citadel/housekeeping.c

   1 /*
   2  * This file contains housekeeping tasks which periodically
   3  * need to be executed.  It keeps a nice little queue...
   4  *
   5  * $Id$
   6  */
   7
   8 #include "sysdep.h"
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <stdio.h>
  12 #include <fcntl.h>
  13 #include <time.h>
  14 #include <ctype.h>
  15 #include <string.h>
  16 #include <errno.h>
  17 #include <limits.h>
  18 #include <sys/types.h>
  19 #include <sys/time.h>
  20 #ifdef HAVE_SYS_SELECT_H
  21 #include <sys/select.h>
  22 #endif
  23 #ifdef HAVE_PTHREAD_H
  24 #include <pthread.h>
  25 #endif
  26 #include "tools.h"
  27 #include "citadel.h"
  28 #include "server.h"
  29 #include "citserver.h"
  30 #include "config.h"
  31 #include "housekeeping.h"
  32 #include "sysdep_decls.h"
  33 #include "room_ops.h"
  34
  35
  36 int housepipe[2];       /* This is the queue for housekeeping tasks */
  37
  38
  39 /*
  40  * Terminate idle sessions.  This function pounds through the session table
  41  * comparing the current time to each session's time-of-last-command.  If an
  42  * idle session is found it is terminated, then the search restarts at the
  43  * beginning because the pointer to our place in the list becomes invalid.
  44  */
  45 void terminate_idle_sessions(void) {
  46         struct CitContext *ccptr;
  47         time_t now;
  48         int session_to_kill;
  49
  50         do {
  51                 now = time(NULL);
  52                 session_to_kill = 0;
  53                 begin_critical_section(S_SESSION_TABLE);
  54                 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
  55                         if (  (ccptr!=CC)
  56                         && (config.c_sleeping > 0)
  57                         && (now - (ccptr->lastcmd) > config.c_sleeping) ) {
  58                                 session_to_kill = ccptr->cs_pid;
  59                                 }
  60                         }
  61                 end_critical_section(S_SESSION_TABLE);
  62                 if (session_to_kill > 0) {
  63                         lprintf(3, "Session %d timed out.  Terminating it...\n",
  64                                 session_to_kill);
  65                         kill_session(session_to_kill);
  66                         }
  67                 } while(session_to_kill > 0);
  68         }
  69
  70
  71
  72 void check_sched_shutdown(void) {
  73         if ((ScheduledShutdown == 1) && (ContextList == NULL)) {
  74                 lprintf(3, "Scheduled shutdown initiating.\n");
  75                 master_cleanup();
  76         }
  77 }
  78
  79
  80
  81 /*
  82  * This is the main loop for the housekeeping thread.  It remains active
  83  * during the entire run of the server.
  84  */
  85 void housekeeping_loop(void) {
  86         long flags;
  87         struct timeval tv;
  88         fd_set readfds;
  89         int did_something;
  90         char house_cmd[256];    /* Housekeep cmds are always 256 bytes long */
  91         char cmd[256];
  92
  93         if (pipe(housepipe) != 0) {
  94                 lprintf(1, "FATAL ERROR: can't create housekeeping pipe: %s\n",
  95                         strerror(errno));
  96                 exit(0);
  97         }
  98
  99         flags = (long) fcntl(housepipe[1], F_GETFL);
 100         flags |= O_NONBLOCK;
 101         fcntl(housepipe[1], F_SETFL, flags);
 102
 103         while(1) {
 104                 do {
 105                         did_something = 0;
 106                         tv.tv_sec = HOUSEKEEPING_WAKEUP;
 107                         tv.tv_usec = 0;
 108                         FD_ZERO(&readfds);
 109                         FD_SET(housepipe[0], &readfds);
 110                         select(housepipe[0] + 1, &readfds, 0L, 0L, &tv);
 111                         if (FD_ISSET(housepipe[0], &readfds)) {
 112                                 did_something = 1;
 113                         }
 114
 115                         if (did_something) {
 116                                 read(housepipe[0], house_cmd, 256);
 117                         }
 118                         else {
 119                                 memset(house_cmd, 0, 256);
 120                                 strcpy(house_cmd, "MINUTE");
 121                         }
 122
 123                         extract(cmd, house_cmd, 0);
 124
 125                         /* Do whatever this cmd requires */
 126
 127                         /* Once-every-minute housekeeper */
 128                         if (!strcmp(cmd, "MINUTE")) {
 129                                 terminate_idle_sessions();
 130                         }
 131
 132                         /* Scheduled shutdown housekeeper */
 133                         else if (!strcmp(cmd, "SCHED_SHUTDOWN")) {
 134                                 check_sched_shutdown();
 135                         }
 136
 137                         /* Unknown */
 138                         else {
 139                                 lprintf(7, "Unknown housekeeping command\n");
 140                         }
 141
 142                 } while (did_something);
 143         }
 144 }
 145
 146
 147
 148
 149
 150
 151 void enter_housekeeping_cmd(char *cmd) {
 152         char cmdbuf[256];
 153
 154         lprintf(9, "enter_housekeeping_cmd(%s)\n", cmd);
 155         safestrncpy(cmdbuf, cmd, 256);
 156         begin_critical_section(S_HOUSEKEEPING);
 157         write(housepipe[1], cmdbuf, 256);
 158         end_critical_section(S_HOUSEKEEPING);
 159         lprintf(9, "leaving enter_housekeeping_cmd()\n");
 160 }
 161
 162
 163
 164 /*
 165  * Check (and fix) floor reference counts.  This doesn't need to be done
 166  * very often, since the counts should remain correct during normal operation.
 167  * NOTE: this function pair should ONLY be called during startup.  It is NOT
 168  * thread safe.
 169  */
 170 void check_ref_counts_backend(struct quickroom *qrbuf) {
 171         struct floor flbuf;
 172
 173         getfloor(&flbuf, qrbuf->QRfloor);
 174         ++flbuf.f_ref_count;
 175         flbuf.f_flags = flbuf.f_flags | QR_INUSE;
 176         putfloor(&flbuf, qrbuf->QRfloor);
 177         }
 178
 179 void check_ref_counts(void) {
 180         struct floor flbuf;
 181         int a;
 182
 183         for (a=0; a<MAXFLOORS; ++a) {
 184                 getfloor(&flbuf, a);
 185                 flbuf.f_ref_count = 0;
 186                 flbuf.f_flags = flbuf.f_flags & ~QR_INUSE;
 187                 putfloor(&flbuf, a);
 188                 }
 189
 190         ForEachRoom(check_ref_counts_backend);
 191         }
 192