From: dan <dan@noemail.net>
Date: Thu, 22 Apr 2010 06:27:04 +0000 (+0000)
Subject: Further tests and changes related to switching between WAL and rollback modes.
X-Git-Tag: version-3.7.2~455^2~64
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ede6eb8d1df9c4751ecb656c337e4bb7a9a534e9;p=thirdparty%2Fsqlite.git

Further tests and changes related to switching between WAL and rollback modes.

FossilOrigin-Name: 1236318477787a612f02cc98caf2931bd2e99d94
---

diff --git a/manifest b/manifest
index 8f9be85819..8b101354cd 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Tests\sfor\s(and\schanges\sto)\sthe\scode\sto\sswitch\sbetween\sWAL\sand\srollback\smodes.
-D 2010-04-21T18:37:57
+C Further\stests\sand\schanges\srelated\sto\sswitching\sbetween\sWAL\sand\srollback\smodes.
+D 2010-04-22T06:27:05
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 4f2f967b7e58a35bb74fb7ec8ae90e0f4ca7868b
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -109,7 +109,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c e86634da8c48357a759694c9c7c471125cd8d5a8
 F src/bitvec.c 06ad2c36a9c3819c0b9cbffec7b15f58d5d834e0
 F src/btmutex.c 96a12f50f7a17475155971a241d85ec5171573ff
-F src/btree.c fcfff21fb259fc5f09d8ae65478c3240553f4cd9
+F src/btree.c f87ed73ef82bccb1e5dd63d6a4919272d3354c8a
 F src/btree.h dd83041eda10c17daf023257c1fc883b5f71f85a
 F src/btreeInt.h b0c87f6725b06a0aa194a6d25d54b16ce9d6e291
 F src/build.c 11100b66fb97638d2d874c1d34d8db90650bb1d7
@@ -154,7 +154,7 @@ F src/os_common.h 240c88b163b02c21a9f21f87d49678a0aa21ff30
 F src/os_os2.c 75a8c7b9a00a2cf1a65f9fa4afbc27d46634bb2f
 F src/os_unix.c 5bf0015cebe2f21635da2af983c348eb88b3b4c1
 F src/os_win.c 1c7453c2df4dab26d90ff6f91272aea18bcf7053
-F src/pager.c f20f9090456b2f4aa3c5174e390a3cfd61bd3cc1
+F src/pager.c 06fb9b8b7c5283c62f5258e098d6d1649dde7635
 F src/pager.h cee4487ab4f0911dd9f22a40e3cd55afdb7ef444
 F src/parse.y ace5c7a125d9f2a410e431ee3209034105045f7e
 F src/pcache.c ace8f6a5ecd4711cc66a1b23053be7109bd437cf
@@ -214,7 +214,7 @@ F src/update.c c0dc6b75ad28b76b619042d934f337b02acee208
 F src/utf.c 1baeeac91707a4df97ccc6141ec0f808278af685
 F src/util.c 32aebf04c10e51ad3977a928b7416bed671b620b
 F src/vacuum.c b1d542c8919d4d11119f78069e1906a1ad07e0ee
-F src/vdbe.c 4d99d175264ef5b2ac57b19396f2b78199539e22
+F src/vdbe.c 09e88e8b01b413271b5ccd8c902c424cd563e342
 F src/vdbe.h 471f6a3dcec4817ca33596fe7f6654d56c0e75f3
 F src/vdbeInt.h 19ebc8c2a2e938340051ee65af3f377fb99102d1
 F src/vdbeapi.c 466044df5bc916f778833e927165fd02cdef6086
@@ -761,7 +761,7 @@ F test/vtab_shared.test 0eff9ce4f19facbe0a3e693f6c14b80711a4222d
 F test/wal.test fd0e5914599b205172dae33c765368a75feb2462
 F test/walcrash.test f022cee7eb7baa5fb898726120a6a4073dd831d1
 F test/walhook.test 76a559e262f0715c470bade4a8d8333035f8ee47
-F test/walmode.test 004da14c0d6be8314bba076d2d89c16458b6f849
+F test/walmode.test c2f4e30ad64910b2d8faf6cf4e940b3f201b41df
 F test/walslow.test 38076d5fad49e3678027be0f8110e6a32d531dc2
 F test/walthread.test 27e44ee6fd02f1f494a24f999c97086af3ab739d
 F test/where.test de337a3fe0a459ec7c93db16a519657a90552330
@@ -807,7 +807,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 33cabf271b8f4dda508a610bf59964273fe2cb84
-R ce8d5df20a1a383d4fb608ef1b16a4c8
+P 9f4f933f2c6596064fcfc7fb5add87e8c5b57448
+R cdccc9135123b3edc2fcb17c83fbd857
 U dan
-Z 9951e081ef8379216185ea5ef99b745d
+Z 891f9ffc6892beb06734f78c0f8e5711
diff --git a/manifest.uuid b/manifest.uuid
index 8514b695f3..0aa3e70b8f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9f4f933f2c6596064fcfc7fb5add87e8c5b57448
\ No newline at end of file
+1236318477787a612f02cc98caf2931bd2e99d94
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 71de1ef681..2fd3fedc1e 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -8004,7 +8004,7 @@ int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
   if( rc==SQLITE_OK ){
     u8 *aData = pBt->pPage1->aData;
     if( aData[18]!=(u8)iVersion || aData[19]!=(u8)iVersion ){
-      rc = sqlite3BtreeBeginTrans(pBtree, 1);
+      rc = sqlite3BtreeBeginTrans(pBtree, 2);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
         if( rc==SQLITE_OK ){
diff --git a/src/pager.c b/src/pager.c
index 7e96049d3b..157413e9b0 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -3732,18 +3732,13 @@ static int hasHotJournal(Pager *pPager, int *pExists){
 ** an SQLite error code.
 **
 ** The caller must hold a SHARED lock on the database file to call this
-** function.
+** function. Because an EXCLUSIVE lock on the db file is required to delete 
+** a WAL, this ensures there is no race condition between the xAccess() 
+** below and an xDelete() being executed by some other connection.
 */
 static int pagerHasWAL(Pager *pPager, int *pExists){
   int rc;                         /* Return code */
 
-  /* Check that a SHARED lock is held on the database file. Because an
-  ** EXCLUSIVE lock on the db file is required to delete a WAL, this
-  ** ensures there is no race condition between the xAccess() below and
-  ** an xDelete() being executed by some other connection.
-  */
-  assert( pPager->state>=PAGER_SHARED );
-
   if( !pPager->tempFile ){
     char *zLog = sqlite3_mprintf("%s-wal", pPager->zFilename);
     if( !zLog ){
@@ -5755,12 +5750,29 @@ int sqlite3PagerOpenLog(Pager *pPager, int *pisOpen){
 */
 int sqlite3PagerCloseLog(Pager *pPager){
   int rc = SQLITE_OK;
-  if( pPager->pLog ){
 
-    /* Try to obtain an EXCLUSIVE lock on the database file. */
-    rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_EXCLUSIVE);
+  assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );
 
-    /* If the EXCLUSIVE lock was obtained, checkpoint and close the log. */
+  /* If the log file is not already open, but does exist in the file-system,
+  ** it may need to be checkpointed before the connection can switch to
+  ** rollback mode. Open it now so this can happen.
+  */
+  if( !pPager->pLog ){
+    int logexists = 0;
+    rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_SHARED);
+    if( rc==SQLITE_OK ){
+      rc = pagerHasWAL(pPager, &logexists);
+    }
+    if( rc==SQLITE_OK && logexists ){
+      rc = sqlite3LogOpen(pPager->pVfs, pPager->zFilename, &pPager->pLog);
+    }
+  }
+    
+  /* Checkpoint and close the log. Because an EXCLUSIVE lock is held on
+  ** the database file, the log and log-summary files will be deleted.
+  */
+  if( rc==SQLITE_OK && pPager->pLog ){
+    rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_EXCLUSIVE);
     if( rc==SQLITE_OK ){
       rc = sqlite3LogClose(pPager->pLog, pPager->fd,
         (pPager->noSync ? 0 : pPager->sync_flags), 
diff --git a/src/vdbe.c b/src/vdbe.c
index 5e2316678f..2af5c7384c 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -5244,11 +5244,12 @@ case OP_JournalMode: {
         );
       }else{
   
-        /* If leaving WAL mode, close the log file. If successful, the call to
-        ** PagerCloseLog() checkpoints and deletes the write-ahead-log file.
-        ** An EXCLUSIVE lock is still held on the database file after returning.
-        */
         if( eOld==PAGER_JOURNALMODE_WAL ){
+          /* If leaving WAL mode, close the log file. If successful, the call
+          ** to PagerCloseLog() checkpoints and deletes the write-ahead-log 
+          ** file. An EXCLUSIVE lock may still be held on the database file 
+          ** after a successful return. 
+          */
           rc = sqlite3PagerCloseLog(pPager);
           if( rc!=SQLITE_OK ) goto abort_due_to_error;
           sqlite3PagerJournalMode(pPager, eNew);
diff --git a/test/walmode.test b/test/walmode.test
index 8d3b882f01..91b5b92049 100644
--- a/test/walmode.test
+++ b/test/walmode.test
@@ -72,6 +72,8 @@ do_test walmode-3.2 {
   list $sqlite_sync_count [file exists test.db-wal] [file size test.db-wal]
 } {0 1 0}
 
+# Test that changing back to journal_mode=persist works.
+#
 do_test walmode-4.1 {
   execsql { INSERT INTO t1 VALUES(1, 2) }
   execsql { PRAGMA journal_mode = persist }
@@ -91,5 +93,55 @@ do_test walmode-4.5 {
   list [file exists test.db-journal] [file exists test.db-wal]
 } {1 0}
 
+# Test that nothing goes wrong if a connection is prevented from changing
+# from WAL to rollback mode because a second connection has the database
+# open. Or from rollback to WAL.
+#
+do_test walmode-4.1 {
+  sqlite3 db2 test.db
+  execsql { PRAGMA main.journal_mode } db2
+} {delete}
+do_test walmode-4.2 {
+  execsql { PRAGMA main.journal_mode = wal } db
+} {wal}
+do_test walmode-4.3 {
+  execsql { SELECT * FROM t1 } db2
+} {1 2}
+do_test walmode-4.4 {
+  catchsql { PRAGMA journal_mode = delete } db
+} {1 {database is locked}}
+do_test walmode-4.5 {
+  execsql { PRAGMA main.journal_mode } db
+} {wal}
+do_test walmode-4.6 {
+  db2 close
+  execsql { PRAGMA journal_mode = delete } db
+} {delete}
+do_test walmode-4.7 {
+  execsql { PRAGMA main.journal_mode } db
+} {delete}
+do_test walmode-4.8 {
+  list [file exists test.db-journal] [file exists test.db-wal]
+} {0 0}
+do_test walmode-4.9 {
+  sqlite3 db2 test.db
+  execsql {
+    BEGIN;
+      SELECT * FROM t1;
+  } db2
+} {1 2}
+do_test walmode-4.11 {
+  execsql { PRAGMA main.journal_mode } db
+} {delete}
+do_test walmode-4.10 {
+  catchsql { PRAGMA main.journal_mode = wal } db
+} {1 {database is locked}}
+do_test walmode-4.11 {
+  execsql { PRAGMA main.journal_mode } db
+} {delete}
+
+
+catch { db close }
+catch { db2 close }
 finish_test