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qp2/src/utils/fortran_mmap.c

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2019-01-25 11:39:31 +01:00
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
void* mmap_fortran(char* filename, size_t bytes, int* file_descr, int read_only)
{
int i;
int fd;
int result;
void* map;
if (read_only == 1)
{
fd = open(filename, O_RDONLY, (mode_t)0600);
if (fd == -1) {
printf("%s:\n", filename);
perror("Error opening mmap file for reading");
exit(EXIT_FAILURE);
}
map = mmap(NULL, bytes, PROT_READ, MAP_SHARED | MAP_HUGETLB, fd, 0);
if (map == MAP_FAILED) {
/* try again without huge pages */
map = mmap(NULL, bytes, PROT_READ, MAP_SHARED, fd, 0);
}
}
else
{
fd = open(filename, O_RDWR | O_CREAT, (mode_t)0600);
if (fd == -1) {
printf("%s:\n", filename);
perror("Error opening mmap file for writing");
exit(EXIT_FAILURE);
}
result = lseek(fd, bytes+1, SEEK_SET);
if (result == -1) {
close(fd);
printf("%s:\n", filename);
perror("Error calling lseek() to stretch the file");
exit(EXIT_FAILURE);
}
result = write(fd, "", 1);
if (result != 1) {
close(fd);
printf("%s:\n", filename);
perror("Error writing last byte of the file");
exit(EXIT_FAILURE);
}
map = mmap(NULL, bytes, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_HUGETLB, fd, 0);
if (map == MAP_FAILED) {
/* try again without huge pages */
map = mmap(NULL, bytes, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
}
}
if (map == MAP_FAILED) {
close(fd);
printf("%s:\n", filename);
perror("Error mmapping the file");
exit(EXIT_FAILURE);
}
*file_descr = fd;
return map;
}
void munmap_fortran(size_t bytes, int fd, void* map)
{
if (munmap(map, bytes) == -1) {
perror("Error un-mmapping the file");
}
close(fd);
}
void msync_fortran(size_t bytes, int fd, void* map)
{
if (msync(map, bytes, MS_SYNC) == -1) {
perror("Error syncing the mmap file");
}
}