SQLite

** 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 1.291 2007/03/19 13:53:38 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

static void pager_reset(Pager *pPager){
  PgHdr *pPg, *pNext;
  if( pPager->errCode ) return;
  for(pPg=pPager->pAll; pPg; pPg=pNext){
    pNext = pPg->pNextAll;
    sqliteFree(pPg);
  }
  pPager->pStmt = 0;
  pPager->pFirst = 0;
  pPager->pFirstSynced = 0;
  pPager->pLast = 0;
  pPager->pAll = 0;
  pPager->nHash = 0;
  sqliteFree(pPager->aHash);
  pPager->nPage = 0;

#
#***********************************************************************
#
# The focus of the tests in this file are IO errors that occur in a shared
# cache context. What happens to connection B if one connection A encounters
# an IO-error whilst reading or writing the file-system?
#
# $Id: shared_err.test,v 1.10 2007/03/19 13:53:38 danielk1977 Exp $

proc skip {args} {}


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

ifcapable !shared_cache||!subquery {
  finish_test
  return
}
set ::enable_shared_cache [sqlite3_enable_shared_cache 1]


# Todo: This is a copy of the [do_malloc_test] proc in malloc.test
# It would be better if these were consolidated.

# Usage: do_malloc_test <test number> <options...>
#
# The first argument, <test number>, is an integer used to name the

  execsql {
    BEGIN;
    INSERT INTO t1 VALUES('201.201.201.201.201', NULL);
    UPDATE t1 SET a = '202.202.202.202.202' WHERE a LIKE '201%';
    COMMIT;
  }
} -cleanup {
  set ::steprc  [sqlite3_step $::STMT]
  set ::column  [sqlite3_column_text $::STMT 0]
  set ::finalrc [sqlite3_finalize $::STMT]

  # There are three possible outcomes here (assuming persistent IO errors):
  #
  # 1. If the [sqlite3_step] did not require any IO (required pages in
  #    the cache), then the next row ("002...") may be retrieved 
  #    successfully.
  #
  # 2. If the [sqlite3_step] does require IO, then [sqlite3_step] returns
  #    SQLITE_ERROR and [sqlite3_finalize] returns IOERR.
  #
  # 3. If, after the initial IO error, SQLite tried to rollback the
  #    active transaction and a second IO error was encountered, then
  #    statement $::STMT will have been aborted. This means [sqlite3_stmt]
  #    returns SQLITE_ABORT, and the statement cursor does not move. i.e.
  #    [sqlite3_column] still returns the current row ("001...") and
  #    [sqlite3_finalize] returns SQLITE_OK.
  #

  do_test shared_ioerr-3.$n.cleanup.1 {
    expr {
      $::steprc eq "SQLITE_ROW" || 
      $::steprc eq "SQLITE_ERROR" ||
      $::steprc eq "SQLITE_ABORT" 
    }
  } {1}
  do_test shared_ioerr-3.$n.cleanup.2 {
    expr {
      ($::steprc eq "SQLITE_ROW" && $::column eq "002.002.002.002.002") ||
      ($::steprc eq "SQLITE_ERROR" && $::column eq "") ||
      ($::steprc eq "SQLITE_ABORT" && $::column eq "001.001.001.001.001") 
    }
  } {1}
  do_test shared_ioerr-3.$n.cleanup.3 {
    expr {
      ($::steprc eq "SQLITE_ROW" && $::finalrc eq "SQLITE_OK") ||
      ($::steprc eq "SQLITE_ERROR" && $::finalrc eq "SQLITE_IOERR") ||
      ($::steprc eq "SQLITE_ABORT" && $::finalrc eq "SQLITE_OK")
    }
  } {1}

# db2 eval {select * from sqlite_master}
  db2 close
}

# Only run these tests if memory debugging is turned on.
#
if {[info command sqlite_malloc_stat]==""} {