The Tor Browser: nsprpub/pr/src/io/prpolevt.c@ca08bd8f51b2 (annotated)

nsprpub/pr/src/io/prpolevt.c@ca08bd8f51b2 (annotated)

nsprpub/pr/src/io/prpolevt.c

Wed, 31 Dec 2014 06:55:46 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:46 +0100
changeset 1: ca08bd8f51b2
permissions: -rw-r--r--

Added tag TORBROWSER_REPLICA for changeset 6474c204b198

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  *********************************************************************
  *
  * Pollable events
  *
  * Pollable events are implemented using layered I/O.  The only
  * I/O methods that are implemented for pollable events are poll
  * and close.  No other methods can be invoked on a pollable
  * event.
  *
  * A pipe or socket pair is created and the pollable event layer
  * is pushed onto the read end.  A pointer to the write end is
  * saved in the PRFilePrivate structure of the pollable event.
  *
  *********************************************************************
  */
 #include "prinit.h"
 #include "prio.h"
 #include "prmem.h"
 #include "prerror.h"
 #include "prlog.h"
 /*
  * These internal functions are declared in primpl.h,
  * but we can't include primpl.h because the definition
  * of struct PRFilePrivate in this file (for the pollable
  * event layer) will conflict with the definition of
  * struct PRFilePrivate in primpl.h (for the NSPR layer).
  */
 extern PRIntn _PR_InvalidInt(void);
 extern PRInt64 _PR_InvalidInt64(void);
 extern PRStatus _PR_InvalidStatus(void);
 extern PRFileDesc *_PR_InvalidDesc(void);
 /*
  * PRFilePrivate structure for the NSPR pollable events layer
  */
 struct PRFilePrivate {
     PRFileDesc *writeEnd;  /* the write end of the pipe/socketpair */
 };
 static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd);
 static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
     PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags);
 static PRIOMethods _pr_polevt_methods = {
     PR_DESC_LAYERED,
     _pr_PolEvtClose,
     (PRReadFN)_PR_InvalidInt,
     (PRWriteFN)_PR_InvalidInt,
     (PRAvailableFN)_PR_InvalidInt,
     (PRAvailable64FN)_PR_InvalidInt64,
     (PRFsyncFN)_PR_InvalidStatus,
     (PRSeekFN)_PR_InvalidInt,
     (PRSeek64FN)_PR_InvalidInt64,
     (PRFileInfoFN)_PR_InvalidStatus,
     (PRFileInfo64FN)_PR_InvalidStatus,
     (PRWritevFN)_PR_InvalidInt,
     (PRConnectFN)_PR_InvalidStatus,
     (PRAcceptFN)_PR_InvalidDesc,
     (PRBindFN)_PR_InvalidStatus,
     (PRListenFN)_PR_InvalidStatus,
     (PRShutdownFN)_PR_InvalidStatus,
     (PRRecvFN)_PR_InvalidInt,
     (PRSendFN)_PR_InvalidInt,
     (PRRecvfromFN)_PR_InvalidInt,
     (PRSendtoFN)_PR_InvalidInt,
     _pr_PolEvtPoll,
     (PRAcceptreadFN)_PR_InvalidInt,
     (PRTransmitfileFN)_PR_InvalidInt,
     (PRGetsocknameFN)_PR_InvalidStatus,
     (PRGetpeernameFN)_PR_InvalidStatus,
     (PRReservedFN)_PR_InvalidInt,
     (PRReservedFN)_PR_InvalidInt,
     (PRGetsocketoptionFN)_PR_InvalidStatus,
     (PRSetsocketoptionFN)_PR_InvalidStatus,
     (PRSendfileFN)_PR_InvalidInt,
     (PRConnectcontinueFN)_PR_InvalidStatus,
     (PRReservedFN)_PR_InvalidInt,
     (PRReservedFN)_PR_InvalidInt,
     (PRReservedFN)_PR_InvalidInt,
     (PRReservedFN)_PR_InvalidInt
 };
 static PRDescIdentity _pr_polevt_id;
 static PRCallOnceType _pr_polevt_once_control;
 static PRStatus PR_CALLBACK _pr_PolEvtInit(void);
 static PRInt16 PR_CALLBACK _pr_PolEvtPoll(
     PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags)
 {
     return (fd->lower->methods->poll)(fd->lower, in_flags, out_flags);
 }
 static PRStatus PR_CALLBACK _pr_PolEvtInit(void)
 {
     _pr_polevt_id = PR_GetUniqueIdentity("NSPR pollable events");
     if (PR_INVALID_IO_LAYER == _pr_polevt_id) {
         return PR_FAILURE;
     }
     return PR_SUCCESS;
 }
 #if !defined(XP_UNIX)
 #define USE_TCP_SOCKETPAIR
 #endif
 PR_IMPLEMENT(PRFileDesc *) PR_NewPollableEvent(void)
 {
     PRFileDesc *event;
     PRFileDesc *fd[2]; /* fd[0] is the read end; fd[1] is the write end */
 #ifdef USE_TCP_SOCKETPAIR
     PRSocketOptionData socket_opt;
     PRStatus rv;
 #endif
     fd[0] = fd[1] = NULL;
     if (PR_CallOnce(&_pr_polevt_once_control, _pr_PolEvtInit) == PR_FAILURE) {
         return NULL;
     }
     event = PR_CreateIOLayerStub(_pr_polevt_id, &_pr_polevt_methods);
     if (NULL == event) {
         goto errorExit;
     }
     event->secret = PR_NEW(PRFilePrivate);
     if (event->secret == NULL) {
         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
         goto errorExit;
     }
 #ifndef USE_TCP_SOCKETPAIR
     if (PR_CreatePipe(&fd[0], &fd[1]) == PR_FAILURE) {
         fd[0] = fd[1] = NULL;
         goto errorExit;
     }
 #else
     if (PR_NewTCPSocketPair(fd) == PR_FAILURE) {
         fd[0] = fd[1] = NULL;
         goto errorExit;
     }
 	/*
 	 * set the TCP_NODELAY option to reduce notification latency
 	 */
     socket_opt.option = PR_SockOpt_NoDelay;
     socket_opt.value.no_delay = PR_TRUE;
     rv = PR_SetSocketOption(fd[1], &socket_opt);
     PR_ASSERT(PR_SUCCESS == rv);
 #endif
     event->secret->writeEnd = fd[1];
     if (PR_PushIOLayer(fd[0], PR_TOP_IO_LAYER, event) == PR_FAILURE) {
         goto errorExit;
     }
     return fd[0];
 errorExit:
     if (fd[0]) {
         PR_Close(fd[0]);
         PR_Close(fd[1]);
     }
     if (event) {
         PR_DELETE(event->secret);
         event->dtor(event);
     }
     return NULL;
 }
 static PRStatus PR_CALLBACK _pr_PolEvtClose(PRFileDesc *fd)
 {
     PRFileDesc *event;
     event = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
     PR_ASSERT(NULL == event->higher && NULL == event->lower);
     PR_Close(fd);
     PR_Close(event->secret->writeEnd);
     PR_DELETE(event->secret);
     event->dtor(event);
     return PR_SUCCESS;
 }
 PR_IMPLEMENT(PRStatus) PR_DestroyPollableEvent(PRFileDesc *event)
 {
     return PR_Close(event);
 }
 static const char magicChar = '\x38';
 PR_IMPLEMENT(PRStatus) PR_SetPollableEvent(PRFileDesc *event)
 {
     if (PR_Write(event->secret->writeEnd, &magicChar, 1) != 1) {
         return PR_FAILURE;
     }
     return PR_SUCCESS;
 }
 PR_IMPLEMENT(PRStatus) PR_WaitForPollableEvent(PRFileDesc *event)
 {
     char buf[1024];
     PRInt32 nBytes;
 #ifdef DEBUG
     PRIntn i;
 #endif
     nBytes = PR_Read(event->lower, buf, sizeof(buf));
     if (nBytes == -1) {
         return PR_FAILURE;
     }
 #ifdef DEBUG
     /*
      * Make sure people do not write to the pollable event fd
      * directly.
      */
     for (i = 0; i < nBytes; i++) {
         PR_ASSERT(buf[i] == magicChar);
     }
 #endif
     return PR_SUCCESS;
 }

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nsprpub/pr/src/io/prpolevt.c@ca08bd8f51b2 (annotated)

nsprpub/pr/src/io/prpolevt.c