lseek.cpp File Reference

#include <corecrt_internal_lowio.h>
#include <corecrt_internal_ptd_propagation.h>
#include <stdlib.h>

Include dependency graph for lseek.cpp:

Go to the source code of this file.

Functions
static long __cdecl	common_lseek_do_seek_nolock (HANDLE const os_handle, long const offset, int const origin, __crt_cached_ptd_host &ptd) throw ()
static __int64 __cdecl	common_lseek_do_seek_nolock (HANDLE const os_handle, __int64 const offset, int const origin, __crt_cached_ptd_host &ptd) throw ()
template<typename Integer >
static Integer __cdecl	common_lseek_nolock (int const fh, Integer const offset, int const origin, __crt_cached_ptd_host &ptd) throw ()
template<typename Integer >
static Integer __cdecl	common_lseek (int const fh, Integer const offset, int const origin, __crt_cached_ptd_host &ptd) throw ()
long __cdecl	_lseek_internal (int const fh, long const offset, int const origin, __crt_cached_ptd_host &ptd)
__int64 __cdecl	_lseeki64_internal (int const fh, __int64 const offset, int const origin, __crt_cached_ptd_host &ptd)
long __cdecl	_lseek_nolock_internal (int const fh, long const offset, int const origin, __crt_cached_ptd_host &ptd)
__int64 __cdecl	_lseeki64_nolock_internal (int const fh, __int64 const offset, int const origin, __crt_cached_ptd_host &ptd)
long __cdecl	_lseek (int const fh, long const offset, int const origin)
__int64 __cdecl	_lseeki64 (int const fh, __int64 const offset, int const origin)
long __cdecl	_lseek_nolock (int const fh, long const offset, int const origin)
__int64 __cdecl	_lseeki64_nolock (int const fh, __int64 const offset, int const origin)

Function Documentation

_lseek()

long __cdecl _lseek	(	int const	fh,
		long const	offset,
		int const	origin
	)

Definition at line 150 of file lseek.cpp.

{
    __crt_cached_ptd_host ptd;
    return common_lseek(fh, offset, origin, ptd);
}

_lseek_internal()

long __cdecl _lseek_internal	(	int const	fh,
		long const	offset,
		int const	origin,
		__crt_cached_ptd_host &	ptd
	)

Definition at line 130 of file lseek.cpp.

{
    return common_lseek(fh, offset, origin, ptd);
}

_lseek_nolock()

long __cdecl _lseek_nolock	(	int const	fh,
		long const	offset,
		int const	origin
	)

Definition at line 162 of file lseek.cpp.

{
    __crt_cached_ptd_host ptd;
    return common_lseek_nolock(fh, offset, origin, ptd);
}

_lseek_nolock_internal()

long __cdecl _lseek_nolock_internal	(	int const	fh,
		long const	offset,
		int const	origin,
		__crt_cached_ptd_host &	ptd
	)

Definition at line 140 of file lseek.cpp.

{
    return common_lseek_nolock(fh, offset, origin, ptd);
}

_lseeki64()

__int64 __cdecl _lseeki64	(	int const	fh,
		__int64 const	offset,
		int const	origin
	)

Definition at line 156 of file lseek.cpp.

{
    __crt_cached_ptd_host ptd;
    return common_lseek(fh, offset, origin, ptd);
}

_lseeki64_internal()

__int64 __cdecl _lseeki64_internal	(	int const	fh,
		__int64 const	offset,
		int const	origin,
		__crt_cached_ptd_host &	ptd
	)

Definition at line 135 of file lseek.cpp.

{
    return common_lseek(fh, offset, origin, ptd);
}

_lseeki64_nolock()

__int64 __cdecl _lseeki64_nolock	(	int const	fh,
		__int64 const	offset,
		int const	origin
	)

Definition at line 168 of file lseek.cpp.

{
    __crt_cached_ptd_host ptd;
    return common_lseek_nolock(fh, offset, origin, ptd);
}

_lseeki64_nolock_internal()

__int64 __cdecl _lseeki64_nolock_internal	(	int const	fh,
		__int64 const	offset,
		int const	origin,
		__crt_cached_ptd_host &	ptd
	)

Definition at line 145 of file lseek.cpp.

{
    return common_lseek_nolock(fh, offset, origin, ptd);
}

common_lseek()

template<typename Integer >

static Integer __cdecl common_lseek ( int const  fh, Integer const  offset, int const  origin, __crt_cached_ptd_host &  ptd  ) throw ( )

static

Definition at line 102 of file lseek.cpp.

{
    _UCRT_CHECK_FH_CLEAR_OSSERR_RETURN(ptd, fh, EBADF, -1);
    _UCRT_VALIDATE_CLEAR_OSSERR_RETURN(ptd, fh >= 0 && (unsigned)fh < (unsigned)_nhandle, EBADF, -1);
    _UCRT_VALIDATE_CLEAR_OSSERR_RETURN(ptd, _osfile(fh) & FOPEN, EBADF, -1);
 
    __acrt_lowio_lock_fh(fh);
    Integer result = -1;
    __try
    {
        if ((_osfile(fh) & FOPEN) == 0)
        {
            ptd.get_errno().set(EBADF);
            ptd.get_doserrno().set(0);
            _ASSERTE(("Invalid file descriptor. File possibly closed by a different thread",0));
            __leave;
        }
 
        result = common_lseek_nolock(fh, offset, origin, ptd);
    }
    __finally
    {
        __acrt_lowio_unlock_fh(fh);
    }
    __endtry
    return result;
}

Referenced by _lseek(), _lseek_internal(), _lseeki64(), and _lseeki64_internal().

common_lseek_do_seek_nolock() [1/2]

static __int64 __cdecl common_lseek_do_seek_nolock ( HANDLE const  os_handle, __int64 const  offset, int const  origin, __crt_cached_ptd_host &  ptd  ) throw ( )

static

Definition at line 55 of file lseek.cpp.

{
    LARGE_INTEGER new_pos;
    if (!SetFilePointerEx(os_handle, *reinterpret_cast<LARGE_INTEGER const*>(&offset), &new_pos, origin))
    {
        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
        return -1;
    }
 
    return new_pos.QuadPart;
}

common_lseek_do_seek_nolock() [2/2]

static long __cdecl common_lseek_do_seek_nolock ( HANDLE const  os_handle, long const  offset, int const  origin, __crt_cached_ptd_host &  ptd  ) throw ( )

static

Definition at line 21 of file lseek.cpp.

{
    LARGE_INTEGER const origin_pos = { 0 };
 
    LARGE_INTEGER saved_pos;
    if (!SetFilePointerEx(os_handle, origin_pos, &saved_pos, FILE_CURRENT))
    {
        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
        return -1;
    }
 
    LARGE_INTEGER seek_pos = { 0 };
    seek_pos.QuadPart = offset;
 
    LARGE_INTEGER new_pos = { 0 };
    if (!SetFilePointerEx(os_handle, seek_pos, &new_pos, origin))
    {
        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
        return -1;
    }
 
    // The call succeeded, but the new file pointer location is too large for
    // the return type or is a negative value.  So, restore the file pointer
    // to the saved location and return an error:
    if (new_pos.QuadPart > LONG_MAX)
    {
        SetFilePointerEx(os_handle, saved_pos, nullptr, FILE_BEGIN);
        ptd.get_errno().set(EINVAL);
        return -1;
    }
 
    return static_cast<long>(new_pos.LowPart);
}

Referenced by common_lseek_nolock().

common_lseek_nolock()

template<typename Integer >

static Integer __cdecl common_lseek_nolock ( int const  fh, Integer const  offset, int const  origin, __crt_cached_ptd_host &  ptd  ) throw ( )

static

Definition at line 69 of file lseek.cpp.

{
    HANDLE const os_handle = reinterpret_cast<HANDLE>(_get_osfhandle(fh));
    if (os_handle == reinterpret_cast<HANDLE>(-1))
    {
        ptd.get_errno().set(EBADF);
        _ASSERTE(("Invalid file descriptor",0));
        return -1;
    }
 
    Integer const new_position = common_lseek_do_seek_nolock(os_handle, offset, origin, ptd);
    if (new_position == -1)
    {
        return -1;
    }
 
    // The call succeeded, so return success:
    _osfile(fh) &= ~FEOFLAG; // Clear the Ctrl-Z flag
    return new_position;
}

Referenced by _lseek_nolock(), _lseek_nolock_internal(), _lseeki64_nolock(), _lseeki64_nolock_internal(), and common_lseek().