1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/nsprpub/pr/src/io/prpolevt.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,230 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + *********************************************************************
1.11 + *
1.12 + * Pollable events
1.13 + *
1.14 + * Pollable events are implemented using layered I/O. The only
1.15 + * I/O methods that are implemented for pollable events are poll
1.16 + * and close. No other methods can be invoked on a pollable
1.17 + * event.
1.18 + *
1.19 + * A pipe or socket pair is created and the pollable event layer
1.20 + * is pushed onto the read end. A pointer to the write end is
1.21 + * saved in the PRFilePrivate structure of the pollable event.
1.22 + *
1.23 + *********************************************************************
1.24 + */
1.25 +
1.26 +#include "prinit.h"
1.27 +#include "prio.h"
1.28 +#include "prmem.h"
1.29 +#include "prerror.h"
1.30 +#include "prlog.h"
1.31 +
1.32 +/*
1.33 + * These internal functions are declared in primpl.h,
1.34 + * but we can't include primpl.h because the definition
1.35 + * of struct PRFilePrivate in this file (for the pollable
1.36 + * event layer) will conflict with the definition of
1.37 + * struct PRFilePrivate in primpl.h (for the NSPR layer).
1.38 + */
1.39 +extern PRIntn _PR_InvalidInt(void);
1.40 +extern PRInt64 _PR_InvalidInt64(void);
1.41 +extern PRStatus _PR_InvalidStatus(void);
1.42 +extern PRFileDesc *_PR_InvalidDesc(void);
1.43 +
1.44 +/*
1.45 + * PRFilePrivate structure for the NSPR pollable events layer
1.46 + */
1.47 +struct PRFilePrivate {
1.48 + PRFileDesc *writeEnd; /* the write end of the pipe/socketpair */
1.49 +};
1.50 +
1.51 +static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd);
1.52 +
1.53 +static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
1.54 + PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags);
1.55 +
1.56 +static PRIOMethods _pr_polevt_methods = {
1.57 + PR_DESC_LAYERED,
1.58 + _pr_PolEvtClose,
1.59 + (PRReadFN)_PR_InvalidInt,
1.60 + (PRWriteFN)_PR_InvalidInt,
1.61 + (PRAvailableFN)_PR_InvalidInt,
1.62 + (PRAvailable64FN)_PR_InvalidInt64,
1.63 + (PRFsyncFN)_PR_InvalidStatus,
1.64 + (PRSeekFN)_PR_InvalidInt,
1.65 + (PRSeek64FN)_PR_InvalidInt64,
1.66 + (PRFileInfoFN)_PR_InvalidStatus,
1.67 + (PRFileInfo64FN)_PR_InvalidStatus,
1.68 + (PRWritevFN)_PR_InvalidInt,
1.69 + (PRConnectFN)_PR_InvalidStatus,
1.70 + (PRAcceptFN)_PR_InvalidDesc,
1.71 + (PRBindFN)_PR_InvalidStatus,
1.72 + (PRListenFN)_PR_InvalidStatus,
1.73 + (PRShutdownFN)_PR_InvalidStatus,
1.74 + (PRRecvFN)_PR_InvalidInt,
1.75 + (PRSendFN)_PR_InvalidInt,
1.76 + (PRRecvfromFN)_PR_InvalidInt,
1.77 + (PRSendtoFN)_PR_InvalidInt,
1.78 + _pr_PolEvtPoll,
1.79 + (PRAcceptreadFN)_PR_InvalidInt,
1.80 + (PRTransmitfileFN)_PR_InvalidInt,
1.81 + (PRGetsocknameFN)_PR_InvalidStatus,
1.82 + (PRGetpeernameFN)_PR_InvalidStatus,
1.83 + (PRReservedFN)_PR_InvalidInt,
1.84 + (PRReservedFN)_PR_InvalidInt,
1.85 + (PRGetsocketoptionFN)_PR_InvalidStatus,
1.86 + (PRSetsocketoptionFN)_PR_InvalidStatus,
1.87 + (PRSendfileFN)_PR_InvalidInt,
1.88 + (PRConnectcontinueFN)_PR_InvalidStatus,
1.89 + (PRReservedFN)_PR_InvalidInt,
1.90 + (PRReservedFN)_PR_InvalidInt,
1.91 + (PRReservedFN)_PR_InvalidInt,
1.92 + (PRReservedFN)_PR_InvalidInt
1.93 +};
1.94 +
1.95 +static PRDescIdentity _pr_polevt_id;
1.96 +static PRCallOnceType _pr_polevt_once_control;
1.97 +static PRStatus PR_CALLBACK _pr_PolEvtInit(void);
1.98 +
1.99 +static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
1.100 + PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags)
1.101 +{
1.102 + return (fd->lower->methods->poll)(fd->lower, in_flags, out_flags);
1.103 +}
1.104 +
1.105 +static PRStatus PR_CALLBACK _pr_PolEvtInit(void)
1.106 +{
1.107 + _pr_polevt_id = PR_GetUniqueIdentity("NSPR pollable events");
1.108 + if (PR_INVALID_IO_LAYER == _pr_polevt_id) {
1.109 + return PR_FAILURE;
1.110 + }
1.111 + return PR_SUCCESS;
1.112 +}
1.113 +
1.114 +#if !defined(XP_UNIX)
1.115 +#define USE_TCP_SOCKETPAIR
1.116 +#endif
1.117 +
1.118 +PR_IMPLEMENT(PRFileDesc *) PR_NewPollableEvent(void)
1.119 +{
1.120 + PRFileDesc *event;
1.121 + PRFileDesc *fd[2]; /* fd[0] is the read end; fd[1] is the write end */
1.122 +#ifdef USE_TCP_SOCKETPAIR
1.123 + PRSocketOptionData socket_opt;
1.124 + PRStatus rv;
1.125 +#endif
1.126 +
1.127 + fd[0] = fd[1] = NULL;
1.128 +
1.129 + if (PR_CallOnce(&_pr_polevt_once_control, _pr_PolEvtInit) == PR_FAILURE) {
1.130 + return NULL;
1.131 + }
1.132 +
1.133 + event = PR_CreateIOLayerStub(_pr_polevt_id, &_pr_polevt_methods);
1.134 + if (NULL == event) {
1.135 + goto errorExit;
1.136 + }
1.137 + event->secret = PR_NEW(PRFilePrivate);
1.138 + if (event->secret == NULL) {
1.139 + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
1.140 + goto errorExit;
1.141 + }
1.142 +
1.143 +#ifndef USE_TCP_SOCKETPAIR
1.144 + if (PR_CreatePipe(&fd[0], &fd[1]) == PR_FAILURE) {
1.145 + fd[0] = fd[1] = NULL;
1.146 + goto errorExit;
1.147 + }
1.148 +#else
1.149 + if (PR_NewTCPSocketPair(fd) == PR_FAILURE) {
1.150 + fd[0] = fd[1] = NULL;
1.151 + goto errorExit;
1.152 + }
1.153 + /*
1.154 + * set the TCP_NODELAY option to reduce notification latency
1.155 + */
1.156 + socket_opt.option = PR_SockOpt_NoDelay;
1.157 + socket_opt.value.no_delay = PR_TRUE;
1.158 + rv = PR_SetSocketOption(fd[1], &socket_opt);
1.159 + PR_ASSERT(PR_SUCCESS == rv);
1.160 +#endif
1.161 +
1.162 + event->secret->writeEnd = fd[1];
1.163 + if (PR_PushIOLayer(fd[0], PR_TOP_IO_LAYER, event) == PR_FAILURE) {
1.164 + goto errorExit;
1.165 + }
1.166 +
1.167 + return fd[0];
1.168 +
1.169 +errorExit:
1.170 + if (fd[0]) {
1.171 + PR_Close(fd[0]);
1.172 + PR_Close(fd[1]);
1.173 + }
1.174 + if (event) {
1.175 + PR_DELETE(event->secret);
1.176 + event->dtor(event);
1.177 + }
1.178 + return NULL;
1.179 +}
1.180 +
1.181 +static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd)
1.182 +{
1.183 + PRFileDesc *event;
1.184 +
1.185 + event = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
1.186 + PR_ASSERT(NULL == event->higher && NULL == event->lower);
1.187 + PR_Close(fd);
1.188 + PR_Close(event->secret->writeEnd);
1.189 + PR_DELETE(event->secret);
1.190 + event->dtor(event);
1.191 + return PR_SUCCESS;
1.192 +}
1.193 +
1.194 +PR_IMPLEMENT(PRStatus) PR_DestroyPollableEvent(PRFileDesc *event)
1.195 +{
1.196 + return PR_Close(event);
1.197 +}
1.198 +
1.199 +static const char magicChar = '\x38';
1.200 +
1.201 +PR_IMPLEMENT(PRStatus) PR_SetPollableEvent(PRFileDesc *event)
1.202 +{
1.203 + if (PR_Write(event->secret->writeEnd, &magicChar, 1) != 1) {
1.204 + return PR_FAILURE;
1.205 + }
1.206 + return PR_SUCCESS;
1.207 +}
1.208 +
1.209 +PR_IMPLEMENT(PRStatus) PR_WaitForPollableEvent(PRFileDesc *event)
1.210 +{
1.211 + char buf[1024];
1.212 + PRInt32 nBytes;
1.213 +#ifdef DEBUG
1.214 + PRIntn i;
1.215 +#endif
1.216 +
1.217 + nBytes = PR_Read(event->lower, buf, sizeof(buf));
1.218 + if (nBytes == -1) {
1.219 + return PR_FAILURE;
1.220 + }
1.221 +
1.222 +#ifdef DEBUG
1.223 + /*
1.224 + * Make sure people do not write to the pollable event fd
1.225 + * directly.
1.226 + */
1.227 + for (i = 0; i < nBytes; i++) {
1.228 + PR_ASSERT(buf[i] == magicChar);
1.229 + }
1.230 +#endif
1.231 +
1.232 + return PR_SUCCESS;
1.233 +}
