SAFE public projects git trees. - safe/jmp/vzgot/blob - lib/unilck.c

   1 /************************************************/
   2 /*                                              */
   3 /*      Copyright:                              */
   4 /*       Jean-Marc Pigeon <jmp@safe.ca>  2009   */
   5 /*                                              */
   6 /************************************************/
   7 /* This program is free software; you can       */
   8 /* redistribute it and/or modify it under the   */
   9 /* terms of the GNU General Public License as   */
  10 /* published by the Free Software Foundation    */
  11 /* version 2 of the License                     */
  12 /*                                              */
  13 /* This program is distributed in the hope that */
  14 /* it will be useful, but WITHOUT ANY WARRANTY; */
  15 /* without even the implied warranty of         */
  16 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR  */
  17 /* PURPOSE.  See the GNU General Public License */
  18 /* for more details.                            */
  19 /*                                              */
  20 /* You should have received a copy of the GNU   */
  21 /* General Public License along with this       */
  22 /* program; if not, write to the Free Software  */
  23 /* Foundation, Inc., 51 Franklin Street,        */
  24 /* Fifth Floor, Boston, MA  02110-1301, USA.    */
  25 /************************************************/
  26 /*                                              */
  27 /*      UNILCK:                                 */
  28 /*      Take Care of all process locking        */
  29 /*      function.                               */
  30 /*                                              */
  31 /************************************************/
  32 #include        <string.h>
  33 #include        <stdio.h>
  34 #include        <syslog.h>
  35 #include        <fcntl.h>
  36 #include        <unistd.h>
  37 #include        "lowtyp.h"
  38 #include        "dbgmem.h"
  39 #include        "utlprc.h"
  40 #include        "subapl.h"
  41 #include        "unilck.h"
  42
  43 /*Application locking directory                 */
  44 #define LOCKEXT "-lock" /*lock file extension   */
  45
  46 /*
  47 \f
  48 */
  49 /************************************************/
  50 /*                                              */
  51 /*      procedure to set/unset a lock           */
  52 /*      return true if successful,              */
  53 /*      false otherwise.                        */
  54 /*                                              */
  55 /************************************************/
  56 int lck_locking(const char *ident,int lock,int tentative)
  57
  58 {
  59 int done;
  60 char *dlock;
  61 char *lockname;
  62
  63 done=false;
  64 dlock=apl_appdir(d_lock);
  65 (void) asprintf(&lockname,"%s%s%s",dlock,ident,LOCKEXT);
  66 if (lock==LCK_LOCK) {
  67   (void) apl_alert(9,"Request locking <%s>",lockname);
  68   while (tentative>0) {
  69     int handle;
  70
  71     tentative--;
  72     if ((handle=open(lockname,O_RDWR|O_EXCL|O_CREAT,0640))<0) {
  73       FILE *fichier;
  74
  75       if ((fichier=fopen(lockname,"r"))!=(FILE *)0) {
  76         int pid;
  77         char strloc[80];
  78
  79         (void) fgets(strloc,sizeof(strloc)-1,fichier);
  80         (void) fclose(fichier);
  81         if (sscanf(strloc,"%d",&pid)==1) {
  82           (void) apl_alert(1,"Locking, check %d process active",pid);
  83           if (prc_checkprocess(pid)==false) {
  84             (void) apl_alert(1,"Locking, remove unactive lock");
  85             (void) unlink(lockname);
  86             }
  87           else {
  88             if (tentative>0)
  89               {
  90               (void) apl_alert(2,"waiting 1 sec to be unlocked");
  91               (void) sleep(1);
  92               }
  93             }
  94           }
  95         }
  96       continue;
  97       }
  98     else
  99       {
 100       char numid[30];
 101
 102       (void) snprintf(numid,sizeof(numid),"%06d\n",getpid());
 103       (void) write(handle,numid,strlen(numid));
 104       (void) close(handle);
 105       done=true;
 106       break;
 107       }
 108     }
 109   if (done==false)
 110     (void) apl_alert(0,"Unable to set locking <%s>",lockname);
 111   }
 112 else
 113   {
 114   (void) apl_alert(9,"Request unlocking <%s>",lockname);
 115   (void) unlink(lockname);
 116   done=true;
 117   }
 118 (void) free(lockname);
 119 (void) free(dlock);
 120 return done;
 121 }