在FORTRAN中调用子程序而不阻塞主程序 [英] Calling a subroutine in FORTRAN without blocking the main program
问题描述
假设用mpif90编译的过度简化的FORTRAN代码为:
程序main
!
使用mpi
隐式无
整数:: j,numtasks,taskid,ierr
integer :: master = 0
!
调用mpi_init(ierr)
调用mpi_comm_rank(mpi_comm_world,taskid,ierr)
!
if(taskid .eq。master)then
j = 5
call child(j)
!做的东西
结束如果
调用mpi_finalize(ierr)
!
结束程序主
$ b $子程序子(j)
!
隐式无
整数,意图(in):: j
!使用j
做一些事情结束子例程子
默认情况下,主CPU等待孩子完成其计算。但是,我希望它在给孩子打电话之后继续完成任务,而孩子也在完成任务。我希望孩子成为主要的子程序,因为我需要将一些数据从主体传递给孩子(但不是相反)。我想知道是否可以在FORTRAN中使用(可能是使用某种非阻塞子例程调用或多线程,例如mpi_comm_spawn)。
我会为此使用POSIX线程。也许也是一个OpenMP任务,但我的经验是有限的。我假定你不会在子
中调用任何MPI过程。
通过C
#include< pthread.h>
void pthread_create_opaque(pthread_t * threadptr,void * procptr,void * dataptr,int * err){
//使用指向pthread_t结构的不透明指针创建新线程
* err = pthread_create(threadptr,NULL,procptr,dataptr);
}
void pthread_join_opaque(pthread_t * threadptr,int * err){
//使用opaque指针指向pthread_t结构
* err = pthread_join (* threadptr,NULL);
}
和Fortran
< pre pre $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $' pthread_create_opaque)
使用iso_c_binding
类型(c_ptr):: threadptr
类型(c_funptr),value :: procptr
类型(c_ptr),value :: dataptr
整数(c_int),intent(out):: err
结束子程序
子程序pthread_join_opaque(thread,err)bind(C,name =pthread_join_opaque)
use iso_c_binding
$(b_btr),value :: thread
integer(c_int),intent(out):: err
结束子程序
结束接口
结束模块Pthreads
你可以调用一个孩子,如果它是C可互操作的
子例程子(j)绑定(C)
!
隐式无
整数,意图(in):: j
!做一些与j
结尾子程序子
的东西简单地作为
type(c_ptr):: thread
integer :: err
call pthread_create_opaque(thread,c_funloc(join), loc(j),err)
然后在某个方便的地方(在程序结束或任何地方)等待为它完成工作
call pthread_join_opaque(thread,err)
我在一个MPI并行程序中成功地使用它来异步输出时间步数据。
Assuming an over-simplified FORTRAN code compiled with mpif90 as:
program main
!
use mpi
implicit none
integer:: j, numtasks, taskid, ierr
integer:: master = 0
!
call mpi_init(ierr)
call mpi_comm_rank(mpi_comm_world, taskid, ierr)
!
if (taskid .eq. master) then
j = 5
call child (j)
! do stuff
end if
call mpi_finalize(ierr)
!
end program main
subroutine child(j)
!
implicit none
integer, intent(in):: j
! do some stuff with j
end subroutine child
By default, the master CPU from the main waits until the child is done with its calculations. However, I want it to continue its tasks after calling the child, while the child is also doing its tasks. I would like the child to be a subroutine for the main since I need to pass some data from the main to the child (but not vice versa). I was wondering to know if this is possible in FORTRAN (maybe by using some kind of non-blocking subroutine call or multi-threading such as mpi_comm_spawn).
I would use a POSIX thread for this. Maybe also an OpenMP task, but my experience with them is limited. I will assume you do not call any MPI procedures in the child
.
With a simple interface in C
#include <pthread.h>
void pthread_create_opaque(pthread_t *threadptr, void *procptr, void *dataptr, int *err){
// creates a new thread using an opaque pointer to the pthread_t structure
*err = pthread_create(threadptr, NULL, procptr, dataptr);
}
void pthread_join_opaque(pthread_t *threadptr, int *err) {
// joines a thread using an opaque pointer to the pthread_t structure
*err = pthread_join(*threadptr, NULL);
}
and in Fortran
module Pthreads
implicit none
interface
subroutine pthread_create_opaque(threadptr, procptr, dataptr, err) bind(C,name="pthread_create_opaque")
use iso_c_binding
type(c_ptr) :: threadptr
type(c_funptr),value :: procptr
type(c_ptr),value :: dataptr
integer(c_int),intent(out) :: err
end subroutine
subroutine pthread_join_opaque(thread, err) bind(C,name="pthread_join_opaque")
use iso_c_binding
type(c_ptr),value :: thread
integer(c_int),intent(out) :: err
end subroutine
end interface
end module Pthreads
you can call a child if it is C interoperable
subroutine child(j) bind(C)
!
implicit none
integer, intent(in):: j
! do some stuff with j
end subroutine child
simply as
type(c_ptr) :: thread
integer :: err
call pthread_create_opaque(thread, c_funloc(join), loc(j), err)
and later at some convenient place (before program end or wherever) wait for it to finish its work
call pthread_join_opaque(thread, err)
I use this successfully in an MPI parallel program for asynchronous output of time-step data.
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