Message ID | 20210409113639.1124756-2-adhemerval.zanella@linaro.org |
---|---|
State | New |
Headers | show |
Series | [v2,1/2] linux: Normalize and return timeout on select (BZ #27651) | expand |
* Adhemerval Zanella via Libc-alpha: > diff --git a/misc/tst-select.c b/misc/tst-select.c > index dc7717a7a6..9c817f4035 100644 > --- a/misc/tst-select.c > +++ b/misc/tst-select.c > @@ -23,6 +23,7 @@ > #include <support/timespec.h> > #include <support/xunistd.h> > #include <support/xtime.h> > +#include <support/xsignal.h> > > struct child_args > { > @@ -30,6 +31,12 @@ struct child_args > struct timeval tmo; > }; > > +static void > +alarm_handler (int signum) > +{ > + /* Do nothing. */ > +} > + > static void > do_test_child (void *clousure) > { > @@ -59,6 +66,22 @@ do_test_child (void *clousure) > xwrite (args->fds[1][1], "foo", 3); > } > > +static void > +do_test_child_alarm (void *clousure) > +{ > + struct sigaction act = { .sa_handler = alarm_handler }; > + xsigaction (SIGALRM, &act, NULL); > + alarm (1); > + > + struct timeval tv = { .tv_sec = 10, .tv_usec = 0 }; > + int r = select (0, NULL, NULL, NULL, &tv); > + TEST_COMPARE (r, -1); > + TEST_COMPARE (errno, EINTR); > + > + if (support_select_modify_timeout ()) > + TEST_VERIFY (tv.tv_sec < 10); > +} > + > static int > do_test (void) > { > @@ -98,6 +121,13 @@ do_test (void) > xclose (args.fds[0][0]); > xclose (args.fds[1][1]); > > + { > + struct support_capture_subprocess result; > + result = support_capture_subprocess (do_test_child_alarm, NULL); > + support_capture_subprocess_check (&result, "tst-select-child", 0, > + sc_allow_none); > + } > + > { > fd_set rfds; > FD_ZERO (&rfds); I thought a bit about how this would interact with SIGALRM in the test suite, but this should be okay: the SIGALRM handler is in the parent wrapper process, not in the child process, and in --direct mode (without a wrapper), there is no timeout at all. So the test should be okay. The actual code change looks okay to me too. Thanks, Florian
diff --git a/misc/tst-select.c b/misc/tst-select.c index dc7717a7a6..9c817f4035 100644 --- a/misc/tst-select.c +++ b/misc/tst-select.c @@ -23,6 +23,7 @@ #include <support/timespec.h> #include <support/xunistd.h> #include <support/xtime.h> +#include <support/xsignal.h> struct child_args { @@ -30,6 +31,12 @@ struct child_args struct timeval tmo; }; +static void +alarm_handler (int signum) +{ + /* Do nothing. */ +} + static void do_test_child (void *clousure) { @@ -59,6 +66,22 @@ do_test_child (void *clousure) xwrite (args->fds[1][1], "foo", 3); } +static void +do_test_child_alarm (void *clousure) +{ + struct sigaction act = { .sa_handler = alarm_handler }; + xsigaction (SIGALRM, &act, NULL); + alarm (1); + + struct timeval tv = { .tv_sec = 10, .tv_usec = 0 }; + int r = select (0, NULL, NULL, NULL, &tv); + TEST_COMPARE (r, -1); + TEST_COMPARE (errno, EINTR); + + if (support_select_modify_timeout ()) + TEST_VERIFY (tv.tv_sec < 10); +} + static int do_test (void) { @@ -98,6 +121,13 @@ do_test (void) xclose (args.fds[0][0]); xclose (args.fds[1][1]); + { + struct support_capture_subprocess result; + result = support_capture_subprocess (do_test_child_alarm, NULL); + support_capture_subprocess_check (&result, "tst-select-child", 0, + sc_allow_none); + } + { fd_set rfds; FD_ZERO (&rfds); diff --git a/sysdeps/unix/sysv/linux/select.c b/sysdeps/unix/sysv/linux/select.c index d075270ff4..4e426f9aed 100644 --- a/sysdeps/unix/sysv/linux/select.c +++ b/sysdeps/unix/sysv/linux/select.c @@ -110,7 +110,7 @@ __select64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, r = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, pts32, NULL); # endif - if (r >= 0 && timeout != NULL) + if (timeout != NULL) *timeout = valid_timespec_to_timeval64 (ts32); #endif @@ -131,7 +131,7 @@ __select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, ptv64 = &tv64; } int r = __select64 (nfds, readfds, writefds, exceptfds, ptv64); - if (r >= 0 && timeout != NULL) + if (timeout != NULL) /* The remanining timeout will be always less the input TIMEOUT. */ *timeout = valid_timeval64_to_timeval (tv64); return r;