[test.cpp]
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
extern int errno;
int main()
{
int fd;
fd = shm_open("/Test/123456789", O_CREAT | O_CLOEXEC | O_RDWR, S_IRUSR | S_IWUSR);
if (fd == -1)
fprintf(stderr, "errno[%d] \n", errno);
return 0;
}
$ gcc test.cpp -lrt
$ ./a.out
errno[38] // usually return 2, path problem
I first thought it is absurd because shm_open function is really basic function provided by glibc. Later, I got realized this was from emulation environment specifically mount problem.
There was '/dev/shm' linked to '/run/...' but actually '/run/...' path wasn't existed. So I mounted '/run' to virtual path on emulator like '/var/tmp/blahblah/run' and solved the problem. You can do like this 'sudo mount -o bind /run /var/tmp/blahblah/run'.
Hope this might help.
