root / main-loop.h @ d7582078
History | View | Annotate | Download (13.5 kB)
1 | 44a9b356 | Paolo Bonzini | /*
|
---|---|---|---|
2 | 44a9b356 | Paolo Bonzini | * QEMU System Emulator
|
3 | 44a9b356 | Paolo Bonzini | *
|
4 | 44a9b356 | Paolo Bonzini | * Copyright (c) 2003-2008 Fabrice Bellard
|
5 | 44a9b356 | Paolo Bonzini | *
|
6 | 44a9b356 | Paolo Bonzini | * Permission is hereby granted, free of charge, to any person obtaining a copy
|
7 | 44a9b356 | Paolo Bonzini | * of this software and associated documentation files (the "Software"), to deal
|
8 | 44a9b356 | Paolo Bonzini | * in the Software without restriction, including without limitation the rights
|
9 | 44a9b356 | Paolo Bonzini | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
10 | 44a9b356 | Paolo Bonzini | * copies of the Software, and to permit persons to whom the Software is
|
11 | 44a9b356 | Paolo Bonzini | * furnished to do so, subject to the following conditions:
|
12 | 44a9b356 | Paolo Bonzini | *
|
13 | 44a9b356 | Paolo Bonzini | * The above copyright notice and this permission notice shall be included in
|
14 | 44a9b356 | Paolo Bonzini | * all copies or substantial portions of the Software.
|
15 | 44a9b356 | Paolo Bonzini | *
|
16 | 44a9b356 | Paolo Bonzini | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
17 | 44a9b356 | Paolo Bonzini | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
18 | 44a9b356 | Paolo Bonzini | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
19 | 44a9b356 | Paolo Bonzini | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
20 | 44a9b356 | Paolo Bonzini | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
21 | 44a9b356 | Paolo Bonzini | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
22 | 44a9b356 | Paolo Bonzini | * THE SOFTWARE.
|
23 | 44a9b356 | Paolo Bonzini | */
|
24 | 44a9b356 | Paolo Bonzini | |
25 | 44a9b356 | Paolo Bonzini | #ifndef QEMU_MAIN_LOOP_H
|
26 | 44a9b356 | Paolo Bonzini | #define QEMU_MAIN_LOOP_H 1 |
27 | 44a9b356 | Paolo Bonzini | |
28 | 44a9b356 | Paolo Bonzini | #define SIG_IPI SIGUSR1
|
29 | 44a9b356 | Paolo Bonzini | |
30 | 44a9b356 | Paolo Bonzini | /**
|
31 | 44a9b356 | Paolo Bonzini | * qemu_init_main_loop: Set up the process so that it can run the main loop.
|
32 | 44a9b356 | Paolo Bonzini | *
|
33 | 44a9b356 | Paolo Bonzini | * This includes setting up signal handlers. It should be called before
|
34 | 44a9b356 | Paolo Bonzini | * any other threads are created. In addition, threads other than the
|
35 | 44a9b356 | Paolo Bonzini | * main one should block signals that are trapped by the main loop.
|
36 | 44a9b356 | Paolo Bonzini | * For simplicity, you can consider these signals to be safe: SIGUSR1,
|
37 | 44a9b356 | Paolo Bonzini | * SIGUSR2, thread signals (SIGFPE, SIGILL, SIGSEGV, SIGBUS) and real-time
|
38 | 44a9b356 | Paolo Bonzini | * signals if available. Remember that Windows in practice does not have
|
39 | 44a9b356 | Paolo Bonzini | * signals, though.
|
40 | d34e8f6e | Michael Roth | *
|
41 | d34e8f6e | Michael Roth | * In the case of QEMU tools, this will also start/initialize timers.
|
42 | 44a9b356 | Paolo Bonzini | */
|
43 | 44a9b356 | Paolo Bonzini | int qemu_init_main_loop(void); |
44 | 44a9b356 | Paolo Bonzini | |
45 | 44a9b356 | Paolo Bonzini | /**
|
46 | d34e8f6e | Michael Roth | * main_loop_init: Initializes main loop
|
47 | d34e8f6e | Michael Roth | *
|
48 | d34e8f6e | Michael Roth | * Internal (but shared for compatibility reasons) initialization routine
|
49 | d34e8f6e | Michael Roth | * for the main loop. This should not be used by applications directly,
|
50 | d34e8f6e | Michael Roth | * use qemu_init_main_loop() instead.
|
51 | d34e8f6e | Michael Roth | *
|
52 | d34e8f6e | Michael Roth | */
|
53 | d34e8f6e | Michael Roth | int main_loop_init(void); |
54 | d34e8f6e | Michael Roth | |
55 | d34e8f6e | Michael Roth | /**
|
56 | 44a9b356 | Paolo Bonzini | * main_loop_wait: Run one iteration of the main loop.
|
57 | 44a9b356 | Paolo Bonzini | *
|
58 | 44a9b356 | Paolo Bonzini | * If @nonblocking is true, poll for events, otherwise suspend until
|
59 | 44a9b356 | Paolo Bonzini | * one actually occurs. The main loop usually consists of a loop that
|
60 | 44a9b356 | Paolo Bonzini | * repeatedly calls main_loop_wait(false).
|
61 | 44a9b356 | Paolo Bonzini | *
|
62 | 44a9b356 | Paolo Bonzini | * Main loop services include file descriptor callbacks, bottom halves
|
63 | 44a9b356 | Paolo Bonzini | * and timers (defined in qemu-timer.h). Bottom halves are similar to timers
|
64 | 44a9b356 | Paolo Bonzini | * that execute immediately, but have a lower overhead and scheduling them
|
65 | 44a9b356 | Paolo Bonzini | * is wait-free, thread-safe and signal-safe.
|
66 | 44a9b356 | Paolo Bonzini | *
|
67 | 44a9b356 | Paolo Bonzini | * It is sometimes useful to put a whole program in a coroutine. In this
|
68 | 44a9b356 | Paolo Bonzini | * case, the coroutine actually should be started from within the main loop,
|
69 | 44a9b356 | Paolo Bonzini | * so that the main loop can run whenever the coroutine yields. To do this,
|
70 | 44a9b356 | Paolo Bonzini | * you can use a bottom half to enter the coroutine as soon as the main loop
|
71 | 44a9b356 | Paolo Bonzini | * starts:
|
72 | 44a9b356 | Paolo Bonzini | *
|
73 | 44a9b356 | Paolo Bonzini | * void enter_co_bh(void *opaque) {
|
74 | 44a9b356 | Paolo Bonzini | * QEMUCoroutine *co = opaque;
|
75 | 44a9b356 | Paolo Bonzini | * qemu_coroutine_enter(co, NULL);
|
76 | 44a9b356 | Paolo Bonzini | * }
|
77 | 44a9b356 | Paolo Bonzini | *
|
78 | 44a9b356 | Paolo Bonzini | * ...
|
79 | 44a9b356 | Paolo Bonzini | * QEMUCoroutine *co = qemu_coroutine_create(coroutine_entry);
|
80 | 44a9b356 | Paolo Bonzini | * QEMUBH *start_bh = qemu_bh_new(enter_co_bh, co);
|
81 | 44a9b356 | Paolo Bonzini | * qemu_bh_schedule(start_bh);
|
82 | 44a9b356 | Paolo Bonzini | * while (...) {
|
83 | 44a9b356 | Paolo Bonzini | * main_loop_wait(false);
|
84 | 44a9b356 | Paolo Bonzini | * }
|
85 | 44a9b356 | Paolo Bonzini | *
|
86 | 44a9b356 | Paolo Bonzini | * (In the future we may provide a wrapper for this).
|
87 | 44a9b356 | Paolo Bonzini | *
|
88 | 44a9b356 | Paolo Bonzini | * @nonblocking: Whether the caller should block until an event occurs.
|
89 | 44a9b356 | Paolo Bonzini | */
|
90 | 44a9b356 | Paolo Bonzini | int main_loop_wait(int nonblocking); |
91 | 44a9b356 | Paolo Bonzini | |
92 | 44a9b356 | Paolo Bonzini | /**
|
93 | 44a9b356 | Paolo Bonzini | * qemu_notify_event: Force processing of pending events.
|
94 | 44a9b356 | Paolo Bonzini | *
|
95 | 44a9b356 | Paolo Bonzini | * Similar to signaling a condition variable, qemu_notify_event forces
|
96 | 44a9b356 | Paolo Bonzini | * main_loop_wait to look at pending events and exit. The caller of
|
97 | 44a9b356 | Paolo Bonzini | * main_loop_wait will usually call it again very soon, so qemu_notify_event
|
98 | 44a9b356 | Paolo Bonzini | * also has the side effect of recalculating the sets of file descriptors
|
99 | 44a9b356 | Paolo Bonzini | * that the main loop waits for.
|
100 | 44a9b356 | Paolo Bonzini | *
|
101 | 44a9b356 | Paolo Bonzini | * Calling qemu_notify_event is rarely necessary, because main loop
|
102 | 44a9b356 | Paolo Bonzini | * services (bottom halves and timers) call it themselves. One notable
|
103 | 44a9b356 | Paolo Bonzini | * exception occurs when using qemu_set_fd_handler2 (see below).
|
104 | 44a9b356 | Paolo Bonzini | */
|
105 | 44a9b356 | Paolo Bonzini | void qemu_notify_event(void); |
106 | 44a9b356 | Paolo Bonzini | |
107 | 44a9b356 | Paolo Bonzini | #ifdef _WIN32
|
108 | 44a9b356 | Paolo Bonzini | /* return TRUE if no sleep should be done afterwards */
|
109 | 44a9b356 | Paolo Bonzini | typedef int PollingFunc(void *opaque); |
110 | 44a9b356 | Paolo Bonzini | |
111 | 44a9b356 | Paolo Bonzini | /**
|
112 | 44a9b356 | Paolo Bonzini | * qemu_add_polling_cb: Register a Windows-specific polling callback
|
113 | 44a9b356 | Paolo Bonzini | *
|
114 | 44a9b356 | Paolo Bonzini | * Currently, under Windows some events are polled rather than waited for.
|
115 | 44a9b356 | Paolo Bonzini | * Polling callbacks do not ensure that @func is called timely, because
|
116 | 44a9b356 | Paolo Bonzini | * the main loop might wait for an arbitrarily long time. If possible,
|
117 | 44a9b356 | Paolo Bonzini | * you should instead create a separate thread that does a blocking poll
|
118 | 44a9b356 | Paolo Bonzini | * and set a Win32 event object. The event can then be passed to
|
119 | 44a9b356 | Paolo Bonzini | * qemu_add_wait_object.
|
120 | 44a9b356 | Paolo Bonzini | *
|
121 | 44a9b356 | Paolo Bonzini | * Polling callbacks really have nothing Windows specific in them, but
|
122 | 07f35073 | Dong Xu Wang | * as they are a hack and are currently not necessary under POSIX systems,
|
123 | 44a9b356 | Paolo Bonzini | * they are only available when QEMU is running under Windows.
|
124 | 44a9b356 | Paolo Bonzini | *
|
125 | 44a9b356 | Paolo Bonzini | * @func: The function that does the polling, and returns 1 to force
|
126 | 44a9b356 | Paolo Bonzini | * immediate completion of main_loop_wait.
|
127 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-size value that is passed to @func.
|
128 | 44a9b356 | Paolo Bonzini | */
|
129 | 44a9b356 | Paolo Bonzini | int qemu_add_polling_cb(PollingFunc *func, void *opaque); |
130 | 44a9b356 | Paolo Bonzini | |
131 | 44a9b356 | Paolo Bonzini | /**
|
132 | 44a9b356 | Paolo Bonzini | * qemu_del_polling_cb: Unregister a Windows-specific polling callback
|
133 | 44a9b356 | Paolo Bonzini | *
|
134 | 44a9b356 | Paolo Bonzini | * This function removes a callback that was registered with
|
135 | 44a9b356 | Paolo Bonzini | * qemu_add_polling_cb.
|
136 | 44a9b356 | Paolo Bonzini | *
|
137 | 44a9b356 | Paolo Bonzini | * @func: The function that was passed to qemu_add_polling_cb.
|
138 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-size value that was passed to qemu_add_polling_cb.
|
139 | 44a9b356 | Paolo Bonzini | */
|
140 | 44a9b356 | Paolo Bonzini | void qemu_del_polling_cb(PollingFunc *func, void *opaque); |
141 | 44a9b356 | Paolo Bonzini | |
142 | 44a9b356 | Paolo Bonzini | /* Wait objects handling */
|
143 | 44a9b356 | Paolo Bonzini | typedef void WaitObjectFunc(void *opaque); |
144 | 44a9b356 | Paolo Bonzini | |
145 | 44a9b356 | Paolo Bonzini | /**
|
146 | 44a9b356 | Paolo Bonzini | * qemu_add_wait_object: Register a callback for a Windows handle
|
147 | 44a9b356 | Paolo Bonzini | *
|
148 | 44a9b356 | Paolo Bonzini | * Under Windows, the iohandler mechanism can only be used with sockets.
|
149 | 44a9b356 | Paolo Bonzini | * QEMU must use the WaitForMultipleObjects API to wait on other handles.
|
150 | 44a9b356 | Paolo Bonzini | * This function registers a #HANDLE with QEMU, so that it will be included
|
151 | 44a9b356 | Paolo Bonzini | * in the main loop's calls to WaitForMultipleObjects. When the handle
|
152 | 44a9b356 | Paolo Bonzini | * is in a signaled state, QEMU will call @func.
|
153 | 44a9b356 | Paolo Bonzini | *
|
154 | 44a9b356 | Paolo Bonzini | * @handle: The Windows handle to be observed.
|
155 | 44a9b356 | Paolo Bonzini | * @func: A function to be called when @handle is in a signaled state.
|
156 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-size value that is passed to @func.
|
157 | 44a9b356 | Paolo Bonzini | */
|
158 | 44a9b356 | Paolo Bonzini | int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque); |
159 | 44a9b356 | Paolo Bonzini | |
160 | 44a9b356 | Paolo Bonzini | /**
|
161 | 44a9b356 | Paolo Bonzini | * qemu_del_wait_object: Unregister a callback for a Windows handle
|
162 | 44a9b356 | Paolo Bonzini | *
|
163 | 44a9b356 | Paolo Bonzini | * This function removes a callback that was registered with
|
164 | 44a9b356 | Paolo Bonzini | * qemu_add_wait_object.
|
165 | 44a9b356 | Paolo Bonzini | *
|
166 | 44a9b356 | Paolo Bonzini | * @func: The function that was passed to qemu_add_wait_object.
|
167 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-size value that was passed to qemu_add_wait_object.
|
168 | 44a9b356 | Paolo Bonzini | */
|
169 | 44a9b356 | Paolo Bonzini | void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque); |
170 | 44a9b356 | Paolo Bonzini | #endif
|
171 | 44a9b356 | Paolo Bonzini | |
172 | 44a9b356 | Paolo Bonzini | /* async I/O support */
|
173 | 44a9b356 | Paolo Bonzini | |
174 | 44a9b356 | Paolo Bonzini | typedef void IOReadHandler(void *opaque, const uint8_t *buf, int size); |
175 | 44a9b356 | Paolo Bonzini | typedef int IOCanReadHandler(void *opaque); |
176 | 44a9b356 | Paolo Bonzini | typedef void IOHandler(void *opaque); |
177 | 44a9b356 | Paolo Bonzini | |
178 | 44a9b356 | Paolo Bonzini | /**
|
179 | 44a9b356 | Paolo Bonzini | * qemu_set_fd_handler2: Register a file descriptor with the main loop
|
180 | 44a9b356 | Paolo Bonzini | *
|
181 | 44a9b356 | Paolo Bonzini | * This function tells the main loop to wake up whenever one of the
|
182 | 44a9b356 | Paolo Bonzini | * following conditions is true:
|
183 | 44a9b356 | Paolo Bonzini | *
|
184 | 44a9b356 | Paolo Bonzini | * 1) if @fd_write is not %NULL, when the file descriptor is writable;
|
185 | 44a9b356 | Paolo Bonzini | *
|
186 | 44a9b356 | Paolo Bonzini | * 2) if @fd_read is not %NULL, when the file descriptor is readable.
|
187 | 44a9b356 | Paolo Bonzini | *
|
188 | 44a9b356 | Paolo Bonzini | * @fd_read_poll can be used to disable the @fd_read callback temporarily.
|
189 | 44a9b356 | Paolo Bonzini | * This is useful to avoid calling qemu_set_fd_handler2 every time the
|
190 | 44a9b356 | Paolo Bonzini | * client becomes interested in reading (or dually, stops being interested).
|
191 | 44a9b356 | Paolo Bonzini | * A typical example is when @fd is a listening socket and you want to bound
|
192 | 44a9b356 | Paolo Bonzini | * the number of active clients. Remember to call qemu_notify_event whenever
|
193 | 44a9b356 | Paolo Bonzini | * the condition may change from %false to %true.
|
194 | 44a9b356 | Paolo Bonzini | *
|
195 | 44a9b356 | Paolo Bonzini | * The callbacks that are set up by qemu_set_fd_handler2 are level-triggered.
|
196 | 44a9b356 | Paolo Bonzini | * If @fd_read does not read from @fd, or @fd_write does not write to @fd
|
197 | 44a9b356 | Paolo Bonzini | * until its buffers are full, they will be called again on the next
|
198 | 44a9b356 | Paolo Bonzini | * iteration.
|
199 | 44a9b356 | Paolo Bonzini | *
|
200 | 44a9b356 | Paolo Bonzini | * @fd: The file descriptor to be observed. Under Windows it must be
|
201 | 44a9b356 | Paolo Bonzini | * a #SOCKET.
|
202 | 44a9b356 | Paolo Bonzini | *
|
203 | 44a9b356 | Paolo Bonzini | * @fd_read_poll: A function that returns 1 if the @fd_read callback
|
204 | 44a9b356 | Paolo Bonzini | * should be fired. If the function returns 0, the main loop will not
|
205 | 44a9b356 | Paolo Bonzini | * end its iteration even if @fd becomes readable.
|
206 | 44a9b356 | Paolo Bonzini | *
|
207 | 44a9b356 | Paolo Bonzini | * @fd_read: A level-triggered callback that is fired if @fd is readable
|
208 | 44a9b356 | Paolo Bonzini | * at the beginning of a main loop iteration, or if it becomes readable
|
209 | 44a9b356 | Paolo Bonzini | * during one.
|
210 | 44a9b356 | Paolo Bonzini | *
|
211 | 44a9b356 | Paolo Bonzini | * @fd_write: A level-triggered callback that is fired when @fd is writable
|
212 | 44a9b356 | Paolo Bonzini | * at the beginning of a main loop iteration, or if it becomes writable
|
213 | 44a9b356 | Paolo Bonzini | * during one.
|
214 | 44a9b356 | Paolo Bonzini | *
|
215 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-sized value that is passed to @fd_read_poll,
|
216 | 44a9b356 | Paolo Bonzini | * @fd_read and @fd_write.
|
217 | 44a9b356 | Paolo Bonzini | */
|
218 | 44a9b356 | Paolo Bonzini | int qemu_set_fd_handler2(int fd, |
219 | 44a9b356 | Paolo Bonzini | IOCanReadHandler *fd_read_poll, |
220 | 44a9b356 | Paolo Bonzini | IOHandler *fd_read, |
221 | 44a9b356 | Paolo Bonzini | IOHandler *fd_write, |
222 | 44a9b356 | Paolo Bonzini | void *opaque);
|
223 | 44a9b356 | Paolo Bonzini | |
224 | 44a9b356 | Paolo Bonzini | /**
|
225 | 44a9b356 | Paolo Bonzini | * qemu_set_fd_handler: Register a file descriptor with the main loop
|
226 | 44a9b356 | Paolo Bonzini | *
|
227 | 44a9b356 | Paolo Bonzini | * This function tells the main loop to wake up whenever one of the
|
228 | 44a9b356 | Paolo Bonzini | * following conditions is true:
|
229 | 44a9b356 | Paolo Bonzini | *
|
230 | 44a9b356 | Paolo Bonzini | * 1) if @fd_write is not %NULL, when the file descriptor is writable;
|
231 | 44a9b356 | Paolo Bonzini | *
|
232 | 44a9b356 | Paolo Bonzini | * 2) if @fd_read is not %NULL, when the file descriptor is readable.
|
233 | 44a9b356 | Paolo Bonzini | *
|
234 | 44a9b356 | Paolo Bonzini | * The callbacks that are set up by qemu_set_fd_handler are level-triggered.
|
235 | 44a9b356 | Paolo Bonzini | * If @fd_read does not read from @fd, or @fd_write does not write to @fd
|
236 | 44a9b356 | Paolo Bonzini | * until its buffers are full, they will be called again on the next
|
237 | 44a9b356 | Paolo Bonzini | * iteration.
|
238 | 44a9b356 | Paolo Bonzini | *
|
239 | 44a9b356 | Paolo Bonzini | * @fd: The file descriptor to be observed. Under Windows it must be
|
240 | 44a9b356 | Paolo Bonzini | * a #SOCKET.
|
241 | 44a9b356 | Paolo Bonzini | *
|
242 | 44a9b356 | Paolo Bonzini | * @fd_read: A level-triggered callback that is fired if @fd is readable
|
243 | 44a9b356 | Paolo Bonzini | * at the beginning of a main loop iteration, or if it becomes readable
|
244 | 44a9b356 | Paolo Bonzini | * during one.
|
245 | 44a9b356 | Paolo Bonzini | *
|
246 | 44a9b356 | Paolo Bonzini | * @fd_write: A level-triggered callback that is fired when @fd is writable
|
247 | 44a9b356 | Paolo Bonzini | * at the beginning of a main loop iteration, or if it becomes writable
|
248 | 44a9b356 | Paolo Bonzini | * during one.
|
249 | 44a9b356 | Paolo Bonzini | *
|
250 | 44a9b356 | Paolo Bonzini | * @opaque: A pointer-sized value that is passed to @fd_read and @fd_write.
|
251 | 44a9b356 | Paolo Bonzini | */
|
252 | 44a9b356 | Paolo Bonzini | int qemu_set_fd_handler(int fd, |
253 | 44a9b356 | Paolo Bonzini | IOHandler *fd_read, |
254 | 44a9b356 | Paolo Bonzini | IOHandler *fd_write, |
255 | 44a9b356 | Paolo Bonzini | void *opaque);
|
256 | 44a9b356 | Paolo Bonzini | |
257 | 44a9b356 | Paolo Bonzini | typedef struct QEMUBH QEMUBH; |
258 | 44a9b356 | Paolo Bonzini | typedef void QEMUBHFunc(void *opaque); |
259 | 44a9b356 | Paolo Bonzini | |
260 | 44a9b356 | Paolo Bonzini | /**
|
261 | 44a9b356 | Paolo Bonzini | * qemu_bh_new: Allocate a new bottom half structure.
|
262 | 44a9b356 | Paolo Bonzini | *
|
263 | 44a9b356 | Paolo Bonzini | * Bottom halves are lightweight callbacks whose invocation is guaranteed
|
264 | 44a9b356 | Paolo Bonzini | * to be wait-free, thread-safe and signal-safe. The #QEMUBH structure
|
265 | 44a9b356 | Paolo Bonzini | * is opaque and must be allocated prior to its use.
|
266 | 44a9b356 | Paolo Bonzini | */
|
267 | 44a9b356 | Paolo Bonzini | QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque);
|
268 | 44a9b356 | Paolo Bonzini | |
269 | 44a9b356 | Paolo Bonzini | /**
|
270 | 44a9b356 | Paolo Bonzini | * qemu_bh_schedule: Schedule a bottom half.
|
271 | 44a9b356 | Paolo Bonzini | *
|
272 | 44a9b356 | Paolo Bonzini | * Scheduling a bottom half interrupts the main loop and causes the
|
273 | 44a9b356 | Paolo Bonzini | * execution of the callback that was passed to qemu_bh_new.
|
274 | 44a9b356 | Paolo Bonzini | *
|
275 | 44a9b356 | Paolo Bonzini | * Bottom halves that are scheduled from a bottom half handler are instantly
|
276 | 44a9b356 | Paolo Bonzini | * invoked. This can create an infinite loop if a bottom half handler
|
277 | 44a9b356 | Paolo Bonzini | * schedules itself.
|
278 | 44a9b356 | Paolo Bonzini | *
|
279 | 44a9b356 | Paolo Bonzini | * @bh: The bottom half to be scheduled.
|
280 | 44a9b356 | Paolo Bonzini | */
|
281 | 44a9b356 | Paolo Bonzini | void qemu_bh_schedule(QEMUBH *bh);
|
282 | 44a9b356 | Paolo Bonzini | |
283 | 44a9b356 | Paolo Bonzini | /**
|
284 | 44a9b356 | Paolo Bonzini | * qemu_bh_cancel: Cancel execution of a bottom half.
|
285 | 44a9b356 | Paolo Bonzini | *
|
286 | 44a9b356 | Paolo Bonzini | * Canceling execution of a bottom half undoes the effect of calls to
|
287 | 44a9b356 | Paolo Bonzini | * qemu_bh_schedule without freeing its resources yet. While cancellation
|
288 | 44a9b356 | Paolo Bonzini | * itself is also wait-free and thread-safe, it can of course race with the
|
289 | 44a9b356 | Paolo Bonzini | * loop that executes bottom halves unless you are holding the iothread
|
290 | 44a9b356 | Paolo Bonzini | * mutex. This makes it mostly useless if you are not holding the mutex.
|
291 | 44a9b356 | Paolo Bonzini | *
|
292 | 44a9b356 | Paolo Bonzini | * @bh: The bottom half to be canceled.
|
293 | 44a9b356 | Paolo Bonzini | */
|
294 | 44a9b356 | Paolo Bonzini | void qemu_bh_cancel(QEMUBH *bh);
|
295 | 44a9b356 | Paolo Bonzini | |
296 | 44a9b356 | Paolo Bonzini | /**
|
297 | 44a9b356 | Paolo Bonzini | *qemu_bh_delete: Cancel execution of a bottom half and free its resources.
|
298 | 44a9b356 | Paolo Bonzini | *
|
299 | 44a9b356 | Paolo Bonzini | * Deleting a bottom half frees the memory that was allocated for it by
|
300 | 44a9b356 | Paolo Bonzini | * qemu_bh_new. It also implies canceling the bottom half if it was
|
301 | 44a9b356 | Paolo Bonzini | * scheduled.
|
302 | 44a9b356 | Paolo Bonzini | *
|
303 | 44a9b356 | Paolo Bonzini | * @bh: The bottom half to be deleted.
|
304 | 44a9b356 | Paolo Bonzini | */
|
305 | 44a9b356 | Paolo Bonzini | void qemu_bh_delete(QEMUBH *bh);
|
306 | 44a9b356 | Paolo Bonzini | |
307 | 44a9b356 | Paolo Bonzini | #ifdef CONFIG_POSIX
|
308 | 44a9b356 | Paolo Bonzini | /**
|
309 | 44a9b356 | Paolo Bonzini | * qemu_add_child_watch: Register a child process for reaping.
|
310 | 44a9b356 | Paolo Bonzini | *
|
311 | 44a9b356 | Paolo Bonzini | * Under POSIX systems, a parent process must read the exit status of
|
312 | 44a9b356 | Paolo Bonzini | * its child processes using waitpid, or the operating system will not
|
313 | 44a9b356 | Paolo Bonzini | * free some of the resources attached to that process.
|
314 | 44a9b356 | Paolo Bonzini | *
|
315 | 44a9b356 | Paolo Bonzini | * This function directs the QEMU main loop to observe a child process
|
316 | 44a9b356 | Paolo Bonzini | * and call waitpid as soon as it exits; the watch is then removed
|
317 | 44a9b356 | Paolo Bonzini | * automatically. It is useful whenever QEMU forks a child process
|
318 | 44a9b356 | Paolo Bonzini | * but will find out about its termination by other means such as a
|
319 | 44a9b356 | Paolo Bonzini | * "broken pipe".
|
320 | 44a9b356 | Paolo Bonzini | *
|
321 | 44a9b356 | Paolo Bonzini | * @pid: The pid that QEMU should observe.
|
322 | 44a9b356 | Paolo Bonzini | */
|
323 | 44a9b356 | Paolo Bonzini | int qemu_add_child_watch(pid_t pid);
|
324 | 44a9b356 | Paolo Bonzini | #endif
|
325 | 44a9b356 | Paolo Bonzini | |
326 | d3b12f5d | Paolo Bonzini | /**
|
327 | d3b12f5d | Paolo Bonzini | * qemu_mutex_lock_iothread: Lock the main loop mutex.
|
328 | d3b12f5d | Paolo Bonzini | *
|
329 | d3b12f5d | Paolo Bonzini | * This function locks the main loop mutex. The mutex is taken by
|
330 | d3b12f5d | Paolo Bonzini | * qemu_init_main_loop and always taken except while waiting on
|
331 | d3b12f5d | Paolo Bonzini | * external events (such as with select). The mutex should be taken
|
332 | d3b12f5d | Paolo Bonzini | * by threads other than the main loop thread when calling
|
333 | d3b12f5d | Paolo Bonzini | * qemu_bh_new(), qemu_set_fd_handler() and basically all other
|
334 | d3b12f5d | Paolo Bonzini | * functions documented in this file.
|
335 | cbcfa041 | Paolo Bonzini | *
|
336 | cbcfa041 | Paolo Bonzini | * NOTE: tools currently are single-threaded and qemu_mutex_lock_iothread
|
337 | cbcfa041 | Paolo Bonzini | * is a no-op there.
|
338 | d3b12f5d | Paolo Bonzini | */
|
339 | d3b12f5d | Paolo Bonzini | void qemu_mutex_lock_iothread(void); |
340 | d3b12f5d | Paolo Bonzini | |
341 | d3b12f5d | Paolo Bonzini | /**
|
342 | d3b12f5d | Paolo Bonzini | * qemu_mutex_unlock_iothread: Unlock the main loop mutex.
|
343 | d3b12f5d | Paolo Bonzini | *
|
344 | d3b12f5d | Paolo Bonzini | * This function unlocks the main loop mutex. The mutex is taken by
|
345 | d3b12f5d | Paolo Bonzini | * qemu_init_main_loop and always taken except while waiting on
|
346 | d3b12f5d | Paolo Bonzini | * external events (such as with select). The mutex should be unlocked
|
347 | d3b12f5d | Paolo Bonzini | * as soon as possible by threads other than the main loop thread,
|
348 | d3b12f5d | Paolo Bonzini | * because it prevents the main loop from processing callbacks,
|
349 | d3b12f5d | Paolo Bonzini | * including timers and bottom halves.
|
350 | cbcfa041 | Paolo Bonzini | *
|
351 | cbcfa041 | Paolo Bonzini | * NOTE: tools currently are single-threaded and qemu_mutex_unlock_iothread
|
352 | cbcfa041 | Paolo Bonzini | * is a no-op there.
|
353 | d3b12f5d | Paolo Bonzini | */
|
354 | d3b12f5d | Paolo Bonzini | void qemu_mutex_unlock_iothread(void); |
355 | d3b12f5d | Paolo Bonzini | |
356 | 44a9b356 | Paolo Bonzini | /* internal interfaces */
|
357 | 44a9b356 | Paolo Bonzini | |
358 | d3385eb4 | Paolo Bonzini | void qemu_fd_register(int fd); |
359 | 44a9b356 | Paolo Bonzini | void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds); |
360 | 44a9b356 | Paolo Bonzini | void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int rc); |
361 | 44a9b356 | Paolo Bonzini | |
362 | 44a9b356 | Paolo Bonzini | void qemu_bh_schedule_idle(QEMUBH *bh);
|
363 | 44a9b356 | Paolo Bonzini | int qemu_bh_poll(void); |
364 | 7c7db755 | Stefano Stabellini | void qemu_bh_update_timeout(uint32_t *timeout);
|
365 | 44a9b356 | Paolo Bonzini | |
366 | 44a9b356 | Paolo Bonzini | #endif |