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#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/types.h>
#define _GNU_SOURCE /* See feature_test_macros(7) */
#define __USE_GNU
#include <fcntl.h>
#include <unistd.h>
void test_sync_file_range(char *output, char *text, size_t length)
{
int fd = open (output, O_WRONLY | O_CREAT | O_APPEND, 0660);
if (fd < 0 ) {
perror("Cannot get page size");
return;
}
int i;
size_t offset = 0;
for ( i = 0 ; i < 10000; i++ ) {
write(fd, text, length);
sync_file_range(fd, offset, length, SYNC_FILE_RANGE_WRITE);
offset += length;
}
close(fd);
sleep(5);
}
// test based on IBM example https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_71/apis/msync.htm
void test_msync(char *output, char *text, size_t length)
{
int pagesize = sysconf(_SC_PAGE_SIZE);
if (pagesize < 0) {
perror("Cannot get page size");
return;
}
int fd = open(output, (O_CREAT | O_TRUNC | O_RDWR), (S_IRWXU | S_IRWXG | S_IRWXO));
if (fd < 0 ) {
perror("Cannot open file");
return;
}
off_t lastoffset = lseek( fd, pagesize, SEEK_SET);
ssize_t written = write(fd, " ", 1);
if ( written != 1 ) {
perror("Write error. ");
close(fd);
return;
}
off_t my_offset = 0;
void *address = mmap(NULL, pagesize, PROT_WRITE, MAP_SHARED, fd, my_offset);
if ( address == MAP_FAILED ) {
perror("Map error. ");
close(fd);
return;
}
(void) strcpy( (char*) address, text);
if ( msync( address, pagesize, MS_SYNC) < 0 ) {
perror("msync failed with error:");
}
close(fd);
sleep(5);
}
void test_synchronization(char *output, char *text, size_t length, int (*fcnt)(int))
{
int fd = open (output, O_WRONLY | O_CREAT | O_APPEND, 0660);
if (fd < 0 ) {
perror("Cannot get page size");
return;
}
int i;
for ( i = 0 ; i < 10000; i++ )
write(fd, text, length);
fcnt(fd);
close(fd);
sleep(5);
}
void remove_files(char **files) {
size_t i = 0;
while (files[i]) {
unlink(files[i]);
i++;
}
}
int main()
{
char *default_text = { "This is a simple example to test a PR. The sleep is used to create different peaks on charts.\n" };
char *files[] = { "fsync.txt", "fdatasync.txt", "syncfs.txt", "msync.txt", "sync_file_range.txt", NULL };
size_t length = strlen(default_text);
test_synchronization(files[0], default_text, length, fsync);
test_synchronization(files[1], default_text, length, fdatasync);
test_synchronization(files[2], default_text, length, syncfs);
test_msync(files[3], default_text, length);
test_sync_file_range(files[4], default_text, length);
sync();
remove_files(files);
return 0;
}
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