Avoid a race condition in the sqlite3_release_memory() logic within pager.c.

FossilOrigin-Name: a718e6634795a48b5dd5c08833ab561e6381a62d

diff --git a/manifest b/manifest
index 1c62facc6915eed5188dc285dd3995cd458a4456..ef8711913d10d205cda5ea6692af39505c902ce5 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Remove\sall\scache\spages\sfrom\sthe\sLRU\slist\sprior\sto\sremoving\sthe\spager\sfrom\sthe\npager\slist\swhen\sclosing\sa\spager.
-D 2010-01-30T19:00:55
+C Avoid\sa\srace\scondition\sin\sthe\ssqlite3_release_memory()\slogic\swithin\spager.c.
+D 2010-01-30T19:17:07
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in 79aeba12300a54903f1b1257c1e7c190234045dd
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -124,7 +124,7 @@ F src/os_common.h e8b748b2f2ecc8a498e50bfe5d8721f189c19d2a
 F src/os_os2.c 0c3a5802bc4fdb7cb5f66771552b081c4e48a216
 F src/os_unix.c a810e2aefdaddacf479407f76f8f4ca381d231b2
 F src/os_win.c 3a60bddd07ea6f8adb2314dd5996ac97b988f403
-F src/pager.c ce1e53959413c5e41b9242c3b28800a2bcb1e2ae
+F src/pager.c 3b7e5e4e250deac18b1a0a9ef651debc0690d6ae
 F src/pager.h 4f051fd856de6fd3c19aef5f82eace54122b9173
 F src/parse.y fc4bd35c6088901f7c8daead26c6fb11c87d22e7
 F src/pragma.c 2e4bb2e76e48a32750529fdc4bfe86ac5f54e01b
@@ -637,14 +637,14 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P c50e972f1bea2e357f64ffd5df868bf51d942e2d
-R 36f835414aa04d98dddf953ed614b296
+P 9d13acc4493ee8be9e6cbf887cd7876d6239b952
+R 25875cbaa3332e847212b49923ec3929
 U drh
-Z fffc5f9ba8ca83294c88a45d2f860720
+Z 2718af45d2ca11e075da3a339f4d03bc
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.6 (GNU/Linux)
 
-iD8DBQFLZIHqoxKgR168RlERArFRAJoD8+F7K7rddFbpXj9QxFnE7UaDXwCeINqB
-ifiO8Ws6773K464iIx4YI3I=
-=byhl
+iD8DBQFLZIW2oxKgR168RlERApuGAKCA4g/+5TbRsKOnLtfTD7whFywjuQCcDhRS
+xtMVTORcy2iXShF+utiz32I=
+=WeIu
 -----END PGP SIGNATURE-----

diff --git a/manifest.uuid b/manifest.uuid
index b8e10715b1c47c515c50519da2d5329a5aa28297..0f9415df4a1f86f97c36905ee523ddc4ab1074dc 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9d13acc4493ee8be9e6cbf887cd7876d6239b952
\ No newline at end of file
+a718e6634795a48b5dd5c08833ab561e6381a62d
\ No newline at end of file

diff --git a/src/pager.c b/src/pager.c
index ede0aa155687917a5390c8b04a725d4a511735d0..9b0177fadc79eed4ae370ba079078b1f9e80c48a 100644 (file)
--- a/src/pager.c
+++ b/src/pager.c
@@ -3294,7 +3294,6 @@ int sqlite3PagerReleaseMemory(int nReq){
 
   while( rc==SQLITE_OK && (nReq<0 || nReleased<nReq) ){
     PgHdr *pPg;
-    PgHdr *pRecycled;
  
     /* Try to find a page to recycle that does not require a sync(). If
     ** this is not possible, find one that does require a sync().
@@ -3319,14 +3318,10 @@ int sqlite3PagerReleaseMemory(int nReq){
     if( !pPg ) break;
 
     pPager = pPg->pPager;
-    assert(!pPg->needSync || pPg==pPager->lru.pFirst);
-    assert(pPg->needSync || pPg==pPager->lru.pFirstSynced);
-  
     savedBusy = pPager->pBusyHandler;
     pPager->pBusyHandler = 0;
-    rc = pager_recycle(pPager, &pRecycled);
+    rc = pager_recycle(pPager, &pPg);
     pPager->pBusyHandler = savedBusy;
-    assert(pRecycled==pPg || rc!=SQLITE_OK);
     if( rc==SQLITE_OK ){
       /* We've found a page to free. At this point the page has been 
       ** removed from the page hash-table, free-list and synced-list