SQLite

/*
** If we compile with the SQLITE_TEST macro set, then the following block
** of code will give us the ability to simulate a disk I/O error.  This
** is used for testing the I/O recovery logic.
*/
#ifdef SQLITE_TEST
int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
int sqlite3_io_error_benign = 0;         /* True if errors are benign */
int sqlite3_diskfull_pending = 0;
int sqlite3_diskfull = 0;
#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
#define SimulateIOError(CODE)  \
  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
       || sqlite3_io_error_pending-- == 1 )  \

              { local_ioerr(); CODE; }
static void local_ioerr(){
  IOTRACE(("IOERR\n"));
  sqlite3_io_error_hit++;
  if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;
}
#define SimulateDiskfullError(CODE) \
   if( sqlite3_diskfull_pending ){ \
     if( sqlite3_diskfull_pending == 1 ){ \
       local_ioerr(); \
       sqlite3_diskfull = 1; \
       sqlite3_io_error_hit = 1; \
       CODE; \
     }else{ \
       sqlite3_diskfull_pending--; \
     } \
   }
#else
#define SimulateIOErrorBenign(X)
#define SimulateIOError(A)
#define SimulateDiskfullError(A)
#endif

/*
** When testing, keep a count of the number of open files.
*/

** the requested locking level, this routine is a no-op.
*/
static int unixUnlock(sqlite3_file *id, int locktype){
  struct lockInfo *pLock;
  struct flock lock;
  int rc = SQLITE_OK;
  unixFile *pFile = (unixFile*)id;
  int h;

  assert( pFile );
  OSTRACE7("UNLOCK  %d %d was %d(%d,%d) pid=%d\n", pFile->h, locktype,
      pFile->locktype, pFile->pLock->locktype, pFile->pLock->cnt, getpid());

  assert( locktype<=SHARED_LOCK );
  if( pFile->locktype<=locktype ){
    return SQLITE_OK;
  }
  if( CHECK_THREADID(pFile) ){
    return SQLITE_MISUSE;
  }
  enterMutex();
  h = pFile->h;
  pLock = pFile->pLock;
  assert( pLock->cnt!=0 );
  if( pFile->locktype>SHARED_LOCK ){
    assert( pLock->locktype==pFile->locktype );
    SimulateIOErrorBenign(1);
    SimulateIOError( h=(-1) )
    SimulateIOErrorBenign(0);
    if( locktype==SHARED_LOCK ){
      lock.l_type = F_RDLCK;
      lock.l_whence = SEEK_SET;
      lock.l_start = SHARED_FIRST;
      lock.l_len = SHARED_SIZE;
      if( fcntl(h, F_SETLK, &lock)==(-1) ){

        rc = SQLITE_IOERR_RDLOCK;
      }
    }
    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = PENDING_BYTE;
    lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );
    if( fcntl(h, F_SETLK, &lock)!=(-1) ){
      pLock->locktype = SHARED_LOCK;
    }else{
      rc = SQLITE_IOERR_UNLOCK;
    }
  }
  if( locktype==NO_LOCK ){
    struct openCnt *pOpen;

    /* Decrement the shared lock counter.  Release the lock using an
    ** OS call only when all threads in this same process have released
    ** the lock.
    */
    pLock->cnt--;
    if( pLock->cnt==0 ){
      lock.l_type = F_UNLCK;
      lock.l_whence = SEEK_SET;
      lock.l_start = lock.l_len = 0L;
      SimulateIOErrorBenign(1);
      SimulateIOError( h=(-1) )
      SimulateIOErrorBenign(0);
      if( fcntl(h, F_SETLK, &lock)!=(-1) ){
        pLock->locktype = NO_LOCK;
      }else{
        rc = SQLITE_IOERR_UNLOCK;
        pLock->cnt = 1;
      }
    }

    /* Decrement the count of locks against this same file.  When the
    ** count reaches zero, close any other file descriptors whose close
    ** was deferred because of outstanding locks.
    */
    if( rc==SQLITE_OK ){
      pOpen = pFile->pOpen;
      pOpen->nLock--;
      assert( pOpen->nLock>=0 );
      if( pOpen->nLock==0 && pOpen->nPending>0 ){
        int i;
        for(i=0; i<pOpen->nPending; i++){
          close(pOpen->aPending[i]);
        }
        free(pOpen->aPending);
        pOpen->nPending = 0;
        pOpen->aPending = 0;
      }
    }
  }
  leaveMutex();
  if( rc==SQLITE_OK ) pFile->locktype = locktype;
  return rc;
}

/*
** Close a file.
*/
static int unixClose(sqlite3_file *id){

#pragma mark AFP Support

/*
 ** The afpLockingContext structure contains all afp lock specific state
 */
typedef struct afpLockingContext afpLockingContext;
struct afpLockingContext {
  unsigned long long sharedLockByte;
  char *filePath;
};

struct ByteRangeLockPB2
{
  unsigned long long offset;        /* offset to first byte to lock */
  unsigned long long length;        /* nbr of bytes to lock */
  unsigned long long retRangeStart; /* nbr of 1st byte locked if successful */

  unixFile *pFile = (unixFile*)id;

  if( !pFile ) return SQLITE_OK;
  afpUnixUnlock(id, NO_LOCK);
  sqlite3_free(pFile->lockingContext);
  if( pFile->dirfd>=0 ) close(pFile->dirfd);
  pFile->dirfd = -1;
  enterMutex();
  close(pFile->h);
  leaveMutex();
  OSTRACE2("CLOSE   %-3d\n", pFile->h);
  OpenCounter(-1);
  memset(pFile, 0, sizeof(unixFile));
  return SQLITE_OK;
}

  unixFile *pFile = (unixFile*)id;
  
  if( !pFile ) return SQLITE_OK;
  flockUnixUnlock(id, NO_LOCK);
  
  if( pFile->dirfd>=0 ) close(pFile->dirfd);
  pFile->dirfd = -1;

  enterMutex();
  close(pFile->h);  
  leaveMutex();
  OSTRACE2("CLOSE   %-3d\n", pFile->h);
  OpenCounter(-1);
  memset(pFile, 0, sizeof(unixFile));
  return SQLITE_OK;
}

#pragma mark Old-School .lock file based locking

  unixFile *pFile = (unixFile*)id;
  
  if( !pFile ) return SQLITE_OK;
  dotlockUnixUnlock(id, NO_LOCK);
  sqlite3_free(pFile->lockingContext);
  if( pFile->dirfd>=0 ) close(pFile->dirfd);
  pFile->dirfd = -1;
  enterMutex();  
  close(pFile->h);
  leaveMutex();
  OSTRACE2("CLOSE   %-3d\n", pFile->h);
  OpenCounter(-1);
  memset(pFile, 0, sizeof(unixFile));
  return SQLITE_OK;
}

*/
static int nolockUnixClose(sqlite3_file *id) {
  unixFile *pFile = (unixFile*)id;
  
  if( !pFile ) return SQLITE_OK;
  if( pFile->dirfd>=0 ) close(pFile->dirfd);
  pFile->dirfd = -1;
  enterMutex();
  close(pFile->h);
  leaveMutex();
  OSTRACE2("CLOSE   %-3d\n", pFile->h);
  OpenCounter(-1);
  memset(pFile, 0, sizeof(unixFile));
  return SQLITE_OK;
}

#endif /* SQLITE_ENABLE_LOCKING_STYLE */

** 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 1.413 2008/03/07 19:51:14 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*

** an open journal-file, then the next time a shared-lock is obtained
** on the pager file (by this or any other process), it will be
** treated as a hot-journal and rolled back.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    if( !MEMDB ){

      int rc = osUnlock(pPager->fd, NO_LOCK);

      if( rc ) pager_error(pPager, rc);
      pPager->dbSize = -1;
      IOTRACE(("UNLOCK %p\n", pPager))

      /* If Pager.errCode is set, the contents of the pager cache cannot be
      ** trusted. Now that the pager file is unlocked, the contents of the
      ** cache can be discarded and the error code safely cleared.
      */
      if( pPager->errCode ){
        if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
        pager_reset(pPager);
        if( pPager->stmtOpen ){
          sqlite3OsClose(pPager->stfd);
          sqlite3BitvecDestroy(pPager->pInStmt);
          pPager->pInStmt = 0;
        }
        if( pPager->journalOpen ){

              rc = SQLITE_BUSY;
              sqlite3OsClose(pPager->jfd);
            }
          }
        }
        if( rc!=SQLITE_OK ){
          pager_unlock(pPager);
          switch( rc ){
            case SQLITE_NOMEM:
            case SQLITE_IOERR_UNLOCK:
            case SQLITE_IOERR_NOMEM:
              return rc;
            default:
              return SQLITE_BUSY;
          }
        }
        pPager->journalOpen = 1;
        pPager->journalStarted = 0;
        pPager->journalOff = 0;
        pPager->setMaster = 0;
        pPager->journalHdr = 0;
 

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the pager.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test2.c,v 1.54 2008/03/07 19:51:14 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

/*

/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest2_Init(Tcl_Interp *interp){
  extern int sqlite3_io_error_persist;
  extern int sqlite3_io_error_pending;
  extern int sqlite3_io_error_hit;
  extern int sqlite3_io_error_hardhit;
  extern int sqlite3_diskfull_pending;
  extern int sqlite3_diskfull;
  extern int sqlite3_pager_n_sort_bucket;
  static struct {
    char *zName;
    Tcl_CmdProc *xProc;
  } aCmd[] = {

  }
  Tcl_LinkVar(interp, "sqlite_io_error_pending",
     (char*)&sqlite3_io_error_pending, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_io_error_persist",
     (char*)&sqlite3_io_error_persist, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_io_error_hit",
     (char*)&sqlite3_io_error_hit, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_io_error_hardhit",
     (char*)&sqlite3_io_error_hardhit, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_diskfull_pending",
     (char*)&sqlite3_diskfull_pending, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_diskfull",
     (char*)&sqlite3_diskfull, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_pending_byte",
     (char*)&sqlite3_pending_byte, TCL_LINK_INT);
  Tcl_LinkVar(interp, "pager_pagesize",
     (char*)&test_pagesize, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_pager_n_sort_bucket",
     (char*)&sqlite3_pager_n_sort_bucket, TCL_LINK_INT);
  return TCL_OK;
}

# This file implements regression tests for SQLite library.  The
# focus of this file is testing for correct handling of I/O errors
# such as writes failing because the disk is full.
# 
# The tests in this file use special facilities that are only
# available in the SQLite test fixture.
#
# $Id: ioerr2.test,v 1.7 2008/03/07 19:51:15 drh Exp $

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

ifcapable !integrityck {
  finish_test
  return

  set ::sqlite_io_error_pending 0

  # Run an integrity-check. If "disk I/O error" is returned, the
  # pager must be in error state. In this case open a new database
  # connection. Otherwise, try a ROLLBACK, in case a transaction 
  # is still active.
  set rc [catch {execsql {PRAGMA integrity_check}} msg]
  if {$rc && ($msg eq "disk I/O error" || $msg eq "database is locked")} {
    db close
    sqlite3 db test.db
    set refcnt 0
  } else {
    if {$rc || $msg ne "ok"} {
      error $msg
    }

# 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 some common TCL routines used for regression
# testing the SQLite library
#
# $Id: tester.tcl,v 1.106 2008/03/07 19:51:15 drh Exp $


set tcl_precision 15
set sqlite_pending_byte 0x0010000

# 
# Check the command-line arguments for a default soft-heap-limit.

      append ::ioerrorbody "db eval {$::ioerropts(-sqlbody)}"
    }

    # Execute the TCL Script created in the above block. If
    # there are at least N IO operations performed by SQLite as
    # a result of the script, the Nth will fail.
    do_test $testname.$n.3 {
      set ::sqlite_io_error_hit 0
      set ::sqlite_io_error_hardhit 0
      set r [catch $::ioerrorbody msg]
      set ::errseen $r
      set rc [sqlite3_errcode $::DB]
      if {$::ioerropts(-erc)} {
        # If we are in extended result code mode, make sure all of the
        # IOERRs we get back really do have their extended code values.
        # If an extended result code is returned, the sqlite3_errcode
        # TCLcommand will return a string of the form:  SQLITE_IOERR+nnnn
        # where nnnn is a number

        set q 0
        set ::sqlite_io_error_pending 0
      } else {
        set q 1
      }

      set s [expr $::sqlite_io_error_hit==0]
      if {$::sqlite_io_error_hit>$::sqlite_io_error_hardhit && $r==0} {
        set r 1
      }
      set ::sqlite_io_error_hit 0

      # One of two things must have happened. either
      #   1.  We never hit the IO error and the SQL returned OK
      #   2.  An IO error was hit and the SQL failed
      #
      expr { ($s && !$r && !$q) || (!$s && $r && $q) }
    } {1}

    # If an IO error occured, then the checksum of the database should
    # be the same as before the script that caused the IO error was run.
    if {$::go && $::sqlite_io_error_hardhit && $::ioerropts(-cksum)} {
      do_test $testname.$n.4 {
        catch {db close}
        set ::DB [sqlite3 db test.db; sqlite3_connection_pointer db]
        cksum
      } $checksum
    }

    set ::sqlite_io_error_hardhit 0
    set ::sqlite_io_error_pending 0
    if {[info exists ::ioerropts(-cleanup)]} {
      catch $::ioerropts(-cleanup)
    }
  }
  set ::sqlite_io_error_pending 0
  set ::sqlite_io_error_persist 0