Github/emacs
2
0
Fork 1
mirror of git://git.sv.gnu.org/emacs.git synced 2026-02-17 01:34:21 +00:00
Code Issues Projects Releases Packages Wiki Activity

Fix problems identified by dl in review <https://info.ravenbrook.com/mail/2014/06/05/14-49-13/0/>.

Browse source 
Copied from Perforce
 Change: 186445
 ServerID: perforce.ravenbrook.com
This commit is contained in:
Gareth Rees 2014-06-08 17:45:44 +01:00
parent 299bfb2992
commit 220e23a758
3 changed files with 17 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
mps/code/tract.c
View file

@ -7,6 +7,17 @@
* free but never allocated as alloc starts searching after the tables.
* TractOfAddr uses the fact that these pages are marked as free in order
* to detect "references" to these pages as being bogus.
*
* .chunk.at.base: The chunks are stored in a balanced binary tree.
* Looking up an address in this tree is on the critical path, and
* therefore vital that it runs quickly. It is an implementation
* detail of chunks that they are always stored at the base of the
* region of address space they represent. Thus chunk happens to
* always be the same as chunk->base. We take advantage of this in the
* tree search by using chunk as its own key (instead of looking up
* chunk->base): this saves a dereference and perhaps a cache miss.
* See ChunkKey and ChunkCompare for this optimization. The necessary
* property is asserted in ChunkCheck.
*/
#include "tract.h"
@ -117,7 +128,7 @@ Bool ChunkCheck(Chunk chunk)
CHECKL(chunk->base != (Addr)0);
CHECKL(chunk->base < chunk->limit);
/* .chunk.at.base: check chunk structure is at its own base */
/* check chunk structure is at its own base: see .chunk.at.base. */
CHECKL(chunk->base == (Addr)chunk);
CHECKL((Addr)(chunk+1) <= chunk->limit);
CHECKL(ChunkSizeToPages(chunk, ChunkSize(chunk)) == chunk->pages);
@ -276,6 +287,7 @@ Compare ChunkCompare(Tree tree, TreeKey key)
AVERT_CRITICAL(Tree, tree);
AVER_CRITICAL(tree != TreeEMPTY);
/* See .chunk.at.base. */
chunk = ChunkOfTree(tree);
AVERT_CRITICAL(Chunk, chunk);

6
mps/code/tree.c
View file

@ -85,9 +85,9 @@ Compare TreeFind(Tree *treeReturn, Tree root, TreeKey key, TreeCompare compare)
Tree node, parent;
Compare cmp = CompareEQUAL;
AVERT(Tree, root);
AVER(treeReturn != NULL);
AVER(FUNCHECK(compare));
AVERT_CRITICAL(Tree, root);
AVER_CRITICAL(treeReturn != NULL);
AVER_CRITICAL(FUNCHECK(compare));
/* key is arbitrary */
parent = NULL;

2
mps/code/tree.h
View file

@ -138,7 +138,7 @@ extern void TreeBalance(Tree *treeIO);
*
* root is an lvalue storing a pointer to the root of the tree. It is
* evaluated twice.
* treeref and nextref are variable of type Tree*.
* treeref and nextref are variables of type Tree*.
* tree and next are variables of type Tree.
*
* In the body of the loop, tree and next are the current and next