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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-11-08 22:43:38 +01:00
qp2/src/utils/mmap.f90
2019-01-25 11:39:31 +01:00

93 lines
3.1 KiB
Fortran

module mmap_module
use iso_c_binding
interface
! File descriptors
! ----------------
type(c_ptr) function c_mmap_fortran(filename, length, fd, read_only) bind(c,name='mmap_fortran')
use iso_c_binding
character(c_char), intent(in) :: filename(*)
integer(c_size_t), intent(in), value :: length
integer(c_int), intent(out) :: fd
integer(c_int), intent(in), value :: read_only
end function
subroutine c_munmap_fortran(length, fd, map) bind(c,name='munmap_fortran')
use iso_c_binding
integer(c_size_t), intent(in), value :: length
integer(c_int), intent(in), value :: fd
type(c_ptr), intent(in), value :: map
end subroutine
subroutine c_msync_fortran(length, fd, map) bind(c,name='msync_fortran')
use iso_c_binding
integer(c_size_t), intent(in), value :: length
integer(c_int), intent(in), value :: fd
type(c_ptr), intent(in), value :: map
end subroutine
end interface
contains
subroutine mmap(filename, shape, bytes, fd, read_only, map)
use iso_c_binding
implicit none
character*(*), intent(in) :: filename ! Name of the mapped file
integer*8, intent(in) :: shape(:) ! Shape of the array to map
integer, intent(in) :: bytes ! Number of bytes per element
logical, intent(in) :: read_only ! If true, mmap is read-only
integer, intent(out) :: fd ! File descriptor
type(c_ptr), intent(out) :: map ! C Pointer
integer(c_size_t) :: length
integer(c_int) :: fd_
length = PRODUCT( shape(:) ) * bytes
if (read_only) then
map = c_mmap_fortran( trim(filename)//char(0), length, fd_, 1)
else
map = c_mmap_fortran( trim(filename)//char(0), length, fd_, 0)
endif
fd = fd_
end subroutine
subroutine munmap(shape, bytes, fd, map)
use iso_c_binding
implicit none
integer*8, intent(in) :: shape(:) ! Shape of the array to map
integer, intent(in) :: bytes ! Number of bytes per element
integer, intent(in) :: fd ! File descriptor
type(c_ptr), intent(in) :: map ! C pointer
integer(c_size_t) :: length
integer(c_int) :: fd_
length = PRODUCT( shape(:) ) * bytes
fd_ = fd
call c_munmap_fortran( length, fd_, map)
end subroutine
subroutine msync(shape, bytes, fd, map)
use iso_c_binding
implicit none
integer*8, intent(in) :: shape(:) ! Shape of the array to map
integer, intent(in) :: bytes ! Number of bytes per element
integer, intent(in) :: fd ! File descriptor
type(c_ptr), intent(in) :: map ! C pointer
integer(c_size_t) :: length
integer(c_int) :: fd_
length = PRODUCT( shape(:) ) * bytes
fd_ = fd
call c_msync_fortran( length, fd_, map)
end subroutine
end module mmap_module