1 /*
2 * Copyright 2005-2016, Haiku.
3 * Distributed under the terms of the MIT License.
4 *
5 * Authors:
6 * Axel Dörfler, axeld@pinc-software.de
7 */
8
9
10 #include "MessageLooper.h"
11
12 #include <malloc.h>
13 #include <stdio.h>
14 #include <string.h>
15
16 #include <Autolock.h>
17
18
MessageLooper(const char * name)19 MessageLooper::MessageLooper(const char* name)
20 :
21 BLocker(name),
22 fName(strdup(name)),
23 fThread(-1),
24 fQuitting(false),
25 fDeathSemaphore(-1)
26 {
27 }
28
29
~MessageLooper()30 MessageLooper::~MessageLooper()
31 {
32 free((void*)fName);
33 }
34
35
36 status_t
Run()37 MessageLooper::Run()
38 {
39 BAutolock locker(this);
40
41 fQuitting = false;
42
43 char name[B_OS_NAME_LENGTH];
44 _GetLooperName(name, sizeof(name));
45
46 // Spawn our message-monitoring thread
47 fThread = spawn_thread(_message_thread, name, B_DISPLAY_PRIORITY, this);
48 if (fThread < B_OK) {
49 fQuitting = true;
50 return fThread;
51 }
52
53 if (resume_thread(fThread) != B_OK) {
54 fQuitting = true;
55 kill_thread(fThread);
56 fThread = -1;
57 return B_BAD_THREAD_ID;
58 }
59
60 return B_OK;
61 }
62
63
64 void
Quit()65 MessageLooper::Quit()
66 {
67 fQuitting = true;
68 _PrepareQuit();
69
70 if (fThread < B_OK) {
71 // thread has not been started yet
72 delete this;
73 return;
74 }
75
76 if (fThread == find_thread(NULL)) {
77 // called from our message looper
78 delete this;
79 exit_thread(0);
80 } else {
81 // called from a different thread
82 PostMessage(kMsgQuitLooper);
83 }
84 }
85
86
87 /*!
88 \brief Send a message to the looper without any attachments
89 \param code ID code of the message to post
90 */
91 status_t
PostMessage(int32 code,bigtime_t timeout)92 MessageLooper::PostMessage(int32 code, bigtime_t timeout)
93 {
94 BPrivate::LinkSender link(MessagePort());
95 link.StartMessage(code);
96 return link.Flush(timeout);
97 }
98
99
100 /*static*/
101 status_t
WaitForQuit(sem_id semaphore,bigtime_t timeout)102 MessageLooper::WaitForQuit(sem_id semaphore, bigtime_t timeout)
103 {
104 status_t status;
105 do {
106 status = acquire_sem_etc(semaphore, 1, B_RELATIVE_TIMEOUT, timeout);
107 } while (status == B_INTERRUPTED);
108
109 if (status == B_TIMED_OUT)
110 return status;
111
112 return B_OK;
113 }
114
115
116 void
_PrepareQuit()117 MessageLooper::_PrepareQuit()
118 {
119 // to be implemented by subclasses
120 }
121
122
123 void
_GetLooperName(char * name,size_t length)124 MessageLooper::_GetLooperName(char* name, size_t length)
125 {
126 if (fName != NULL)
127 strlcpy(name, fName, length);
128 else
129 strlcpy(name, "unnamed looper", length);
130 }
131
132
133 void
_DispatchMessage(int32 code,BPrivate::LinkReceiver & link)134 MessageLooper::_DispatchMessage(int32 code, BPrivate::LinkReceiver &link)
135 {
136 }
137
138
139 void
_MessageLooper()140 MessageLooper::_MessageLooper()
141 {
142 BPrivate::LinkReceiver& receiver = fLink.Receiver();
143
144 while (true) {
145 int32 code;
146 status_t status = receiver.GetNextMessage(code);
147 if (status < B_OK) {
148 // that shouldn't happen, it's our port
149 char name[256];
150 _GetLooperName(name, 256);
151 printf("MessageLooper \"%s\": Someone deleted our message port %"
152 B_PRId32 ", %s!\n", name, receiver.Port(), strerror(status));
153 break;
154 }
155
156 Lock();
157
158 if (code == kMsgQuitLooper)
159 Quit();
160 else
161 _DispatchMessage(code, receiver);
162
163 Unlock();
164 }
165 }
166
167
168 /*!
169 \brief Message-dispatching loop starter
170 */
171 /*static*/
172 int32
_message_thread(void * _looper)173 MessageLooper::_message_thread(void* _looper)
174 {
175 MessageLooper* looper = (MessageLooper*)_looper;
176
177 looper->_MessageLooper();
178 return 0;
179 }
180
181