1 /* Host support routines for MinGW, for GDB, the GNU debugger.
3 Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "event-loop.h"
25 #include "gdb_assert.h"
26 #include "gdb_select.h"
27 #include "gdb_string.h"
28 #include "readline/readline.h"
32 /* This event is signalled whenever an asynchronous SIGINT handler
33 needs to perform an action in the main thread. */
34 static HANDLE sigint_event
;
36 /* When SIGINT_EVENT is signalled, gdb_select will call this
38 struct async_signal_handler
*sigint_handler
;
40 /* The strerror() function can return NULL for errno values that are
41 out of range. Provide a "safe" version that always returns a
44 The Windows runtime implementation of strerror never returns NULL,
45 but does return a useless string for anything above sys_nerr;
46 unfortunately this includes all socket-related error codes.
47 This replacement tries to find a system-provided error message. */
50 safe_strerror (int errnum
)
55 if (errnum
>= 0 && errnum
< sys_nerr
)
56 return strerror (errnum
);
64 if (FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER
65 | FORMAT_MESSAGE_FROM_SYSTEM
,
67 MAKELANGID (LANG_NEUTRAL
, SUBLANG_DEFAULT
),
68 (LPTSTR
) &buffer
, 0, NULL
) == 0)
71 xsnprintf (buf
, sizeof buf
, "(undocumented errno %d)", errnum
);
75 /* Windows error messages end with a period and a CR-LF; strip that
77 len
= strlen (buffer
);
78 if (len
> 3 && strcmp (buffer
+ len
- 3, ".\r\n") == 0)
79 buffer
[len
- 3] = '\0';
84 /* Wrapper for select. On Windows systems, where the select interface
85 only works for sockets, this uses the GDB serial abstraction to
86 handle sockets, consoles, pipes, and serial ports.
88 The arguments to this function are the same as the traditional
89 arguments to select on POSIX platforms. */
92 gdb_select (int n
, fd_set
*readfds
, fd_set
*writefds
, fd_set
*exceptfds
,
93 struct timeval
*timeout
)
95 static HANDLE never_handle
;
96 HANDLE handles
[MAXIMUM_WAIT_OBJECTS
];
100 /* SCBS contains serial control objects corresponding to file
101 descriptors in READFDS and WRITEFDS. */
102 struct serial
*scbs
[MAXIMUM_WAIT_OBJECTS
];
103 /* The number of valid entries in SCBS. */
112 for (fd
= 0; fd
< n
; ++fd
)
114 HANDLE read
= NULL
, except
= NULL
;
117 /* There is no support yet for WRITEFDS. At present, this isn't
118 used by GDB -- but we do not want to silently ignore WRITEFDS
119 if something starts using it. */
120 gdb_assert (!writefds
|| !FD_ISSET (fd
, writefds
));
122 if ((!readfds
|| !FD_ISSET (fd
, readfds
))
123 && (!exceptfds
|| !FD_ISSET (fd
, exceptfds
)))
126 scb
= serial_for_fd (fd
);
129 serial_wait_handle (scb
, &read
, &except
);
130 scbs
[num_scbs
++] = scb
;
134 read
= (HANDLE
) _get_osfhandle (fd
);
138 never_handle
= CreateEvent (0, FALSE
, FALSE
, 0);
140 except
= never_handle
;
143 if (readfds
&& FD_ISSET (fd
, readfds
))
145 gdb_assert (num_handles
< MAXIMUM_WAIT_OBJECTS
);
146 handles
[num_handles
++] = read
;
149 if (exceptfds
&& FD_ISSET (fd
, exceptfds
))
151 gdb_assert (num_handles
< MAXIMUM_WAIT_OBJECTS
);
152 handles
[num_handles
++] = except
;
156 gdb_assert (num_handles
< MAXIMUM_WAIT_OBJECTS
);
157 handles
[num_handles
++] = sigint_event
;
159 event
= WaitForMultipleObjects (num_handles
,
163 ? (timeout
->tv_sec
* 1000
164 + timeout
->tv_usec
/ 1000)
166 /* EVENT can only be a value in the WAIT_ABANDONED_0 range if the
167 HANDLES included an abandoned mutex. Since GDB doesn't use
168 mutexes, that should never occur. */
169 gdb_assert (!(WAIT_ABANDONED_0
<= event
170 && event
< WAIT_ABANDONED_0
+ num_handles
));
171 /* We no longer need the helper threads to check for activity. */
172 for (indx
= 0; indx
< num_scbs
; ++indx
)
173 serial_done_wait_handle (scbs
[indx
]);
174 if (event
== WAIT_FAILED
)
176 if (event
== WAIT_TIMEOUT
)
178 /* Run through the READFDS, clearing bits corresponding to descriptors
179 for which input is unavailable. */
180 h
= handles
[event
- WAIT_OBJECT_0
];
181 for (fd
= 0, indx
= 0; fd
< n
; ++fd
)
185 if ((!readfds
|| !FD_ISSET (fd
, readfds
))
186 && (!exceptfds
|| !FD_ISSET (fd
, exceptfds
)))
189 if (readfds
&& FD_ISSET (fd
, readfds
))
191 fd_h
= handles
[indx
++];
192 /* This handle might be ready, even though it wasn't the handle
193 returned by WaitForMultipleObjects. */
194 if (fd_h
!= h
&& WaitForSingleObject (fd_h
, 0) != WAIT_OBJECT_0
)
195 FD_CLR (fd
, readfds
);
200 if (exceptfds
&& FD_ISSET (fd
, exceptfds
))
202 fd_h
= handles
[indx
++];
203 /* This handle might be ready, even though it wasn't the handle
204 returned by WaitForMultipleObjects. */
205 if (fd_h
!= h
&& WaitForSingleObject (fd_h
, 0) != WAIT_OBJECT_0
)
206 FD_CLR (fd
, exceptfds
);
212 /* With multi-threaded SIGINT handling, there is a race between the
213 readline signal handler and GDB. It may still be in
214 rl_prep_terminal in another thread. Do not return until it is
215 done; we can check the state here because we never longjmp from
216 signal handlers on Windows. */
217 while (RL_ISSTATE (RL_STATE_SIGHANDLER
))
220 if (h
== sigint_event
221 || WaitForSingleObject (sigint_event
, 0) == WAIT_OBJECT_0
)
223 if (sigint_handler
!= NULL
)
224 call_async_signal_handler (sigint_handler
);
236 /* Wrapper for the body of signal handlers. On Windows systems, a
237 SIGINT handler runs in its own thread. We can't longjmp from
238 there, and we shouldn't even prompt the user. Delay HANDLER
239 until the main thread is next in gdb_select. */
242 gdb_call_async_signal_handler (struct async_signal_handler
*handler
,
246 sigint_handler
= handler
;
249 mark_async_signal_handler (handler
);
250 sigint_handler
= NULL
;
252 SetEvent (sigint_event
);
256 _initialize_mingw_hdep (void)
258 sigint_event
= CreateEvent (0, FALSE
, FALSE
, 0);