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#include <malloc.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
// how many mmap areas to create
#define mapMax 100
// how large should they be
#define mapSize ((size_t)1024 * 1024 * 1024 * 100)
int fd[mapMax];
char name[mapMax][100];
void quit(int ret) {
for (int i=0; i<mapMax; i++) {
// close(fd[i]);
unlink(name[i]);
}
exit(ret);
}
int main() {
memset(name[0], 0, sizeof(name));
fprintf(stderr, "Allocating\t%f GB\t=\t%d\tx\t%f GB\n", ((double) mapMax * mapSize) / 1024.0 / 1024 / 1024, mapMax, (double) mapSize / 1024.0 / 1024 / 1024 );
// create tmp files
for (int i=0; i<mapMax; i++) {
tmpnam(name[i]);
fd[i] = open( name[i], O_CREAT | O_EXCL | O_RDWR, S_IRWXU );
if (fd[i] == -1) {
fprintf(stderr, "opening tmp file #%d failed\n", i);
quit(-1);
}
}
// mmap them
for (int i=0; i<mapMax; i++) {
if (MAP_FAILED == mmap((void*) NULL, mapSize, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NONBLOCK, fd[i], 0)) {
fprintf(stderr, "mmap #%d failed (errno: %d, errstr: %s)\n", i, errno, strerror(errno));
quit(-1);
}
}
quit(0);
}
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