/* Serial interface for local (hardwired) serial ports on Windows systems
- Copyright (C) 2006-2013 Free Software Foundation, Inc.
+ Copyright (C) 2006-2014 Free Software Foundation, Inc.
This file is part of GDB.
#include <unistd.h>
#include <sys/types.h>
-#include "gdb_assert.h"
-#include <string.h>
-
#include "command.h"
void _initialize_ser_windows (void);
static struct pipe_state *
make_pipe_state (void)
{
- struct pipe_state *ps = XMALLOC (struct pipe_state);
+ struct pipe_state *ps = XNEW (struct pipe_state);
memset (ps, 0, sizeof (*ps));
ps->wait.read_event = INVALID_HANDLE_VALUE;
HANDLE sock_event;
};
+/* Check whether the socket has any pending data to be read. If so,
+ set the select thread's read event. On error, set the select
+ thread's except event. If any event was set, return true,
+ otherwise return false. */
+
+static int
+net_windows_socket_check_pending (struct serial *scb)
+{
+ struct net_windows_state *state = scb->state;
+ unsigned long available;
+
+ if (ioctlsocket (scb->fd, FIONREAD, &available) != 0)
+ {
+ /* The socket closed, or some other error. */
+ SetEvent (state->base.except_event);
+ return 1;
+ }
+ else if (available > 0)
+ {
+ SetEvent (state->base.read_event);
+ return 1;
+ }
+
+ return 0;
+}
+
static DWORD WINAPI
net_windows_select_thread (void *arg)
{
wait_events[0] = state->base.stop_select;
wait_events[1] = state->sock_event;
- event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);
-
- if (event_index == WAIT_OBJECT_0
- || WaitForSingleObject (state->base.stop_select, 0) == WAIT_OBJECT_0)
- /* We have been requested to stop. */
- ;
- else if (event_index != WAIT_OBJECT_0 + 1)
- /* Some error has occured. Assume that this is an error
- condition. */
- SetEvent (state->base.except_event);
- else
+ /* Wait for something to happen on the socket. */
+ while (1)
{
+ event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);
+
+ if (event_index == WAIT_OBJECT_0
+ || WaitForSingleObject (state->base.stop_select, 0) == WAIT_OBJECT_0)
+ {
+ /* We have been requested to stop. */
+ break;
+ }
+
+ if (event_index != WAIT_OBJECT_0 + 1)
+ {
+ /* Some error has occured. Assume that this is an error
+ condition. */
+ SetEvent (state->base.except_event);
+ break;
+ }
+
/* Enumerate the internal network events, and reset the
object that signalled us to catch the next event. */
- WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);
-
- gdb_assert (events.lNetworkEvents & (FD_READ | FD_CLOSE));
-
+ if (WSAEnumNetworkEvents (scb->fd, state->sock_event, &events) != 0)
+ {
+ /* Something went wrong. Maybe the socket is gone. */
+ SetEvent (state->base.except_event);
+ break;
+ }
+
if (events.lNetworkEvents & FD_READ)
- SetEvent (state->base.read_event);
-
+ {
+ if (net_windows_socket_check_pending (scb))
+ break;
+
+ /* Spurious wakeup. That is, the socket's event was
+ signalled before we last called recv. */
+ }
+
if (events.lNetworkEvents & FD_CLOSE)
- SetEvent (state->base.except_event);
+ {
+ SetEvent (state->base.except_event);
+ break;
+ }
}
SetEvent (state->base.have_stopped);
}
+ return 0;
}
static void
*read = state->base.read_event;
*except = state->base.except_event;
- /* Check any pending events. This both avoids starting the thread
- unnecessarily, and handles stray FD_READ events (see below). */
- if (WaitForSingleObject (state->sock_event, 0) == WAIT_OBJECT_0)
- {
- WSANETWORKEVENTS events;
- int any = 0;
-
- /* Enumerate the internal network events, and reset the object that
- signalled us to catch the next event. */
- WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);
-
- /* You'd think that FD_READ or FD_CLOSE would be set here. But,
- sometimes, neither is. I suspect that the FD_READ is set and
- the corresponding event signalled while recv is running, and
- the FD_READ is then lowered when recv consumes all the data,
- but there's no way to un-signal the event. This isn't a
- problem for the call in net_select_thread, since any new
- events after this point will not have been drained by recv.
- It just means that we can't have the obvious assert here. */
-
- /* If there is a read event, it might be still valid, or it might
- not be - it may have been signalled before we last called
- recv. Double-check that there is data. */
- if (events.lNetworkEvents & FD_READ)
- {
- unsigned long available;
-
- if (ioctlsocket (scb->fd, FIONREAD, &available) == 0
- && available > 0)
- {
- SetEvent (state->base.read_event);
- any = 1;
- }
- else
- /* Oops, no data. This call to recv will cause future
- data to retrigger the event, e.g. while we are
- in net_select_thread. */
- recv (scb->fd, NULL, 0, 0);
- }
-
- /* If there's a close event, then record it - it is obviously
- still valid, and it will not be resignalled. */
- if (events.lNetworkEvents & FD_CLOSE)
- {
- SetEvent (state->base.except_event);
- any = 1;
- }
-
- /* If we set either handle, there's no need to wake the thread. */
- if (any)
- return;
- }
-
- start_select_thread (&state->base);
+ /* Check any pending events. Otherwise, start the select
+ thread. */
+ if (!net_windows_socket_check_pending (scb))
+ start_select_thread (&state->base);
}
static void
projects / platform / upstream / binutils.git / blobdiff