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Overview
Comment:Update the anti-virus retry logic for DeleteFile(). Invoke sqlite3_log() for each anti-virus retry. Make the retry delay configurable at compile-time.
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SHA1: 89f1848d7f7d98b4f7da9218f99ed90d22dd43a8
User & Date: drh 2011-07-12 11:04:18
Original Comment: Update the anti-virus retry logic for DeleteFile(). Invoke sqlite3_log() for each anti-virus retry. Make the retry delay configurable at compile-time.
Context
2011-07-12
13:51
Improvements to the logging that occurs on an antivirus I/O retry. check-in: ff0ff75c user: drh tags: av-defense
11:04
Update the anti-virus retry logic for DeleteFile(). Invoke sqlite3_log() for each anti-virus retry. Make the retry delay configurable at compile-time. check-in: 89f1848d user: drh tags: av-defense
2011-07-11
23:45
Update the TCL commands for setting windows manditory locks. Add test cases for manditory lock delays under windows. check-in: 03af4c17 user: drh tags: trunk
Changes
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Changes to src/os_win.c.

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      iLine, iErrno, zFunc, zPath, zMsg
  );

  return errcode;
}

/*
** The number of times that a ReadFile() or WriteFile() will be retried
** following a locking error.


*/
#ifndef SQLITE_WIN32_IOERR_RETRY
# define SQLITE_WIN32_IOERR_RETRY 5



#endif

/*
** If a ReadFile() or WriteFile() error occurs, invoke this routine
** to see if it should be retried.  Return TRUE to retry.  Return FALSE
** to give up with an error.
*/
................................................................................
static int retryIoerr(int *pnRetry){
  DWORD e;
  if( *pnRetry>=SQLITE_WIN32_IOERR_RETRY ){
    return 0;
  }
  e = GetLastError();
  if( e==ERROR_LOCK_VIOLATION || e==ERROR_SHARING_VIOLATION ){
    Sleep(50 + 50*(*pnRetry));



    ++*pnRetry;
    return 1;
  }
  return 0;
}

#if SQLITE_OS_WINCE
................................................................................
** will open a journal file shortly after it is created in order to do
** whatever it does.  While this other process is holding the
** file open, we will be unable to delete it.  To work around this
** problem, we delay 100 milliseconds and try to delete again.  Up
** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
** up and returning an error.
*/
#define MX_DELETION_ATTEMPTS 5
static int winDelete(
  sqlite3_vfs *pVfs,          /* Not used on win32 */
  const char *zFilename,      /* Name of file to delete */
  int syncDir                 /* Not used on win32 */
){
  int cnt = 0;
  DWORD rc;
  DWORD error = 0;
  void *zConverted;
  UNUSED_PARAMETER(pVfs);
  UNUSED_PARAMETER(syncDir);

  SimulateIOError(return SQLITE_IOERR_DELETE);
  zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  if( isNT() ){
    do{
      DeleteFileW(zConverted);
    }while(   (   ((rc = GetFileAttributesW(zConverted)) != INVALID_FILE_ATTRIBUTES)
               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
           && (++cnt < MX_DELETION_ATTEMPTS)
           && (Sleep(100), 1) );
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    do{
      DeleteFileA(zConverted);
    }while(   (   ((rc = GetFileAttributesA(zConverted)) != INVALID_FILE_ATTRIBUTES)
               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
           && (++cnt < MX_DELETION_ATTEMPTS)
           && (Sleep(100), 1) );
#endif
  }

  free(zConverted);
  OSTRACE(("DELETE \"%s\" %s\n", zFilename,
       ( (rc==INVALID_FILE_ATTRIBUTES) && (error==ERROR_FILE_NOT_FOUND)) ?
         "ok" : "failed" ));
 
  return (   (rc == INVALID_FILE_ATTRIBUTES) 
          && (error == ERROR_FILE_NOT_FOUND)) ? SQLITE_OK :
                 winLogError(SQLITE_IOERR_DELETE, "winDelete", zFilename);

}

/*
** Check the existance and status of a file.
*/
static int winAccess(
  sqlite3_vfs *pVfs,         /* Not used on win32 */







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      iLine, iErrno, zFunc, zPath, zMsg
  );

  return errcode;
}

/*
** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
** will be retried following a locking error - probably caused by 
** antivirus software.  Also the initial delay before the first retry.
** The delay increases linearly with each retry.
*/
#ifndef SQLITE_WIN32_IOERR_RETRY
# define SQLITE_WIN32_IOERR_RETRY 10
#endif
#ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
# define SQLITE_WIN32_IOERR_RETRY_DELAY 25
#endif

/*
** If a ReadFile() or WriteFile() error occurs, invoke this routine
** to see if it should be retried.  Return TRUE to retry.  Return FALSE
** to give up with an error.
*/
................................................................................
static int retryIoerr(int *pnRetry){
  DWORD e;
  if( *pnRetry>=SQLITE_WIN32_IOERR_RETRY ){
    return 0;
  }
  e = GetLastError();
  if( e==ERROR_LOCK_VIOLATION || e==ERROR_SHARING_VIOLATION ){
    int delay = SQLITE_WIN32_IOERR_RETRY_DELAY*(1+*pnRetry);
    sqlite3_log(SQLITE_IOERR, "delay %dms for lock/sharing violation - "
                              "probably due to antivirus software", delay);
    Sleep(delay);
    ++*pnRetry;
    return 1;
  }
  return 0;
}

#if SQLITE_OS_WINCE
................................................................................
** will open a journal file shortly after it is created in order to do
** whatever it does.  While this other process is holding the
** file open, we will be unable to delete it.  To work around this
** problem, we delay 100 milliseconds and try to delete again.  Up
** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
** up and returning an error.
*/

static int winDelete(
  sqlite3_vfs *pVfs,          /* Not used on win32 */
  const char *zFilename,      /* Name of file to delete */
  int syncDir                 /* Not used on win32 */
){
  int cnt = 0;
  int rc;

  void *zConverted;
  UNUSED_PARAMETER(pVfs);
  UNUSED_PARAMETER(syncDir);

  SimulateIOError(return SQLITE_IOERR_DELETE);
  zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  if( isNT() ){

    while( (rc = DeleteFileW(zConverted))!=0 || retryIoerr(&cnt) ){}




/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    while( (rc = DeleteFileW(zConverted))!=0 || retryIoerr(&cnt) ){}





#endif
  }
  if( rc ) rc = winLogError(SQLITE_IOERR_DELETE, "winDelete", zFilename);
  free(zConverted);
  OSTRACE(("DELETE \"%s\" %s\n", zFilename, (rc ? "failed" : "ok" )));






  return rc;
}

/*
** Check the existance and status of a file.
*/
static int winAccess(
  sqlite3_vfs *pVfs,         /* Not used on win32 */

Changes to test/wal6.test.

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	    CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
	    INSERT INTO t1 VALUES(1,2);
	    SELECT * FROM t1;
	  }
	} {1 2}

# Under Windows, you'll get an error trying to delete
# a file this is already opened.  For now, make sure 
# we get that error, then close the first connection
# so the other tests work.
if {$tcl_platform(platform)=="windows"} {
  if {$jmode=="persist" || $jmode=="truncate"} {
	  do_test wal6-1.2.$jmode.win {
	    sqlite3 db2 test.db
	    catchsql {
		    PRAGMA journal_mode=WAL;
	    } db2
	  } {1 {disk I/O error}}
  	db2 close
	  db close
  }
}

	do_test wal6-1.2.$jmode {
	  sqlite3 db2 test.db
	  execsql {
		PRAGMA journal_mode=WAL;
................................................................................
	db close
	db2 close
  forcedelete test.db

}

finish_test








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	    CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
	    INSERT INTO t1 VALUES(1,2);
	    SELECT * FROM t1;
	  }
	} {1 2}

# Under Windows, you'll get an error trying to delete
# a file this is already opened.  Close the first connection

# so the other tests work.
if {$tcl_platform(platform)=="windows"} {
  if {$jmode=="persist" || $jmode=="truncate"} {







    db close
  }
}

	do_test wal6-1.2.$jmode {
	  sqlite3 db2 test.db
	  execsql {
		PRAGMA journal_mode=WAL;
................................................................................
	db close
	db2 close
  forcedelete test.db

}

finish_test