Take the following trivial program:
#include <unistd.h>
int main(void)
{
sleep(10);
return 0;
}
Run it in an xterm. Note that resizing the xterm has no effect on the
process. Now do the same with strace:
brk(0x80495bc) = 0x80495bc
brk(0x804a000) = 0x804a000
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({10, 0}, 0xbffff548) = -1 EINTR (Interrupted system
call)
--- SIGWINCH (Window changed) ---
_exit(0) = ?
In short, nanosleep is getting interrupted by signals that are
supposedly ignored when a process is being praced. This appears to be
a long-standing bug.
It also appears to be a long-known bug. I found some old discussion of this
problem here but no sign of any resolution:
http://www.ussg.iu.edu/hypermail/linux/kernel/0108.1/1448.html
What's the current thinking on this?