SQLite

      if( rc!=SQLITE_OK ) return rc;
    }
  }

  return SQLITE_OK;
}

/* #define TRACE_WRITECACHE */

/*
** Write the cache of pFile to disk. If crash is non-zero, randomly
** skip blocks when writing. The cache is deleted before returning.
*/
static int writeCache2(OsTestFile *pFile, int crash){
  int i;

    if( p ){
      int skip = 0;
      int trash = 0;
      if( crash ){
        char random;
        sqlite3Randomness(1, &random);
        if( random & 0x01 ){
          if( random & 0x02 ){
            trash = 1;
#ifdef TRACE_WRITECACHE
printf("Trashing block %d of %s\n", i, pFile->zName); 
#endif
          }else{
            skip = 1;
#ifdef TRACE_WRITECACHE

*/
static int writeCache(OsTestFile *pFile){
  if( pFile->apBlk ){
    int c = crashRequired(pFile->zName);
    if( c ){
      OsTestFile *p;
#ifdef TRACE_WRITECACHE
      printf("\nCrash during sync of %s\n", pFile->zName);
#endif
      for(p=pAllFiles; p; p=p->pNext){
        writeCache2(p, 1);
      }
      exit(-1);
    }else{
      return writeCache2(pFile, 0);

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.139 2004/06/25 06:23:23 danielk1977 Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

          /* If in full-sync mode, write a new journal header into the
	  ** journal file. This is done to avoid ever modifying a journal
	  ** header that is involved in the rollback of pages that have
	  ** already been written to the database (in case the header is
	  ** trashed when the nRec field is updated).
          */
          pPager->nRec = 0;
          assert( pPager->journalOff > 0 );
          rc = writeJournalHdr(pPager);
          if( rc!=0 ){
            sqlite3pager_rollback(pPager);
            return SQLITE_IOERR;
          }
        }
        pPg = pPager->pFirst;

# 2001 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 implements regression tests for SQLite library.
#
# $Id: crash.test,v 1.4 2004/06/25 06:23:23 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

set repeats 100
# set repeats 10

# This proc execs a seperate process that crashes midway through executing
# the SQL script $sql on database test.db.
#
# The crash occurs during a sync() of file $crashfile. When the crash
# occurs a random subset of all unsynced writes made by the process are
# written into the files on disk. Argument $crashdelay indicates the
# number of file syncs to wait before crashing.
#
# The return value is a list of two elements. The first element is a
# boolean, indicating whether or not the process actually crashed or
# reported some other error. The second element in the returned list is the
# error message. This is "child process exited abnormally" if the crash
# occured.
proc crashsql {crashdelay crashfile sql} {
  set cfile [file join [pwd] $crashfile]

  set f [open crash.tcl w]
  puts $f "sqlite3_crashparams $crashdelay $cfile"
  puts $f "sqlite3 db test.db"
  puts $f "db eval {pragma synchronous = full}"
  puts $f "db eval {pragma cache_size = 10}"
  puts $f "db eval {"
  puts $f   "$sql"
  puts $f "}"
  close $f

  set r [catch {
    exec [file join . crashtest] crash.tcl >@stdout
  } msg]
  lappend r $msg
}

# The following procedure computes a "signature" for table "abc".  If
# abc changes in any way, the signature should change.  
proc signature {} {
  return [db eval {SELECT count(*), md5sum(a), md5sum(b), md5sum(c) FROM abc}]
}
proc signature2 {} {
  return [db eval {SELECT count(*), md5sum(a), md5sum(b), md5sum(c) FROM abc2}]
}






#--------------------------------------------------------------------------
# Simple crash test:
#
# crash-1.1: Create a database with a table with two rows.
# crash-1.2: Run a 'DELETE FROM abc WHERE a = 1' that crashes during
#            the first journal-sync.
# crash-1.3: Ensure the database is in the same state as after crash-1.1.
# crash-1.4: Run a 'DELETE FROM abc WHERE a = 1' that crashes during
#            the first database-sync.
# crash-1.5: Ensure the database is in the same state as after crash-1.1.
# crash-1.6: Run a 'DELETE FROM abc WHERE a = 1' that crashes during
#            the second journal-sync.
# crash-1.7: Ensure the database is in the same state as after crash-1.1.
#
# Tests 1.8 through 1.11 test for crashes on the third journal sync and
# second database sync.  Neither of these is required in such a small test
# case, so these tests are just to verify that the test infrastructure
# operates as expected.
#
do_test crash-1.1 {
  execsql {
    CREATE TABLE abc(a, b, c);
    INSERT INTO abc VALUES(1, 2, 3);
    INSERT INTO abc VALUES(4, 5, 6);
  }
  set ::sig [signature]
  expr 0
} {0}
do_test crash-1.2 {
  crashsql 1 test.db-journal {
    DELETE FROM abc WHERE a = 1;
  }
} {1 {child process exited abnormally}}



do_test crash-1.3 {
  signature
} $::sig
do_test crash-1.4 {
  crashsql 1 test.db {
    DELETE FROM abc WHERE a = 1;
  }
} {1 {child process exited abnormally}}
do_test crash-1.5 {
  signature
} $::sig
do_test crash-1.6 {
  crashsql 2 test.db-journal {
    DELETE FROM abc WHERE a = 1;
  }
} {1 {child process exited abnormally}}
do_test crash-1.7 {
  catchsql {
    SELECT * FROM abc;
  }
} {0 {1 2 3 4 5 6}}

do_test crash-1.8 {
  crashsql 3 test.db-journal {
    DELETE FROM abc WHERE a = 1;
  }
} {0 {}}
do_test crash-1.9 {
  catchsql {
    SELECT * FROM abc;
  }
} {0 {4 5 6}}
do_test crash-1.10 {
  crashsql 2 test.db {
    DELETE FROM abc WHERE a = 4;
  }
} {0 {}}
do_test crash-1.11 {
  catchsql {
    SELECT * FROM abc;
  }
} {0 {}}

#--------------------------------------------------------------------------
# The following tests test recovery when both the database file and the the

# crash-4.3.*: Test recovery when crash occurs during sync() of the master
#              journal file. 
#
do_test crash-4.0 {
  file delete -force test2.db
  file delete -force test2.db-journal
  sqlite3 db2 test2.db
  execsql {
    pragma default_cache_size = 10;
    pragma default_synchronous = full;
  } db2
  db2 close
  execsql {
    ATTACH 'test2.db' AS aux;
    CREATE TABLE aux.abc2 AS SELECT 2*a as a, 2*b as b, 2*c as c FROM abc;
  }
  expr [file size test2.db] / 1024
} {559}

    signature
  } $sig
  do_test crash-4.3.$i.3 {
    signature2
  } $sig2
}