Simplify lock manager data structures by making a clear separation between

the data defining the semantics of a lock method (ie, conflict resolution
table and ancillary data, which is all constant) and the hash tables
storing the current state.  The only thing we give up by this is the
ability to use separate hashtables for different lock methods, but there
is no need for that anyway.  Put some extra fields into the LockMethod
definition structs to clean up some other uglinesses, like hard-wired
tests for DEFAULT_LOCKMETHOD and USER_LOCKMETHOD.  This commit doesn't
do anything about the performance issues we were discussing, but it clears
away some of the underbrush that's in the way of fixing that.

1 files changed, 9 insertions, 24 deletions

diff --git a/src/tools/backend/index.html b/src/tools/backend/index.html
index af255f912fe..db531744653 100644
--- a/src/tools/backend/index.html
+++ b/src/tools/backend/index.html
@@ -128,31 +128,16 @@ Block</a> - data/index buffer cache block</li>
 addresses using table name and block number( <a
 href="../../include/storage/buf_internals.h">BufferTag</a>)</li>
 
-<li>MultiLevelLockTable (ctl) - control structure for each locking
-method. Currently, only multi-level locking is used(<a
-href="../../include/storage/lock.h">LOCKMETHODCTL</a>).</li>
-
-<li>MultiLevelLockTable (lock hash) - the <a
+<li>Lock Manager Tables (lock hash) - the <a
 href="../../include/storage/lock.h">LOCK</a> structure, looked up
-using relation, database object ids(<a
-href="../../include/storage/lock.h">LOCKTAG)</a>. The lock table
-structure contains the lock modes(read/write or shared/exclusive)
-and circular linked list of backends (<a
-href="../../include/storage/proc.h">PROC</a> structure pointers)
-waiting on the lock.</li>
-
-<li>MultiLevelLockTable (xid hash) - lookup of LOCK structure
-address using transaction id, LOCK address. It is used to quickly
-check if the current transaction already has any locks on a table,
-rather than having to search through all the held locks. It also
-stores the modes (read/write) of the locks held by the current
-transaction. The returned <a
-href="../../include/storage/lock.h">XIDLookupEnt</a> structure also
-contains a pointer to the backend's PROC.lockQueue.</li>
-
-<li><a href="../../include/storage/proc.h">Proc Header</a> -
-information about each backend, including locks held/waiting,
-indexed by process id</li>
+using a <a href="../../include/storage/lock.h">LOCKTAG</a>.
+A LOCK structure exists for each lockable object that is currently
+locked by any backend.  Also, there is a subsidiary <a
+href="../../include/storage/lock.h">PROCLOCK</a> structure for each
+backend currently interested in a given LOCK</li>
+
+<li><a href="../../include/storage/proc.h">PGPROC Structures</a> -
+information about each backend, including locks held/waiting</li>
 </ul>
 
 <p>Each data structure is created by calling <a