Modifications to malloc5.test to account for the fact that sqlite3_release_memory() no longer reclaims dirty pages. (CVS 5625)

FossilOrigin-Name: b01c65b065c62e3dd71e88866a953668b5e2f25f

manifest

@@ -1,5 +1,5 @@
-C Clear\sthe\s$result\svariable\sprior\sto\susing\sit\sin\scorrupt2.test.\s(CVS\s5624)
+C Modifications\sto\smalloc5.test\sto\saccount\sfor\sthe\sfact\sthat\ssqlite3_release_memory()\sno\slonger\sreclaims\sdirty\spages.\s(CVS\s5625)
-D 2008-08-27T16:14:21
+D 2008-08-27T16:38:57
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 689e14735f862a5553bceef206d8c13e29504e44
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -137,7 +137,7 @@ F src/os_win.c aefe9ee26430678a19a058a874e4e2bd91398142
 F src/pager.c a38742815a6b2238d0b91d1dd64bda50d6ee95fc
 F src/pager.h 914103bb62dbcc3d8e9f14baec812d027264d457
 F src/parse.y d0f76d2cb8d6883d5600dc20beb961a6022b94b8
-F src/pcache.c 94050f68015c883813e39cd222b21d7728ad1203
+F src/pcache.c 3d9d933bb22f10956ab78d83798d88ca9a147e86
 F src/pcache.h 7a50b77f06c220ff7696be1a9f2a17c9e6ddc486
 F src/pragma.c f5b271b090af7fcedd308d7c5807a5503f7a853d
 F src/prepare.c c197041e0c4770672cda75e6bfe10242f885e510
@@ -401,7 +401,7 @@ F test/main.test 8d77c161757ef7d96eaff0413daa7120c3b316fe
 F test/malloc.test 69f5bb5a13b24edb1322fc1f42894f9d2f6446b1
 F test/malloc3.test 094f8195fe8e409bd4da0f1d769f7745faec62c8
 F test/malloc4.test 957337613002b7058a85116493a262f679f3a261
-F test/malloc5.test 8b18857f37c1c409b914789934aeb1346b778b3a
+F test/malloc5.test c8d0f7673337e8a29afa558735ae937a0d629751
 F test/malloc6.test 2f039d9821927eacae43e1831f815e157659a151
 F test/malloc7.test 7c68a32942858bc715284856c5507446bba88c3a
 F test/malloc8.test 9b7a3f8cb9cf0b12fff566e80a980b1767bd961d
@@ -623,7 +623,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P d4438251dd66c4168e09eb421a8c2081228357dd
+P 12f2d24f88e55d170dd7750e7904ff14e84e820e
-R c758c0690635db76a5c5bb3d1f9c5535
+R b53ac5363faaa116cc8b7dfcfecb5950
-U drh
+U danielk1977
-Z c69b32c45298adb6ff9560d2f547e841
+Z c5747597064276f7a0eeb73c949573eb

manifest.uuid

@@ -1 +1 @@
-12f2d24f88e55d170dd7750e7904ff14e84e820e
+b01c65b065c62e3dd71e88866a953668b5e2f25f

src/pcache.c

@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file implements that page cache.
 **
-** @(#) $Id: pcache.c,v 1.17 2008/08/27 15:16:34 danielk1977 Exp $
+** @(#) $Id: pcache.c,v 1.18 2008/08/27 16:38:57 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -553,7 +553,7 @@ static int pcacheRecycleOrAlloc(PCache *pCache, PgHdr **ppPage){
   }
 
   /* If the global page limit has been reached, try to recycle a page. */
-  if( pcache.nCurrentPage>=pcache.nMaxPage ){
+  if( pCache->bPurgeable && pcache.nCurrentPage>=pcache.nMaxPage ){
     p = pcacheRecyclePage();
   }
 
@@ -620,7 +620,7 @@ void sqlite3PcacheOpen(
   p->xStress = xStress;
   p->pStress = pStress;
   p->nMax = 100;
-  p->nMin = 20;
+  p->nMin = 10;
 
   pcacheEnterGlobal();
   if( bPurgeable ){

test/malloc5.test

@@ -12,13 +12,13 @@
 # This file contains test cases focused on the two memory-management APIs, 
 # sqlite3_soft_heap_limit() and sqlite3_release_memory().
 #
-# $Id: malloc5.test,v 1.19 2008/08/21 15:54:01 danielk1977 Exp $
+# Prior to version 3.6.2, calling sqlite3_release_memory() or exceeding
-
+# the configured soft heap limit could cause sqlite to upgrade database 
-#---------------------------------------------------------------------------
+# locks and flush dirty pages to the file system. As of 3.6.2, this is
-# NOTES ON EXPECTED BEHAVIOUR
+# no longer the case. In version 3.6.2, sqlite3_release_memory() only
+# reclaims clean pages. This test file has been updated accordingly.
 #
-#---------------------------------------------------------------------------
+# $Id: malloc5.test,v 1.20 2008/08/27 16:38:57 danielk1977 Exp $
-
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -44,35 +44,38 @@ sqlite3 db test.db
 
 do_test malloc5-1.1 {
   # Simplest possible test. Call sqlite3_release_memory when there is exactly
-  # one unused page in a single pager cache. This test case set's the 
+  # one unused page in a single pager cache. The page cannot be freed, as
-  # value of the ::pgalloc variable, which is used in subsequent tests.
+  # it is dirty. So sqlite3_release_memory() returns 0.
   #
-  # Note: Even though executing this statement on an empty database 
-  # modifies 2 pages (the root of sqlite_master and the new root page), 
-  # the sqlite_master root (page 1) is never freed because the btree layer
-  # retains a reference to it for the entire transaction. 
   execsql {
     PRAGMA auto_vacuum=OFF;
     BEGIN;
     CREATE TABLE abc(a, b, c);
   }
+  sqlite3_release_memory
+} {0}
+
+do_test malloc5-1.2 {
+  # Test that the transaction started in the above test is still active.
+  # The lock on the database file should not have been upgraded (this was
+  # not the case before version 3.6.2).
+  #
+  sqlite3 db2 test.db
+  execsql { SELECT * FROM sqlite_master } db2
+} {}
+do_test malloc5-1.3 {
+  # Call [sqlite3_release_memory] when there is exactly one unused page 
+  # in the cache belonging to db2.
+  #
   set ::pgalloc [sqlite3_release_memory]
   expr $::pgalloc > 0
 } {1}
-do_test malloc5-1.2 {
+
-  # Test that the transaction started in the above test is still active.
+do_test malloc5-1.4 {
-  # Because the page freed had been written to, freeing it required a
+  # Commit the transaction and open a new one. Read 1 page into the cache.
-  # journal sync and exclusive lock on the database file. Test the file
+  # Because the page is not dirty, it is eligible for collection even
-  # appears to be locked.
+  # before the transaction is concluded.
-  sqlite3 db2 test.db
+  #
-  catchsql {
-    SELECT * FROM abc;
-  } db2
-} {1 {database is locked}}
-do_test malloc5-1.3 {
-  # Again call [sqlite3_release_memory] when there is exactly one unused page 
-  # in the cache. The same amount of memory is required, but no journal-sync
-  # or exclusive lock should be established.
   execsql {
     COMMIT;
     BEGIN;
@@ -80,43 +83,44 @@ do_test malloc5-1.3 {
   }
   sqlite3_release_memory
 } $::pgalloc
-do_test malloc5-1.4 {
+
-  # Database should not be locked this time.
-  catchsql {
-    SELECT * FROM abc;
-  } db2
-} {0 {}}
 do_test malloc5-1.5 {
+  # Conclude the transaction opened in the previous [do_test] block. This
+  # causes another page (page 1) to become eligible for recycling.
+  #
+  execsql { COMMIT }
+  sqlite3_release_memory
+} $::pgalloc
+
+do_test malloc5-1.6 {
   # Manipulate the cache so that it contains two unused pages. One requires 
   # a journal-sync to free, the other does not.
   db2 close
   execsql {
+    BEGIN;
     SELECT * FROM abc;
     CREATE TABLE def(d, e, f);
   }
   sqlite3_release_memory 500
 } $::pgalloc
-do_test malloc5-1.6 {
+
-  # Database should not be locked this time. The above test case only
-  # requested 500 bytes of memory, which can be obtained by freeing the page
-  # that does not require an fsync().
-  sqlite3 db2 test.db
-  catchsql {
-    SELECT * FROM abc;
-  } db2
-} {0 {}}
 do_test malloc5-1.7 {
-  # Release another 500 bytes of memory. This time we require a sync(), 
+  # Database should not be locked this time. 
-  # so the database file will be locked afterwards.
+  sqlite3 db2 test.db
+  catchsql { SELECT * FROM abc } db2
+} {0 {}}
+do_test malloc5-1.8 {
+  # Try to release another block of memory. This will fail as the only
+  # pages currently in the cache are dirty (page 3) or pinned (page 1).
   db2 close
   sqlite3_release_memory 500
-} $::pgalloc
+} 0
 do_test malloc5-1.8 {
+  # Database is still not locked.
+  #
   sqlite3 db2 test.db
-  catchsql {
+  catchsql { SELECT * FROM abc } db2
-    SELECT * FROM abc;
+} {0 {}}
-  } db2
-} {1 {database is locked}}
 do_test malloc5-1.9 {
   execsql {
     COMMIT;
@@ -138,6 +142,7 @@ do_test malloc5-2.2 {
   # Halfway through the query call sqlite3_release_memory(). The goal of this
   # test is to make sure we don't free pages that are in use (specifically, 
   # the root of table abc).
+  sqlite3_release_memory
   set nRelease 0
   execsql { 
     BEGIN;
@@ -200,45 +205,28 @@ do_test malloc5-4.1 {
     execsql "INSERT INTO abc VALUES($i, $i, '[string repeat X 100]');"
   }
   execsql {COMMIT;}
+  sqlite3_release_memory
+  sqlite3_memory_highwater 1
+  execsql {SELECT * FROM abc}
   set nMaxBytes [sqlite3_memory_highwater 1]
   puts -nonewline " (Highwater mark: $nMaxBytes) "
   expr $nMaxBytes > 1000000
 } {1}
 do_test malloc5-4.2 {
   sqlite3_release_memory
-  sqlite3_soft_heap_limit 110000
+  sqlite3_soft_heap_limit 100000
   sqlite3_memory_highwater 1
-  execsql {BEGIN;}
+  execsql {SELECT * FROM abc}
-  for {set i 0} {$i < 10000} {incr i} {
-    execsql "INSERT INTO abc VALUES($i, $i, '[string repeat X 100]');"
-  }
-  execsql {COMMIT;}
   set nMaxBytes [sqlite3_memory_highwater 1]
   puts -nonewline " (Highwater mark: $nMaxBytes) "
-
+  expr $nMaxBytes <= 100000
-  # We used to test ($nMaxBytes<100000), because the soft-heap-limit is
-  # 100000 bytes. But if an allocation that will exceed the 
-  # soft-heap-limit is requested from within the only pager instance in 
-  # the system, then there is no way to free memory and the limit has to 
-  # be exceeded. An exception is memory allocated to store actual page
-  # data (the code contains a special case for this).
-  #
-  # This is not a problem because all allocations apart from those
-  # used to store cached page data are both small and transient.
-  #
-  # Summary: the actual high-water mark for memory usage may be slightly 
-  # higher than the soft-heap-limit. The specific allocations that cause
-  # the problem are the calls to sqlite3_malloc() inserted into selected
-  # sqlite3OsXXX() functions in test builds.
-  #
-  expr $nMaxBytes <= 110100
 } {1}
 do_test malloc5-4.3 {
   # Check that the content of table abc is at least roughly as expected.
   execsql {
     SELECT count(*), sum(a), sum(b) FROM abc;
   }
-} [list 20000 [expr int(20000.0 * 4999.5)] [expr int(20000.0 * 4999.5)]]
+} [list 10000 [expr int(10000.0 * 4999.5)] [expr int(10000.0 * 4999.5)]]
 
 # Restore the soft heap limit.
 sqlite3_soft_heap_limit $::soft_limit
@@ -326,6 +314,7 @@ do_test malloc5-6.1.2 {
 } {10 10}
 
 do_test malloc5-6.2.1 {
+breakpoint
   execsql {SELECT * FROM abc} db2
   execsql {SELECT * FROM abc} db
   expr [nPage db] + [nPage db2]
@@ -382,16 +371,17 @@ do_test malloc5-6.3.4 {
 } {0 3}
 do_test malloc5-6.3.5 {
   # But if we are really insistent, SQLite will consent to call sync()
-  # if there is no other option.
+  # if there is no other option. UPDATE: As of 3.6.2, SQLite will not
+  # call sync() in this scenario. So no further memory can be reclaimed.
   sqlite3_release_memory 1000
   list [nPage db] [nPage db2]
-} {0 2}
+} {0 3}
 do_test malloc5-6.3.6 {
   # The referenced page (page 1 of the db2 cache) will not be freed no
   # matter how much memory we ask for:
   sqlite3_release_memory 31459
   list [nPage db] [nPage db2]
-} {0 1}
+} {0 3}
 
 db2 close