From: Adam Dickmeiss <adam@indexdata.dk>
Date: Fri, 8 Dec 1995 16:22:53 +0000 (+0000)
Subject: Work on update while servers are running. Three lock files introduced.
X-Git-Tag: ZEBRA.1.0~601
X-Git-Url: http://git.indexdata.com/?p=idzebra-moved-to-github.git;a=commitdiff_plain;h=bf27228e5485151ee52bfd87dd91b025544ab6b2

Work on update while servers are running. Three lock files introduced.
The servers reload their registers when necessary, but they don't
reestablish result sets yet.
---

diff --git a/index/index.h b/index/index.h
index 620ffcf..a6ad7d9 100644
--- a/index/index.h
+++ b/index/index.h
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: index.h,v $
- * Revision 1.32  1995-12-07 17:38:46  adam
+ * Revision 1.33  1995-12-08 16:22:53  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.32  1995/12/07  17:38:46  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  * Revision 1.31  1995/12/06  12:41:22  adam
@@ -205,13 +210,12 @@ void rec_prstat (void);
 
 void zebraLockPrefix (char *pathPrefix);
 
-int zebraServerLock (void);
-void zebraServerUnlock (void);
-
 void zebraIndexLockMsg (const char *str);
-void zebraIndexUnlock (int rw);
-void zebraIndexLock (int rw);
-void zebraIndexLockCommit (void);
-int zebraServerLockGetState (void);
-
-#define FNAME_MAIN_LOCK "zebra.lock"
+void zebraIndexUnlock (void);
+void zebraIndexLock (int commitNow);
+int zebraIndexWait (int commitPhase);
+
+#define FNAME_MAIN_LOCK   "zebraidx.LCK"
+#define FNAME_COMMIT_LOCK "zebracmt.LCK"
+#define FNAME_ORG_LOCK    "zebraorg.LCK"
+#define FNAME_TOUCH_TIME  "zebraidx.time"
diff --git a/index/lockidx.c b/index/lockidx.c
index ed7c7f8..75bec86 100644
--- a/index/lockidx.c
+++ b/index/lockidx.c
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: lockidx.c,v $
- * Revision 1.1  1995-12-07 17:38:47  adam
+ * Revision 1.2  1995-12-08 16:22:54  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.1  1995/12/07  17:38:47  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  */
@@ -20,10 +25,72 @@
 #include "index.h"
 
 static int lock_fd = -1;
+static int server_lock_cmt = -1;
+static int server_lock_org = -1;
+
+int zebraIndexWait (int commitPhase)
+{
+    char pathPrefix[1024];
+    char path[1024];
+    int fd;
+    
+    zebraLockPrefix (pathPrefix);
+
+    if (server_lock_cmt == -1)
+    {
+        sprintf (path, "%s%s", FNAME_COMMIT_LOCK, pathPrefix);
+        if ((server_lock_cmt = open (path, O_CREAT|O_RDWR|O_SYNC, 0666))
+            == -1)
+        {
+            logf (LOG_FATAL|LOG_ERRNO, "create %s", path);
+            return -1;
+        }
+    }
+    else
+        flock (server_lock_cmt, LOCK_UN);
+    if (server_lock_org == -1)
+    {
+        sprintf (path, "%s%s", FNAME_ORG_LOCK, pathPrefix);
+        if ((server_lock_org = open (path, O_CREAT|O_RDWR|O_SYNC, 0666))
+            == -1)
+        {
+            logf (LOG_FATAL|LOG_ERRNO, "create %s", path);
+            return -1;
+        }
+    }
+    else
+        flock (server_lock_org, LOCK_UN);
+    if (commitPhase)
+        fd = server_lock_cmt;
+    else
+        fd = server_lock_org;
+    if (flock (fd, LOCK_EX|LOCK_NB) == -1)
+    {
+        if (errno != EWOULDBLOCK)
+        {
+            logf (LOG_FATAL|LOG_ERRNO, "flock");
+            exit (1);
+        }
+        if (commitPhase)
+            logf (LOG_LOG, "Waiting for lock cmt");
+        else
+            logf (LOG_LOG, "Waiting for lock org");
+        if (flock (fd, LOCK_EX) == -1)
+        {
+            logf (LOG_FATAL|LOG_ERRNO, "flock");
+            exit (1);
+        }
+    }
+    flock (fd, LOCK_UN);
+    return 0;
+}
+
 
 void zebraIndexLockMsg (const char *str)
 {
-    int l, r;
+    char path[1024];
+    char pathPrefix[1024];
+    int l, r, fd;
 
     assert (lock_fd != -1);
     lseek (lock_fd, 0L, SEEK_SET);
@@ -34,105 +101,115 @@ void zebraIndexLockMsg (const char *str)
         logf (LOG_FATAL|LOG_ERRNO, "write lock file");
         exit (1);
     }
+    zebraLockPrefix (pathPrefix);
+    sprintf (path, "%s%s", pathPrefix, FNAME_TOUCH_TIME);
+    fd = creat (path, 0666);
+    close (fd);
 }
 
-void zebraIndexUnlock (int rw)
+void zebraIndexUnlock (void)
 {
     char path[1024];
     char pathPrefix[1024];
 
-    if (lock_fd == -1)
-        return;
-
     zebraLockPrefix (pathPrefix);
     sprintf (path, "%s%s", pathPrefix, FNAME_MAIN_LOCK);
     unlink (path);
 }
 
-void zebraIndexLock (int rw)
+void zebraIndexLock (int commitNow)
 {
     char path[1024];
     char pathPrefix[1024];
     char buf[256];
     int r;
 
+    if (lock_fd != -1)
+        return ;
     zebraLockPrefix (pathPrefix);
     sprintf (path, "%s%s", pathPrefix, FNAME_MAIN_LOCK);
-    if (rw)
+    while (1)
     {
-        while (1)
+        lock_fd = open (path, O_CREAT|O_RDWR|O_EXCL|O_SYNC, 0666);
+        if (lock_fd == -1)
         {
-            lock_fd = open (path, O_CREAT|O_RDWR|O_EXCL|O_SYNC, 0666);
-            if (lock_fd == -1)
+            lock_fd = open (path, O_RDONLY);
+            assert (lock_fd != -1);
+            if (flock (lock_fd, LOCK_EX|LOCK_NB) == -1)
             {
-                lock_fd = open (path, O_RDONLY);
-                assert (lock_fd != -1);
-                if (flock (lock_fd, LOCK_EX|LOCK_NB) == -1)
+                if (errno == EWOULDBLOCK)
                 {
-                    if (errno == EWOULDBLOCK)
-                    {
-                        logf (LOG_LOG, "Waiting for other index process");
-                        flock (lock_fd, LOCK_EX);
-                        continue;
-                    }
-                    else
-                    {
-                        logf (LOG_FATAL|LOG_ERRNO, "flock %s", path);
-                        exit (1);
-                    }
+                    logf (LOG_LOG, "Waiting for other index process");
+                    flock (lock_fd, LOCK_EX);
+                    continue;
                 }
                 else
                 {
-                    logf (LOG_WARN, "Unlocked %s", path);
-                    r = read (lock_fd, buf, 256);
-                    if (r == 0)
-                    {
-                        logf (LOG_WARN, "Zero length %s", path);
-                        unlink (path);
-                        close (lock_fd);
-                        continue;
-                    }
-                    else if (r == -1)
-                    {
-                        logf (LOG_FATAL|LOG_ERRNO, "read  %s", path);
-                        exit (1);
-                    }
-                    if (*buf == 'r')
+                    logf (LOG_FATAL|LOG_ERRNO, "flock %s", path);
+                    exit (1);
+                }
+            }
+            else
+            {
+                logf (LOG_WARN, "Unlocked %s", path);
+                r = read (lock_fd, buf, 256);
+                if (r == 0)
+                {
+                    logf (LOG_WARN, "Zero length %s", path);
+                    close (lock_fd);
+                    unlink (path);
+                    continue;
+                }
+                else if (r == -1)
+                {
+                    logf (LOG_FATAL|LOG_ERRNO, "read  %s", path);
+                    exit (1);
+                }
+                if (*buf == 'r')
+                {
+                    logf (LOG_WARN, "Previous transaction didn't"
+                          " reach commit");
+                    close (lock_fd);
+                    bf_commitClean ();
+                    unlink (path);
+                    continue;
+                }
+                else if (*buf == 'd')
+                {
+                    logf (LOG_WARN, "Commit file wan't deleted after commit");
+                    close (lock_fd);
+                    bf_commitClean ();
+                    unlink (path);
+                    continue;
+                }                    
+                else if (*buf == 'w')
+                {
+                    logf (LOG_WARN, "Your index may be inconsistent");
+                    exit (1);
+                }
+                else if (*buf == 'c')
+                {
+                    if (commitNow)
                     {
-                        logf (LOG_WARN, "Previous transaction didn't"
-                              " reach commit");
                         unlink (path);
                         close (lock_fd);
                         continue;
                     }
-                    else if (*buf == 'w')
-                    {
-                        logf (LOG_WARN, "Your index may be inconsistent");
-                        exit (1);
-                    }
-                    else if (*buf == 'c')
-                    {
-                        logf (LOG_FATAL, "Previous transaction didn't"
-                              " finish commit. Restore now!");
-                        exit (1);
-                    }
-                    else 
-                    {
-                        logf (LOG_FATAL, "Unknown id 0x%02x in %s", *buf,
-                              path);
-                        exit (1);
-                    }
+                    logf (LOG_FATAL, "Previous transaction didn't"
+                          " finish commit. Commit now!");
+                    exit (1);
+                }
+                else 
+                {
+                    logf (LOG_FATAL, "Unknown id 0x%02x in %s", *buf,
+                          path);
+                    exit (1);
                 }
             }
-            else
-                break;
         }
-        flock (lock_fd, LOCK_EX);
+        else
+            break;
     }
-}
-
-void zebraIndexLockCommit (void)
-{
-
+    flock (lock_fd, LOCK_EX);
 }
 
diff --git a/index/locksrv.c b/index/locksrv.c
index 517e680..535af27 100644
--- a/index/locksrv.c
+++ b/index/locksrv.c
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: locksrv.c,v $
- * Revision 1.1  1995-12-07 17:38:47  adam
+ * Revision 1.2  1995-12-08 16:22:55  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.1  1995/12/07  17:38:47  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  */
@@ -12,84 +17,100 @@
 #include <assert.h>
 #include <unistd.h>
 #include <sys/file.h>
+#include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
 #include <errno.h>
 
 #include <alexutil.h>
-#include "index.h"
+#include "zserver.h"
 
-static int server_lock_fd = -1;
+static int server_lock_cmt = -1;
+static int server_lock_org = -1;
 
-int zebraServerLock (void)
+int zebraServerLock (int commitPhase)
 {
     char pathPrefix[1024];
     char path[1024];
     
     zebraLockPrefix (pathPrefix);
 
-    assert (server_lock_fd == -1);
-    sprintf (path, "%szebrasrv.%ld", pathPrefix, (long) getpid());
-    if ((server_lock_fd = open (path, O_CREAT|O_RDWR|O_SYNC|O_EXCL, 0666))
-        == -1)
+    if (server_lock_cmt == -1)
     {
-        logf (LOG_WARN|LOG_ERRNO, "remove stale %s", path);
-        unlink (path);
-        if ((server_lock_fd = open (path, O_CREAT|O_RDWR|O_SYNC|O_EXCL, 0666))
+        sprintf (path, "%s%s", FNAME_COMMIT_LOCK, pathPrefix);
+        if ((server_lock_cmt = open (path, O_CREAT|O_RDWR, 0666))
             == -1)
         {
             logf (LOG_FATAL|LOG_ERRNO, "create %s", path);
             return -1;
         }
-    }
-    flock (server_lock_fd, LOCK_EX);
+        assert (server_lock_org == -1);
 
+        sprintf (path, "%s%s", FNAME_ORG_LOCK, pathPrefix);
+        if ((server_lock_org = open (path, O_CREAT|O_RDWR, 0666))
+            == -1)
+        {
+            logf (LOG_FATAL|LOG_ERRNO, "create %s", path);
+            return -1;
+        }
+    }
+    if (commitPhase)
+    {
+        logf (LOG_LOG, "Server locks org");
+        flock (server_lock_org, LOCK_SH);
+    }
+    else
+    {
+        logf (LOG_LOG, "Server locks cmt");
+        flock (server_lock_cmt, LOCK_SH);
+    }
     return 0;
 }
 
-int zebraServerLockGetState (void)
+void zebraServerUnlock (int commitPhase)
+{
+    if (server_lock_org == -1)
+        return;
+    if (commitPhase)
+    {
+        logf (LOG_LOG, "Server unlocks org");
+        flock (server_lock_org, LOCK_UN);
+    }
+    else
+    {
+        logf (LOG_LOG, "Server unlocks cmt");
+        flock (server_lock_cmt, LOCK_UN);
+    }
+}
+
+int zebraServerLockGetState (time_t *timep)
 {
     char pathPrefix[1024];
     char path[1024];
     char buf[256];
     int fd;
+    struct stat xstat;
     
     zebraLockPrefix (pathPrefix);
 
+    sprintf (path, "%s%s", pathPrefix, FNAME_TOUCH_TIME);
+    if (stat (path, &xstat) == -1)
+        *timep = 1;
+    else
+        *timep = xstat.st_ctime;
+    
     sprintf (path, "%s%s", pathPrefix, FNAME_MAIN_LOCK);
     fd = open (path, O_RDONLY);
     if (fd == -1)
+    {
+        *buf = 0;
         return 0;
+    }
     if (read (fd, buf, 2) == 0)
+    {
+        *buf = 0;
         return 0;
+    }
     close (fd);
     return *buf;
 }
-
-void zebraServerLockMsg (const char *str)
-{
-    int l, r;
-
-    assert (server_lock_fd != -1);
-    lseek (server_lock_fd, 0L, SEEK_SET);
-    l = strlen(str);
-    r = write (server_lock_fd, str, l);
-    if (r != l)
-    {
-        logf (LOG_FATAL|LOG_ERRNO, "write server lock file");
-        exit (1);
-    }
-}
-
-void zebraServerUnlock (void)
-{
-    char pathPrefix[1024];
-    char path[1024];
-    
-    assert (server_lock_fd != -1);
-    zebraLockPrefix (pathPrefix);
-    flock (server_lock_fd, LOCK_UN);
-    sprintf (path, "%szebrasrv.%ld", pathPrefix, (long) getpid());
-    unlink (path);
-}
-
diff --git a/index/main.c b/index/main.c
index 5375e09..f40cd03 100644
--- a/index/main.c
+++ b/index/main.c
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: main.c,v $
- * Revision 1.27  1995-12-07 17:38:47  adam
+ * Revision 1.28  1995-12-08 16:22:56  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.27  1995/12/07  17:38:47  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  * Revision 1.26  1995/12/06  12:41:23  adam
@@ -150,11 +155,11 @@ int main (int argc, char **argv)
     {
         if (ret == 0)
         {
+            const char *rval;
             if(cmd == 0) /* command */
             {
                 if (!common_resource)
                 {
-                    const char *rval;
                     common_resource = res_open (configName ?
                                                 configName : FNAME_CONFIG);
                     if (!common_resource)
@@ -164,16 +169,6 @@ int main (int argc, char **argv)
                         exit (1);
                     }
                     data1_tabpath = res_get (common_resource, "profilePath");
-                    rval = res_get (common_resource, "commitEnable");
-
-                    zebraIndexLock (1);
-                    if (rval && atoi(rval))
-                    {
-                        zebraIndexLockMsg ("r");
-                        bf_cache ();
-                    }
-                    else
-                        zebraIndexLockMsg ("w");
                 }
                 if (!strcmp (arg, "update"))
                     cmd = 'u';
@@ -181,12 +176,41 @@ int main (int argc, char **argv)
                     cmd = 'd';
                 else if (!strcmp (arg, "commit"))
                 {
-                    logf (LOG_LOG, "Commit");
-                    zebraIndexLockMsg ("c");
-                    bf_commit ();
+                    zebraIndexLock (1);
+                    rval = res_get (common_resource, "commitEnable");
+                    if (rval && atoi (rval))
+                        bf_cache (1);
+
+                    if (bf_commitExists ())
+                    {
+                        logf (LOG_LOG, "Commit start");
+                        zebraIndexLockMsg ("c");
+                        zebraIndexWait (1);
+                        logf (LOG_LOG, "Commit execute");
+                        bf_commitExec ();
+                        zebraIndexLockMsg ("d");
+                        zebraIndexWait (0);
+                        logf (LOG_LOG, "Commit clean");
+                        bf_commitClean ();
+                    }
+                    else
+                        logf (LOG_LOG, "Nothing to commit");
                 }
                 else if (!strcmp (arg, "stat") || !strcmp (arg, "status"))
                 {
+                    zebraIndexLock (0);
+                    bf_cache (0);
+                    rec_prstat ();
+                }
+                else if (!strcmp (arg, "cstat") || !strcmp (arg, "cstatus"))
+                {
+                    zebraIndexLock (1);
+                    rval = res_get (common_resource, "commitEnable");
+                    if (rval && atoi(rval))
+                    {
+                        bf_cache (1);
+                        zebraIndexLockMsg ("r");
+                    }
                     rec_prstat ();
                 }
                 else
@@ -199,6 +223,17 @@ int main (int argc, char **argv)
             {
                 struct recordGroup rGroup;
 
+                zebraIndexLock (0);
+                rval = res_get (common_resource, "commitEnable");
+                if (rval && atoi(rval))
+                {
+                    bf_cache (1);
+                    zebraIndexLockMsg ("r");
+                }
+                else
+                    zebraIndexLockMsg ("w");
+                zebraIndexWait (0);
+
                 memcpy (&rGroup, &rGroupDef, sizeof(rGroup));
                 key_open (mem_max);
                 rGroup.path = arg;
@@ -248,7 +283,7 @@ int main (int argc, char **argv)
             exit (1);
         }
     }
-    zebraIndexUnlock (1);
+    zebraIndexUnlock ();
     exit (0);
 }
 
diff --git a/index/zserver.c b/index/zserver.c
index c718b70..9013c55 100644
--- a/index/zserver.c
+++ b/index/zserver.c
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: zserver.c,v $
- * Revision 1.30  1995-12-07 17:38:48  adam
+ * Revision 1.31  1995-12-08 16:22:56  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.30  1995/12/07  17:38:48  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  * Revision 1.29  1995/12/04  14:22:32  adam
@@ -119,9 +124,10 @@
 
 ZServerInfo server_info;
 
-static int register_check (ZServerInfo *zi)
+static int register_lock (ZServerInfo *zi)
 {
-    int state = zebraServerLockGetState();
+    time_t lastChange;
+    int state = zebraServerLockGetState(&lastChange);
 
     switch (state)
     {
@@ -131,26 +137,43 @@ static int register_check (ZServerInfo *zi)
     default:
         state = 0;
     }
+    zebraServerLock (state);
     if (zi->registerState == state)
-        return 0;
-
-    zi->registerState = state;
-    if (server_info.records)
     {
-        dict_close (server_info.wordDict);
-        is_close (server_info.wordIsam);
-        rec_close (&server_info.records);
+        if (zi->registerChange >= lastChange)
+            return 0;
+        logf (LOG_LOG, "Register completely updated since last access");
     }
-    /* enable commit if state is 1 */
-    server_info.records = rec_open (0);
-    if (!(server_info.wordDict = dict_open (FNAME_WORD_DICT, 40, 0)))
+    else if (zi->registerState == -1)
+        logf (LOG_LOG, "Reading register using state %d pid=%ld", state,
+              (long) getpid());
+    else
+        logf (LOG_LOG, "Register has changed state from %d to %d",
+              zi->registerState, state);
+    zi->registerChange = lastChange;
+    if (zi->records)
+    {
+        dict_close (zi->wordDict);
+        is_close (zi->wordIsam);
+        rec_close (&zi->records);
+    }
+    bf_cache (state);
+    zi->registerState = state;
+    zi->records = rec_open (0);
+    if (!(zi->wordDict = dict_open (FNAME_WORD_DICT, 40, 0)))
         return -1;
-    if (!(server_info.wordIsam = is_open (FNAME_WORD_ISAM, key_compare, 0,
-                                          sizeof (struct it_key))))
+    if (!(zi->wordIsam = is_open (FNAME_WORD_ISAM, key_compare, 0,
+                                  sizeof (struct it_key))))
         return -1;
     return 0;
 }
 
+static int register_unlock (ZServerInfo *zi)
+{
+    if (zi->registerState != -1)
+        zebraServerUnlock (zi->registerState);
+}
+
 bend_initresult *bend_init (bend_initrequest *q)
 {
     static bend_initresult r;
@@ -174,34 +197,14 @@ bend_initresult *bend_init (bend_initrequest *q)
             exit (1);
         }
     }
-    zebraServerLock ();
-
     data1_tabpath = res_get(common_resource, "profilePath");
     server_info.sets = NULL;
     server_info.registerState = -1;  /* trigger open of registers! */
-#if 1
+    server_info.registerChange = 0;
+
     server_info.records = NULL;
     server_info.wordDict = NULL;
     server_info.wordIsam = NULL;
-#else
-    server_info.records = rec_open (0);
-    if (!(server_info.wordDict = dict_open (FNAME_WORD_DICT, 40, 0)))
-    {
-        logf (LOG_WARN, "dict_open fail: word dict");
-        r.errcode = 1;
-        r.errstring = "dict_open fail: word dict";
-        return &r;
-    }    
-    if (!(server_info.wordIsam = is_open (FNAME_WORD_ISAM, key_compare, 0,
-                                          sizeof (struct it_key))))
-    {
-        logf (LOG_WARN, "is_open fail: word isam");
-        dict_close (server_info.wordDict);
-        r.errcode = 1;
-        r.errstring = "is_open fail: word isam";
-        return &r;
-    }
-#endif
     server_info.odr = odr_createmem (ODR_ENCODE);
     return &r;
 }
@@ -214,7 +217,7 @@ bend_searchresult *bend_search (void *handle, bend_searchrequest *q, int *fd)
     r.errstring = 0;
     r.hits = 0;
 
-    register_check (&server_info);
+    register_lock (&server_info);
     odr_reset (server_info.odr);
     server_info.errCode = 0;
     server_info.errString = NULL;
@@ -231,6 +234,7 @@ bend_searchresult *bend_search (void *handle, bend_searchrequest *q, int *fd)
     default:
         r.errcode = 107;
     }
+    register_unlock (&server_info);
     return &r;
 }
 
@@ -321,7 +325,7 @@ bend_fetchresult *bend_fetch (void *handle, bend_fetchrequest *q, int *num)
     int positions[2];
     ZServerSetSysno *records;
 
-    register_check (&server_info);
+    register_lock (&server_info);
 
     r.errstring = 0;
     r.last_in_set = 0;
@@ -336,24 +340,28 @@ bend_fetchresult *bend_fetch (void *handle, bend_fetchrequest *q, int *num)
     {
         logf (LOG_DEBUG, "resultSetRecordGet, error");
         r.errcode = 13;
+        register_unlock (&server_info);
         return &r;
     }
     if (!records[0].sysno)
     {
         r.errcode = 13;
         logf (LOG_DEBUG, "Out of range. pos=%d", q->number);
+        register_unlock (&server_info);
         return &r;
     }
     r.errcode = record_fetch (&server_info, records[0].sysno,
                               records[0].score, q->stream, q->format,
                               q->comp, &r.format, &r.record, &r.len);
     resultSetSysnoDel (&server_info, records, 1);
+    register_unlock (&server_info);
     return &r;
 }
 
 bend_deleteresult *bend_delete (void *handle, bend_deleterequest *q, int *num)
 {
-    register_check (&server_info);
+    register_lock (&server_info);
+    register_unlock (&server_info);
     return 0;
 }
 
@@ -362,7 +370,7 @@ bend_scanresult *bend_scan (void *handle, bend_scanrequest *q, int *num)
     static bend_scanresult r;
     int status;
 
-    register_check (&server_info);
+    register_lock (&server_info);
     odr_reset (server_info.odr);
     server_info.errCode = 0;
     server_info.errString = 0;
@@ -375,6 +383,7 @@ bend_scanresult *bend_scan (void *handle, bend_scanrequest *q, int *num)
                           &r.num_entries, &r.entries, &status);
     r.errstring = server_info.errString;
     r.status = status;
+    register_unlock (&server_info);
     return &r;
 }
 
@@ -385,8 +394,8 @@ void bend_close (void *handle)
         dict_close (server_info.wordDict);
         is_close (server_info.wordIsam);
         rec_close (&server_info.records);
+        register_unlock (&server_info);
     }
-    zebraServerUnlock ();
     return;
 }
 
diff --git a/index/zserver.h b/index/zserver.h
index d234356..9ee5afc 100644
--- a/index/zserver.h
+++ b/index/zserver.h
@@ -4,7 +4,12 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: zserver.h,v $
- * Revision 1.16  1995-12-07 17:38:48  adam
+ * Revision 1.17  1995-12-08 16:22:57  adam
+ * Work on update while servers are running. Three lock files introduced.
+ * The servers reload their registers when necessary, but they don't
+ * reestablish result sets yet.
+ *
+ * Revision 1.16  1995/12/07  17:38:48  adam
  * Work locking mechanisms for concurrent updates/commit.
  *
  * Revision 1.15  1995/11/21  15:29:13  adam
@@ -76,6 +81,7 @@ typedef struct ZServerSet_ {
    
 typedef struct {
     int registerState; /* 0 (no commit pages), 1 (use commit pages) */
+    time_t registerChange;
     ZServerSet *sets;
     Dict wordDict;
     ISAM wordIsam;
@@ -101,3 +107,7 @@ ZServerSetSysno *resultSetSysnoGet (ZServerInfo *zi, const char *name,
                                     int num, int *positions);
 void resultSetSysnoDel (ZServerInfo *zi, ZServerSetSysno *records, int num);
 void zlog_rpn (Z_RPNQuery *rpn);
+
+int zebraServerLock (int lockCommit);
+void zebraServerUnlock (int commitPhase);
+int zebraServerLockGetState (time_t *timep);