mirror of
https://github.com/QuantumPackage/qp2.git
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90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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void* mmap_fortran(char* filename, size_t bytes, int* file_descr, int read_only)
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{
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int i;
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int fd;
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int result;
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void* map;
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if (read_only == 1)
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{
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fd = open(filename, O_RDONLY, (mode_t)0600);
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if (fd == -1) {
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printf("%s:\n", filename);
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perror("Error opening mmap file for reading");
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exit(EXIT_FAILURE);
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}
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map = mmap(NULL, bytes, PROT_READ, MAP_SHARED | MAP_HUGETLB, fd, 0);
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if (map == MAP_FAILED) {
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/* try again without huge pages */
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map = mmap(NULL, bytes, PROT_READ, MAP_SHARED, fd, 0);
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}
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}
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else
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{
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fd = open(filename, O_RDWR | O_CREAT, (mode_t)0600);
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if (fd == -1) {
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printf("%s:\n", filename);
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perror("Error opening mmap file for writing");
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exit(EXIT_FAILURE);
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}
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result = lseek(fd, bytes+1, SEEK_SET);
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if (result == -1) {
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close(fd);
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printf("%s:\n", filename);
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perror("Error calling lseek() to stretch the file");
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exit(EXIT_FAILURE);
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}
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result = write(fd, "", 1);
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if (result != 1) {
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close(fd);
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printf("%s:\n", filename);
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perror("Error writing last byte of the file");
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exit(EXIT_FAILURE);
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}
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map = mmap(NULL, bytes, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_HUGETLB, fd, 0);
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if (map == MAP_FAILED) {
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/* try again without huge pages */
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map = mmap(NULL, bytes, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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}
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}
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if (map == MAP_FAILED) {
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close(fd);
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printf("%s:\n", filename);
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perror("Error mmapping the file");
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exit(EXIT_FAILURE);
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}
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*file_descr = fd;
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return map;
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}
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void munmap_fortran(size_t bytes, int fd, void* map)
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{
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if (munmap(map, bytes) == -1) {
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perror("Error un-mmapping the file");
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}
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close(fd);
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}
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void msync_fortran(size_t bytes, int fd, void* map)
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{
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if (msync(map, bytes, MS_SYNC) == -1) {
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perror("Error syncing the mmap file");
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}
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}
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