As can be seen, I'm trying to do some work on shm; in
case we keep using ftok(...,1) for SysV, I want to make
posix shm a viable alternative, but I'm running into
some issues.
One semi-immediate on is that we do the following:
tmpfd = shm_open(shm_name, O_RDWR | O_CREAT | O_EXCL, 0644);
...
status = apr_os_file_put(&file, &tmpfd,
...
status = apr_file_trunc(file, new_m->realsize);
And the apr_file_trunc fails for me with an Illegal
seek. In apr_file_trunc we do:
if (ftruncate(fp->filedes, offset) == -1) {
return errno;
}
return apr_file_seek(fp, APR_SET, &offset);
and apr_file_seek() does a lseek(). And that's where
the problem is because lseek() returns -1 with ESPIPE.
That seems like a valid error in this case, which begs
the following questions:
1. Why are we doing the apr_file_trunc() in shm?
2. Assuming it's required, why do we expect the lseek
on it to succeed?
3. Assuming the failure is NOT expected, or is system
dependent, how should apr_file_seek handle it?
