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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /netwerk/base/PollableEvent.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'netwerk/base/PollableEvent.cpp')
-rw-r--r--netwerk/base/PollableEvent.cpp347
1 files changed, 347 insertions, 0 deletions
diff --git a/netwerk/base/PollableEvent.cpp b/netwerk/base/PollableEvent.cpp
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+++ b/netwerk/base/PollableEvent.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#include "nsSocketTransportService2.h"
+#include "PollableEvent.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Logging.h"
+#include "prerror.h"
+#include "prio.h"
+#include "private/pprio.h"
+#include "prnetdb.h"
+
+#ifdef XP_WIN
+#include "ShutdownLayer.h"
+#else
+#include <fcntl.h>
+#define USEPIPE 1
+#endif
+
+namespace mozilla {
+namespace net {
+
+#ifndef USEPIPE
+static PRDescIdentity sPollableEventLayerIdentity;
+static PRIOMethods sPollableEventLayerMethods;
+static PRIOMethods *sPollableEventLayerMethodsPtr = nullptr;
+
+static void LazyInitSocket()
+{
+ MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+ if (sPollableEventLayerMethodsPtr) {
+ return;
+ }
+ sPollableEventLayerIdentity = PR_GetUniqueIdentity("PollableEvent Layer");
+ sPollableEventLayerMethods = *PR_GetDefaultIOMethods();
+ sPollableEventLayerMethodsPtr = &sPollableEventLayerMethods;
+}
+
+static bool NewTCPSocketPair(PRFileDesc *fd[], bool aSetRecvBuff)
+{
+ // this is a replacement for PR_NewTCPSocketPair that manually
+ // sets the recv buffer to 64K. A windows bug (1248358)
+ // can result in using an incompatible rwin and window
+ // scale option on localhost pipes if not set before connect.
+
+ SOCKET_LOG(("NewTCPSocketPair %s a recv buffer tuning\n", aSetRecvBuff ? "with" : "without"));
+
+ PRFileDesc *listener = nullptr;
+ PRFileDesc *writer = nullptr;
+ PRFileDesc *reader = nullptr;
+ PRSocketOptionData recvBufferOpt;
+ recvBufferOpt.option = PR_SockOpt_RecvBufferSize;
+ recvBufferOpt.value.recv_buffer_size = 65535;
+
+ PRSocketOptionData nodelayOpt;
+ nodelayOpt.option = PR_SockOpt_NoDelay;
+ nodelayOpt.value.no_delay = true;
+
+ PRSocketOptionData noblockOpt;
+ noblockOpt.option = PR_SockOpt_Nonblocking;
+ noblockOpt.value.non_blocking = true;
+
+ listener = PR_OpenTCPSocket(PR_AF_INET);
+ if (!listener) {
+ goto failed;
+ }
+
+ if (aSetRecvBuff) {
+ PR_SetSocketOption(listener, &recvBufferOpt);
+ }
+ PR_SetSocketOption(listener, &nodelayOpt);
+
+ PRNetAddr listenAddr;
+ memset(&listenAddr, 0, sizeof(listenAddr));
+ if ((PR_InitializeNetAddr(PR_IpAddrLoopback, 0, &listenAddr) == PR_FAILURE) ||
+ (PR_Bind(listener, &listenAddr) == PR_FAILURE) ||
+ (PR_GetSockName(listener, &listenAddr) == PR_FAILURE) || // learn the dynamic port
+ (PR_Listen(listener, 5) == PR_FAILURE)) {
+ goto failed;
+ }
+
+ writer = PR_OpenTCPSocket(PR_AF_INET);
+ if (!writer) {
+ goto failed;
+ }
+ if (aSetRecvBuff) {
+ PR_SetSocketOption(writer, &recvBufferOpt);
+ }
+ PR_SetSocketOption(writer, &nodelayOpt);
+ PR_SetSocketOption(writer, &noblockOpt);
+ PRNetAddr writerAddr;
+ if (PR_InitializeNetAddr(PR_IpAddrLoopback, ntohs(listenAddr.inet.port), &writerAddr) == PR_FAILURE) {
+ goto failed;
+ }
+
+ if (PR_Connect(writer, &writerAddr, PR_INTERVAL_NO_TIMEOUT) == PR_FAILURE) {
+ if ((PR_GetError() != PR_IN_PROGRESS_ERROR) ||
+ (PR_ConnectContinue(writer, PR_POLL_WRITE) == PR_FAILURE)) {
+ goto failed;
+ }
+ }
+
+ reader = PR_Accept(listener, &listenAddr, PR_MillisecondsToInterval(200));
+ if (!reader) {
+ goto failed;
+ }
+ if (aSetRecvBuff) {
+ PR_SetSocketOption(reader, &recvBufferOpt);
+ }
+ PR_SetSocketOption(reader, &nodelayOpt);
+ PR_SetSocketOption(reader, &noblockOpt);
+ PR_Close(listener);
+
+ fd[0] = reader;
+ fd[1] = writer;
+ return true;
+
+failed:
+ if (listener) {
+ PR_Close(listener);
+ }
+ if (reader) {
+ PR_Close(reader);
+ }
+ if (writer) {
+ PR_Close(writer);
+ }
+ return false;
+}
+
+#endif
+
+PollableEvent::PollableEvent()
+ : mWriteFD(nullptr)
+ , mReadFD(nullptr)
+ , mSignaled(false)
+{
+ MOZ_COUNT_CTOR(PollableEvent);
+ MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+ // create pair of prfiledesc that can be used as a poll()ble
+ // signal. on windows use a localhost socket pair, and on
+ // unix use a pipe.
+#ifdef USEPIPE
+ SOCKET_LOG(("PollableEvent() using pipe\n"));
+ if (PR_CreatePipe(&mReadFD, &mWriteFD) == PR_SUCCESS) {
+ // make the pipe non blocking. NSPR asserts at
+ // trying to use SockOpt here
+ PROsfd fd = PR_FileDesc2NativeHandle(mReadFD);
+ int flags = fcntl(fd, F_GETFL, 0);
+ (void)fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+ fd = PR_FileDesc2NativeHandle(mWriteFD);
+ flags = fcntl(fd, F_GETFL, 0);
+ (void)fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+ } else {
+ mReadFD = nullptr;
+ mWriteFD = nullptr;
+ SOCKET_LOG(("PollableEvent() pipe failed\n"));
+ }
+#else
+ SOCKET_LOG(("PollableEvent() using socket pair\n"));
+ PRFileDesc *fd[2];
+ LazyInitSocket();
+
+ // Try with a increased recv buffer first (bug 1248358).
+ if (NewTCPSocketPair(fd, true)) {
+ mReadFD = fd[0];
+ mWriteFD = fd[1];
+ // If the previous fails try without recv buffer increase (bug 1305436).
+ } else if (NewTCPSocketPair(fd, false)) {
+ mReadFD = fd[0];
+ mWriteFD = fd[1];
+ // If both fail, try the old version.
+ } else if (PR_NewTCPSocketPair(fd) == PR_SUCCESS) {
+ mReadFD = fd[0];
+ mWriteFD = fd[1];
+
+ PRSocketOptionData socket_opt;
+ DebugOnly<PRStatus> status;
+ socket_opt.option = PR_SockOpt_NoDelay;
+ socket_opt.value.no_delay = true;
+ PR_SetSocketOption(mWriteFD, &socket_opt);
+ PR_SetSocketOption(mReadFD, &socket_opt);
+ socket_opt.option = PR_SockOpt_Nonblocking;
+ socket_opt.value.non_blocking = true;
+ status = PR_SetSocketOption(mWriteFD, &socket_opt);
+ MOZ_ASSERT(status == PR_SUCCESS);
+ status = PR_SetSocketOption(mReadFD, &socket_opt);
+ MOZ_ASSERT(status == PR_SUCCESS);
+ }
+
+ if (mReadFD && mWriteFD) {
+ // compatibility with LSPs such as McAfee that assume a NSPR
+ // layer for read ala the nspr Pollable Event - Bug 698882. This layer is a nop.
+ PRFileDesc *topLayer =
+ PR_CreateIOLayerStub(sPollableEventLayerIdentity,
+ sPollableEventLayerMethodsPtr);
+ if (topLayer) {
+ if (PR_PushIOLayer(fd[0], PR_TOP_IO_LAYER, topLayer) == PR_FAILURE) {
+ topLayer->dtor(topLayer);
+ } else {
+ SOCKET_LOG(("PollableEvent() nspr layer ok\n"));
+ mReadFD = topLayer;
+ }
+ }
+
+ } else {
+ SOCKET_LOG(("PollableEvent() socketpair failed\n"));
+ }
+#endif
+
+ if (mReadFD && mWriteFD) {
+ // prime the system to deal with races invovled in [dc]tor cycle
+ SOCKET_LOG(("PollableEvent() ctor ok\n"));
+ mSignaled = true;
+ PR_Write(mWriteFD, "I", 1);
+ }
+}
+
+PollableEvent::~PollableEvent()
+{
+ MOZ_COUNT_DTOR(PollableEvent);
+ if (mWriteFD) {
+#if defined(XP_WIN)
+ AttachShutdownLayer(mWriteFD);
+#endif
+ PR_Close(mWriteFD);
+ }
+ if (mReadFD) {
+#if defined(XP_WIN)
+ AttachShutdownLayer(mReadFD);
+#endif
+ PR_Close(mReadFD);
+ }
+}
+
+// we do not record signals on the socket thread
+// because the socket thread can reliably look at its
+// own runnable queue before selecting a poll time
+// this is the "service the network without blocking" comment in
+// nsSocketTransportService2.cpp
+bool
+PollableEvent::Signal()
+{
+ SOCKET_LOG(("PollableEvent::Signal\n"));
+
+ if (!mWriteFD) {
+ SOCKET_LOG(("PollableEvent::Signal Failed on no FD\n"));
+ return false;
+ }
+#ifndef XP_WIN
+ // On windows poll can hang and this became worse when we introduced the
+ // patch for bug 698882 (see also bug 1292181), therefore we reverted the
+ // behavior on windows to be as before bug 698882, e.g. write to the socket
+ // also if an event dispatch is on the socket thread and writing to the
+ // socket for each event. See bug 1292181.
+ if (PR_GetCurrentThread() == gSocketThread) {
+ SOCKET_LOG(("PollableEvent::Signal OnSocketThread nop\n"));
+ return true;
+ }
+#endif
+
+#ifndef XP_WIN
+ // To wake up the poll writing once is enough, but for Windows that can cause
+ // hangs so we will write for every event.
+ // For non-Windows systems it is enough to write just once.
+ if (mSignaled) {
+ return true;
+ }
+#endif
+
+ mSignaled = true;
+ int32_t status = PR_Write(mWriteFD, "M", 1);
+ SOCKET_LOG(("PollableEvent::Signal PR_Write %d\n", status));
+ if (status != 1) {
+ NS_WARNING("PollableEvent::Signal Failed\n");
+ SOCKET_LOG(("PollableEvent::Signal Failed\n"));
+ mSignaled = false;
+ }
+ return (status == 1);
+}
+
+bool
+PollableEvent::Clear()
+{
+ // necessary because of the "dont signal on socket thread" optimization
+ MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+ SOCKET_LOG(("PollableEvent::Clear\n"));
+ mSignaled = false;
+ if (!mReadFD) {
+ SOCKET_LOG(("PollableEvent::Clear mReadFD is null\n"));
+ return false;
+ }
+ char buf[2048];
+ int32_t status;
+#ifdef XP_WIN
+ // On Windows we are writing to the socket for each event, to be sure that we
+ // do not have any deadlock read from the socket as much as we can.
+ while (true) {
+ status = PR_Read(mReadFD, buf, 2048);
+ SOCKET_LOG(("PollableEvent::Signal PR_Read %d\n", status));
+ if (status == 0) {
+ SOCKET_LOG(("PollableEvent::Clear EOF!\n"));
+ return false;
+ }
+ if (status < 0) {
+ PRErrorCode code = PR_GetError();
+ if (code == PR_WOULD_BLOCK_ERROR) {
+ return true;
+ } else {
+ SOCKET_LOG(("PollableEvent::Clear unexpected error %d\n", code));
+ return false;
+ }
+ }
+ }
+#else
+ status = PR_Read(mReadFD, buf, 2048);
+ SOCKET_LOG(("PollableEvent::Signal PR_Read %d\n", status));
+
+ if (status == 1) {
+ return true;
+ }
+ if (status == 0) {
+ SOCKET_LOG(("PollableEvent::Clear EOF!\n"));
+ return false;
+ }
+ if (status > 1) {
+ MOZ_ASSERT(false);
+ SOCKET_LOG(("PollableEvent::Clear Unexpected events\n"));
+ Clear();
+ return true;
+ }
+ PRErrorCode code = PR_GetError();
+ if (code == PR_WOULD_BLOCK_ERROR) {
+ return true;
+ }
+ SOCKET_LOG(("PollableEvent::Clear unexpected error %d\n", code));
+ return false;
+#endif //XP_WIN
+
+}
+} // namespace net
+} // namespace mozilla