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Overview
Comment:Fix a problem wherein changing the journal-mode immediately after leaving exclusive-locking mode could lead to the database being unlocked without clearing the changeCountDone flag.
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SHA1: 531abc808526d607768bf6f503268d4cc66ab169
User & Date: dan 2010-08-07 09:31:14.000
Context
2010-08-07
16:17
Fix minor problems and update comments in pager.c. (check-in: 92e456374b user: dan tags: experimental)
09:31
Fix a problem wherein changing the journal-mode immediately after leaving exclusive-locking mode could lead to the database being unlocked without clearing the changeCountDone flag. (check-in: 531abc8085 user: dan tags: experimental)
05:15
Add test case 'cgt_pager_1', intended for use with callgrind to detect performance regression in the pager module, to threadtest3.c. (check-in: b5d46f1ea0 user: dan tags: experimental)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/pager.c.
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      eMode = eOld;
    }
  }

  if( eMode!=eOld ){

    /* Change the journal mode. */

    pPager->journalMode = (u8)eMode;

    /* When transistioning from TRUNCATE or PERSIST to any other journal
    ** mode except WAL (and we are not in locking_mode=EXCLUSIVE) then 
    ** delete the journal file.
    */
    assert( (PAGER_JOURNALMODE_TRUNCATE & 5)==1 );
    assert( (PAGER_JOURNALMODE_PERSIST & 5)==1 );
    assert( (PAGER_JOURNALMODE_DELETE & 5)==0 );
    assert( (PAGER_JOURNALMODE_MEMORY & 5)==4 );
    assert( (PAGER_JOURNALMODE_OFF & 5)==0 );
    assert( (PAGER_JOURNALMODE_WAL & 5)==5 );

    assert( isOpen(pPager->fd) || pPager->exclusiveMode );
    if( !pPager->exclusiveMode && (eOld & 5)==1 && (eMode & 1)==0 ){

      sqlite3OsClose(pPager->jfd);

      /* In this case we would like to delete the journal file. If it is
      ** not possible, then that is not a problem. Deleting the journal file
      ** here is an optimization only.
      **
      ** Before deleting the journal file, obtain a RESERVED lock on the
      ** database file. This ensures that the journal file is not deleted
      ** while it is in use by some other client.
      */




      int rc = SQLITE_OK;
      int state = pPager->eState;
      if( state==PAGER_OPEN ){
        rc = sqlite3PagerSharedLock(pPager);
      }
      if( pPager->eState==PAGER_READER ){
        assert( rc==SQLITE_OK );
        rc = pagerLockDb(pPager, RESERVED_LOCK);
      }
      if( rc==SQLITE_OK ){
        sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
      if( rc==SQLITE_OK && state==PAGER_READER ){
        pagerUnlockDb(pPager, SHARED_LOCK);
      }else if( state==PAGER_OPEN ){
        pager_unlock(pPager);
      }
      assert( state==pPager->eState );

    }
  }

  /* Return the new journal mode */
  return (int)pPager->journalMode;
}









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      eMode = eOld;
    }
  }

  if( eMode!=eOld ){

    /* Change the journal mode. */
    assert( pPager->eState!=PAGER_ERROR );
    pPager->journalMode = (u8)eMode;

    /* When transistioning from TRUNCATE or PERSIST to any other journal
    ** mode except WAL, unless the pager is in locking_mode=exclusive mode,
    ** delete the journal file.
    */
    assert( (PAGER_JOURNALMODE_TRUNCATE & 5)==1 );
    assert( (PAGER_JOURNALMODE_PERSIST & 5)==1 );
    assert( (PAGER_JOURNALMODE_DELETE & 5)==0 );
    assert( (PAGER_JOURNALMODE_MEMORY & 5)==4 );
    assert( (PAGER_JOURNALMODE_OFF & 5)==0 );
    assert( (PAGER_JOURNALMODE_WAL & 5)==5 );

    assert( isOpen(pPager->fd) || pPager->exclusiveMode );
    if( !pPager->exclusiveMode && (eOld & 5)==1 && (eMode & 1)==0 ){



      /* In this case we would like to delete the journal file. If it is
      ** not possible, then that is not a problem. Deleting the journal file
      ** here is an optimization only.
      **
      ** Before deleting the journal file, obtain a RESERVED lock on the
      ** database file. This ensures that the journal file is not deleted
      ** while it is in use by some other client.
      */
      sqlite3OsClose(pPager->jfd);
      if( pPager->eLock>=RESERVED_LOCK ){
        sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }else{
        int rc = SQLITE_OK;
        int state = pPager->eState;
        if( state==PAGER_OPEN ){
          rc = sqlite3PagerSharedLock(pPager);
        }
        if( pPager->eState==PAGER_READER ){
          assert( rc==SQLITE_OK );
          rc = pagerLockDb(pPager, RESERVED_LOCK);
        }
        if( rc==SQLITE_OK ){
          sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
        }
        if( rc==SQLITE_OK && state==PAGER_READER ){
          pagerUnlockDb(pPager, SHARED_LOCK);
        }else if( state==PAGER_OPEN ){
          pager_unlock(pPager);
        }
        assert( state==pPager->eState );
      }
    }
  }

  /* Return the new journal mode */
  return (int)pPager->journalMode;
}
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Changes to test/jrnlmode.test.
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      PRAGMA page_size = 1024;
      PRAGMA user_version = 5;
      PRAGMA user_version;
    }
  } {memory 5}
  do_test jrnlmode-7.2 { file size test.db } {1024}
}
































finish_test








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      PRAGMA page_size = 1024;
      PRAGMA user_version = 5;
      PRAGMA user_version;
    }
  } {memory 5}
  do_test jrnlmode-7.2 { file size test.db } {1024}
}

do_execsql_test jrnlmode-8.1  { PRAGMA locking_mode=EXCLUSIVE } {exclusive}
do_execsql_test jrnlmode-8.2  { CREATE TABLE t1(x) }            {}
do_execsql_test jrnlmode-8.3  { INSERT INTO t1 VALUES(123) }    {}
do_execsql_test jrnlmode-8.4  { SELECT * FROM t1 }              {123}
do_execsql_test jrnlmode-8.5  { PRAGMA journal_mode=PERSIST }   {persist}
do_execsql_test jrnlmode-8.6  { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.7  { PRAGMA journal_mode=TRUNCATE }  {truncate}
do_execsql_test jrnlmode-8.8  { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.9  { CREATE TABLE t2(y) }            {}
do_execsql_test jrnlmode-8.10 { INSERT INTO t2 VALUES(456) }    {}
do_execsql_test jrnlmode-8.11 { SELECT * FROM t1, t2 }          {123 456}
do_execsql_test jrnlmode-8.12 { PRAGMA locking_mode=NORMAL }    {normal}
do_execsql_test jrnlmode-8.13 { PRAGMA journal_mode=PERSIST }   {persist}
do_execsql_test jrnlmode-8.14 { PRAGMA journal_mode=TRUNCATE }  {truncate}
do_execsql_test jrnlmode-8.15 { PRAGMA journal_mode=PERSIST }   {persist}
do_execsql_test jrnlmode-8.16 { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.17 { PRAGMA journal_mode=TRUNCATE }  {truncate}
do_execsql_test jrnlmode-8.18 { PRAGMA locking_mode=EXCLUSIVE } {exclusive}
do_execsql_test jrnlmode-8.19 { CREATE TABLE t3(z) }            {}
do_execsql_test jrnlmode-8.20 { BEGIN IMMEDIATE }               {}
do_execsql_test jrnlmode-8.21 { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.22 { COMMIT }                        {}
do_execsql_test jrnlmode-8.23 { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.24 { PRAGMA journal_mode=TRUNCATE }  {truncate}
do_execsql_test jrnlmode-8.25 { PRAGMA locking_mode=NORMAL }    {normal}
do_execsql_test jrnlmode-8.26 { CREATE TABLE t4(w) }            {}
do_execsql_test jrnlmode-8.27 { BEGIN IMMEDIATE }               {}
do_execsql_test jrnlmode-8.28 { PRAGMA journal_mode=DELETE }    {delete}
do_execsql_test jrnlmode-8.29 { COMMIT }                        {}
do_execsql_test jrnlmode-8.30 { PRAGMA journal_mode=DELETE }    {delete}

finish_test