socat V1.6.0.0 (initial GIT commit)

xiolockfile.c

@@ -0,0 +1,118 @@
+/* $Id: xiolockfile.c,v 1.2 2006/02/08 19:51:24 gerhard Exp $ */
+/* Copyright Gerhard Rieger 2005-2006 */
+/* Published under the GNU General Public License V.2, see file COPYING */
+
+/* this file contains socats explicit locking mechanisms */
+
+#include "xiosysincludes.h"
+
+#include "compat.h"
+#include "mytypes.h"
+#include "error.h"
+#include "utils.h"
+#include "sysutils.h"
+
+#include "sycls.h"
+
+#include "xio.h"
+#include "xiolockfile.h"
+
+
+/* returns 0 if it could create lock; 1 if the lock exists; -1 on error */
+int xiogetlock(const char *lockfile) {
+   char *s;
+   struct stat strat;
+   int fd;
+   pid_t pid;
+   char pidbuf[3*sizeof(pid_t)+1];
+   size_t bytes;
+
+   if (Lstat(lockfile, &strat) == 0) {
+      return 1;
+   }
+   switch (errno) {
+   case ENOENT: break;
+   default:
+      Error3("Lstat(\"%s\", %p): %s", lockfile, &strat, strerror(errno));
+      return -1;
+   }
+   /* in this moment, the file did not exist */
+
+   if ((s = Malloc(strlen(lockfile)+8)) == NULL) {
+      errno = ENOMEM;
+      return -1;
+   }
+   strcpy(s, lockfile);
+   strcat(s, ".XXXXXX");
+
+   if ((fd = Mkstemp(s)) < 0) {
+      Error2("mkstemp(\"%s\"): %s", s, strerror(errno));
+      return -1;
+   }
+  
+   pid = Getpid();
+   bytes = sprintf(pidbuf, F_pid, pid);
+   Write(fd, pidbuf, bytes);
+   Close(fd);
+
+   /* Chmod(lockfile, 0600); */
+   if (Link(s, lockfile) < 0) {
+      int _errno = errno;
+      Error3("link(\"%s\", \"%s\"): %s", s, lockfile, strerror(errno));
+      Unlink(s);
+      errno = _errno;
+      return -1;
+   }
+   Unlink(s);
+
+   return 0;
+}
+
+int xiounlock(const char *lockfile) {
+   return Unlink(lockfile);
+}
+
+
+/* returns 0 when it could create lock, or -1 on error */
+int xiowaitlock(const char *lockfile, struct timespec *intervall) {
+   int rc;
+   int level = E_NOTICE;	/* first print a notice */
+
+   while ((rc = xiogetlock(lockfile)) == 1) {
+      Msg1(level, "waiting for lock \"%s\"", lockfile);
+      level = E_INFO;		/* afterwards only make info */
+      Nanosleep(intervall, NULL);
+   }
+   return rc;
+}
+
+
+/* returns 0 when it could obtain lock or the lock is not valid
+   (lockfile==NULL), 1 if it could not obtain the lock, or -1 on error */
+int xiolock(xiolock_t *lock) {
+   int result;
+
+   if (lock->lockfile == NULL) {
+      return 0;
+   }
+   if (lock->waitlock) {
+      result = xiowaitlock(lock->lockfile, &lock->intervall);
+   } else {
+      result = xiogetlock(lock->lockfile);
+   }
+   if (result == 0) {
+      Info1("obtained lock \"%s\"", lock->lockfile);
+   }
+   return result;
+}
+
+
+int xiofiledroplock(xiofile_t *xfd) {
+   if (xfd->tag == XIO_TAG_DUAL) {
+      xiofiledroplock((xiofile_t *)xfd->dual.stream[0]);
+      xiofiledroplock((xiofile_t *)xfd->dual.stream[1]);
+   } else {
+      xfd->stream.havelock = false;
+   }
+   return 0;
+}