Repo created

TMessagesProj/jni/voip/webrtc/base/sync_socket_posix.cc

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+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/sync_socket.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <poll.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#if defined(OS_SOLARIS)
+#include <sys/filio.h>
+#endif
+
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#include "base/threading/scoped_blocking_call.h"
+#include "build/build_config.h"
+
+namespace base {
+
+namespace {
+// To avoid users sending negative message lengths to Send/Receive
+// we clamp message lengths, which are size_t, to no more than INT_MAX.
+const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
+
+// Writes |length| of |buffer| into |handle|.  Returns the number of bytes
+// written or zero on error.  |length| must be greater than 0.
+size_t SendHelper(SyncSocket::Handle handle,
+                  const void* buffer,
+                  size_t length) {
+  DCHECK_GT(length, 0u);
+  DCHECK_LE(length, kMaxMessageLength);
+  DCHECK_NE(handle, SyncSocket::kInvalidHandle);
+  const char* charbuffer = static_cast<const char*>(buffer);
+  return WriteFileDescriptor(handle, charbuffer, length)
+             ? static_cast<size_t>(length)
+             : 0;
+}
+
+}  // namespace
+
+// static
+bool SyncSocket::CreatePair(SyncSocket* socket_a, SyncSocket* socket_b) {
+  DCHECK_NE(socket_a, socket_b);
+  DCHECK(!socket_a->IsValid());
+  DCHECK(!socket_b->IsValid());
+
+#if defined(OS_MACOSX)
+  int nosigpipe = 1;
+#endif  // defined(OS_MACOSX)
+
+  ScopedHandle handles[2];
+
+  {
+    Handle raw_handles[2] = {kInvalidHandle, kInvalidHandle};
+    if (socketpair(AF_UNIX, SOCK_STREAM, 0, raw_handles) != 0) {
+      return false;
+    }
+    handles[0].reset(raw_handles[0]);
+    handles[1].reset(raw_handles[1]);
+  }
+
+#if defined(OS_MACOSX)
+  // On OSX an attempt to read or write to a closed socket may generate a
+  // SIGPIPE rather than returning -1.  setsockopt will shut this off.
+  if (0 != setsockopt(handles[0].get(), SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe,
+                      sizeof(nosigpipe)) ||
+      0 != setsockopt(handles[1].get(), SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe,
+                      sizeof(nosigpipe))) {
+    return false;
+  }
+#endif
+
+  // Copy the handles out for successful return.
+  socket_a->handle_ = std::move(handles[0]);
+  socket_b->handle_ = std::move(handles[1]);
+
+  return true;
+}
+
+void SyncSocket::Close() {
+  handle_.reset();
+}
+
+size_t SyncSocket::Send(const void* buffer, size_t length) {
+  ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
+  return SendHelper(handle(), buffer, length);
+}
+
+size_t SyncSocket::Receive(void* buffer, size_t length) {
+  ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
+  DCHECK_GT(length, 0u);
+  DCHECK_LE(length, kMaxMessageLength);
+  DCHECK(IsValid());
+  char* charbuffer = static_cast<char*>(buffer);
+  if (ReadFromFD(handle(), charbuffer, length))
+    return length;
+  return 0;
+}
+
+size_t SyncSocket::ReceiveWithTimeout(void* buffer,
+                                      size_t length,
+                                      TimeDelta timeout) {
+  ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
+  DCHECK_GT(length, 0u);
+  DCHECK_LE(length, kMaxMessageLength);
+  DCHECK(IsValid());
+
+  // Only timeouts greater than zero and less than one second are allowed.
+  DCHECK_GT(timeout.InMicroseconds(), 0);
+  DCHECK_LT(timeout.InMicroseconds(),
+            TimeDelta::FromSeconds(1).InMicroseconds());
+
+  // Track the start time so we can reduce the timeout as data is read.
+  TimeTicks start_time = TimeTicks::Now();
+  const TimeTicks finish_time = start_time + timeout;
+
+  struct pollfd pollfd;
+  pollfd.fd = handle();
+  pollfd.events = POLLIN;
+  pollfd.revents = 0;
+
+  size_t bytes_read_total = 0;
+  while (bytes_read_total < length) {
+    const TimeDelta this_timeout = finish_time - TimeTicks::Now();
+    const int timeout_ms =
+        static_cast<int>(this_timeout.InMillisecondsRoundedUp());
+    if (timeout_ms <= 0)
+      break;
+    const int poll_result = poll(&pollfd, 1, timeout_ms);
+    // Handle EINTR manually since we need to update the timeout value.
+    if (poll_result == -1 && errno == EINTR)
+      continue;
+    // Return if other type of error or a timeout.
+    if (poll_result <= 0)
+      return bytes_read_total;
+
+    // poll() only tells us that data is ready for reading, not how much.  We
+    // must Peek() for the amount ready for reading to avoid blocking.
+    // At hang up (POLLHUP), the write end has been closed and there might still
+    // be data to be read.
+    // No special handling is needed for error (POLLERR); we can let any of the
+    // following operations fail and handle it there.
+    DCHECK(pollfd.revents & (POLLIN | POLLHUP | POLLERR)) << pollfd.revents;
+    const size_t bytes_to_read = std::min(Peek(), length - bytes_read_total);
+
+    // There may be zero bytes to read if the socket at the other end closed.
+    if (!bytes_to_read)
+      return bytes_read_total;
+
+    const size_t bytes_received =
+        Receive(static_cast<char*>(buffer) + bytes_read_total, bytes_to_read);
+    bytes_read_total += bytes_received;
+    if (bytes_received != bytes_to_read)
+      return bytes_read_total;
+  }
+
+  return bytes_read_total;
+}
+
+size_t SyncSocket::Peek() {
+  DCHECK(IsValid());
+  int number_chars = 0;
+  if (ioctl(handle_.get(), FIONREAD, &number_chars) == -1) {
+    // If there is an error in ioctl, signal that the channel would block.
+    return 0;
+  }
+  DCHECK_GE(number_chars, 0);
+  return number_chars;
+}
+
+bool SyncSocket::IsValid() const {
+  return handle_.is_valid();
+}
+
+SyncSocket::Handle SyncSocket::handle() const {
+  return handle_.get();
+}
+
+SyncSocket::Handle SyncSocket::Release() {
+  return handle_.release();
+}
+
+bool CancelableSyncSocket::Shutdown() {
+  DCHECK(IsValid());
+  return HANDLE_EINTR(shutdown(handle(), SHUT_RDWR)) >= 0;
+}
+
+size_t CancelableSyncSocket::Send(const void* buffer, size_t length) {
+  DCHECK_GT(length, 0u);
+  DCHECK_LE(length, kMaxMessageLength);
+  DCHECK(IsValid());
+
+  const int flags = fcntl(handle(), F_GETFL);
+  if (flags != -1 && (flags & O_NONBLOCK) == 0) {
+    // Set the socket to non-blocking mode for sending if its original mode
+    // is blocking.
+    fcntl(handle(), F_SETFL, flags | O_NONBLOCK);
+  }
+
+  const size_t len = SendHelper(handle(), buffer, length);
+
+  if (flags != -1 && (flags & O_NONBLOCK) == 0) {
+    // Restore the original flags.
+    fcntl(handle(), F_SETFL, flags);
+  }
+
+  return len;
+}
+
+// static
+bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a,
+                                      CancelableSyncSocket* socket_b) {
+  return SyncSocket::CreatePair(socket_a, socket_b);
+}
+
+}  // namespace base