void
gdb_call_async_signal_handler (struct async_signal_handler *handler,
int immediate_p)
{
if (immediate_p)
call_async_signal_handler (handler);
else
mark_async_signal_handler (handler);
}
int
gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout)
{
static HANDLE never_handle;
HANDLE handles[MAXIMUM_WAIT_OBJECTS];
HANDLE h;
DWORD event;
DWORD num_handles;
/* SCBS contains serial control objects corresponding to file
descriptors in READFDS and WRITEFDS. */
struct serial *scbs[MAXIMUM_WAIT_OBJECTS];
/* The number of valid entries in SCBS. */
size_t num_scbs;
int fd;
int num_ready;
size_t indx;
num_ready = 0;
num_handles = 0;
num_scbs = 0;
for (fd = 0; fd < n; ++fd)
{
HANDLE read = NULL, except = NULL;
struct serial *scb;
/* 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 (!writefds || !FD_ISSET (fd, writefds));
if ((!readfds || !FD_ISSET (fd, readfds))
&& (!exceptfds || !FD_ISSET (fd, exceptfds)))
continue;
scb = serial_for_fd (fd);
if (scb)
{
serial_wait_handle (scb, &read, &except);
scbs[num_scbs++] = scb;
}
if (read == NULL)
read = (HANDLE) _get_osfhandle (fd);
if (except == NULL)
{
if (!never_handle)
never_handle = CreateEvent (0, FALSE, FALSE, 0);
except = never_handle;
}
if (readfds && FD_ISSET (fd, readfds))
{
gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS);
handles[num_handles++] = read;
}
if (exceptfds && FD_ISSET (fd, exceptfds))
{
gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS);
handles[num_handles++] = except;
}
}
gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS);
handles[num_handles++] = sigint_event;
event = WaitForMultipleObjects (num_handles,
handles,
FALSE,
timeout
? (timeout->tv_sec * 1000
+ timeout->tv_usec / 1000)
: 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));
/* We no longer need the helper threads to check for activity. */
for (indx = 0; indx < num_scbs; ++indx)
serial_done_wait_handle (scbs[indx]);
if (event == WAIT_FAILED)
return -1;
if (event == WAIT_TIMEOUT)
return 0;
/* Run through the READFDS, clearing bits corresponding to descriptors
for which input is unavailable. */
h = handles[event - WAIT_OBJECT_0];
for (fd = 0, indx = 0; fd < n; ++fd)
{
HANDLE fd_h;
if ((!readfds || !FD_ISSET (fd, readfds))
&& (!exceptfds || !FD_ISSET (fd, exceptfds)))
continue;
if (readfds && FD_ISSET (fd, readfds))
{
fd_h = handles[indx++];
/* 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);
else
num_ready++;
}
if (exceptfds && FD_ISSET (fd, exceptfds))
{
fd_h = handles[indx++];
/* 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, exceptfds);
else
num_ready++;
}
}
/* With multi-threaded SIGINT handling, there is a race between the
readline signal handler and GDB. It may still be in
rl_prep_terminal in another thread. Do not return until it is
done; we can check the state here because we never longjmp from
signal handlers on Windows. */
while (RL_ISSTATE (RL_STATE_SIGHANDLER))
Sleep (1);
if (h == sigint_event
|| WaitForSingleObject (sigint_event, 0) == WAIT_OBJECT_0)
{
if (sigint_handler != NULL)
call_async_signal_handler (sigint_handler);
if (num_ready == 0)
{
errno = EINTR;
return -1;
}
}
return num_ready;
}
