3 * tailing reliable realtime streaming feeder for inn
4 * statemc.c - state machine core (see README.states).
6 * Copyright (C) 2010 Ian Jackson <ijackson@chiark.greenend.org.uk>
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 * (I believe that when you compile and link this as part of the inn2
22 * build, with the Makefile runes I have provided, all the libraries
23 * and files which end up included in innduct are licence-compatible
24 * with GPLv3. If not then please let me know. -Ian Jackson.)
30 /* statemc_init initialises */
31 StateMachineState sms;
33 InputFile *main_input_file, *flushing_input_file, *backlog_input_file;
34 Counts backlog_counts;
35 int backlog_counts_report;
38 /* initialisation to 0 is good */
39 int until_connect, until_backlog_nextscan;
40 double accept_proportion;
41 int nocheck, nocheck_reported, in_child;
42 sig_atomic_t terminate_sig_flag;
45 static void startup_set_input_file(InputFile *f) {
46 assert(!main_input_file);
48 inputfile_reading_start(f);
51 void statemc_lock(void) {
53 struct stat stab, stabf;
56 lockfd= open(path_lock, O_CREAT|O_RDWR, 0600);
57 if (lockfd<0) sysdie("open lockfile %s", path_lock);
60 memset(&fl,0,sizeof(fl));
62 fl.l_whence= SEEK_SET;
63 int r= fcntl(lockfd, F_SETLK, &fl);
65 if (errno==EACCES || isewouldblock(errno)) {
66 if (quiet_multiple) exit(0);
67 die("another duct holds the lockfile");
69 sysdie("fcntl F_SETLK lockfile %s", path_lock);
72 xfstat_isreg(lockfd, &stabf, path_lock, "lockfile");
74 xlstat_isreg(path_lock, &stab, &lock_noent, "lockfile");
76 if (!lock_noent && samefile(&stab, &stabf))
79 xclose(lockfd, "stale lockfile ", path_lock);
82 FILE *lockfile= fdopen(lockfd, "w");
83 if (!lockfile) syscrash("fdopen lockfile");
85 int r= ftruncate(lockfd, 0);
86 if (r) syscrash("truncate lockfile to write new info");
88 if (fprintf(lockfile, "pid %ld\nsite %s\nfeedfile %s\nfqdn %s\n",
89 (unsigned long)self_pid,
90 sitename, feedfile, remote_host) == EOF ||
92 sysdie("write info to lockfile %s", path_lock);
94 dbg("startup: locked");
97 void statemc_init(void) {
98 struct stat stabdefer;
100 search_backlog_file();
103 xlstat_isreg(path_defer, &stabdefer, &defer_noent, "defer file");
105 dbg("startup: ductdefer ENOENT");
107 dbg("startup: ductdefer nlink=%ld", (long)stabdefer.st_nlink);
108 switch (stabdefer.st_nlink) {
110 open_defer(); /* so that we will later close it and rename it */
113 xunlink(path_defer, "stale defer file link"
114 " (presumably hardlink to backlog file)");
117 crash("defer file %s has unexpected link count %ld",
118 path_defer, (long)stabdefer.st_nlink);
122 struct stat stab_f, stab_d;
125 InputFile *file_d= open_input_file(path_flushing);
126 if (file_d) xfstat_isreg(file_d->fd, &stab_d, path_flushing,"flushing file");
128 xlstat_isreg(feedfile, &stab_f, &noent_f, "feedfile");
130 if (!noent_f && file_d && samefile(&stab_f, &stab_d)) {
131 dbg("startup: F==D => Hardlinked");
132 xunlink(feedfile, "feed file (during startup)"); /* => Moved */
137 dbg("startup: F ENOENT => Moved");
138 if (file_d) startup_set_input_file(file_d);
139 spawn_inndcomm_flush("feedfile missing at startup");
140 /* => Flushing, sms:=FLUSHING */
143 dbg("startup: F!=D => Separated");
144 startup_set_input_file(file_d);
145 flushing_input_file= main_input_file;
146 main_input_file= open_input_file(feedfile);
147 if (!main_input_file) crash("feedfile vanished during startup");
148 SMS(SEPARATED, max_separated_periods,
149 "found both old and current feed files");
151 dbg("startup: F exists, D ENOENT => Normal");
152 InputFile *file_f= open_input_file(feedfile);
153 if (!file_f) crash("feed file vanished during startup");
154 startup_set_input_file(file_f);
155 SMS(NORMAL, spontaneous_flush_periods, "normal startup");
160 void statemc_start_flush(const char *why) { /* Normal => Flushing */
161 assert(sms == sm_NORMAL);
163 dbg("starting flush (%s) (%lu >?= %lu) (%d)",
165 (unsigned long)(main_input_file ? main_input_file->offset : 0),
166 (unsigned long)target_max_feedfile_size,
169 int r= link(feedfile, path_flushing);
170 if (r) sysdie("link feedfile %s to flushing file %s",
171 feedfile, path_flushing);
174 xunlink(feedfile, "old feedfile link");
177 spawn_inndcomm_flush(why); /* => Flushing FLUSHING */
180 int trigger_flush_ok(const char *why) {
184 statemc_start_flush(why ? why : "periodic");
185 return 1; /* Normal => Flushing; => FLUSHING */
188 spawn_inndcomm_flush(why ? why : "retry");
189 return 1; /* Moved => Flushing; => FLUSHING */
194 warn("abandoning old feedfile after flush (%s), autodeferring",
195 why ? why : "took too long to complete");
197 info("autodeferring after flush (%s)",
198 why ? why : "no connections");
199 assert(flushing_input_file);
200 autodefer_input_file(flushing_input_file);
208 void statemc_period_poll(void) {
209 if (!until_flush) return;
211 assert(until_flush>=0);
213 if (until_flush) return;
214 int ok= trigger_flush_ok(0);
218 static int inputfile_is_done(InputFile *ipf) {
220 if (ipf->inprogress) return 0; /* new article in the meantime */
221 if (ipf->rd) return 0; /* not had EOF */
225 static void notice_processed_counts(Counts *counts, int completed,
226 InputFile *ipf_xtra, const char *what) {
228 #define RCI_NOTHING(x) /* nothing */
229 #define RCI_TRIPLE_FMT(x) " " #x "=" RCI_TRIPLE_FMT_BASE
230 #define RCI_TRIPLE_VALS(x) , RCI_TRIPLE_VALS_BASE(counts->results, [RC_##x])
232 #define CNT(art,rc) (counts->results[art_##art][RC_##rc])
234 char *inprog= ipf_xtra && !completed
235 ? masprintf(" inprogress=%ld", ipf_xtra->inprogress)
236 : masprintf("%s",""); /* GCC produces a stupid warning for printf("") ! */
237 char *autodefer= ipf_xtra && ipf_xtra->autodefer >= 0
238 ? masprintf(" autodeferred=%ld", ipf_xtra->autodefer)
239 : masprintf("%s","");
241 notice("%s %s read=%d (+bl=%d,+err=%d)%s%s missing=%d"
242 " offered=%d (ch=%d,nc=%d)"
243 " accepted=%d (ch=%d,nc=%d)"
244 RESULT_COUNTS(RCI_NOTHING, RCI_TRIPLE_FMT)
246 completed?"completed":"processed", what,
247 counts->events[read_ok], counts->events[read_blank],
248 counts->events[read_err],
249 inprog, autodefer, counts->events[nooffer_missing],
250 CNT(Unchecked,sent) + CNT(Unsolicited,sent)
251 , CNT(Unchecked,sent), CNT(Unsolicited,sent),
252 CNT(Wanted,accepted) + CNT(Wanted,accepted)
253 , CNT(Wanted,accepted), CNT(Wanted,accepted)
254 RESULT_COUNTS(RCI_NOTHING, RCI_TRIPLE_VALS)
257 memset(counts, 0, sizeof(*counts));
265 static void notice_processed_inputfile(InputFile *ipf, int completed,
267 if (!ipf) return; /* allows showstats to be lazy */
268 notice_processed_counts(&ipf->counts, completed, ipf, what);
271 static void backlog_accumulate_counts(InputFile *ipf) {
275 for (i=0; i<art_MaxState; i++)
276 for (j=0; j<RCI_max; j++)
277 backlog_counts.results[i][j] += ipf->counts.results[i][j];
279 for (i=0; i<ECI_max; i++)
280 backlog_counts.events[i] += ipf->counts.events[i];
282 memset(&ipf->counts, 0, sizeof(ipf->counts));
283 backlog_counts_report= 1;
286 void statemc_check_backlog_done(void) {
287 InputFile *ipf= backlog_input_file;
288 if (!inputfile_is_done(ipf)) return;
290 dbg("backlog file %p %s complete", ipf, ipf->path);
291 backlog_accumulate_counts(ipf);
292 close_input_file(ipf);
293 if (unlink(ipf->path)) {
295 syscrash("could not unlink processed backlog file %s", ipf->path);
296 warn("backlog file %s vanished while we were reading it"
297 " so we couldn't remove it (but it's done now, anyway)",
301 backlog_input_file= 0;
302 search_backlog_file();
306 void statemc_check_flushing_done(void) {
307 InputFile *ipf= flushing_input_file;
308 if (!inputfile_is_done(ipf)) return;
310 assert(sms==sm_SEPARATED || sms==sm_DROPPING);
312 notice_processed_inputfile(ipf,1,"batch");
316 xunlink(path_flushing, "old flushing file");
318 close_input_file(flushing_input_file);
319 free(flushing_input_file);
320 flushing_input_file= 0;
322 if (sms==sm_SEPARATED) {
323 notice("flush complete");
324 SMS(NORMAL, spontaneous_flush_periods, "flush complete");
325 } else if (sms==sm_DROPPING) {
326 SMS(DROPPED, max_separated_periods, "old flush complete");
327 search_backlog_file();
328 notice("feed dropped, but will continue until backlog is finished");
332 static void *statemc_check_input_done(oop_source *lp, struct timeval now,
334 /* main input file may be idle but if so that's because
335 * we haven't got to it yet, but that doesn't mean it's really done */
336 statemc_check_flushing_done();
337 statemc_check_backlog_done();
341 void queue_check_input_done(void) {
342 loop->on_time(loop, OOP_TIME_NOW, statemc_check_input_done, 0);
345 void statemc_setstate(StateMachineState newsms, int periods,
346 const char *forlog, const char *why) {
348 until_flush= periods;
350 const char *xtra= "";
354 if (!main_input_file) xtra= "-ABSENT";
358 xtra= flushing_input_file->rd ? "-1" : "-2";
364 info("state %s%s[%d] %s",forlog,xtra,periods,why);
366 info("state %s%s %s",forlog,xtra,why);
370 /*========== flushing the feed ==========*/
372 pid_t inndcomm_child;
373 static int inndcomm_sentinel_fd;
375 static void *inndcomm_event(oop_source *lp, int fd, oop_event e, void *u) {
376 assert(inndcomm_child);
377 assert(fd == inndcomm_sentinel_fd);
378 int status= xwaitpid(&inndcomm_child, "inndcomm");
381 cancel_fd_read_except(fd);
382 xclose_perhaps(&fd, "inndcomm sentinel pipe",0);
383 inndcomm_sentinel_fd= 0;
385 assert(!flushing_input_file);
387 if (WIFEXITED(status)) {
388 switch (WEXITSTATUS(status)) {
390 case INNDCOMMCHILD_ESTATUS_FAIL:
393 case INNDCOMMCHILD_ESTATUS_NONESUCH:
394 notice("feed has been dropped by innd, finishing up");
395 flushing_input_file= main_input_file;
396 tailing_make_readable(flushing_input_file);
397 /* we probably previously returned EAGAIN from our fake read method
398 * when in fact we were at EOF, so signal another readable event
399 * so we actually see the EOF */
403 if (flushing_input_file) {
404 SMS(DROPPING, max_separated_periods,
405 "feed dropped by innd, but must finish last flush");
408 SMS(DROPPED, 0, "feed dropped by innd");
409 search_backlog_file();
415 flushing_input_file= main_input_file;
416 tailing_make_readable(flushing_input_file);
418 main_input_file= open_input_file(feedfile);
419 if (!main_input_file)
420 crash("flush succeeded but feedfile %s does not exist!"
421 " (this probably means feedfile does not correspond"
422 " to site %s in newsfeeds)", feedfile, sitename);
424 if (flushing_input_file) {
425 SMS(SEPARATED, max_separated_periods, "flush complete");
428 SMS(NORMAL, spontaneous_flush_periods, "recovery flush complete");
433 goto unexpected_exitstatus;
436 } else if (WIFSIGNALED(status) && WTERMSIG(status) == SIGALRM) {
437 warn("flush timed out trying to talk to innd");
440 unexpected_exitstatus:
441 report_child_status("inndcomm child", status);
445 SMS(FLUSHFAILED, flushfail_retry_periods, "flush failed, will retry");
449 static void inndcommfail(const char *what) {
450 syswarn("error communicating with innd: %s failed: %s", what, ICCfailure);
451 exit(INNDCOMMCHILD_ESTATUS_FAIL);
454 void spawn_inndcomm_flush(const char *why) { /* Moved => Flushing */
457 notice("flushing %s",why);
459 assert(sms==sm_NORMAL || sms==sm_FLUSHFAILED);
460 assert(!inndcomm_child);
461 assert(!inndcomm_sentinel_fd);
463 if (pipe(pipefds)) sysdie("create pipe for inndcomm child sentinel");
465 inndcomm_child= xfork("inndcomm child");
467 if (!inndcomm_child) {
468 const char *flushargv[2]= { sitename, 0 };
472 xclose(pipefds[0], "(in child) inndcomm sentinel parent's end",0);
473 /* parent spots the autoclose of pipefds[1] when we die or exit */
475 if (simulate_flush>=0) {
476 warn("SIMULATING flush child status %d", simulate_flush);
477 if (simulate_flush>128) raise(simulate_flush-128);
478 else exit(simulate_flush);
481 alarm(inndcomm_flush_timeout);
482 r= ICCopen(); if (r) inndcommfail("connect");
483 r= ICCcommand('f',flushargv,&reply); if (r<0) inndcommfail("transmit");
484 if (!r) exit(0); /* yay! */
486 if (!strcmp(reply, "1 No such site")) exit(INNDCOMMCHILD_ESTATUS_NONESUCH);
487 syswarn("innd ctlinnd flush failed: innd said %s", reply);
488 exit(INNDCOMMCHILD_ESTATUS_FAIL);
493 xclose(pipefds[1], "inndcomm sentinel child's end",0);
494 inndcomm_sentinel_fd= pipefds[0];
495 assert(inndcomm_sentinel_fd);
496 on_fd_read_except(inndcomm_sentinel_fd, inndcomm_event);
498 SMS(FLUSHING, 0, why);
501 /*---------- shutdown and signal handling ----------*/
503 void preterminate(void) {
504 if (in_child) return;
508 void showstats(void) {
509 notice_conns_stats();
510 notice_processed_inputfile(main_input_file, 0, "feedfile");
511 notice_processed_inputfile(flushing_input_file, 0, "flushing");
513 backlog_accumulate_counts(backlog_input_file);
514 if (backlog_counts_report) {
515 notice_processed_counts(&backlog_counts, 0,
516 backlog_input_file, "backlogs");
517 backlog_counts_report= 0;
519 until_stats_log= stats_log_periods;
522 static int signal_self_pipe[2];
524 static void *sigarrived_event(oop_source *lp, int fd, oop_event e, void *u) {
525 assert(fd==signal_self_pipe[0]);
527 int r= read(signal_self_pipe[0], buf, sizeof(buf));
528 if (r<0 && !isewouldblock(errno))
529 syscrash("failed to read signal self pipe");
530 if (r==0) crash("eof on signal self pipe");
531 if (terminate_sig_flag) {
533 notice("terminating (%s)", strsignal(terminate_sig_flag));
534 raise_default(terminate_sig_flag);
539 static void sigarrived_handler(int signum) {
545 if (!terminate_sig_flag) terminate_sig_flag= signum;
550 int r = write(signal_self_pipe[1],&x,1);
551 if (!(r==1 || isewouldblock(errno))) abort();
555 void init_signals(void) {
556 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
557 syscrash("could not ignore SIGPIPE");
559 if (pipe(signal_self_pipe)) sysdie("create self-pipe for signals");
561 xsetnonblock(signal_self_pipe[0],1);
562 xsetnonblock(signal_self_pipe[1],1);
565 memset(&sa,0,sizeof(sa));
566 sa.sa_handler= sigarrived_handler;
567 sa.sa_flags= SA_RESTART;
568 xsigaction(SIGTERM,&sa);
569 xsigaction(SIGINT,&sa);
571 on_fd_read_except(signal_self_pipe[0], sigarrived_event);