X-Git-Url: http://git.indexdata.com/?p=idzebra-moved-to-github.git;a=blobdiff_plain;f=util%2Fflock.c;h=3157f3689cb1acc5a328bb68663ce92cf9266c43;hp=009c971d6fdd7847e6a364dff4a8a1992af77072;hb=d513d15e315601b730b0b3a6126c3163d00223fb;hpb=32389c925760f3dadf9091390e039075c99470c5

diff --git a/util/flock.c b/util/flock.c
index 009c971..3157f36 100644
--- a/util/flock.c
+++ b/util/flock.c
@@ -1,8 +1,5 @@
-/* $Id: flock.c,v 1.14 2006-07-03 09:50:51 adam Exp $
-   Copyright (C) 1995-2006
-   Index Data ApS
-
-This file is part of the Zebra server.
+/* This file is part of the Zebra server.
+   Copyright (C) 1994-2011 Index Data
 
 Zebra is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
@@ -15,12 +12,15 @@ FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 for more details.
 
 You should have received a copy of the GNU General Public License
-along with Zebra; see the file LICENSE.zebra.  If not, write to the
-Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA.
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
 */
 
 
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
 #include <stdio.h>
 #include <assert.h>
 #include <string.h>
@@ -40,13 +40,10 @@ Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #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 */
@@ -253,7 +250,7 @@ static int unixLock(int fd, int type, int cmd)
 
 int zebra_lock_w(ZebraLockHandle h)
 {
-    int r;
+    int r = 0;
     int do_lock = 0;
     yaz_log(log_level, "zebra_lock_w fd=%d p=%p fname=%s begin", 
             h->p->fd, h, h->p->fname);
@@ -290,7 +287,7 @@ int zebra_lock_w(ZebraLockHandle h)
 
 int zebra_lock_r(ZebraLockHandle h)
 {
-    int r;
+    int r = 0;
     int do_lock = 0;
 
     yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s begin", 
@@ -327,7 +324,6 @@ int zebra_lock_r(ZebraLockHandle h)
 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
@@ -335,17 +331,23 @@ int zebra_unlock(ZebraLockHandle h)
 #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)
@@ -361,23 +363,30 @@ int zebra_unlock(ZebraLockHandle h)
     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(void)
 {
+#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()
 {
@@ -385,21 +394,17 @@ 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");
 }
 
 /*
  * Local variables:
  * c-basic-offset: 4
+ * c-file-style: "Stroustrup"
  * indent-tabs-mode: nil
  * End:
  * vim: shiftwidth=4 tabstop=8 expandtab