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