bk commit into 4.1 tree (stewart:1.2313) BUG#9826

[Stewart Smith]

Below is the list of changes that have just been committed into a local
4.1 repository of stewart. When stewart does a push these changes will
be propagated to the main repository and, within 24 hours after the
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ChangeSet
  1.2313 05/06/04 18:14:34 stewart@stripped +2 -0
  BUG#10948 NDB Replication: Race condition with ALTER/DROP table
  BUG#9826  Server crash on schema change ("drop table", "alter table") with NDB
  
  See note on 10948 for detailed explanation.
  
  struct a { void* a; long long b[1]; };
  
  on PPC32 (and 32bit pa risc): 16
  on x86: 12
  
  so a malloc(sizeof(void*)+extra_bits) is wrong.
  
  Assuming that the long long is 64 bit aligned as non-aligned 64bit accesses
  are rather expensive on ppc.
  
  Thanks to paulus for doing the PPC port of valgrind.
  Without which I would no doubt still be trying to find this.

  ndb/src/ndbapi/DictCache.hpp
    1.7 05/06/04 18:14:28 stewart@stripped +1 -1
    Add warning about having to be the last member in the structure

  ndb/src/ndbapi/DictCache.cpp
    1.12 05/06/04 18:14:28 stewart@stripped +2 -1
    Fix allocation size for Ndb_local_table_info for architectures such as PPC and PA-RISC
(32bit)
    where
    struct a { void* a; long long b;};
    is 64 bit aligned (i.e. sizeof(struct a)==16)

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	stewart
# Host:	kennedy.(none)
# Root:	/home/stewart/Documents/MySQL/4.1/bug10948

--- 1.11/ndb/src/ndbapi/DictCache.cpp	2005-03-23 08:12:07 +11:00
+++ 1.12/ndb/src/ndbapi/DictCache.cpp	2005-06-04 18:14:28 +10:00
@@ -24,7 +24,8 @@
 Ndb_local_table_info *
 Ndb_local_table_info::create(NdbTableImpl *table_impl, Uint32 sz)
 {
-  Uint32 tot_size= sizeof(NdbTableImpl *) + ((sz+7)>>3)<<3; // round to
Uint64
+  Uint32 tot_size= sizeof(Ndb_local_table_info) - sizeof(Uint64)
+    + ((sz+7) & ~7); // round to Uint64
   void *data= malloc(tot_size);
   if (data == 0)
     return 0;

--- 1.6/ndb/src/ndbapi/DictCache.hpp	2004-12-20 22:36:03 +11:00
+++ 1.7/ndb/src/ndbapi/DictCache.hpp	2005-06-04 18:14:28 +10:00
@@ -33,7 +33,7 @@
   static Ndb_local_table_info *create(NdbTableImpl *table_impl, Uint32 sz=0);
   static void destroy(Ndb_local_table_info *);
   NdbTableImpl *m_table_impl;
-  Uint64 m_local_data[1];
+  Uint64 m_local_data[1]; // Must be last member. Used to access extra space.
 private:
   Ndb_local_table_info(NdbTableImpl *table_impl);
   ~Ndb_local_table_info();