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