]>
Commit | Line | Data |
---|---|---|
00340e1b | 1 | /* Serial interface for a selectable event. |
1d506c26 | 2 | Copyright (C) 2016-2024 Free Software Foundation, Inc. |
00340e1b PA |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include "defs.h" | |
20 | #include "ser-event.h" | |
21 | #include "serial.h" | |
268a13a5 | 22 | #include "gdbsupport/filestuff.h" |
00340e1b PA |
23 | |
24 | /* On POSIX hosts, a serial_event is basically an abstraction for the | |
25 | classical self-pipe trick. | |
26 | ||
27 | On Windows, a serial_event is a wrapper around a native Windows | |
28 | event object. Because we want to interface with gdb_select, which | |
29 | takes file descriptors, we need to wrap that Windows event object | |
30 | in a file descriptor. As _open_osfhandle can not be used with | |
31 | event objects, we instead create a dummy file wrap that in a file | |
32 | descriptor with _open_osfhandle, and pass that as selectable | |
33 | descriptor to callers. As Windows' gdb_select converts file | |
34 | descriptors back to Windows handles by calling serial->wait_handle, | |
35 | nothing ever actually waits on that file descriptor. */ | |
36 | ||
37 | struct serial_event_state | |
38 | { | |
39 | #ifdef USE_WIN32API | |
40 | /* The Windows event object, created with CreateEvent. */ | |
41 | HANDLE event; | |
42 | #else | |
43 | /* The write side of the pipe. The read side is in | |
44 | serial->fd. */ | |
45 | int write_fd; | |
46 | #endif | |
47 | }; | |
48 | ||
49 | /* Open a new serial event. */ | |
50 | ||
a2e0acea | 51 | static void |
00340e1b PA |
52 | serial_event_open (struct serial *scb, const char *name) |
53 | { | |
54 | struct serial_event_state *state; | |
55 | ||
56 | state = XNEW (struct serial_event_state); | |
57 | scb->state = state; | |
58 | ||
59 | #ifndef USE_WIN32API | |
60 | { | |
61 | int fds[2]; | |
62 | ||
63 | if (gdb_pipe_cloexec (fds) == -1) | |
f34652de | 64 | internal_error ("creating serial event pipe failed."); |
00340e1b PA |
65 | |
66 | fcntl (fds[0], F_SETFL, O_NONBLOCK); | |
67 | fcntl (fds[1], F_SETFL, O_NONBLOCK); | |
68 | ||
69 | scb->fd = fds[0]; | |
70 | state->write_fd = fds[1]; | |
71 | } | |
72 | #else | |
73 | { | |
74 | /* A dummy file object that can be wrapped in a file descriptor. | |
75 | We don't need to store this handle because closing the file | |
76 | descriptor automatically closes this. */ | |
77 | HANDLE dummy_file; | |
78 | ||
79 | /* A manual-reset event. */ | |
80 | state->event = CreateEvent (0, TRUE, FALSE, 0); | |
81 | ||
82 | /* The dummy file handle. Created just so we have something | |
83 | wrappable in a file descriptor. */ | |
84 | dummy_file = CreateFile ("nul", 0, 0, NULL, OPEN_EXISTING, 0, NULL); | |
85 | scb->fd = _open_osfhandle ((intptr_t) dummy_file, 0); | |
86 | } | |
87 | #endif | |
00340e1b PA |
88 | } |
89 | ||
90 | static void | |
91 | serial_event_close (struct serial *scb) | |
92 | { | |
93 | struct serial_event_state *state = (struct serial_event_state *) scb->state; | |
94 | ||
95 | close (scb->fd); | |
96 | #ifndef USE_WIN32API | |
97 | close (state->write_fd); | |
98 | #else | |
99 | CloseHandle (state->event); | |
100 | #endif | |
101 | ||
102 | scb->fd = -1; | |
103 | ||
104 | xfree (state); | |
105 | scb->state = NULL; | |
106 | } | |
107 | ||
108 | #ifdef USE_WIN32API | |
109 | ||
110 | /* Implementation of the wait_handle method. Returns the native | |
111 | Windows event object handle. */ | |
112 | ||
113 | static void | |
114 | serial_event_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except) | |
115 | { | |
116 | struct serial_event_state *state = (struct serial_event_state *) scb->state; | |
117 | ||
118 | *read = state->event; | |
119 | } | |
120 | ||
121 | #endif | |
122 | ||
123 | /* The serial_ops for struct serial_event objects. Note we never | |
124 | register this serial type with serial_add_interface, because this | |
125 | is internal implementation detail never to be used by remote | |
126 | targets for protocol transport. */ | |
127 | ||
128 | static const struct serial_ops serial_event_ops = | |
129 | { | |
130 | "event", | |
131 | serial_event_open, | |
132 | serial_event_close, | |
133 | NULL, /* fdopen */ | |
134 | NULL, /* readchar */ | |
135 | NULL, /* write */ | |
136 | NULL, /* flush_output */ | |
137 | NULL, /* flush_input */ | |
138 | NULL, /* send_break */ | |
139 | NULL, /* go_raw */ | |
140 | NULL, /* get_tty_state */ | |
141 | NULL, /* copy_tty_state */ | |
142 | NULL, /* set_tty_state */ | |
143 | NULL, /* print_tty_state */ | |
00340e1b PA |
144 | NULL, /* setbaudrate */ |
145 | NULL, /* setstopbits */ | |
146 | NULL, /* setparity */ | |
147 | NULL, /* drain_output */ | |
148 | NULL, /* async */ | |
149 | NULL, /* read_prim */ | |
150 | NULL, /* write_prim */ | |
151 | NULL, /* avail */ | |
152 | #ifdef USE_WIN32API | |
153 | serial_event_wait_handle, | |
154 | #endif | |
155 | }; | |
156 | ||
157 | /* See ser-event.h. */ | |
158 | ||
159 | struct serial_event * | |
160 | make_serial_event (void) | |
161 | { | |
162 | return (struct serial_event *) serial_open_ops (&serial_event_ops); | |
163 | } | |
164 | ||
165 | /* See ser-event.h. */ | |
166 | ||
167 | int | |
168 | serial_event_fd (struct serial_event *event) | |
169 | { | |
170 | struct serial *ser = (struct serial *) event; | |
171 | ||
172 | return ser->fd; | |
173 | } | |
174 | ||
175 | /* See ser-event.h. */ | |
176 | ||
177 | void | |
178 | serial_event_set (struct serial_event *event) | |
179 | { | |
180 | struct serial *ser = (struct serial *) event; | |
181 | struct serial_event_state *state = (struct serial_event_state *) ser->state; | |
182 | #ifndef USE_WIN32API | |
183 | int r; | |
184 | char c = '+'; /* Anything. */ | |
185 | ||
186 | do | |
187 | { | |
188 | r = write (state->write_fd, &c, 1); | |
189 | } | |
190 | while (r < 0 && errno == EINTR); | |
191 | #else | |
192 | SetEvent (state->event); | |
193 | #endif | |
194 | } | |
195 | ||
196 | /* See ser-event.h. */ | |
197 | ||
198 | void | |
199 | serial_event_clear (struct serial_event *event) | |
200 | { | |
201 | struct serial *ser = (struct serial *) event; | |
00340e1b PA |
202 | #ifndef USE_WIN32API |
203 | int r; | |
204 | ||
205 | do | |
206 | { | |
207 | char c; | |
208 | ||
209 | r = read (ser->fd, &c, 1); | |
210 | } | |
211 | while (r > 0 || (r < 0 && errno == EINTR)); | |
212 | #else | |
798a7429 | 213 | struct serial_event_state *state = (struct serial_event_state *) ser->state; |
00340e1b PA |
214 | ResetEvent (state->event); |
215 | #endif | |
216 | } |