diff options
Diffstat (limited to 'nsprpub/pr/src/io/prpolevt.c')
| -rw-r--r-- | nsprpub/pr/src/io/prpolevt.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/nsprpub/pr/src/io/prpolevt.c b/nsprpub/pr/src/io/prpolevt.c new file mode 100644 index 0000000000..1b664ba24e --- /dev/null +++ b/nsprpub/pr/src/io/prpolevt.c @@ -0,0 +1,230 @@ +/* -*- 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; +} |