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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
/*=============================================================
**
** Source: helper.c
**
** Purpose: A child process which will attempt to read and write to files
** which were locked in the parent. It will also lock another region of the
** same file.
**
**
**============================================================*/
#include <palsuite.h>
#include "../LockFile.h"
#define FILENAME "testfile.txt"
#define WAITFILENAME "waitfile"
#define BUF_SIZE 128
int __cdecl main(int argc, char *argv[])
{
HANDLE TheFile, WaitFile;
int result = 0;
char DataBuffer[BUF_SIZE];
DWORD BytesRead;
if(0 != (PAL_Initialize(argc, argv)))
{
return FAIL;
}
/* Open the same file that the parent has opened and locked */
TheFile = CreateFile(FILENAME,
GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (TheFile == INVALID_HANDLE_VALUE)
{
Trace("ERROR: Could not open file '%s' with CreateFile.",FILENAME);
result = 1;
}
/* Open up the WaitFile that we're using for IPC */
WaitFile = CreateFile(WAITFILENAME,
GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL,
OPEN_ALWAYS,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (WaitFile == INVALID_HANDLE_VALUE)
{
Trace("ERROR: Could not open file '%s' with CreateFile. "
"GetLastError() returned %d.",WAITFILENAME,GetLastError());
result = 1;
}
/* Lock the same file that the parent process locked, but the child
locks bytes 11 through 20
*/
if(LockFile(TheFile, 11, 0, 10, 0) == 0)
{
Trace("ERROR: LockFile failed in the child proccess. "
"GetLastError returns %d.",
GetLastError());
result = 1;
}
/* Check to ensure the parent lock is respected */
if(ReadFile(TheFile, DataBuffer, 10, &BytesRead, NULL) != 0)
{
Trace("ERROR: ReadFile returned success when it should "
"have failed. Attempted to read the first 10 bytes "
"of a file which was locked by the parent process.");
result = 1;
}
/* Check to ensure the lock put on by this proccess doesn't restrict
access
*/
if(SetFilePointer(TheFile, 11, 0, FILE_BEGIN) == INVALID_SET_FILE_POINTER)
{
Trace("ERROR: SetFilePointer was unable to move the file pointer to "
"the 11th byte in the file, within the child proccess. "
"GetLastError() returned %d.",GetLastError());
result = 1;
}
if(ReadFile(TheFile, DataBuffer, 10, &BytesRead, NULL) == 0)
{
Trace("ERROR: ReadFile failed when attempting to read a section of "
"the file which was locked by the current process. It should "
"have been able to read this. GetLastError() returned %d.",
GetLastError());
result = 1;
}
// Sleep for a bit to give the parent a chance to block before we do.
Sleep(1000);
/* Switch back to the parent, so it can check the child's locks */
SignalAndBusyWait(WaitFile);
if(UnlockFile(TheFile, 11, 0, 10, 0) == 0)
{
Fail("ERROR: Failed to Unlock bytes 11-20 in the file. "
"GetLastError returned %d.",GetLastError());
}
PAL_TerminateEx(result);
return result;
}
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