Return 0 from OS_test_select_* ONLY if there are no pending...

...interrupts or subprocess status changes.

diff --git a/src/microcode/uxio.c b/src/microcode/uxio.c
index 6c3a01d6dcf41b35589559b682f6172d104cd856..776523ca9e64df22723ac31b6d1ff27058ebfc05 100644 (file)
--- a/src/microcode/uxio.c
+++ b/src/microcode/uxio.c
@@ -607,14 +607,16 @@ OS_test_select_registry (select_registry_t registry, int blockp)
   while (1)
     {
       int nfds = (safe_poll ((SR_ENTRIES (r)), (SR_N_FDS (r)), blockp));
-      if (nfds >= 0)
+      if (nfds > 0)
        return (nfds);
-      if (errno != EINTR)
+      if (nfds < 0 && errno != EINTR)
        error_system_call (errno, syscall_select);
       if (OS_process_any_status_change ())
        return (SELECT_PROCESS_STATUS_CHANGE);
       if (pending_interrupts_p ())
        return (SELECT_INTERRUPT);
+      if (nfds == 0) /* and no status-change nor interrupts pending */
+       return (0);
     }
 }
 
@@ -629,14 +631,14 @@ OS_test_select_descriptor (int fd, int blockp, unsigned int mode)
       int nfds = (safe_poll (pfds, 1, blockp));
       if (nfds > 0)
        return (ENCODE_MODE ((pfds [0]) . revents));
-      if (nfds == 0)
-       return (0);
-      if (errno != EINTR)
+      if (nfds < 0 && errno != EINTR)
        error_system_call (errno, syscall_select);
       if (OS_process_any_status_change ())
        return (SELECT_PROCESS_STATUS_CHANGE);
       if (pending_interrupts_p ())
        return (SELECT_INTERRUPT);
+      if (nfds == 0) /* and no status-change nor interrupts pending */
+       return (0);
     }
 }
 
@@ -809,14 +811,16 @@ OS_test_select_registry (select_registry_t registry, int blockp)
                               (SR_RREADERS (r)),
                               (SR_RWRITERS (r)),
                               blockp));
-      if (nfds >= 0)
+      if (nfds > 0)
        return (nfds);
-      if (errno != EINTR)
+      if (nfds < 0 && errno != EINTR)
        error_system_call (errno, syscall_select);
       if (OS_process_any_status_change ())
        return (SELECT_PROCESS_STATUS_CHANGE);
       if (pending_interrupts_p ())
        return (SELECT_INTERRUPT);
+      if (nfds == 0) /* and no status-change nor interrupts pending */
+       return (0);
     }
 #else
   error_system_call (ENOSYS, syscall_select);
@@ -846,14 +850,14 @@ OS_test_select_descriptor (int fd, int blockp, unsigned int mode)
        return
          (((FD_ISSET (fd, (&readable))) ? SELECT_MODE_READ : 0)
           | ((FD_ISSET (fd, (&writeable))) ? SELECT_MODE_WRITE : 0));
-      if (nfds == 0)
-       return (0);
-      if (errno != EINTR)
+      if (nfds < 0 && errno != EINTR)
        error_system_call (errno, syscall_select);
       if (OS_process_any_status_change ())
        return (SELECT_PROCESS_STATUS_CHANGE);
       if (pending_interrupts_p ())
        return (SELECT_INTERRUPT);
+      if (nfds == 0) /* and no status-change nor interrupts pending */
+       return (0);
     }
 #else
   error_system_call (ENOSYS, syscall_select);