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 2004-2021 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] 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  *
 183  * \return Newly allocated mainloop source for trigger
 184  */
 185 crm_trigger_t *
 186 mainloop_add_trigger(int priority, int (*dispatch) (gpointer user_data), gpointer userdata)
     /*  */
 187 {
 188     GSource *source = NULL;
 189 
 190     CRM_ASSERT(sizeof(crm_trigger_t) > sizeof(GSource));
 191     source = g_source_new(&crm_trigger_funcs, sizeof(crm_trigger_t));
 192     CRM_ASSERT(source != NULL);
 193 
 194     return mainloop_setup_trigger(source, priority, dispatch, userdata);
 195 }
 196 
 197 void
 198 mainloop_set_trigger(crm_trigger_t * source)
     /*  */
 199 {
 200     if(source) {
 201         source->trigger = TRUE;
 202     }
 203 }
 204 
 205 gboolean
 206 mainloop_destroy_trigger(crm_trigger_t * source)
     /*  */
 207 {
 208     GSource *gs = NULL;
 209 
 210     if(source == NULL) {
 211         return TRUE;
 212     }
 213 
 214     gs = (GSource *)source;
 215 
 216     g_source_destroy(gs); /* Remove from mainloop, ref_count-- */
 217     g_source_unref(gs); /* The caller no longer carries a reference to source
 218                          *
 219                          * At this point the source should be free'd,
 220                          * unless we're currently processing said
 221                          * source, in which case mainloop holds an
 222                          * additional reference and it will be free'd
 223                          * once our processing completes
 224                          */
 225     return TRUE;
 226 }
 227 
 228 // Define a custom glib source for signal handling
 229 
 230 // Data structure for custom glib source
 231 typedef struct signal_s {
 232     crm_trigger_t trigger;      // trigger that invoked source (must be first)
 233     void (*handler) (int sig);  // signal handler
 234     int signal;                 // signal that was received
 235 } crm_signal_t;
 236 
 237 // Table to associate signal handlers with signal numbers
 238 static crm_signal_t *crm_signals[NSIG];
 239 
 240 /*!
 241  * \internal
 242  * \brief Dispatch an event from custom glib source for signals
 243  *
 244  * Given an signal event, clear the event trigger and call any registered
 245  * signal handler.
 246  *
 247  * \param[in] source    glib source that triggered this dispatch
 248  * \param[in] callback  (ignored)
 249  * \param[in] userdata  (ignored)
 250  */
 251 static gboolean
 252 crm_signal_dispatch(GSource * source, GSourceFunc callback, gpointer userdata)
     /*  */
 253 {
 254     crm_signal_t *sig = (crm_signal_t *) source;
 255 
 256     if(sig->signal != SIGCHLD) {
 257         crm_notice("Caught '%s' signal "CRM_XS" %d (%s handler)",
 258                    strsignal(sig->signal), sig->signal,
 259                    (sig->handler? "invoking" : "no"));
 260     }
 261 
 262     sig->trigger.trigger = FALSE;
 263     if (sig->handler) {
 264         sig->handler(sig->signal);
 265     }
 266     return TRUE;
 267 }
 268 
 269 /*!
 270  * \internal
 271  * \brief Handle a signal by setting a trigger for signal source
 272  *
 273  * \param[in] sig  Signal number that was received
 274  *
 275  * \note This is the true signal handler for the mainloop signal source, and
 276  *       must be async-safe.
 277  */
 278 static void
 279 mainloop_signal_handler(int sig)
     /*  */
 280 {
 281     if (sig > 0 && sig < NSIG && crm_signals[sig] != NULL) {
 282         mainloop_set_trigger((crm_trigger_t *) crm_signals[sig]);
 283     }
 284 }
 285 
 286 // Functions implementing our custom glib source for signal handling
 287 static GSourceFuncs crm_signal_funcs = {
 288     crm_trigger_prepare,
 289     crm_trigger_check,
 290     crm_signal_dispatch,
 291     crm_trigger_finalize,
 292 };
 293 
 294 /*!
 295  * \internal
 296  * \brief Set a true signal handler
 297  *
 298  * signal()-like interface to sigaction()
 299  *
 300  * \param[in] sig       Signal number to register handler for
 301  * \param[in] dispatch  Signal handler
 302  *
 303  * \return The previous value of the signal handler, or SIG_ERR on error
 304  * \note The dispatch function must be async-safe.
 305  */
 306 sighandler_t
 307 crm_signal_handler(int sig, sighandler_t dispatch)
     /*  */
 308 {
 309     sigset_t mask;
 310     struct sigaction sa;
 311     struct sigaction old;
 312 
 313     if (sigemptyset(&mask) < 0) {
 314         crm_err("Could not set handler for signal %d: %s",
 315                 sig, pcmk_strerror(errno));
 316         return SIG_ERR;
 317     }
 318 
 319     memset(&sa, 0, sizeof(struct sigaction));
 320     sa.sa_handler = dispatch;
 321     sa.sa_flags = SA_RESTART;
 322     sa.sa_mask = mask;
 323 
 324     if (sigaction(sig, &sa, &old) < 0) {
 325         crm_err("Could not set handler for signal %d: %s",
 326                 sig, pcmk_strerror(errno));
 327         return SIG_ERR;
 328     }
 329     return old.sa_handler;
 330 }
 331 
 332 static void
 333 mainloop_destroy_signal_entry(int sig)
     /*  */
 334 {
 335     crm_signal_t *tmp = crm_signals[sig];
 336 
 337     crm_signals[sig] = NULL;
 338 
 339     crm_trace("Destroying signal %d", sig);
 340     mainloop_destroy_trigger((crm_trigger_t *) tmp);
 341 }
 342 
 343 /*!
 344  * \internal
 345  * \brief Add a signal handler to a mainloop
 346  *
 347  * \param[in] sig       Signal number to handle
 348  * \param[in] dispatch  Signal handler function
 349  *
 350  * \note The true signal handler merely sets a mainloop trigger to call this
 351  *       dispatch function via the mainloop. Therefore, the dispatch function
 352  *       does not need to be async-safe.
 353  */
 354 gboolean
 355 mainloop_add_signal(int sig, void (*dispatch) (int sig))
     /*  */
 356 {
 357     GSource *source = NULL;
 358     int priority = G_PRIORITY_HIGH - 1;
 359 
 360     if (sig == SIGTERM) {
 361         /* TERM is higher priority than other signals,
 362          *   signals are higher priority than other ipc.
 363          * Yes, minus: smaller is "higher"
 364          */
 365         priority--;
 366     }
 367 
 368     if (sig >= NSIG || sig < 0) {
 369         crm_err("Signal %d is out of range", sig);
 370         return FALSE;
 371 
 372     } else if (crm_signals[sig] != NULL && crm_signals[sig]->handler == dispatch) {
 373         crm_trace("Signal handler for %d is already installed", sig);
 374         return TRUE;
 375 
 376     } else if (crm_signals[sig] != NULL) {
 377         crm_err("Different signal handler for %d is already installed", sig);
 378         return FALSE;
 379     }
 380 
 381     CRM_ASSERT(sizeof(crm_signal_t) > sizeof(GSource));
 382     source = g_source_new(&crm_signal_funcs, sizeof(crm_signal_t));
 383 
 384     crm_signals[sig] = (crm_signal_t *) mainloop_setup_trigger(source, priority, NULL, NULL);
 385     CRM_ASSERT(crm_signals[sig] != NULL);
 386 
 387     crm_signals[sig]->handler = dispatch;
 388     crm_signals[sig]->signal = sig;
 389 
 390     if (crm_signal_handler(sig, mainloop_signal_handler) == SIG_ERR) {
 391         mainloop_destroy_signal_entry(sig);
 392         return FALSE;
 393     }
 394 #if 0
 395     /* If we want signals to interrupt mainloop's poll(), instead of waiting for
 396      * the timeout, then we should call siginterrupt() below
 397      *
 398      * For now, just enforce a low timeout
 399      */
 400     if (siginterrupt(sig, 1) < 0) {
 401         crm_perror(LOG_INFO, "Could not enable system call interruptions for signal %d", sig);
 402     }
 403 #endif
 404 
 405     return TRUE;
 406 }
 407 
 408 gboolean
 409 mainloop_destroy_signal(int sig)
     /*  */
 410 {
 411     if (sig >= NSIG || sig < 0) {
 412         crm_err("Signal %d is out of range", sig);
 413         return FALSE;
 414 
 415     } else if (crm_signal_handler(sig, NULL) == SIG_ERR) {
 416         crm_perror(LOG_ERR, "Could not uninstall signal handler for signal %d", sig);
 417         return FALSE;
 418 
 419     } else if (crm_signals[sig] == NULL) {
 420         return TRUE;
 421     }
 422     mainloop_destroy_signal_entry(sig);
 423     return TRUE;
 424 }
 425 
 426 static qb_array_t *gio_map = NULL;
 427 
 428 void
 429 mainloop_cleanup(void) 
     /*  */
 430 {
 431     if (gio_map) {
 432         qb_array_free(gio_map);
 433     }
 434 
 435     for (int sig = 0; sig < NSIG; ++sig) {
 436         mainloop_destroy_signal_entry(sig);
 437     }
 438 }
 439 
 440 /*
 441  * libqb...
 442  */
 443 struct gio_to_qb_poll {
 444     int32_t is_used;
 445     guint source;
 446     int32_t events;
 447     void *data;
 448     qb_ipcs_dispatch_fn_t fn;
 449     enum qb_loop_priority p;
 450 };
 451 
 452 static gboolean
 453 gio_read_socket(GIOChannel * gio, GIOCondition condition, gpointer data)
     /*  */
 454 {
 455     struct gio_to_qb_poll *adaptor = (struct gio_to_qb_poll *)data;
 456     gint fd = g_io_channel_unix_get_fd(gio);
 457 
 458     crm_trace("%p.%d %d", data, fd, condition);
 459 
 460     /* if this assert get's hit, then there is a race condition between
 461      * when we destroy a fd and when mainloop actually gives it up */
 462     CRM_ASSERT(adaptor->is_used > 0);
 463 
 464     return (adaptor->fn(fd, condition, adaptor->data) == 0);
 465 }
 466 
 467 static void
 468 gio_poll_destroy(gpointer data)
     /*  */
 469 {
 470     struct gio_to_qb_poll *adaptor = (struct gio_to_qb_poll *)data;
 471 
 472     adaptor->is_used--;
 473     CRM_ASSERT(adaptor->is_used >= 0);
 474 
 475     if (adaptor->is_used == 0) {
 476         crm_trace("Marking adaptor %p unused", adaptor);
 477         adaptor->source = 0;
 478     }
 479 }
 480 
 481 /*!
 482  * \internal
 483  * \brief Convert libqb's poll priority into GLib's one
 484  *
 485  * \param[in] prio  libqb's poll priority (#QB_LOOP_MED assumed as fallback)
 486  *
 487  * \return  best matching GLib's priority
 488  */
 489 static gint
 490 conv_prio_libqb2glib(enum qb_loop_priority prio)
     /*  */
 491 {
 492     gint ret = G_PRIORITY_DEFAULT;
 493     switch (prio) {
 494         case QB_LOOP_LOW:
 495             ret = G_PRIORITY_LOW;
 496             break;
 497         case QB_LOOP_HIGH:
 498             ret = G_PRIORITY_HIGH;
 499             break;
 500         default:
 501             crm_trace("Invalid libqb's loop priority %d, assuming QB_LOOP_MED",
 502                       prio);
 503             /* fall-through */
 504         case QB_LOOP_MED:
 505             break;
 506     }
 507     return ret;
 508 }
 509 
 510 /*!
 511  * \internal
 512  * \brief Convert libqb's poll priority to rate limiting spec
 513  *
 514  * \param[in] prio  libqb's poll priority (#QB_LOOP_MED assumed as fallback)
 515  *
 516  * \return  best matching rate limiting spec
 517  */
 518 static enum qb_ipcs_rate_limit
 519 conv_libqb_prio2ratelimit(enum qb_loop_priority prio)
     /*  */
 520 {
 521     /* this is an inversion of what libqb's qb_ipcs_request_rate_limit does */
 522     enum qb_ipcs_rate_limit ret = QB_IPCS_RATE_NORMAL;
 523     switch (prio) {
 524         case QB_LOOP_LOW:
 525             ret = QB_IPCS_RATE_SLOW;
 526             break;
 527         case QB_LOOP_HIGH:
 528             ret = QB_IPCS_RATE_FAST;
 529             break;
 530         default:
 531             crm_trace("Invalid libqb's loop priority %d, assuming QB_LOOP_MED",
 532                       prio);
 533             /* fall-through */
 534         case QB_LOOP_MED:
 535             break;
 536     }
 537     return ret;
 538 }
 539 
 540 static int32_t
 541 gio_poll_dispatch_update(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 542                          void *data, qb_ipcs_dispatch_fn_t fn, int32_t add)
 543 {
 544     struct gio_to_qb_poll *adaptor;
 545     GIOChannel *channel;
 546     int32_t res = 0;
 547 
 548     res = qb_array_index(gio_map, fd, (void **)&adaptor);
 549     if (res < 0) {
 550         crm_err("Array lookup failed for fd=%d: %d", fd, res);
 551         return res;
 552     }
 553 
 554     crm_trace("Adding fd=%d to mainloop as adaptor %p", fd, adaptor);
 555 
 556     if (add && adaptor->source) {
 557         crm_err("Adaptor for descriptor %d is still in-use", fd);
 558         return -EEXIST;
 559     }
 560     if (!add && !adaptor->is_used) {
 561         crm_err("Adaptor for descriptor %d is not in-use", fd);
 562         return -ENOENT;
 563     }
 564 
 565     /* channel is created with ref_count = 1 */
 566     channel = g_io_channel_unix_new(fd);
 567     if (!channel) {
 568         crm_err("No memory left to add fd=%d", fd);
 569         return -ENOMEM;
 570     }
 571 
 572     if (adaptor->source) {
 573         g_source_remove(adaptor->source);
 574         adaptor->source = 0;
 575     }
 576 
 577     /* Because unlike the poll() API, glib doesn't tell us about HUPs by default */
 578     evts |= (G_IO_HUP | G_IO_NVAL | G_IO_ERR);
 579 
 580     adaptor->fn = fn;
 581     adaptor->events = evts;
 582     adaptor->data = data;
 583     adaptor->p = p;
 584     adaptor->is_used++;
 585     adaptor->source =
 586         g_io_add_watch_full(channel, conv_prio_libqb2glib(p), evts,
 587                             gio_read_socket, adaptor, gio_poll_destroy);
 588 
 589     /* Now that mainloop now holds a reference to channel,
 590      * thanks to g_io_add_watch_full(), drop ours from g_io_channel_unix_new().
 591      *
 592      * This means that channel will be free'd by:
 593      * g_main_context_dispatch()
 594      *  -> g_source_destroy_internal()
 595      *      -> g_source_callback_unref()
 596      * shortly after gio_poll_destroy() completes
 597      */
 598     g_io_channel_unref(channel);
 599 
 600     crm_trace("Added to mainloop with gsource id=%d", adaptor->source);
 601     if (adaptor->source > 0) {
 602         return 0;
 603     }
 604 
 605     return -EINVAL;
 606 }
 607 
 608 static int32_t
 609 gio_poll_dispatch_add(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 610                       void *data, qb_ipcs_dispatch_fn_t fn)
 611 {
 612     return gio_poll_dispatch_update(p, fd, evts, data, fn, QB_TRUE);
 613 }
 614 
 615 static int32_t
 616 gio_poll_dispatch_mod(enum qb_loop_priority p, int32_t fd, int32_t evts,
     /*  */
 617                       void *data, qb_ipcs_dispatch_fn_t fn)
 618 {
 619     return gio_poll_dispatch_update(p, fd, evts, data, fn, QB_FALSE);
 620 }
 621 
 622 static int32_t
 623 gio_poll_dispatch_del(int32_t fd)
     /*  */
 624 {
 625     struct gio_to_qb_poll *adaptor;
 626 
 627     crm_trace("Looking for fd=%d", fd);
 628     if (qb_array_index(gio_map, fd, (void **)&adaptor) == 0) {
 629         if (adaptor->source) {
 630             g_source_remove(adaptor->source);
 631             adaptor->source = 0;
 632         }
 633     }
 634     return 0;
 635 }
 636 
 637 struct qb_ipcs_poll_handlers gio_poll_funcs = {
 638     .job_add = NULL,
 639     .dispatch_add = gio_poll_dispatch_add,
 640     .dispatch_mod = gio_poll_dispatch_mod,
 641     .dispatch_del = gio_poll_dispatch_del,
 642 };
 643 
 644 static enum qb_ipc_type
 645 pick_ipc_type(enum qb_ipc_type requested)
     /*  */
 646 {
 647     const char *env = getenv("PCMK_ipc_type");
 648 
 649     if (env && strcmp("shared-mem", env) == 0) {
 650         return QB_IPC_SHM;
 651     } else if (env && strcmp("socket", env) == 0) {
 652         return QB_IPC_SOCKET;
 653     } else if (env && strcmp("posix", env) == 0) {
 654         return QB_IPC_POSIX_MQ;
 655     } else if (env && strcmp("sysv", env) == 0) {
 656         return QB_IPC_SYSV_MQ;
 657     } else if (requested == QB_IPC_NATIVE) {
 658         /* We prefer shared memory because the server never blocks on
 659          * send.  If part of a message fits into the socket, libqb
 660          * needs to block until the remainder can be sent also.
 661          * Otherwise the client will wait forever for the remaining
 662          * bytes.
 663          */
 664         return QB_IPC_SHM;
 665     }
 666     return requested;
 667 }
 668 
 669 qb_ipcs_service_t *
 670 mainloop_add_ipc_server(const char *name, enum qb_ipc_type type,
     /*  */
 671                         struct qb_ipcs_service_handlers *callbacks)
 672 {
 673     return mainloop_add_ipc_server_with_prio(name, type, callbacks, QB_LOOP_MED);
 674 }
 675 
 676 qb_ipcs_service_t *
 677 mainloop_add_ipc_server_with_prio(const char *name, enum qb_ipc_type type,
     /*  */
 678                                   struct qb_ipcs_service_handlers *callbacks,
 679                                   enum qb_loop_priority prio)
 680 {
 681     int rc = 0;
 682     qb_ipcs_service_t *server = NULL;
 683 
 684     if (gio_map == NULL) {
 685         gio_map = qb_array_create_2(64, sizeof(struct gio_to_qb_poll), 1);
 686     }
 687 
 688     server = qb_ipcs_create(name, 0, pick_ipc_type(type), callbacks);
 689 
 690     if (server == NULL) {
 691         crm_err("Could not create %s IPC server: %s (%d)", name, pcmk_strerror(rc), rc);
 692         return NULL;
 693     }
 694 
 695     if (prio != QB_LOOP_MED) {
 696         qb_ipcs_request_rate_limit(server, conv_libqb_prio2ratelimit(prio));
 697     }
 698 
 699     /* All clients should use at least ipc_buffer_max as their buffer size */
 700     qb_ipcs_enforce_buffer_size(server, crm_ipc_default_buffer_size());
 701     qb_ipcs_poll_handlers_set(server, &gio_poll_funcs);
 702 
 703     rc = qb_ipcs_run(server);
 704     if (rc < 0) {
 705         crm_err("Could not start %s IPC server: %s (%d)", name, pcmk_strerror(rc), rc);
 706         return NULL;
 707     }
 708 
 709     return server;
 710 }
 711 
 712 void
 713 mainloop_del_ipc_server(qb_ipcs_service_t * server)
     /*  */
 714 {
 715     if (server) {
 716         qb_ipcs_destroy(server);
 717     }
 718 }
 719 
 720 struct mainloop_io_s {
 721     char *name;
 722     void *userdata;
 723 
 724     int fd;
 725     guint source;
 726     crm_ipc_t *ipc;
 727     GIOChannel *channel;
 728 
 729     int (*dispatch_fn_ipc) (const char *buffer, ssize_t length, gpointer userdata);
 730     int (*dispatch_fn_io) (gpointer userdata);
 731     void (*destroy_fn) (gpointer userdata);
 732 
 733 };
 734 
 735 /*!
 736  * \internal
 737  * \brief I/O watch callback function (GIOFunc)
 738  *
 739  * \param[in] gio        I/O channel being watched
 740  * \param[in] condition  I/O condition satisfied
 741  * \param[in] data       User data passed when source was created
 742  *
 743  * \return G_SOURCE_REMOVE to remove source, G_SOURCE_CONTINUE to keep it
 744  */
 745 static gboolean
 746 mainloop_gio_callback(GIOChannel * gio, GIOCondition condition, gpointer data)
     /*  */
 747 {
 748     gboolean rc = G_SOURCE_CONTINUE;
 749     mainloop_io_t *client = data;
 750 
 751     CRM_ASSERT(client->fd == g_io_channel_unix_get_fd(gio));
 752 
 753     if (condition & G_IO_IN) {
 754         if (client->ipc) {
 755             long read_rc = 0L;
 756             int max = 10;
 757 
 758             do {
 759                 read_rc = crm_ipc_read(client->ipc);
 760                 if (read_rc <= 0) {
 761                     crm_trace("Could not read IPC message from %s: %s (%ld)",
 762                               client->name, pcmk_strerror(read_rc), read_rc);
 763 
 764                 } else if (client->dispatch_fn_ipc) {
 765                     const char *buffer = crm_ipc_buffer(client->ipc);
 766 
 767                     crm_trace("New %ld-byte IPC message from %s "
 768                               "after I/O condition %d",
 769                               read_rc, client->name, (int) condition);
 770                     if (client->dispatch_fn_ipc(buffer, read_rc, client->userdata) < 0) {
 771                         crm_trace("Connection to %s no longer required", client->name);
 772                         rc = G_SOURCE_REMOVE;
 773                     }
 774                 }
 775 
 776             } while ((rc == G_SOURCE_CONTINUE) && (read_rc > 0) && --max > 0);
 777 
 778         } else {
 779             crm_trace("New I/O event for %s after I/O condition %d",
 780                       client->name, (int) condition);
 781             if (client->dispatch_fn_io) {
 782                 if (client->dispatch_fn_io(client->userdata) < 0) {
 783                     crm_trace("Connection to %s no longer required", client->name);
 784                     rc = G_SOURCE_REMOVE;
 785                 }
 786             }
 787         }
 788     }
 789 
 790     if (client->ipc && crm_ipc_connected(client->ipc) == FALSE) {
 791         crm_err("Connection to %s closed " CRM_XS "client=%p condition=%d",
 792                 client->name, client, condition);
 793         rc = G_SOURCE_REMOVE;
 794 
 795     } else if (condition & (G_IO_HUP | G_IO_NVAL | G_IO_ERR)) {
 796         crm_trace("The connection %s[%p] has been closed (I/O condition=%d)",
 797                   client->name, client, condition);
 798         rc = G_SOURCE_REMOVE;
 799 
 800     } else if ((condition & G_IO_IN) == 0) {
 801         /*
 802            #define      GLIB_SYSDEF_POLLIN     =1
 803            #define      GLIB_SYSDEF_POLLPRI    =2
 804            #define      GLIB_SYSDEF_POLLOUT    =4
 805            #define      GLIB_SYSDEF_POLLERR    =8
 806            #define      GLIB_SYSDEF_POLLHUP    =16
 807            #define      GLIB_SYSDEF_POLLNVAL   =32
 808 
 809            typedef enum
 810            {
 811            G_IO_IN      GLIB_SYSDEF_POLLIN,
 812            G_IO_OUT     GLIB_SYSDEF_POLLOUT,
 813            G_IO_PRI     GLIB_SYSDEF_POLLPRI,
 814            G_IO_ERR     GLIB_SYSDEF_POLLERR,
 815            G_IO_HUP     GLIB_SYSDEF_POLLHUP,
 816            G_IO_NVAL    GLIB_SYSDEF_POLLNVAL
 817            } GIOCondition;
 818 
 819            A bitwise combination representing a condition to watch for on an event source.
 820 
 821            G_IO_IN      There is data to read.
 822            G_IO_OUT     Data can be written (without blocking).
 823            G_IO_PRI     There is urgent data to read.
 824            G_IO_ERR     Error condition.
 825            G_IO_HUP     Hung up (the connection has been broken, usually for pipes and sockets).
 826            G_IO_NVAL    Invalid request. The file descriptor is not open.
 827          */
 828         crm_err("Strange condition: %d", condition);
 829     }
 830 
 831     /* G_SOURCE_REMOVE results in mainloop_gio_destroy() being called
 832      * just before the source is removed from mainloop
 833      */
 834     return rc;
 835 }
 836 
 837 static void
 838 mainloop_gio_destroy(gpointer c)
     /*  */
 839 {
 840     mainloop_io_t *client = c;
 841     char *c_name = strdup(client->name);
 842 
 843     /* client->source is valid but about to be destroyed (ref_count == 0) in gmain.c
 844      * client->channel will still have ref_count > 0... should be == 1
 845      */
 846     crm_trace("Destroying client %s[%p]", c_name, c);
 847 
 848     if (client->ipc) {
 849         crm_ipc_close(client->ipc);
 850     }
 851 
 852     if (client->destroy_fn) {
 853         void (*destroy_fn) (gpointer userdata) = client->destroy_fn;
 854 
 855         client->destroy_fn = NULL;
 856         destroy_fn(client->userdata);
 857     }
 858 
 859     if (client->ipc) {
 860         crm_ipc_t *ipc = client->ipc;
 861 
 862         client->ipc = NULL;
 863         crm_ipc_destroy(ipc);
 864     }
 865 
 866     crm_trace("Destroyed client %s[%p]", c_name, c);
 867 
 868     free(client->name); client->name = NULL;
 869     free(client);
 870 
 871     free(c_name);
 872 }
 873 
 874 /*!
 875  * \brief Connect to IPC and add it as a main loop source
 876  *
 877  * \param[in]  ipc        IPC connection to add
 878  * \param[in]  priority   Event source priority to use for connection
 879  * \param[in]  userdata   Data to register with callbacks
 880  * \param[in]  callbacks  Dispatch and destroy callbacks for connection
 881  * \param[out] source     Newly allocated event source
 882  *
 883  * \return Standard Pacemaker return code
 884  *
 885  * \note On failure, the caller is still responsible for ipc. On success, the
 886  *       caller should call mainloop_del_ipc_client() when source is no longer
 887  *       needed, which will lead to the disconnection of the IPC later in the
 888  *       main loop if it is connected. However the IPC disconnects,
 889  *       mainloop_gio_destroy() will free ipc and source after calling the
 890  *       destroy callback.
 891  */
 892 int
 893 pcmk__add_mainloop_ipc(crm_ipc_t *ipc, int priority, void *userdata,
     /*  */
 894                        struct ipc_client_callbacks *callbacks,
 895                        mainloop_io_t **source)
 896 {
 897     CRM_CHECK((ipc != NULL) && (callbacks != NULL), return EINVAL);
 898 
 899     if (!crm_ipc_connect(ipc)) {
 900         int rc = errno;
 901         crm_debug("Connection to %s failed: %d", crm_ipc_name(ipc), errno);
 902         return rc;
 903     }
 904     *source = mainloop_add_fd(crm_ipc_name(ipc), priority, crm_ipc_get_fd(ipc),
 905                               userdata, NULL);
 906     if (*source == NULL) {
 907         int rc = errno;
 908 
 909         crm_ipc_close(ipc);
 910         return rc;
 911     }
 912     (*source)->ipc = ipc;
 913     (*source)->destroy_fn = callbacks->destroy;
 914     (*source)->dispatch_fn_ipc = callbacks->dispatch;
 915     return pcmk_rc_ok;
 916 }
 917 
 918 /*!
 919  * \brief Get period for mainloop timer
 920  *
 921  * \param[in]  timer      Timer
 922  *
 923  * \return Period in ms
 924  */
 925 guint
 926 pcmk__mainloop_timer_get_period(mainloop_timer_t *timer)
     /*  */
 927 {
 928     if (timer) {
 929         return timer->period_ms;
 930     }
 931     return 0;
 932 }
 933 
 934 mainloop_io_t *
 935 mainloop_add_ipc_client(const char *name, int priority, size_t max_size,
     /*  */
 936                         void *userdata, struct ipc_client_callbacks *callbacks)
 937 {
 938     crm_ipc_t *ipc = crm_ipc_new(name, max_size);
 939     mainloop_io_t *source = NULL;
 940     int rc = pcmk__add_mainloop_ipc(ipc, priority, userdata, callbacks,
 941                                     &source);
 942 
 943     if (rc != pcmk_rc_ok) {
 944         if (crm_log_level == LOG_STDOUT) {
 945             fprintf(stderr, "Connection to %s failed: %s",
 946                     name, pcmk_rc_str(rc));
 947         }
 948         crm_ipc_destroy(ipc);
 949         if (rc > 0) {
 950             errno = rc;
 951         } else {
 952             errno = ENOTCONN;
 953         }
 954         return NULL;
 955     }
 956     return source;
 957 }
 958 
 959 void
 960 mainloop_del_ipc_client(mainloop_io_t * client)
     /*  */
 961 {
 962     mainloop_del_fd(client);
 963 }
 964 
 965 crm_ipc_t *
 966 mainloop_get_ipc_client(mainloop_io_t * client)
     /*  */
 967 {
 968     if (client) {
 969         return client->ipc;
 970     }
 971     return NULL;
 972 }
 973 
 974 mainloop_io_t *
 975 mainloop_add_fd(const char *name, int priority, int fd, void *userdata,
     /*  */
 976                 struct mainloop_fd_callbacks * callbacks)
 977 {
 978     mainloop_io_t *client = NULL;
 979 
 980     if (fd >= 0) {
 981         client = calloc(1, sizeof(mainloop_io_t));
 982         if (client == NULL) {
 983             return NULL;
 984         }
 985         client->name = strdup(name);
 986         client->userdata = userdata;
 987 
 988         if (callbacks) {
 989             client->destroy_fn = callbacks->destroy;
 990             client->dispatch_fn_io = callbacks->dispatch;
 991         }
 992 
 993         client->fd = fd;
 994         client->channel = g_io_channel_unix_new(fd);
 995         client->source =
 996             g_io_add_watch_full(client->channel, priority,
 997                                 (G_IO_IN | G_IO_HUP | G_IO_NVAL | G_IO_ERR), mainloop_gio_callback,
 998                                 client, mainloop_gio_destroy);
 999 
1000         /* Now that mainloop now holds a reference to channel,
1001          * thanks to g_io_add_watch_full(), drop ours from g_io_channel_unix_new().
1002          *
1003          * This means that channel will be free'd by:
1004          * g_main_context_dispatch() or g_source_remove()
1005          *  -> g_source_destroy_internal()
1006          *      -> g_source_callback_unref()
1007          * shortly after mainloop_gio_destroy() completes
1008          */
1009         g_io_channel_unref(client->channel);
1010         crm_trace("Added connection %d for %s[%p].%d", client->source, client->name, client, fd);
1011     } else {
1012         errno = EINVAL;
1013     }
1014 
1015     return client;
1016 }
1017 
1018 void
1019 mainloop_del_fd(mainloop_io_t * client)
     /*  */
1020 {
1021     if (client != NULL) {
1022         crm_trace("Removing client %s[%p]", client->name, client);
1023         if (client->source) {
1024             /* Results in mainloop_gio_destroy() being called just
1025              * before the source is removed from mainloop
1026              */
1027             g_source_remove(client->source);
1028         }
1029     }
1030 }
1031 
1032 static GList *child_list = NULL;
1033 
1034 pid_t
1035 mainloop_child_pid(mainloop_child_t * child)
     /*  */
1036 {
1037     return child->pid;
1038 }
1039 
1040 const char *
1041 mainloop_child_name(mainloop_child_t * child)
     /*  */
1042 {
1043     return child->desc;
1044 }
1045 
1046 int
1047 mainloop_child_timeout(mainloop_child_t * child)
     /*  */
1048 {
1049     return child->timeout;
1050 }
1051 
1052 void *
1053 mainloop_child_userdata(mainloop_child_t * child)
     /*  */
1054 {
1055     return child->privatedata;
1056 }
1057 
1058 void
1059 mainloop_clear_child_userdata(mainloop_child_t * child)
     /*  */
1060 {
1061     child->privatedata = NULL;
1062 }
1063 
1064 /* good function name */
1065 static void
1066 child_free(mainloop_child_t *child)
     /*  */
1067 {
1068     if (child->timerid != 0) {
1069         crm_trace("Removing timer %d", child->timerid);
1070         g_source_remove(child->timerid);
1071         child->timerid = 0;
1072     }
1073     free(child->desc);
1074     free(child);
1075 }
1076 
1077 /* terrible function name */
1078 static int
1079 child_kill_helper(mainloop_child_t *child)
     /*  */
1080 {
1081     int rc;
1082     if (child->flags & mainloop_leave_pid_group) {
1083         crm_debug("Kill pid %d only. leave group intact.", child->pid);
1084         rc = kill(child->pid, SIGKILL);
1085     } else {
1086         crm_debug("Kill pid %d's group", child->pid);
1087         rc = kill(-child->pid, SIGKILL);
1088     }
1089 
1090     if (rc < 0) {
1091         if (errno != ESRCH) {
1092             crm_perror(LOG_ERR, "kill(%d, KILL) failed", child->pid);
1093         }
1094         return -errno;
1095     }
1096     return 0;
1097 }
1098 
1099 static gboolean
1100 child_timeout_callback(gpointer p)
     /*  */
1101 {
1102     mainloop_child_t *child = p;
1103     int rc = 0;
1104 
1105     child->timerid = 0;
1106     if (child->timeout) {
1107         crm_crit("%s process (PID %d) will not die!", child->desc, (int)child->pid);
1108         return FALSE;
1109     }
1110 
1111     rc = child_kill_helper(child);
1112     if (rc == -ESRCH) {
1113         /* Nothing left to do. pid doesn't exist */
1114         return FALSE;
1115     }
1116 
1117     child->timeout = TRUE;
1118     crm_warn("%s process (PID %d) timed out", child->desc, (int)child->pid);
1119 
1120     child->timerid = g_timeout_add(5000, child_timeout_callback, child);
1121     return FALSE;
1122 }
1123 
1124 static bool
1125 child_waitpid(mainloop_child_t *child, int flags)
     /*  */
1126 {
1127     int rc = 0;
1128     int core = 0;
1129     int signo = 0;
1130     int status = 0;
1131     int exitcode = 0;
1132     bool callback_needed = true;
1133 
1134     rc = waitpid(child->pid, &status, flags);
1135     if (rc == 0) { // WNOHANG in flags, and child status is not available
1136         crm_trace("Child process %d (%s) still active",
1137                   child->pid, child->desc);
1138         callback_needed = false;
1139 
1140     } else if (rc != child->pid) {
1141         /* According to POSIX, possible conditions:
1142          * - child->pid was non-positive (process group or any child),
1143          *   and rc is specific child
1144          * - errno ECHILD (pid does not exist or is not child)
1145          * - errno EINVAL (invalid flags)
1146          * - errno EINTR (caller interrupted by signal)
1147          *
1148          * @TODO Handle these cases more specifically.
1149          */
1150         signo = SIGCHLD;
1151         exitcode = 1;
1152         crm_notice("Wait for child process %d (%s) interrupted: %s",
1153                    child->pid, child->desc, pcmk_strerror(errno));
1154 
1155     } else if (WIFEXITED(status)) {
1156         exitcode = WEXITSTATUS(status);
1157         crm_trace("Child process %d (%s) exited with status %d",
1158                   child->pid, child->desc, exitcode);
1159 
1160     } else if (WIFSIGNALED(status)) {
1161         signo = WTERMSIG(status);
1162         crm_trace("Child process %d (%s) exited with signal %d (%s)",
1163                   child->pid, child->desc, signo, strsignal(signo));
1164 
1165 #ifdef WCOREDUMP // AIX, SunOS, maybe others
1166     } else if (WCOREDUMP(status)) {
1167         core = 1;
1168         crm_err("Child process %d (%s) dumped core",
1169                 child->pid, child->desc);
1170 #endif
1171 
1172     } else { // flags must contain WUNTRACED and/or WCONTINUED to reach this
1173         crm_trace("Child process %d (%s) stopped or continued",
1174                   child->pid, child->desc);
1175         callback_needed = false;
1176     }
1177 
1178     if (callback_needed && child->callback) {
1179         child->callback(child, child->pid, core, signo, exitcode);
1180     }
1181     return callback_needed;
1182 }
1183 
1184 static void
1185 child_death_dispatch(int signal)
     /*  */
1186 {
1187     for (GList *iter = child_list; iter; ) {
1188         GList *saved = iter;
1189         mainloop_child_t *child = iter->data;
1190 
1191         iter = iter->next;
1192         if (child_waitpid(child, WNOHANG)) {
1193             crm_trace("Removing completed process %d from child list",
1194                       child->pid);
1195             child_list = g_list_remove_link(child_list, saved);
1196             g_list_free(saved);
1197             child_free(child);
1198         }
1199     }
1200 }
1201 
1202 static gboolean
1203 child_signal_init(gpointer p)
     /*  */
1204 {
1205     crm_trace("Installed SIGCHLD handler");
1206     /* Do NOT use g_child_watch_add() and friends, they rely on pthreads */
1207     mainloop_add_signal(SIGCHLD, child_death_dispatch);
1208 
1209     /* In case they terminated before the signal handler was installed */
1210     child_death_dispatch(SIGCHLD);
1211     return FALSE;
1212 }
1213 
1214 gboolean
1215 mainloop_child_kill(pid_t pid)
     /*  */
1216 {
1217     GList *iter;
1218     mainloop_child_t *child = NULL;
1219     mainloop_child_t *match = NULL;
1220     /* It is impossible to block SIGKILL, this allows us to
1221      * call waitpid without WNOHANG flag.*/
1222     int waitflags = 0, rc = 0;
1223 
1224     for (iter = child_list; iter != NULL && match == NULL; iter = iter->next) {
1225         child = iter->data;
1226         if (pid == child->pid) {
1227             match = child;
1228         }
1229     }
1230 
1231     if (match == NULL) {
1232         return FALSE;
1233     }
1234 
1235     rc = child_kill_helper(match);
1236     if(rc == -ESRCH) {
1237         /* It's gone, but hasn't shown up in waitpid() yet. Wait until we get
1238          * SIGCHLD and let handler clean it up as normal (so we get the correct
1239          * return code/status). The blocking alternative would be to call
1240          * child_waitpid(match, 0).
1241          */
1242         crm_trace("Waiting for signal that child process %d completed",
1243                   match->pid);
1244         return TRUE;
1245 
1246     } else if(rc != 0) {
1247         /* If KILL for some other reason set the WNOHANG flag since we
1248          * can't be certain what happened.
1249          */
1250         waitflags = WNOHANG;
1251     }
1252 
1253     if (!child_waitpid(match, waitflags)) {
1254         /* not much we can do if this occurs */
1255         return FALSE;
1256     }
1257 
1258     child_list = g_list_remove(child_list, match);
1259     child_free(match);
1260     return TRUE;
1261 }
1262 
1263 /* Create/Log a new tracked process
1264  * To track a process group, use -pid
1265  *
1266  * @TODO Using a non-positive pid (i.e. any child, or process group) would
1267  *       likely not be useful since we will free the child after the first
1268  *       completed process.
1269  */
1270 void
1271 mainloop_child_add_with_flags(pid_t pid, int timeout, const char *desc, void *privatedata, enum mainloop_child_flags flags, 
     /*  */
1272                    void (*callback) (mainloop_child_t * p, pid_t pid, int core, int signo, int exitcode))
1273 {
1274     static bool need_init = TRUE;
1275     mainloop_child_t *child = g_new(mainloop_child_t, 1);
1276 
1277     child->pid = pid;
1278     child->timerid = 0;
1279     child->timeout = FALSE;
1280     child->privatedata = privatedata;
1281     child->callback = callback;
1282     child->flags = flags;
1283 
1284     if(desc) {
1285         child->desc = strdup(desc);
1286     }
1287 
1288     if (timeout) {
1289         child->timerid = g_timeout_add(timeout, child_timeout_callback, child);
1290     }
1291 
1292     child_list = g_list_append(child_list, child);
1293 
1294     if(need_init) {
1295         need_init = FALSE;
1296         /* SIGCHLD processing has to be invoked from mainloop.
1297          * We do not want it to be possible to both add a child pid
1298          * to mainloop, and have the pid's exit callback invoked within
1299          * the same callstack. */
1300         g_timeout_add(1, child_signal_init, NULL);
1301     }
1302 }
1303 
1304 void
1305 mainloop_child_add(pid_t pid, int timeout, const char *desc, void *privatedata,
     /*  */
1306                    void (*callback) (mainloop_child_t * p, pid_t pid, int core, int signo, int exitcode))
1307 {
1308     mainloop_child_add_with_flags(pid, timeout, desc, privatedata, 0, callback);
1309 }
1310 
1311 static gboolean
1312 mainloop_timer_cb(gpointer user_data)
     /*  */
1313 {
1314     int id = 0;
1315     bool repeat = FALSE;
1316     struct mainloop_timer_s *t = user_data;
1317 
1318     CRM_ASSERT(t != NULL);
1319 
1320     id = t->id;
1321     t->id = 0; /* Ensure it's unset during callbacks so that
1322                 * mainloop_timer_running() works as expected
1323                 */
1324 
1325     if(t->cb) {
1326         crm_trace("Invoking callbacks for timer %s", t->name);
1327         repeat = t->repeat;
1328         if(t->cb(t->userdata) == FALSE) {
1329             crm_trace("Timer %s complete", t->name);
1330             repeat = FALSE;
1331         }
1332     }
1333 
1334     if(repeat) {
1335         /* Restore if repeating */
1336         t->id = id;
1337     }
1338 
1339     return repeat;
1340 }
1341 
1342 bool
1343 mainloop_timer_running(mainloop_timer_t *t)
     /*  */
1344 {
1345     if(t && t->id != 0) {
1346         return TRUE;
1347     }
1348     return FALSE;
1349 }
1350 
1351 void
1352 mainloop_timer_start(mainloop_timer_t *t)
     /*  */
1353 {
1354     mainloop_timer_stop(t);
1355     if(t && t->period_ms > 0) {
1356         crm_trace("Starting timer %s", t->name);
1357         t->id = g_timeout_add(t->period_ms, mainloop_timer_cb, t);
1358     }
1359 }
1360 
1361 void
1362 mainloop_timer_stop(mainloop_timer_t *t)
     /*  */
1363 {
1364     if(t && t->id != 0) {
1365         crm_trace("Stopping timer %s", t->name);
1366         g_source_remove(t->id);
1367         t->id = 0;
1368     }
1369 }
1370 
1371 guint
1372 mainloop_timer_set_period(mainloop_timer_t *t, guint period_ms)
     /*  */
1373 {
1374     guint last = 0;
1375 
1376     if(t) {
1377         last = t->period_ms;
1378         t->period_ms = period_ms;
1379     }
1380 
1381     if(t && t->id != 0 && last != t->period_ms) {
1382         mainloop_timer_start(t);
1383     }
1384     return last;
1385 }
1386 
1387 mainloop_timer_t *
1388 mainloop_timer_add(const char *name, guint period_ms, bool repeat, GSourceFunc cb, void *userdata)
     /*  */
1389 {
1390     mainloop_timer_t *t = calloc(1, sizeof(mainloop_timer_t));
1391 
1392     if(t) {
1393         if(name) {
1394             t->name = crm_strdup_printf("%s-%u-%d", name, period_ms, repeat);
1395         } else {
1396             t->name = crm_strdup_printf("%p-%u-%d", t, period_ms, repeat);
1397         }
1398         t->id = 0;
1399         t->period_ms = period_ms;
1400         t->repeat = repeat;
1401         t->cb = cb;
1402         t->userdata = userdata;
1403         crm_trace("Created timer %s with %p %p", t->name, userdata, t->userdata);
1404     }
1405     return t;
1406 }
1407 
1408 void
1409 mainloop_timer_del(mainloop_timer_t *t)
     /*  */
1410 {
1411     if(t) {
1412         crm_trace("Destroying timer %s", t->name);
1413         mainloop_timer_stop(t);
1414         free(t->name);
1415         free(t);
1416     }
1417 }
1418 
1419 /*
1420  * Helpers to make sure certain events aren't lost at shutdown
1421  */
1422 
1423 static gboolean
1424 drain_timeout_cb(gpointer user_data)
     /*  */
1425 {
1426     bool *timeout_popped = (bool*) user_data;
1427 
1428     *timeout_popped = TRUE;
1429     return FALSE;
1430 }
1431 
1432 /*!
1433  * \brief Drain some remaining main loop events then quit it
1434  *
1435  * \param[in] mloop  Main loop to drain and quit
1436  * \param[in] n      Drain up to this many pending events
1437  */
1438 void
1439 pcmk_quit_main_loop(GMainLoop *mloop, unsigned int n)
     /*  */
1440 {
1441     if ((mloop != NULL) && g_main_loop_is_running(mloop)) {
1442         GMainContext *ctx = g_main_loop_get_context(mloop);
1443 
1444         /* Drain up to n events in case some memory clean-up is pending
1445          * (helpful to reduce noise in valgrind output).
1446          */
1447         for (int i = 0; (i < n) && g_main_context_pending(ctx); ++i) {
1448             g_main_context_dispatch(ctx);
1449         }
1450         g_main_loop_quit(mloop);
1451     }
1452 }
1453 
1454 /*!
1455  * \brief Process main loop events while a certain condition is met
1456  *
1457  * \param[in] mloop     Main loop to process
1458  * \param[in] timer_ms  Don't process longer than this amount of time
1459  * \param[in] check     Function that returns TRUE if events should be processed
1460  *
1461  * \note This function is intended to be called at shutdown if certain important
1462  *       events should not be missed. The caller would likely quit the main loop
1463  *       or exit after calling this function. The check() function will be
1464  *       passed the remaining timeout in milliseconds.
1465  */
1466 void
1467 pcmk_drain_main_loop(GMainLoop *mloop, guint timer_ms, bool (*check)(guint))
     /*  */
1468 {
1469     bool timeout_popped = FALSE;
1470     guint timer = 0;
1471     GMainContext *ctx = NULL;
1472 
1473     CRM_CHECK(mloop && check, return);
1474 
1475     ctx = g_main_loop_get_context(mloop);
1476     if (ctx) {
1477         time_t start_time = time(NULL);
1478 
1479         timer = g_timeout_add(timer_ms, drain_timeout_cb, &timeout_popped);
1480         while (!timeout_popped
1481                && check(timer_ms - (time(NULL) - start_time) * 1000)) {
1482             g_main_context_iteration(ctx, TRUE);
1483         }
1484     }
1485     if (!timeout_popped && (timer > 0)) {
1486         g_source_remove(timer);
1487     }
1488 }
1489 
1490 // Deprecated functions kept only for backward API compatibility
1491 
1492 #include <crm/common/mainloop_compat.h>
1493 
1494 gboolean
1495 crm_signal(int sig, void (*dispatch) (int sig))
     /*  */
1496 {
1497     return crm_signal_handler(sig, dispatch) != SIG_ERR;
1498 }
1499 
1500 // End deprecated API
/* */
root/lib/common/mainloop.c

DEFINITIONS
