Adjust the page recycling algorithm so that the number of pages allocated

to each connection does not exceed its cache_size limit. (CVS 5701)

FossilOrigin-Name: 3bc221b940565133ae8d95f59b3b120e57df0124

diff --git a/manifest b/manifest
index cea9f2af6a3e0063d5ae2c1d6e8911ed612b3737..9dc8ade5b30f87243fa64ecef391755dd56ac6aa 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sthe\sasync.test\stest\sscript\sso\sthat\sit\sinvokes\s(finish_test)\seven\sif\sthe\sasynchronous\sbackend\sis\snot\sincluded\sin\sthe\sbuild\s(and\sno\stests\sare\srun).\s(CVS\s5700)
-D 2008-09-15T14:47:21
+C Adjust\sthe\spage\srecycling\salgorithm\sso\sthat\sthe\snumber\sof\spages\sallocated\nto\seach\sconnection\sdoes\snot\sexceed\sits\scache_size\slimit.\s(CVS\s5701)
+D 2008-09-15T15:36:58
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in d15a7ebfe5e057a72a49805ffb302dbb601c8329
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -140,7 +140,7 @@ F src/os_win.c 3209dc0ed734291764393ea8d534ba0d8696a540
 F src/pager.c b1ea487022bf91ffba58fc4c02518398290ac2c2
 F src/pager.h c45380ca9d0933ea5bc4ecb3a43958b6d2ec5a9c
 F src/parse.y d0f76d2cb8d6883d5600dc20beb961a6022b94b8
-F src/pcache.c ff79cb5eb797d0f1a244b4332c2d39cb5cfd066b
+F src/pcache.c d3c0f4ad708929fba15886914b18b82d64e286bf
 F src/pcache.h 53730c33310cdf7a5c94e8333c853d59a3b30226
 F src/pragma.c 9d00ed41b261968757c02707e1508a707f2d46a7
 F src/prepare.c c7e00ed1b0bdcf699b1aad651247d4dc3d281b0b
@@ -452,6 +452,7 @@ F test/pager3.test 2323bf27fd5bd887b580247e5bce500ceee994b4
 F test/pageropt.test 3ee6578891baaca967f0bd349e4abfa736229e1a
 F test/pagesize.test 0d9ff3fedfce6e5ffe8fa7aca9b6d3433a2e843b
 F test/pcache.test 515b4c26e9f57660357dfff5b6b697acac1abc5f
+F test/pcache2.test 2b4fa1bee5cfc338d8c04eb6ed7eaf41f478bf7c
 F test/permutations.test 41832b86c152c140bcdf75a35a7c82badd8912b9
 F test/pragma.test 4461cb1004084b907dd28f9d517af7bcf8f5b35f
 F test/pragma2.test 5364893491b9231dd170e3459bfc2e2342658b47
@@ -635,7 +636,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 38e5ea070a38fe1656e0f5c3024f28ce67eae725
-R 4f6ae6e9e52ddaefcd8ded4941fd5732
-U danielk1977
-Z b072615d26c8fe7520e777696085a2bf
+P 5c954b40ecb71203b1013c23cdac54ff83484b0a
+R dc88c00a1c805cb4941b70045df2df2e
+U drh
+Z c3d0d50b48385323dd5a9627ae00e19c

diff --git a/manifest.uuid b/manifest.uuid
index 9527e2272771ca3bade9f93f158fb92365a0cd8e..4807c86650dbe7f16405d1630d4c78866703513e 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5c954b40ecb71203b1013c23cdac54ff83484b0a
\ No newline at end of file
+3bc221b940565133ae8d95f59b3b120e57df0124
\ No newline at end of file

diff --git a/src/pcache.c b/src/pcache.c
index ece7571651be54ae57b84092904225cfa8bdef5e..2b90bd7e357a5a671505e9ab6c3a32941998694a 100644 (file)
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file implements that page cache.
 **
-** @(#) $Id: pcache.c,v 1.26 2008/09/02 09:38:07 danielk1977 Exp $
+** @(#) $Id: pcache.c,v 1.27 2008/09/15 15:36:58 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -555,15 +555,16 @@ static int pcacheRecycleOrAlloc(PCache *pCache, PgHdr **ppPage){
 
   *ppPage = 0;
 
-  /* If we have reached the limit for pinned/dirty pages, and there is at
-  ** least one dirty page, invoke the xStress callback to cause a page to
-  ** become clean.
+  /* If we have reached either the global or the local limit for 
+  ** pinned+dirty pages, and there is at least one dirty page,
+  ** invoke the xStress callback to cause a page to become clean.
   */
   expensive_assert( pCache->nPinned==pcachePinnedCount(pCache) );
   expensive_assert( pcacheCheckSynced(pCache) );
   if( pCache->xStress
    && pCache->pDirty
-   && pCache->nPinned>=(pcache_g.nMaxPage+pCache->nMin-pcache_g.nMinPage)
+   && (pCache->nPinned>=(pcache_g.nMaxPage+pCache->nMin-pcache_g.nMinPage)
+           || pCache->nPinned>=pCache->nMax)
   ){
     PgHdr *pPg;
     assert(pCache->pDirtyTail);
@@ -586,8 +587,11 @@ static int pcacheRecycleOrAlloc(PCache *pCache, PgHdr **ppPage){
     }
   }
 
-  /* If the global page limit has been reached, try to recycle a page. */
-  if( pCache->bPurgeable && pcache_g.nCurrentPage>=pcache_g.nMaxPage ){
+  /* If either the local or the global page limit has been reached, 
+  ** try to recycle a page. 
+  */
+  if( pCache->bPurgeable && (pCache->nPage>=pCache->nMax-1 ||
+                             pcache_g.nCurrentPage>=pcache_g.nMaxPage) ){
     p = pcacheRecyclePage();
   }
 
@@ -1267,4 +1271,3 @@ void sqlite3PcacheStats(
   *pnRecyclable = nRecyclable;
 }
 #endif
-

diff --git a/test/pcache2.test b/test/pcache2.test
new file mode 100644 (file)
index 0000000..be4bb54
--- /dev/null
+++ b/test/pcache2.test
@@ -0,0 +1,70 @@
+# 2008 September 15
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file is focused on testing the pcache module.
+#
+# $Id: pcache2.test,v 1.1 2008/09/15 15:36:58 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+
+# Set up a pcache memory pool so that we can easily track how many
+# pages are being used for cache.
+#
+do_test pcache2-1.1 {
+  db close
+  sqlite3_shutdown
+  sqlite3_config_pagecache 6000 100
+  sqlite3_initialize
+  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 1
+  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0
+} {0 0 0}
+
+# Open up two database connections to separate files.
+#
+do_test pcache2-1.2 {
+  file delete -force test.db test.db-journal
+  sqlite3 db test.db
+  db eval {PRAGMA cache_size=10}
+  lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 1
+} {2}
+do_test pcache2-1.3 {
+  file delete -force test2.db test2.db-journal
+  sqlite3 db2 test2.db
+  db2 eval {PRAGMA cache_size=50}
+  lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 1
+} {4}
+
+# Make lots of changes on the first connection.  Verify that the
+# page cache usage does not grow to consume the page space set aside
+# for the second connection.
+#
+do_test pcache2-1.4 {
+  db eval {
+     CREATE TABLE t1(a,b);
+     CREATE TABLE t2(x,y);
+     INSERT INTO t1 VALUES(1, zeroblob(800));
+     INSERT INTO t1 VALUES(2, zeroblob(800));
+     INSERT INTO t2 SELECT * FROM t1;
+     INSERT INTO t1 SELECT x+2, y FROM t2;
+     INSERT INTO t2 SELECT a+10, b FROM t1;
+     INSERT INTO t1 SELECT x+10, y FROM t2;
+     INSERT INTO t2 SELECT a+100, b FROM t1;
+     INSERT INTO t1 SELECT x+100, y FROM t2;
+     INSERT INTO t2 SELECT a+1000, b FROM t1;
+     INSERT INTO t1 SELECT x+1000, y FROM t2;
+  }
+  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0
+} {0 13 13}
+
+catch {db2 close}
+finish_test