Land #1321 - honor poll timeout for win32

1 files changed, 26 insertions, 4 deletions

diff --git a/apps/openssl/compat/poll_win.c b/apps/openssl/compat/poll_win.c
index 30f6b60..8e28349 100644
--- a/apps/openssl/compat/poll_win.c
+++ b/apps/openssl/compat/poll_win.c
@@ -166,6 +166,7 @@ poll(struct pollfd *pfds, nfds_t nfds, int timeout_ms)
          * select machinery
          */
         fd_set rfds, wfds, efds;
+        fd_set rfds_in, wfds_in, efds_in;
         int rc;
         int num_sockets;
 
@@ -249,15 +250,36 @@ poll(struct pollfd *pfds, nfds_t nfds, int timeout_ms)
         wait_rc = WAIT_FAILED;
 
         looptime_ms = (timeout_ms > 100 || timeout_ms == -1) ? 100 : timeout_ms;
-        if (timeout_ms == -1)
-                timeout_ms = INFINITE;
+
+        /*
+         * select() clears every descriptor that is not ready from the
+         * fd_sets, so a pass that times out leaves them empty. Keep a
+         * pristine copy and restore it before each select(), otherwise the
+         * next pass hands select() three empty sets and Windows fails it with
+         * WSAEINVAL instead of waiting out the remaining timeout.
+         */
+        rfds_in = rfds;
+        wfds_in = wfds;
+        efds_in = efds;
 
         do {
                 TIMEVAL tv;
+
+                /*
+                 * Cap the wait at the time remaining so the final pass
+                 * does not overshoot the requested timeout.
+                 */
+                if (timeout_ms != -1 && timeout_ms - timespent_ms < looptime_ms)
+                        looptime_ms = timeout_ms - timespent_ms;
+
                 tv.tv_sec = 0;
                 tv.tv_usec = looptime_ms * 1000;
                 int handle_signaled = 0;
 
+                rfds = rfds_in;
+                wfds = wfds_in;
+                efds = efds_in;
+
                 /*
                  * Check if any file handles have signaled
                  */
@@ -280,7 +302,7 @@ poll(struct pollfd *pfds, nfds_t nfds, int timeout_ms)
                 /*
                  * If we signaled on a file handle, don't wait on the sockets.
                  */
-                if (wait_rc >= WAIT_OBJECT_0 &&
+                if (num_handles && wait_rc >= WAIT_OBJECT_0 &&
                     (wait_rc <= WAIT_OBJECT_0 + num_handles - 1)) {
                         tv.tv_usec = 0;
                         handle_signaled = 1;
@@ -298,7 +320,7 @@ poll(struct pollfd *pfds, nfds_t nfds, int timeout_ms)
 
                 timespent_ms += looptime_ms;
 
-        } while (timespent_ms < timeout_ms);
+        } while (timeout_ms == -1 || timespent_ms < timeout_ms);
 
         rc = 0;
         num_handles = 0;