src/core/plugin.c

   1 /*
   2  * SysDB - src/core/plugin.c
   3  * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "sysdb.h"
  29 #include "core/plugin.h"
  30 #include "utils/error.h"
  31 #include "utils/llist.h"
  32 #include "utils/time.h"
  33
  34 #include <assert.h>
  35
  36 #include <errno.h>
  37
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <strings.h>
  42 #include <unistd.h>
  43
  44 #include <ltdl.h>
  45
  46 #include <pthread.h>
  47
  48 /*
  49  * private data types
  50  */
  51
  52 struct sdb_plugin_info {
  53         char *name;
  54
  55         char *description;
  56         char *copyright;
  57         char *license;
  58
  59         int   version;
  60         int   plugin_version;
  61 };
  62 #define SDB_PLUGIN_INFO_INIT { "no name set", "no description set", \
  63         /* copyright */ "", /* license */ "", \
  64         /* version */ -1, /* plugin_version */ -1 }
  65
  66 typedef struct {
  67         sdb_object_t super;
  68         char cb_name[64];
  69         void *cb_callback;
  70         sdb_object_t *cb_user_data;
  71         sdb_plugin_ctx_t cb_ctx;
  72 } sdb_plugin_cb_t;
  73 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, /* name = */ "", \
  74         /* callback = */ NULL, /* user_data = */ NULL, \
  75         SDB_PLUGIN_CTX_INIT }
  76
  77 typedef struct {
  78         sdb_plugin_cb_t super;
  79 #define ccb_name super.cb_name
  80 #define ccb_callback super.cb_callback
  81 #define ccb_user_data super.cb_user_data
  82 #define ccb_ctx super.cb_ctx
  83         sdb_time_t ccb_interval;
  84         sdb_time_t ccb_next_update;
  85 } sdb_plugin_collector_cb_t;
  86
  87 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
  88 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
  89
  90 /*
  91  * private variables
  92  */
  93
  94 static sdb_plugin_ctx_t  plugin_default_ctx = SDB_PLUGIN_CTX_INIT;
  95
  96 static pthread_key_t    plugin_ctx_key;
  97 static _Bool            plugin_ctx_key_initialized = 0;
  98
  99 static sdb_llist_t      *config_list = NULL;
 100 static sdb_llist_t      *init_list = NULL;
 101 static sdb_llist_t      *collector_list = NULL;
 102 static sdb_llist_t      *shutdown_list = NULL;
 103
 104 /*
 105  * private helper functions
 106  */
 107
 108 static void
 109 sdb_plugin_ctx_destructor(void *ctx)
 110 {
 111         if (! ctx)
 112                 return;
 113         free(ctx);
 114 } /* sdb_plugin_ctx_destructor */
 115
 116 static void
 117 sdb_plugin_ctx_init(void)
 118 {
 119         if (plugin_ctx_key_initialized)
 120                 return;
 121
 122         pthread_key_create(&plugin_ctx_key, sdb_plugin_ctx_destructor);
 123         plugin_ctx_key_initialized = 1;
 124 } /* sdb_plugin_ctx_init */
 125
 126 static sdb_plugin_ctx_t *
 127 sdb_plugin_ctx_create(void)
 128 {
 129         sdb_plugin_ctx_t *ctx;
 130
 131         ctx = malloc(sizeof(*ctx));
 132         if (! ctx)
 133                 return NULL;
 134
 135         *ctx = plugin_default_ctx;
 136
 137         if (! plugin_ctx_key_initialized)
 138                 sdb_plugin_ctx_init();
 139         pthread_setspecific(plugin_ctx_key, ctx);
 140         return ctx;
 141 } /* sdb_plugin_ctx_create */
 142
 143 static int
 144 sdb_plugin_cmp_name(const sdb_object_t *a, const sdb_object_t *b)
 145 {
 146         const sdb_plugin_cb_t *cb1 = (const sdb_plugin_cb_t *)a;
 147         const sdb_plugin_cb_t *cb2 = (const sdb_plugin_cb_t *)b;
 148
 149         assert(cb1 && cb2);
 150         return strcasecmp(cb1->cb_name, cb2->cb_name);
 151 } /* sdb_plugin_cmp_name */
 152
 153 static int
 154 sdb_plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 155 {
 156         const sdb_plugin_collector_cb_t *ccb1
 157                 = (const sdb_plugin_collector_cb_t *)a;
 158         const sdb_plugin_collector_cb_t *ccb2
 159                 = (const sdb_plugin_collector_cb_t *)b;
 160
 161         assert(ccb1 && ccb2);
 162
 163         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 164                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 165                 ? -1 : 0;
 166 } /* sdb_plugin_cmp_next_update */
 167
 168 static sdb_plugin_cb_t *
 169 sdb_plugin_find_by_name(sdb_llist_t *list, const char *name)
 170 {
 171         sdb_plugin_cb_t tmp = SDB_PLUGIN_CB_INIT;
 172
 173         sdb_object_t *obj;
 174         assert(name);
 175
 176         if (! list)
 177                 return NULL;
 178
 179         snprintf(tmp.cb_name, sizeof(tmp.cb_name), "%s", name);
 180         tmp.cb_name[sizeof(tmp.cb_name) - 1] = '\0';
 181         obj = sdb_llist_search(list, SDB_OBJ(&tmp), sdb_plugin_cmp_name);
 182         if (! obj)
 183                 return NULL;
 184         return SDB_PLUGIN_CB(obj);
 185 } /* sdb_plugin_find_by_name */
 186
 187 /*
 188  * private types
 189  */
 190
 191 static int
 192 sdb_plugin_cb_init(sdb_object_t *obj, va_list ap)
 193 {
 194         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 195         const char  *type = va_arg(ap, const char *);
 196         const char  *name = va_arg(ap, const char *);
 197         void    *callback = va_arg(ap, void *);
 198         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 199
 200         assert(list);
 201         assert(type);
 202         assert(obj);
 203
 204         if (sdb_plugin_find_by_name(*list, name)) {
 205                 sdb_log(SDB_LOG_WARNING, "plugin: %s callback '%s' "
 206                                 "has already been registered. Ignoring newly "
 207                                 "registered version.", type, name);
 208                 return -1;
 209         }
 210
 211         snprintf(SDB_PLUGIN_CB(obj)->cb_name,
 212                         sizeof(SDB_PLUGIN_CB(obj)->cb_name),
 213                         "%s", name);
 214         SDB_PLUGIN_CB(obj)->cb_name[sizeof(SDB_PLUGIN_CB(obj)->cb_name) - 1] = '\0';
 215         SDB_PLUGIN_CB(obj)->cb_callback = callback;
 216         SDB_PLUGIN_CB(obj)->cb_ctx      = sdb_plugin_get_ctx();
 217
 218         sdb_object_ref(ud);
 219         SDB_PLUGIN_CB(obj)->cb_user_data = ud;
 220         return 0;
 221 } /* sdb_plugin_cb_init */
 222
 223 static void
 224 sdb_plugin_cb_destroy(sdb_object_t *obj)
 225 {
 226         assert(obj);
 227         sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
 228 } /* sdb_plugin_cb_destroy */
 229
 230 static sdb_type_t sdb_plugin_cb_type = {
 231         sizeof(sdb_plugin_cb_t),
 232
 233         sdb_plugin_cb_init,
 234         sdb_plugin_cb_destroy,
 235         /* clone = */ NULL
 236 };
 237
 238 static sdb_type_t sdb_plugin_collector_cb_type = {
 239         sizeof(sdb_plugin_collector_cb_t),
 240
 241         sdb_plugin_cb_init,
 242         sdb_plugin_cb_destroy,
 243         /* clone = */ NULL
 244 };
 245
 246 static int
 247 sdb_plugin_add_callback(sdb_llist_t **list, const char *type,
 248                 const char *name, void *callback, sdb_object_t *user_data)
 249 {
 250         sdb_object_t *obj;
 251
 252         if ((! name) || (! callback))
 253                 return -1;
 254
 255         assert(list);
 256
 257         if (! *list)
 258                 *list = sdb_llist_create();
 259         if (! *list)
 260                 return -1;
 261
 262         obj = sdb_object_create(sdb_plugin_cb_type,
 263                         list, type, name, callback, user_data);
 264         if (! obj)
 265                 return -1;
 266
 267         if (sdb_llist_append(*list, obj)) {
 268                 sdb_object_deref(obj);
 269                 return -1;
 270         }
 271
 272         /* pass control to the list */
 273         sdb_object_deref(obj);
 274
 275         sdb_log(SDB_LOG_INFO, "plugin: Registered %s callback '%s'.",
 276                         type, name);
 277         return 0;
 278 } /* sdb_plugin_add_callback */
 279
 280 /*
 281  * public API
 282  */
 283
 284 int
 285 sdb_plugin_load(const char *name)
 286 {
 287         char  real_name[strlen(name) > 0 ? strlen(name) : 1];
 288         const char *name_ptr;
 289         char *tmp;
 290
 291         char filename[1024];
 292
 293         lt_dlhandle lh;
 294
 295         int (*mod_init)(sdb_plugin_info_t *);
 296         sdb_plugin_info_t plugin_info = SDB_PLUGIN_INFO_INIT;
 297
 298         int status;
 299
 300         if ((! name) || (! *name))
 301                 return -1;
 302
 303         real_name[0] = '\0';
 304         name_ptr = name;
 305
 306         while ((tmp = strstr(name_ptr, "::"))) {
 307                 strncat(real_name, name_ptr, (size_t)(tmp - name_ptr));
 308                 strcat(real_name, "/");
 309                 name_ptr = tmp + strlen("::");
 310         }
 311         strcat(real_name, name_ptr);
 312
 313         snprintf(filename, sizeof(filename), "%s/%s.so",
 314                         PKGLIBDIR, real_name);
 315         filename[sizeof(filename) - 1] = '\0';
 316
 317         if (access(filename, R_OK)) {
 318                 char errbuf[1024];
 319                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s' (%s): %s",
 320                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 321                 return -1;
 322         }
 323
 324         lt_dlinit();
 325         lt_dlerror();
 326
 327         lh = lt_dlopen(filename);
 328         if (! lh) {
 329                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': %s"
 330                                 "The most common cause for this problem are missing "
 331                                 "dependencies.\n", name, lt_dlerror());
 332                 return -1;
 333         }
 334
 335         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 336         if (! mod_init) {
 337                 sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': "
 338                                 "could not find symbol 'sdb_module_init'", name);
 339                 return -1;
 340         }
 341
 342         status = mod_init(&plugin_info);
 343         if (status) {
 344                 sdb_log(SDB_LOG_ERR, "plugin: Failed to initialize "
 345                                 "plugin '%s'", name);
 346                 return -1;
 347         }
 348
 349         /* compare minor version */
 350         if ((plugin_info.version < 0)
 351                         || ((int)(plugin_info.version / 100) != (int)(SDB_VERSION / 100)))
 352                 sdb_log(SDB_LOG_WARNING, "plugin: WARNING: version of "
 353                                 "plugin '%s' (%i.%i.%i) does not match our version "
 354                                 "(%i.%i.%i); this might cause problems",
 355                                 name, SDB_VERSION_DECODE(plugin_info.version),
 356                                 SDB_VERSION_DECODE(SDB_VERSION));
 357
 358         sdb_log(SDB_LOG_INFO, "plugin: Successfully loaded "
 359                         "plugin '%s' v%i (%s)\n\t%s",
 360                         plugin_info.name, plugin_info.plugin_version,
 361                         plugin_info.description, plugin_info.copyright);
 362         return 0;
 363 } /* sdb_plugin_load */
 364
 365 int
 366 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 367 {
 368         va_list ap;
 369
 370         if (! info)
 371                 return -1;
 372
 373         va_start(ap, type);
 374
 375         switch (type) {
 376                 case SDB_PLUGIN_INFO_NAME:
 377                         {
 378                                 char *name = va_arg(ap, char *);
 379                                 info->name = name;
 380                         }
 381                         break;
 382                 case SDB_PLUGIN_INFO_DESC:
 383                         {
 384                                 char *desc = va_arg(ap, char *);
 385                                 info->description = desc;
 386                         }
 387                         break;
 388                 case SDB_PLUGIN_INFO_COPYRIGHT:
 389                         {
 390                                 char *copyright = va_arg(ap, char *);
 391                                 info->copyright = copyright;
 392                         }
 393                         break;
 394                 case SDB_PLUGIN_INFO_LICENSE:
 395                         {
 396                                 char *license = va_arg(ap, char *);
 397                                 info->license = license;
 398                         }
 399                         break;
 400                 case SDB_PLUGIN_INFO_VERSION:
 401                         {
 402                                 int version = va_arg(ap, int);
 403                                 info->version = version;
 404                         }
 405                         break;
 406                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 407                         {
 408                                 int version = va_arg(ap, int);
 409                                 info->plugin_version = version;
 410                         }
 411                         break;
 412                 default:
 413                         va_end(ap);
 414                         return -1;
 415         }
 416
 417         va_end(ap);
 418         return 0;
 419 } /* sdb_plugin_set_info */
 420
 421 int
 422 sdb_plugin_register_config(const char *name, sdb_plugin_config_cb callback)
 423 {
 424         return sdb_plugin_add_callback(&config_list, "init", name,
 425                         callback, NULL);
 426 } /* sdb_plugin_register_config */
 427
 428 int
 429 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 430                 sdb_object_t *user_data)
 431 {
 432         return sdb_plugin_add_callback(&init_list, "init", name,
 433                         callback, user_data);
 434 } /* sdb_plugin_register_init */
 435
 436 int
 437 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 438                 sdb_object_t *user_data)
 439 {
 440         return sdb_plugin_add_callback(&shutdown_list, "shutdown", name,
 441                         callback, user_data);
 442 } /* sdb_plugin_register_shutdown */
 443
 444 int
 445 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 446                 const sdb_time_t *interval, sdb_object_t *user_data)
 447 {
 448         sdb_object_t *obj;
 449
 450         if ((! name) || (! callback))
 451                 return -1;
 452
 453         if (! collector_list)
 454                 collector_list = sdb_llist_create();
 455         if (! collector_list)
 456                 return -1;
 457
 458         obj = sdb_object_create(sdb_plugin_collector_cb_type,
 459                         &collector_list, "collector", name, callback, user_data);
 460         if (! obj)
 461                 return -1;
 462
 463         if (interval)
 464                 SDB_PLUGIN_CCB(obj)->ccb_interval = *interval;
 465         else {
 466                 sdb_time_t tmp = sdb_plugin_get_ctx().interval;
 467
 468                 if (tmp > 0)
 469                         SDB_PLUGIN_CCB(obj)->ccb_interval = tmp;
 470                 else
 471                         SDB_PLUGIN_CCB(obj)->ccb_interval = 0;
 472         }
 473
 474         if (! (SDB_PLUGIN_CCB(obj)->ccb_next_update = sdb_gettime())) {
 475                 char errbuf[1024];
 476                 sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
 477                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 478                 sdb_object_deref(obj);
 479                 return -1;
 480         }
 481
 482         if (sdb_llist_insert_sorted(collector_list, obj,
 483                                 sdb_plugin_cmp_next_update)) {
 484                 sdb_object_deref(obj);
 485                 return -1;
 486         }
 487
 488         /* pass control to the list */
 489         sdb_object_deref(obj);
 490
 491         sdb_log(SDB_LOG_INFO, "plugin: Registered collector callback '%s' "
 492                         "(interval = %.3fs).", name,
 493                         SDB_TIME_TO_DOUBLE(SDB_PLUGIN_CCB(obj)->ccb_interval));
 494         return 0;
 495 } /* sdb_plugin_register_collector */
 496
 497 sdb_plugin_ctx_t
 498 sdb_plugin_get_ctx(void)
 499 {
 500         sdb_plugin_ctx_t *ctx;
 501
 502         if (! plugin_ctx_key_initialized)
 503                 sdb_plugin_ctx_init();
 504         ctx = pthread_getspecific(plugin_ctx_key);
 505
 506         if (! ctx)
 507                 ctx = sdb_plugin_ctx_create();
 508         if (! ctx)
 509                 return plugin_default_ctx;
 510         return *ctx;
 511 } /* sdb_plugin_get_ctx */
 512
 513 sdb_plugin_ctx_t
 514 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx)
 515 {
 516         sdb_plugin_ctx_t *tmp;
 517         sdb_plugin_ctx_t old;
 518
 519         if (! plugin_ctx_key_initialized)
 520                 sdb_plugin_ctx_init();
 521         tmp = pthread_getspecific(plugin_ctx_key);
 522
 523         if (! tmp)
 524                 tmp = sdb_plugin_ctx_create();
 525         if (! tmp)
 526                 return plugin_default_ctx;
 527
 528         old = *tmp;
 529         *tmp = ctx;
 530         return old;
 531 } /* sdb_plugin_set_ctx */
 532
 533 int
 534 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
 535 {
 536         sdb_plugin_cb_t *plugin;
 537         sdb_plugin_config_cb callback;
 538
 539         sdb_plugin_ctx_t old_ctx;
 540
 541         int status;
 542
 543         if ((! name) || (! ci))
 544                 return -1;
 545
 546         plugin = sdb_plugin_find_by_name(config_list, name);
 547         if (! plugin) {
 548                 /* XXX: check if any such plugin has been loaded */
 549                 sdb_log(SDB_LOG_ERR, "plugin: Plugin '%s' did not register "
 550                                 "a config callback.", name);
 551                 errno = ENOENT;
 552                 return -1;
 553         }
 554
 555         old_ctx = sdb_plugin_set_ctx(plugin->cb_ctx);
 556         callback = plugin->cb_callback;
 557         status = callback(ci);
 558         sdb_plugin_set_ctx(old_ctx);
 559         return status;
 560 } /* sdb_plugin_configure */
 561
 562 int
 563 sdb_plugin_init_all(void)
 564 {
 565         sdb_llist_iter_t *iter;
 566
 567         iter = sdb_llist_get_iter(init_list);
 568         while (sdb_llist_iter_has_next(iter)) {
 569                 sdb_plugin_init_cb callback;
 570                 sdb_plugin_ctx_t old_ctx;
 571
 572                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 573                 assert(obj);
 574
 575                 callback = SDB_PLUGIN_CB(obj)->cb_callback;
 576
 577                 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CB(obj)->cb_ctx);
 578                 if (callback(SDB_PLUGIN_CB(obj)->cb_user_data)) {
 579                         /* XXX: unload plugin */
 580                 }
 581                 sdb_plugin_set_ctx(old_ctx);
 582         }
 583         return 0;
 584 } /* sdb_plugin_init_all */
 585
 586 int
 587 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 588 {
 589         if (! collector_list) {
 590                 sdb_log(SDB_LOG_WARNING, "plugin: No collectors registered. "
 591                                 "Quiting main loop.");
 592                 return -1;
 593         }
 594
 595         if (! loop)
 596                 return -1;
 597
 598         while (loop->do_loop) {
 599                 sdb_plugin_collector_cb callback;
 600                 sdb_plugin_ctx_t old_ctx;
 601
 602                 sdb_time_t interval, now;
 603
 604                 sdb_object_t *obj = sdb_llist_shift(collector_list);
 605                 if (! obj)
 606                         return -1;
 607
 608                 callback = SDB_PLUGIN_CCB(obj)->ccb_callback;
 609
 610                 if (! (now = sdb_gettime())) {
 611                         char errbuf[1024];
 612                         sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
 613                                         "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 614                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 615                 }
 616
 617                 if (now < SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 618                         interval = SDB_PLUGIN_CCB(obj)->ccb_next_update - now;
 619
 620                         errno = 0;
 621                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
 622                                 if (errno != EINTR) {
 623                                         char errbuf[1024];
 624                                         sdb_log(SDB_LOG_ERR, "plugin: Failed to sleep: %s",
 625                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 626                                         return -1;
 627                                 }
 628                                 errno = 0;
 629                         }
 630
 631                         if (! loop->do_loop)
 632                                 return 0;
 633                 }
 634
 635                 old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CCB(obj)->ccb_ctx);
 636                 if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
 637                         /* XXX */
 638                 }
 639                 sdb_plugin_set_ctx(old_ctx);
 640
 641                 interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
 642                 if (! interval)
 643                         interval = loop->default_interval;
 644                 if (! interval) {
 645                         sdb_log(SDB_LOG_WARNING, "plugin: No interval configured "
 646                                         "for plugin '%s'; skipping any further "
 647                                         "iterations.", SDB_PLUGIN_CCB(obj)->ccb_name);
 648                         sdb_object_deref(obj);
 649                         continue;
 650                 }
 651
 652                 SDB_PLUGIN_CCB(obj)->ccb_next_update += interval;
 653
 654                 if (! (now = sdb_gettime())) {
 655                         char errbuf[1024];
 656                         sdb_log(SDB_LOG_ERR, "plugin: Failed to determine current "
 657                                         "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 658                         now = SDB_PLUGIN_CCB(obj)->ccb_next_update;
 659                 }
 660
 661                 if (now > SDB_PLUGIN_CCB(obj)->ccb_next_update) {
 662                         sdb_log(SDB_LOG_WARNING, "plugin: Plugin '%s' took too "
 663                                         "long; skipping iterations to keep up.",
 664                                         SDB_PLUGIN_CCB(obj)->ccb_name);
 665                         SDB_PLUGIN_CCB(obj)->ccb_next_update = now;
 666                 }
 667
 668                 if (sdb_llist_insert_sorted(collector_list, obj,
 669                                         sdb_plugin_cmp_next_update)) {
 670                         sdb_log(SDB_LOG_ERR, "plugin: Failed to re-insert "
 671                                         "plugin '%s' into collector list. Unable to further "
 672                                         "use the plugin.",
 673                                         SDB_PLUGIN_CCB(obj)->ccb_name);
 674                         sdb_object_deref(obj);
 675                         return -1;
 676                 }
 677
 678                 /* pass control back to the list */
 679                 sdb_object_deref(obj);
 680         }
 681         return 0;
 682 } /* sdb_plugin_read_loop */
 683
 684 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 685