Changeset 24757 for main/trunk/greenstone2/runtime-src/src

Timestamp:

2011-10-13T21:20:36+13:00 (13 years ago)

Author:

ak19

Message:

Corrections to code to prevent server crash when swapping indexers from MG to another 2 thereafter: mgsearch needs to be set to NULL when the collection server is deleted (which indirectly deletes the mgsearch object), since other parts of the code test against mgsearch being null. The same is done for mgppsearch lucenesearch objects.

File:

• main/trunk/greenstone2/runtime-src/src/colservr/collectset.cpp (modified) (3 diffs)

main/trunk/greenstone2/runtime-src/src/colservr/collectset.cpp

@@ -507 +507 @@
     ++here;
   }
+  // since all collection server objects are deleted (which deleted their source objects 
+  // which in turn deleted their search objects), we now NULL the local reference to the
+  // search objects. See the extensive comment for this in remove_collection(text_t).
+#ifdef ENABLE_MG
+      if (mgsearch != NULL) {
+        mgsearch = NULL;
+      }
+#endif 
+#ifdef ENABLE_MGPP
+      if (mgppsearch != NULL) {
+        mgppsearch = NULL;
+      }
+#endif 
+#ifdef ENABLE_LUCENE
+      if (lucenesearch != NULL) {
+        lucenesearch = NULL;
+      }
+#endif 
+
   cservers.clear();
 }
@@ -583 +602 @@
     if ((*here).second.c != NULL && (*here).first == collection) {
       delete (*here).second.c;
-      cservers.erase (here);
+
+      // The above code deletes the collection server object for this collection, which then
+      // deletes the <indexer>source object, which then deletes the <indexer>search object.
+      // Since we have a reference to the <index>search object here, we have to set it to NULL
+      // at this point, because we test it against null-ness elsewhere in this code. (Without
+      // setting it to NULL, we end up with server crashing issues.)
+      // Ideally, we'd like to know that we are NULLing the pointer to the exact same object
+      // as was freed above, but we can't know that without complicated object access to make
+      // the necessary pointer comparison. Fortunately, this class maintains only one type of 
+      // <index>search object (of a/any kind) at any time, so we can NULL this confidently now.
+#ifdef ENABLE_MG
+      if (mgsearch != NULL) {
+        mgsearch = NULL;
+      }
+#endif 
+#ifdef ENABLE_MGPP
+      if (mgppsearch != NULL) {
+        mgppsearch = NULL;
+      }
+#endif 
+#ifdef ENABLE_LUCENE
+      if (lucenesearch != NULL) {
+        lucenesearch = NULL;
+      }
+#endif 
+
+       // continue cleaning up the collection server
+       cservers.erase (here);
+
       return;
-    }
+    } // end if
     ++here;
   }
@@ -600 +647 @@
 
   outconvertclass text_t2ascii;
-  logout << text_t2ascii << "collectset::remove_collection: failed to remove collectserver for "
+  logout << text_t2ascii << "collectset::remove_collection: Removed collectserver for "
      << collection << "\n";
 }