-/* Wrapper for select. This function is not yet exported from this
- file because it is not sufficiently general. For example,
- ser-base.c uses select to check for socket activity, and this
- function does not support sockets under Windows, so we do not want
- to use gdb_select in ser-base.c. */
-
-static int
-gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
- struct timeval *timeout)
-{
-#ifdef USE_WIN32API
- HANDLE handles[MAXIMUM_WAIT_OBJECTS];
- HANDLE h;
- DWORD event;
- DWORD num_handles;
- int fd;
- int num_ready;
-
- num_ready = 0;
- num_handles = 0;
- for (fd = 0; fd < n; ++fd)
- {
- /* There is no support yet for WRITEFDS. At present, this isn't
- used by GDB -- but we do not want to silently ignore WRITEFDS
- if something starts using it. */
- gdb_assert (!FD_ISSET (fd, writefds));
- if (!FD_ISSET (fd, readfds)
- && !FD_ISSET (fd, exceptfds))
- continue;
- h = (HANDLE) _get_osfhandle (fd);
- if (h == INVALID_HANDLE_VALUE)
- {
- /* If the underlying handle is INVALID_HANDLE_VALUE, then
- this descriptor is no more. */
- if (FD_ISSET (fd, exceptfds))
- ++num_ready;
- continue;
- }
- /* The only exceptional condition we recognize is a closed file
- descriptor. Since we have already checked for that
- condition, clear the exceptional bit for this descriptor. */
- FD_CLR (fd, exceptfds);
- if (FD_ISSET (fd, readfds))
- {
- gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS);
- handles[num_handles++] = h;
- }
- }
- /* If we don't need to wait for any handles, we are done. */
- if (!num_handles)
- return num_ready;
- event = WaitForMultipleObjects (num_handles,
- handles,
- FALSE,
- timeout
- ? (timeout->tv_sec * 1000 + timeout->tv_usec)
- : INFINITE);
- /* EVENT can only be a value in the WAIT_ABANDONED_0 range if the
- HANDLES included an abandoned mutex. Since GDB doesn't use
- mutexes, that should never occur. */
- gdb_assert (!(WAIT_ABANDONED_0 <= event
- && event < WAIT_ABANDONED_0 + num_handles));
- if (event == WAIT_FAILED)
- return -1;
- if (event == WAIT_TIMEOUT)
- return num_ready;
- /* Run through the READFDS, clearing bits corresponding to descriptors
- for which input is unavailable. */
- num_ready += num_handles;
- h = handles[event - WAIT_OBJECT_0];
- for (fd = 0; fd < n; ++fd)
- {
- HANDLE fd_h;
- if (!FD_ISSET (fd, readfds))
- continue;
- fd_h = (HANDLE) _get_osfhandle (fd);
- /* This handle might be ready, even though it wasn't the handle
- returned by WaitForMultipleObjects. */
- if (fd_h != h && WaitForSingleObject (fd_h, 0) != WAIT_OBJECT_0)
- {
- FD_CLR (fd, readfds);
- --num_ready;
- }
- }
-
- return num_ready;
-#else
- return select (n, readfds, writefds, exceptfds, timeout);
-#endif
-}
-
-/* Called by gdb_do_one_event to wait for new events on the
- monitored file descriptors. Queue file events as they are
- detected by the poll.
- If there are no events, this function will block in the
- call to poll.
- Return -1 if there are no files descriptors to monitor,
- otherwise return 0. */