if (child->timerid != 0) {
1050         crm_trace("Removing timer %d", child->timerid);
1051         g_source_remove(child->timerid);
1052         child->timerid = 0;
1053     }
1054     free(child->desc);
1055     free(child);
1056 }
1057 
1058 /* terrible function name */
1059 static int
1060 child_kill_helper(mainloop_child_t *child)
     /*  */
1061 {
1062     int rc;
1063     if (child->flags & mainloop_leave_pid_group) {
1064         crm_debug("Kill pid %d only. leave group intact.", child->pid);
1065         rc = kill(child->pid, SIGKILL);
1066     } else {
1067         crm_debug("Kill pid %d's group", child->pid);
1068         rc = kill(-child->pid, SIGKILL);
1069     }
1070 
1071     if (rc < 0) {
1072         if (errno != ESRCH) {
1073             crm_perror(LOG_ERR, "kill(%d, KILL) failed", child->pid);
1074         }
1075         return -errno;
1076     }
1077     return 0;
1078 }
1079 
1080 static gboolean
1081 child_timeout_callback(gpointer p)
     /*  */
1082 {
1083     mainloop_child_t *child = p;
1084     int rc = 0;
1085 
1086     child->timerid = 0;
1087     if (child->timeout) {
1088         crm_warn("%s process (PID %d) will not die!", child->desc, (int)child->pid);
1089         return FALSE;
1090     }
1091 
1092     rc = child_kill_helper(child);
1093     if (rc == -ESRCH) {
1094         /* Nothing left to do. pid doesn't exist */
1095         return FALSE;
1096     }
1097 
1098     child->timeout = TRUE;
1099     crm_debug("%s process (PID %d) timed out", child->desc, (int)child->pid);
1100 
1101     child->timerid = g_timeout_add(5000, child_timeout_callback, child);
1102     return FALSE;
1103 }
1104 
1105 static bool
1106 child_waitpid(mainloop_child_t *child, int flags)
     /*  */
1107 {
1108     int rc = 0;
1109     int core = 0;
1110     int signo = 0;
1111     int status = 0;
1112     int exitcode = 0;
1113     bool callback_needed = true;
1114 
1115     rc = waitpid(child->pid, &status, flags);
1116     if (rc == 0) { // WNOHANG in flags, and child status is not available
1117         crm_trace("Child process %d (%s) still active",
1118                   child->pid, child->desc);
1119         callback_needed = false;
1120 
1121     } else if (rc != child->pid) {
1122         /* According to POSIX, possible conditions:
1123          * - child->pid was non-positive (process group or any child),
1124          *   and rc is specific child
1125          * - errno ECHILD (pid does not exist or is not child)
1126          * - errno EINVAL (invalid flags)
1127          * - errno EINTR (caller interrupted by signal)
1128          *
1129          * @TODO Handle these cases more specifically.
1130          */
1131         signo = SIGCHLD;
1132         exitcode = 1;
1133         crm_notice("Wait for child process %d (%s) interrupted: %s",
1134                    child->pid, child->desc, pcmk_rc_str(errno));
1135 
1136     } else if (WIFEXITED(status)) {
1137         exitcode = WEXITSTATUS(status);
1138         crm_trace("Child process %d (%s) exited with status %d",
1139                   child->pid, child->desc, exitcode);
1140 
1141     } else if (WIFSIGNALED(status)) {
1142         signo = WTERMSIG(status);
1143         crm_trace("Child process %d (%s) exited with signal %d (%s)",
1144                   child->pid, child->desc, signo, strsignal(signo));
1145 
1146 #ifdef WCOREDUMP // AIX, SunOS, maybe others
1147     } else if (WCOREDUMP(status)) {
1148         core = 1;
1149         crm_err("Child process %d (%s) dumped core",
1150                 child->pid, child->desc);
1151 #endif
1152 
1153     } else { // flags must contain WUNTRACED and/or WCONTINUED to reach this
1154         crm_trace("Child process %d (%s) stopped or continued",
1155                   child->pid, child->desc);
1156         callback_needed = false;
1157     }
1158 
1159     if (callback_needed && child->callback) {
1160         child->callback(child, child->pid, core, signo, exitcode);
1161     }
1162     return callback_needed;
1163 }
1164 
1165 static void
1166 child_death_dispatch(int signal)
     /*  */
1167 {
1168     for (GList *iter = child_list; iter; ) {
1169         GList *saved = iter;
1170         mainloop_child_t *child = iter->data;
1171 
1172         iter = iter->next;
1173         if (child_waitpid(child, WNOHANG)) {
1174             crm_trace("Removing completed process %d from child list",
1175                       child->pid);
1176             child_list = g_list_remove_link(child_list, saved);
1177             g_list_free(saved);
1178             child_free(child);
1179         }
1180     }
1181 }
1182 
1183 static gboolean
1184 child_signal_init(gpointer p)
     /*  */
1185 {
1186     crm_trace("Installed SIGCHLD handler");
1187     /* Do NOT use g_child_watch_add() and friends, they rely on pthreads */
1188     mainloop_add_signal(SIGCHLD, child_death_dispatch);
1189 
1190     /* In case they terminated before the signal handler was installed */
1191     child_death_dispatch(SIGCHLD);
1192     return FALSE;
1193 }
1194 
1195 gboolean
1196 mainloop_child_kill(pid_t pid)
     /*  */
1197 {
1198     GList *iter;
1199     mainloop_child_t *child = NULL;
1200     mainloop_child_t *match = NULL;
1201     /* It is impossible to block SIGKILL, this allows us to
1202      * call waitpid without WNOHANG flag.*/
1203     int waitflags = 0, rc = 0;
1204 
1205     for (iter = child_list; iter != NULL && match == NULL; iter = iter->next) {
1206         child = iter->data;
1207         if (pid == child->pid) {
1208             match = child;
1209         }
1210     }
1211 
1212     if (match == NULL) {
1213         return FALSE;
1214     }
1215 
1216     rc = child_kill_helper(match);
1217     if(rc == -ESRCH) {
1218         /* It's gone, but hasn't shown up in waitpid() yet. Wait until we get
1219          * SIGCHLD and let handler clean it up as normal (so we get the correct
1220          * return code/status). The blocking alternative would be to call
1221          * child_waitpid(match, 0).
1222          */
1223         crm_trace("Waiting for signal that child process %d completed",
1224                   match->pid);
1225         return TRUE;
1226 
1227     } else if(rc != 0) {
1228         /* If KILL for some other reason set the WNOHANG flag since we
1229          * can't be certain what happened.
1230          */
1231         waitflags = WNOHANG;
1232     }
1233 
1234     if (!child_waitpid(match, waitflags)) {
1235         /* not much we can do if this occurs */
1236         return FALSE;
1237     }
1238 
1239     child_list = g_list_remove(child_list, match);
1240     child_free(match);
1241     return TRUE;
1242 }
1243 
1244 /* Create/Log a new tracked process
1245  * To track a process group, use -pid
1246  *
1247  * @TODO Using a non-positive pid (i.e. any child, or process group) would
1248  *       likely not be useful since we will free the child after the first
1249  *       completed process.
1250  */
1251 void
1252 mainloop_child_add_with_flags(pid_t pid, int timeout, const char *desc, void *privatedata, enum mainloop_child_flags flags, 
     /*  */
1253                    void (*callback) (mainloop_child_t * p, pid_t pid, int core, int signo, int exitcode))
1254 {
1255     static bool need_init = TRUE;
1256     mainloop_child_t *child = calloc(1, sizeof(mainloop_child_t));
1257 
1258     child->pid = pid;
1259     child->timerid = 0;
1260     child->timeout = FALSE;
1261     child->privatedata = privatedata;
1262     child->callback = callback;
1263     child->flags = flags;
1264     pcmk__str_update(&child->desc, desc);
1265 
1266     if (timeout) {
1267         child->timerid = g_timeout_add(timeout, child_timeout_callback, child);
1268     }
1269 
1270     child_list = g_list_append(child_list, child);
1271 
1272     if(need_init) {
1273         need_init = FALSE;
1274         /* SIGCHLD processing has to be invoked from mainloop.
1275          * We do not want it to be possible to both add a child pid
1276          * to mainloop, and have the pid's exit callback invoked within
1277          * the same callstack. */
1278         g_timeout_add(1, child_signal_init, NULL);
1279     }
1280 }
1281 
1282 void
1283 mainloop_child_add(pid_t pid, int timeout, const char *desc, void *privatedata,
     /*  */
1284                    void (*callback) (mainloop_child_t * p, pid_t pid, int core, int signo, int exitcode))
1285 {
1286     mainloop_child_add_with_flags(pid, timeout, desc, privatedata, 0, callback);
1287 }
1288 
1289 static gboolean
1290 mainloop_timer_cb(gpointer user_data)
     /*  */
1291 {
1292     int id = 0;
1293     bool repeat = FALSE;
1294     struct mainloop_timer_s *t = user_data;
1295 
1296     CRM_ASSERT(t != NULL);
1297 
1298     id = t->id;
1299     t->id = 0; /* Ensure it's unset during callbacks so that
1300                 * mainloop_timer_running() works as expected
1301                 */
1302 
1303     if(t->cb) {
1304         crm_trace("Invoking callbacks for timer %s", t->name);
1305         repeat = t->repeat;
1306         if(t->cb(t->userdata) == FALSE) {
1307             crm_trace("Timer %s complete", t->name);
1308             repeat = FALSE;
1309         }
1310     }
1311 
1312     if(repeat) {
1313         /* Restore if repeating */
1314         t->id = id;
1315     }
1316 
1317     return repeat;
1318 }
1319 
1320 bool
1321 mainloop_timer_running(mainloop_timer_t *t)
     /*  */
1322 {
1323     if(t && t->id != 0) {
1324         return TRUE;
1325     }
1326     return FALSE;
1327 }
1328 
1329 void
1330 mainloop_timer_start(mainloop_timer_t *t)
     /*  */
1331 {
1332     mainloop_timer_stop(t);
1333     if(t && t->period_ms > 0) {
1334         crm_trace("Starting timer %s", t->name);
1335         t->id = g_timeout_add(t->period_ms, mainloop_timer_cb, t);
1336     }
1337 }
1338 
1339 void
1340 mainloop_timer_stop(mainloop_timer_t *t)
     /*  */
1341 {
1342     if(t && t->id != 0) {
1343         crm_trace("Stopping timer %s", t->name);
1344         g_source_remove(t->id);
1345         t->id = 0;
1346     }
1347 }
1348 
1349 guint
1350 mainloop_timer_set_period(mainloop_timer_t *t, guint period_ms)
     /*  */
1351 {
1352     guint last = 0;
1353 
1354     if(t) {
1355         last = t->period_ms;
1356         t->period_ms = period_ms;
1357     }
1358 
1359     if(t && t->id != 0 && last != t->period_ms) {
1360         mainloop_timer_start(t);
1361     }
1362     return last;
1363 }
1364 
1365 mainloop_timer_t *
1366 mainloop_timer_add(const char *name, guint period_ms, bool repeat, GSourceFunc cb, void *userdata)
     /*  */
1367 {
1368     mainloop_timer_t *t = calloc(1, sizeof(mainloop_timer_t));
1369 
1370     if(t) {
1371         if(name) {
1372             t->name = crm_strdup_printf("%s-%u-%d", name, period_ms, repeat);
1373         } else {
1374             t->name = crm_strdup_printf("%p-%u-%d", t, period_ms, repeat);
1375         }
1376         t->id = 0;
1377         t->period_ms = period_ms;
1378         t->repeat = repeat;
1379         t->cb = cb;
1380         t->userdata = userdata;
1381         crm_trace("Created timer %s with %p %p", t->name, userdata, t->userdata);
1382     }
1383     return t;
1384 }
1385 
1386 void
1387 mainloop_timer_del(mainloop_timer_t *t)
     /*  */
1388 {
1389     if(t) {
1390         crm_trace("Destroying timer %s", t->name);
1391         mainloop_timer_stop(t);
1392         free(t->name);
1393         free(t);
1394     }
1395 }
1396 
1397 /*
1398  * Helpers to make sure certain events aren't lost at shutdown
1399  */
1400 
1401 static gboolean
1402 drain_timeout_cb(gpointer user_data)
     /*  */
1403 {
1404     bool *timeout_popped = (bool*) user_data;
1405 
1406     *timeout_popped = TRUE;
1407     return FALSE;
1408 }
1409 
1410 /*!
1411  * \brief Drain some remaining main loop events then quit it
1412  *
1413  * \param[in,out] mloop  Main loop to drain and quit
1414  * \param[in]     n      Drain up to this many pending events
1415  */
1416 void
1417 pcmk_quit_main_loop(GMainLoop *mloop, unsigned int n)
     /*  */
1418 {
1419     if ((mloop != NULL) && g_main_loop_is_running(mloop)) {
1420         GMainContext *ctx = g_main_loop_get_context(mloop);
1421 
1422         /* Drain up to n events in case some memory clean-up is pending
1423          * (helpful to reduce noise in valgrind output).
1424          */
1425         for (int i = 0; (i < n) && g_main_context_pending(ctx); ++i) {
1426             g_main_context_dispatch(ctx);
1427         }
1428         g_main_loop_quit(mloop);
1429     }
1430 }
1431 
1432 /*!
1433  * \brief Process main loop events while a certain condition is met
1434  *
1435  * \param[in,out] mloop     Main loop to process
1436  * \param[in]     timer_ms  Don't process longer than this amount of time
1437  * \param[in]     check     Function that returns true if events should be
1438  *                          processed
1439  *
1440  * \note This function is intended to be called at shutdown if certain important
1441  *       events should not be missed. The caller would likely quit the main loop
1442  *       or exit after calling this function. The check() function will be
1443  *       passed the remaining timeout in milliseconds.
1444  */
1445 void
1446 pcmk_drain_main_loop(GMainLoop *mloop, guint timer_ms, bool (*check)(guint))
     /*  */
1447 {
1448     bool timeout_popped = FALSE;
1449     guint timer = 0;
1450     GMainContext *ctx = NULL;
1451 
1452     CRM_CHECK(mloop && check, return);
1453 
1454     ctx = g_main_loop_get_context(mloop);
1455     if (ctx) {
1456         time_t start_time = time(NULL);
1457 
1458         timer = g_timeout_add(timer_ms, drain_timeout_cb, &timeout_popped);
1459         while (!timeout_popped
1460                && check(timer_ms - (time(NULL) - start_time) * 1000)) {
1461             g_main_context_iteration(ctx, TRUE);
1462         }
1463     }
1464     if (!timeout_popped && (timer > 0)) {
1465         g_source_remove(timer);
1466     }
1467 }
1468 
1469 // Deprecated functions kept only for backward API compatibility
1470 // LCOV_EXCL_START
1471 
1472 #include <crm/common/mainloop_compat.h>
1473 
1474 gboolean
1475 crm_signal(int sig, void (*dispatch) (int sig))
     /*  */
1476 {
1477     return crm_signal_handler(sig, dispatch) != SIG_ERR;
1478 }
1479 
1480 // LCOV_EXCL_STOP
1481 // End deprecated API
/* */
root/lib/common/mainloop.c

DEFINITIONS
