1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is the Netscape Portable Runtime (NSPR).
16 : *
17 : * The Initial Developer of the Original Code is
18 : * Netscape Communications Corporation.
19 : * Portions created by the Initial Developer are Copyright (C) 1998-2000
20 : * the Initial Developer. All Rights Reserved.
21 : *
22 : * Contributor(s):
23 : *
24 : * Alternatively, the contents of this file may be used under the terms of
25 : * either the GNU General Public License Version 2 or later (the "GPL"), or
26 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 : * in which case the provisions of the GPL or the LGPL are applicable instead
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31 : * decision by deleting the provisions above and replace them with the notice
32 : * and other provisions required by the GPL or the LGPL. If you do not delete
33 : * the provisions above, a recipient may use your version of this file under
34 : * the terms of any one of the MPL, the GPL or the LGPL.
35 : *
36 : * ***** END LICENSE BLOCK ***** */
37 :
38 : /*
39 : *********************************************************************
40 : *
41 : * Pollable events
42 : *
43 : * Pollable events are implemented using layered I/O. The only
44 : * I/O methods that are implemented for pollable events are poll
45 : * and close. No other methods can be invoked on a pollable
46 : * event.
47 : *
48 : * A pipe or socket pair is created and the pollable event layer
49 : * is pushed onto the read end. A pointer to the write end is
50 : * saved in the PRFilePrivate structure of the pollable event.
51 : *
52 : *********************************************************************
53 : */
54 :
55 : #include "prinit.h"
56 : #include "prio.h"
57 : #include "prmem.h"
58 : #include "prerror.h"
59 : #include "prlog.h"
60 :
61 : /*
62 : * These internal functions are declared in primpl.h,
63 : * but we can't include primpl.h because the definition
64 : * of struct PRFilePrivate in this file (for the pollable
65 : * event layer) will conflict with the definition of
66 : * struct PRFilePrivate in primpl.h (for the NSPR layer).
67 : */
68 : extern PRIntn _PR_InvalidInt(void);
69 : extern PRInt64 _PR_InvalidInt64(void);
70 : extern PRStatus _PR_InvalidStatus(void);
71 : extern PRFileDesc *_PR_InvalidDesc(void);
72 :
73 : /*
74 : * PRFilePrivate structure for the NSPR pollable events layer
75 : */
76 : struct PRFilePrivate {
77 : PRFileDesc *writeEnd; /* the write end of the pipe/socketpair */
78 : };
79 :
80 : static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd);
81 :
82 : static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
83 : PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags);
84 :
85 : static PRIOMethods _pr_polevt_methods = {
86 : PR_DESC_LAYERED,
87 : _pr_PolEvtClose,
88 : (PRReadFN)_PR_InvalidInt,
89 : (PRWriteFN)_PR_InvalidInt,
90 : (PRAvailableFN)_PR_InvalidInt,
91 : (PRAvailable64FN)_PR_InvalidInt64,
92 : (PRFsyncFN)_PR_InvalidStatus,
93 : (PRSeekFN)_PR_InvalidInt,
94 : (PRSeek64FN)_PR_InvalidInt64,
95 : (PRFileInfoFN)_PR_InvalidStatus,
96 : (PRFileInfo64FN)_PR_InvalidStatus,
97 : (PRWritevFN)_PR_InvalidInt,
98 : (PRConnectFN)_PR_InvalidStatus,
99 : (PRAcceptFN)_PR_InvalidDesc,
100 : (PRBindFN)_PR_InvalidStatus,
101 : (PRListenFN)_PR_InvalidStatus,
102 : (PRShutdownFN)_PR_InvalidStatus,
103 : (PRRecvFN)_PR_InvalidInt,
104 : (PRSendFN)_PR_InvalidInt,
105 : (PRRecvfromFN)_PR_InvalidInt,
106 : (PRSendtoFN)_PR_InvalidInt,
107 : _pr_PolEvtPoll,
108 : (PRAcceptreadFN)_PR_InvalidInt,
109 : (PRTransmitfileFN)_PR_InvalidInt,
110 : (PRGetsocknameFN)_PR_InvalidStatus,
111 : (PRGetpeernameFN)_PR_InvalidStatus,
112 : (PRReservedFN)_PR_InvalidInt,
113 : (PRReservedFN)_PR_InvalidInt,
114 : (PRGetsocketoptionFN)_PR_InvalidStatus,
115 : (PRSetsocketoptionFN)_PR_InvalidStatus,
116 : (PRSendfileFN)_PR_InvalidInt,
117 : (PRConnectcontinueFN)_PR_InvalidStatus,
118 : (PRReservedFN)_PR_InvalidInt,
119 : (PRReservedFN)_PR_InvalidInt,
120 : (PRReservedFN)_PR_InvalidInt,
121 : (PRReservedFN)_PR_InvalidInt
122 : };
123 :
124 : static PRDescIdentity _pr_polevt_id;
125 : static PRCallOnceType _pr_polevt_once_control;
126 : static PRStatus PR_CALLBACK _pr_PolEvtInit(void);
127 :
128 61371 : static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
129 : PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags)
130 : {
131 61371 : return (fd->lower->methods->poll)(fd->lower, in_flags, out_flags);
132 : }
133 :
134 1419 : static PRStatus PR_CALLBACK _pr_PolEvtInit(void)
135 : {
136 1419 : _pr_polevt_id = PR_GetUniqueIdentity("NSPR pollable events");
137 1419 : if (PR_INVALID_IO_LAYER == _pr_polevt_id) {
138 0 : return PR_FAILURE;
139 : }
140 1419 : return PR_SUCCESS;
141 : }
142 :
143 : #if !defined(XP_UNIX)
144 : #define USE_TCP_SOCKETPAIR
145 : #endif
146 :
147 1419 : PR_IMPLEMENT(PRFileDesc *) PR_NewPollableEvent(void)
148 : {
149 : PRFileDesc *event;
150 : PRFileDesc *fd[2]; /* fd[0] is the read end; fd[1] is the write end */
151 : #ifdef USE_TCP_SOCKETPAIR
152 : PRSocketOptionData socket_opt;
153 : PRStatus rv;
154 : #endif
155 :
156 1419 : fd[0] = fd[1] = NULL;
157 :
158 1419 : if (PR_CallOnce(&_pr_polevt_once_control, _pr_PolEvtInit) == PR_FAILURE) {
159 0 : return NULL;
160 : }
161 :
162 1419 : event = PR_CreateIOLayerStub(_pr_polevt_id, &_pr_polevt_methods);
163 1419 : if (NULL == event) {
164 0 : goto errorExit;
165 : }
166 1419 : event->secret = PR_NEW(PRFilePrivate);
167 1419 : if (event->secret == NULL) {
168 0 : PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
169 0 : goto errorExit;
170 : }
171 :
172 : #ifndef USE_TCP_SOCKETPAIR
173 1419 : if (PR_CreatePipe(&fd[0], &fd[1]) == PR_FAILURE) {
174 0 : fd[0] = fd[1] = NULL;
175 0 : goto errorExit;
176 : }
177 : #else
178 : if (PR_NewTCPSocketPair(fd) == PR_FAILURE) {
179 : fd[0] = fd[1] = NULL;
180 : goto errorExit;
181 : }
182 : /*
183 : * set the TCP_NODELAY option to reduce notification latency
184 : */
185 : socket_opt.option = PR_SockOpt_NoDelay;
186 : socket_opt.value.no_delay = PR_TRUE;
187 : rv = PR_SetSocketOption(fd[1], &socket_opt);
188 : PR_ASSERT(PR_SUCCESS == rv);
189 : #endif
190 :
191 1419 : event->secret->writeEnd = fd[1];
192 1419 : if (PR_PushIOLayer(fd[0], PR_TOP_IO_LAYER, event) == PR_FAILURE) {
193 0 : goto errorExit;
194 : }
195 :
196 1419 : return fd[0];
197 :
198 : errorExit:
199 0 : if (fd[0]) {
200 0 : PR_Close(fd[0]);
201 0 : PR_Close(fd[1]);
202 : }
203 0 : if (event) {
204 0 : PR_DELETE(event->secret);
205 0 : event->dtor(event);
206 : }
207 0 : return NULL;
208 : }
209 :
210 1415 : static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd)
211 : {
212 : PRFileDesc *event;
213 :
214 1415 : event = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
215 1415 : PR_ASSERT(NULL == event->higher && NULL == event->lower);
216 1415 : PR_Close(fd);
217 1415 : PR_Close(event->secret->writeEnd);
218 1415 : PR_DELETE(event->secret);
219 1415 : event->dtor(event);
220 1415 : return PR_SUCCESS;
221 : }
222 :
223 1415 : PR_IMPLEMENT(PRStatus) PR_DestroyPollableEvent(PRFileDesc *event)
224 : {
225 1415 : return PR_Close(event);
226 : }
227 :
228 : static const char magicChar = '\x38';
229 :
230 52407 : PR_IMPLEMENT(PRStatus) PR_SetPollableEvent(PRFileDesc *event)
231 : {
232 52407 : if (PR_Write(event->secret->writeEnd, &magicChar, 1) != 1) {
233 0 : return PR_FAILURE;
234 : }
235 52407 : return PR_SUCCESS;
236 : }
237 :
238 44755 : PR_IMPLEMENT(PRStatus) PR_WaitForPollableEvent(PRFileDesc *event)
239 : {
240 : char buf[1024];
241 : PRInt32 nBytes;
242 : #ifdef DEBUG
243 : PRIntn i;
244 : #endif
245 :
246 44755 : nBytes = PR_Read(event->lower, buf, sizeof(buf));
247 44755 : if (nBytes == -1) {
248 0 : return PR_FAILURE;
249 : }
250 :
251 : #ifdef DEBUG
252 : /*
253 : * Make sure people do not write to the pollable event fd
254 : * directly.
255 : */
256 96490 : for (i = 0; i < nBytes; i++) {
257 51735 : PR_ASSERT(buf[i] == magicChar);
258 : }
259 : #endif
260 :
261 44755 : return PR_SUCCESS;
262 : }
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