-/* $Id: flock.c,v 1.14 2006-07-03 09:50:51 adam Exp $
+/* $Id: flock.c,v 1.17 2006-07-05 12:02:12 adam Exp $
Copyright (C) 1995-2006
Index Data ApS
#include <yaz/xmalloc.h>
#include <yaz/log.h>
-/** whether this module should debug */
-#define DEBUG_FLOCK 1
-
/** have this module (mutex) been initialized? */
static int initialized = 0;
-/** whether fcntl locks are shared for all threads in a process */
+/** whether fcntl locks are shared for all threads in a process (POSIX) */
static int posix_locks = 1;
/** mutex for lock_list below */
int zebra_unlock(ZebraLockHandle h)
{
int r = 0;
- int do_unlock = 0;
yaz_log(log_level, "zebra_unlock fd=%d p=%p fname=%s begin",
h->p->fd, h, h->p->fname);
#ifdef WIN32
#else
zebra_mutex_lock(&h->p->file_mutex);
if (h->write_flag)
- h->p->no_file_write_lock--;
+ {
+ if (h->p->no_file_write_lock > 0)
+ h->p->no_file_write_lock--;
+ }
else
- h->p->no_file_read_lock--;
+ {
+ if (h->p->no_file_read_lock > 0)
+ h->p->no_file_read_lock--;
+ }
if (h->p->no_file_read_lock == 0 && h->p->no_file_write_lock == 0)
- do_unlock = 1;
- if (do_unlock)
r = unixLock(h->p->fd, F_UNLCK, F_SETLKW);
else
{
+ r = 0;
assert(posix_locks);
}
+
zebra_mutex_unlock(&h->p->file_mutex);
if (posix_locks)
return r;
}
-#if HAVE_CONFSTR
-static int test_for_linuxthreads()
+/** \brief see if the fcntl locking is not POSIX
+ *
+ * The default posix_locks=1 is assumed.. This function sets posix_locks
+ * to zero if linuxthreads is in use.
+ */
+static int check_for_linuxthreads()
{
+#if __linux
+#ifdef _CS_GNU_LIBPTHREAD_VERSION
char conf_buf[512];
- size_t r;
-
- r = confstr(_CS_GNU_LIBPTHREAD_VERSION, conf_buf, sizeof(conf_buf));
+ size_t r = confstr(_CS_GNU_LIBPTHREAD_VERSION, conf_buf, sizeof(conf_buf));
if (r == 0)
{
yaz_log(YLOG_WARN|YLOG_ERRNO, "confstr failed");
return -1;
}
if (strncmp(conf_buf, "linuxthreads", 12) == 0)
- posix_locks = 0;
+ posix_locks = 0; /* Using linuxthreads.. */
+#else
+ posix_locks = 0; /* Old GLIBC on Linux. Assume linuxthreads */
+#endif
+#endif
return 0;
}
-#endif
void zebra_flock_init()
{
{
initialized = 1;
log_level = yaz_log_module_level("flock");
-#if DEBUG_FLOCK
- log_level = YLOG_LOG|YLOG_FLUSH;
-#endif
-#if HAVE_CONFSTR
- test_for_linuxthreads();
-#endif
+ yaz_log(log_level, "zebra_flock_init");
+ check_for_linuxthreads();
zebra_mutex_init(&lock_list_mutex);
yaz_log(log_level, "posix_locks: %d", posix_locks);
}
- yaz_log(log_level, "zebra_flock_init");
}
/*