Add the socketpair_full test from [1], fixed by [2], slightly improved by the addition of a timeout.
This test might perhaps be better named. This might also serve as an example of how to add new tests. [1] https://cygwin.com/pipermail/cygwin-developers/2023-July/012640.html [2] dedbbd74d0a8 ("Cygwin: select: workaround FD_WRITE network event handling") --- winsup/testsuite/Makefile.am | 1 + winsup/testsuite/winsup.api/socketpair_full.c | 59 +++++++++++++++++++ 2 files changed, 60 insertions(+) create mode 100644 winsup/testsuite/winsup.api/socketpair_full.c diff --git a/winsup/testsuite/Makefile.am b/winsup/testsuite/Makefile.am index 228955668..28b23b758 100644 --- a/winsup/testsuite/Makefile.am +++ b/winsup/testsuite/Makefile.am @@ -48,6 +48,7 @@ check_PROGRAMS = \ winsup.api/shmtest \ winsup.api/sigchld \ winsup.api/signal-into-win32-api \ + winsup.api/socketpair_full \ winsup.api/systemcall \ winsup.api/user_malloc \ winsup.api/waitpid \ diff --git a/winsup/testsuite/winsup.api/socketpair_full.c b/winsup/testsuite/winsup.api/socketpair_full.c new file mode 100644 index 000000000..d432bc76d --- /dev/null +++ b/winsup/testsuite/winsup.api/socketpair_full.c @@ -0,0 +1,59 @@ +// +// This test verifies that a socket correctly indicates not ready to write when +// poll()ed if a subsequent write() would block +// +// + +#include <assert.h> +#include <poll.h> +#include <stdio.h> +#include <sys/socket.h> +#include <unistd.h> + +static void timeout(int signum) +{ + exit(1); +} + +int main() +{ + char wbuf[100] = { 0, }; + int out; + + signal(SIGALRM, timeout); + + { + int sv[2]; + int s; + + s = socketpair (AF_UNIX, SOCK_STREAM, 0, sv); + assert (s == 0); + + out = sv[0]; + } + + size_t in_flight = 0; + while (1) + { + struct pollfd fds[1]; + fds[0].fd = out; + fds[0].events = POLLOUT; + + int r = poll(fds, 1, 0); + assert(r >= 0); + + // fd is not ready to write + if (!(fds[0].revents & POLLOUT)) + break; + + alarm(5); + + // otherwise, fd is ready to write, implies some data may be written without blocking + ssize_t s = write (out, wbuf, sizeof wbuf); + assert (s > 0); + in_flight += s; + printf("%zd written, total in_flight %zd\n", s, in_flight); + + alarm(0); + } +} -- 2.39.0
