5 files changed, 610 insertions, 159 deletions

diff --git a/source/Host/common/MainLoop.cpp b/source/Host/common/MainLoop.cpp
new file mode 100644
index 0000000000000..8a9d4f020d5f0
--- /dev/null
+++ b/source/Host/common/MainLoop.cpp
@@ -0,0 +1,382 @@
+//===-- MainLoop.cpp --------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/llvm-config.h"
+
+#include "lldb/Host/MainLoop.h"
+#include "lldb/Utility/Error.h"
+#include <algorithm>
+#include <cassert>
+#include <cerrno>
+#include <csignal>
+#include <vector>
+#include <time.h>
+
+#if HAVE_SYS_EVENT_H
+#include <sys/event.h>
+#elif defined(LLVM_ON_WIN32)
+#include <winsock2.h>
+#else
+#include <poll.h>
+#endif
+
+#ifdef LLVM_ON_WIN32
+#define POLL WSAPoll
+#else
+#define POLL poll
+#endif
+
+#ifdef __ANDROID__
+#define FORCE_PSELECT
+#endif
+
+#if SIGNAL_POLLING_UNSUPPORTED
+#ifdef LLVM_ON_WIN32
+typedef int sigset_t;
+typedef int siginfo_t;
+#endif
+
+int ppoll(struct pollfd *fds, size_t nfds, const struct timespec *timeout_ts,
+          const sigset_t *) {
+  int timeout =
+      (timeout_ts == nullptr)
+          ? -1
+          : (timeout_ts->tv_sec * 1000 + timeout_ts->tv_nsec / 1000000);
+  return POLL(fds, nfds, timeout);
+}
+
+#endif
+
+using namespace lldb;
+using namespace lldb_private;
+
+static sig_atomic_t g_signal_flags[NSIG];
+
+static void SignalHandler(int signo, siginfo_t *info, void *) {
+  assert(signo < NSIG);
+  g_signal_flags[signo] = 1;
+}
+
+class MainLoop::RunImpl {
+public:
+  // TODO: Use llvm::Expected<T>
+  static std::unique_ptr<RunImpl> Create(MainLoop &loop, Error &error);
+  ~RunImpl();
+
+  Error Poll();
+
+  template <typename F> void ForEachReadFD(F &&f);
+  template <typename F> void ForEachSignal(F &&f);
+
+private:
+  MainLoop &loop;
+
+#if HAVE_SYS_EVENT_H
+  int queue_id;
+  std::vector<struct kevent> in_events;
+  struct kevent out_events[4];
+  int num_events = -1;
+
+  RunImpl(MainLoop &loop, int queue_id) : loop(loop), queue_id(queue_id) {
+    in_events.reserve(loop.m_read_fds.size() + loop.m_signals.size());
+  }
+#else
+  std::vector<int> signals;
+#ifdef FORCE_PSELECT
+  fd_set read_fd_set;
+#else
+  std::vector<struct pollfd> read_fds;
+#endif
+
+  RunImpl(MainLoop &loop) : loop(loop) {
+    signals.reserve(loop.m_signals.size());
+  }
+
+  sigset_t get_sigmask();
+#endif
+};
+
+#if HAVE_SYS_EVENT_H
+MainLoop::RunImpl::~RunImpl() {
+  int r = close(queue_id);
+  assert(r == 0);
+  (void)r;
+}
+std::unique_ptr<MainLoop::RunImpl> MainLoop::RunImpl::Create(MainLoop &loop, Error &error)
+{
+  error.Clear();
+  int queue_id = kqueue();
+  if(queue_id < 0) {
+    error = Error(errno, eErrorTypePOSIX);
+    return nullptr;
+  }
+  return std::unique_ptr<RunImpl>(new RunImpl(loop, queue_id));
+}
+
+Error MainLoop::RunImpl::Poll() {
+  in_events.resize(loop.m_read_fds.size() + loop.m_signals.size());
+  unsigned i = 0;
+  for (auto &fd : loop.m_read_fds)
+    EV_SET(&in_events[i++], fd.first, EVFILT_READ, EV_ADD, 0, 0, 0);
+
+  for (const auto &sig : loop.m_signals)
+    EV_SET(&in_events[i++], sig.first, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
+
+  num_events = kevent(queue_id, in_events.data(), in_events.size(), out_events,
+                      llvm::array_lengthof(out_events), nullptr);
+
+  if (num_events < 0)
+    return Error("kevent() failed with error %d\n", num_events);
+  return Error();
+}
+
+template <typename F> void MainLoop::RunImpl::ForEachReadFD(F &&f) {
+  assert(num_events >= 0);
+  for (int i = 0; i < num_events; ++i) {
+    f(out_events[i].ident);
+    if (loop.m_terminate_request)
+      return;
+  }
+}
+template <typename F> void MainLoop::RunImpl::ForEachSignal(F && f) {}
+#else
+MainLoop::RunImpl::~RunImpl() {}
+std::unique_ptr<MainLoop::RunImpl> MainLoop::RunImpl::Create(MainLoop &loop, Error &error)
+{
+  error.Clear();
+  return std::unique_ptr<RunImpl>(new RunImpl(loop));
+}
+
+sigset_t MainLoop::RunImpl::get_sigmask() {
+#if SIGNAL_POLLING_UNSUPPORTED
+  return 0;
+#else
+  sigset_t sigmask;
+  int ret = pthread_sigmask(SIG_SETMASK, nullptr, &sigmask);
+  assert(ret == 0);
+  (void) ret;
+
+  for (const auto &sig : loop.m_signals) {
+    signals.push_back(sig.first);
+    sigdelset(&sigmask, sig.first);
+  }
+  return sigmask;
+#endif
+}
+
+#ifdef FORCE_PSELECT
+Error MainLoop::RunImpl::Poll() {
+  signals.clear();
+
+  FD_ZERO(&read_fd_set);
+  int nfds = 0;
+  for (const auto &fd : loop.m_read_fds) {
+    FD_SET(fd.first, &read_fd_set);
+    nfds = std::max(nfds, fd.first + 1);
+  }
+
+  sigset_t sigmask = get_sigmask();
+  if (pselect(nfds, &read_fd_set, nullptr, nullptr, nullptr, &sigmask) == -1 &&
+      errno != EINTR)
+    return Error(errno, eErrorTypePOSIX);
+
+  return Error();
+}
+
+template <typename F> void MainLoop::RunImpl::ForEachReadFD(F &&f) {
+  for (const auto &fd : loop.m_read_fds) {
+    if(!FD_ISSET(fd.first, &read_fd_set))
+      continue;
+
+    f(fd.first);
+    if (loop.m_terminate_request)
+      return;
+  }
+}
+#else
+Error MainLoop::RunImpl::Poll() {
+  signals.clear();
+  read_fds.clear();
+
+  sigset_t sigmask = get_sigmask();
+
+  for (const auto &fd : loop.m_read_fds) {
+    struct pollfd pfd;
+    pfd.fd = fd.first;
+    pfd.events = POLLIN;
+    pfd.revents = 0;
+    read_fds.push_back(pfd);
+  }
+
+  if (ppoll(read_fds.data(), read_fds.size(), nullptr, &sigmask) == -1 &&
+      errno != EINTR)
+    return Error(errno, eErrorTypePOSIX);
+
+  return Error();
+}
+
+template <typename F> void MainLoop::RunImpl::ForEachReadFD(F &&f) {
+  for (const auto &fd : read_fds) {
+    if ((fd.revents & POLLIN) == 0)
+      continue;
+
+    f(fd.fd);
+    if (loop.m_terminate_request)
+      return;
+  }
+}
+#endif
+
+template <typename F> void MainLoop::RunImpl::ForEachSignal(F &&f) {
+  for (int sig : signals) {
+    if (g_signal_flags[sig] == 0)
+      continue; // No signal
+    g_signal_flags[sig] = 0;
+    f(sig);
+
+    if (loop.m_terminate_request)
+      return;
+  }
+}
+#endif
+
+MainLoop::~MainLoop() {
+  assert(m_read_fds.size() == 0);
+  assert(m_signals.size() == 0);
+}
+
+MainLoop::ReadHandleUP
+MainLoop::RegisterReadObject(const IOObjectSP &object_sp,
+                                  const Callback &callback, Error &error) {
+#ifdef LLVM_ON_WIN32
+  if (object_sp->GetFdType() != IOObject:: eFDTypeSocket) {
+    error.SetErrorString("MainLoop: non-socket types unsupported on Windows");
+    return nullptr;
+  }
+#endif
+  if (!object_sp || !object_sp->IsValid()) {
+    error.SetErrorString("IO object is not valid.");
+    return nullptr;
+  }
+
+  const bool inserted =
+      m_read_fds.insert({object_sp->GetWaitableHandle(), callback}).second;
+  if (!inserted) {
+    error.SetErrorStringWithFormat("File descriptor %d already monitored.",
+                                   object_sp->GetWaitableHandle());
+    return nullptr;
+  }
+
+  return CreateReadHandle(object_sp);
+}
+
+// We shall block the signal, then install the signal handler. The signal will
+// be unblocked in
+// the Run() function to check for signal delivery.
+MainLoop::SignalHandleUP
+MainLoop::RegisterSignal(int signo, const Callback &callback,
+                              Error &error) {
+#ifdef SIGNAL_POLLING_UNSUPPORTED
+  error.SetErrorString("Signal polling is not supported on this platform.");
+  return nullptr;
+#else
+  if (m_signals.find(signo) != m_signals.end()) {
+    error.SetErrorStringWithFormat("Signal %d already monitored.", signo);
+    return nullptr;
+  }
+
+  SignalInfo info;
+  info.callback = callback;
+  struct sigaction new_action;
+  new_action.sa_sigaction = &SignalHandler;
+  new_action.sa_flags = SA_SIGINFO;
+  sigemptyset(&new_action.sa_mask);
+  sigaddset(&new_action.sa_mask, signo);
+
+  sigset_t old_set;
+  if (int ret = pthread_sigmask(SIG_BLOCK, &new_action.sa_mask, &old_set)) {
+    error.SetErrorStringWithFormat("pthread_sigmask failed with error %d\n",
+                                   ret);
+    return nullptr;
+  }
+
+  info.was_blocked = sigismember(&old_set, signo);
+  if (sigaction(signo, &new_action, &info.old_action) == -1) {
+    error.SetErrorToErrno();
+    if (!info.was_blocked)
+      pthread_sigmask(SIG_UNBLOCK, &new_action.sa_mask, nullptr);
+    return nullptr;
+  }
+
+  m_signals.insert({signo, info});
+  g_signal_flags[signo] = 0;
+
+  return SignalHandleUP(new SignalHandle(*this, signo));
+#endif
+}
+
+void MainLoop::UnregisterReadObject(IOObject::WaitableHandle handle) {
+  bool erased = m_read_fds.erase(handle);
+  UNUSED_IF_ASSERT_DISABLED(erased);
+  assert(erased);
+}
+
+void MainLoop::UnregisterSignal(int signo) {
+#if SIGNAL_POLLING_UNSUPPORTED
+  Error("Signal polling is not supported on this platform.");
+#else
+  // We undo the actions of RegisterSignal on a best-effort basis.
+  auto it = m_signals.find(signo);
+  assert(it != m_signals.end());
+
+  sigaction(signo, &it->second.old_action, nullptr);
+
+  sigset_t set;
+  sigemptyset(&set);
+  sigaddset(&set, signo);
+  pthread_sigmask(it->second.was_blocked ? SIG_BLOCK : SIG_UNBLOCK, &set,
+                  nullptr);
+
+  m_signals.erase(it);
+#endif
+}
+
+Error MainLoop::Run() {
+  m_terminate_request = false;
+  
+  Error error;
+  auto impl = RunImpl::Create(*this, error);
+  if (!impl)
+    return error;
+
+  // run until termination or until we run out of things to listen to
+  while (!m_terminate_request && (!m_read_fds.empty() || !m_signals.empty())) {
+
+    error = impl->Poll();
+    if (error.Fail())
+      return error;
+
+    impl->ForEachSignal([&](int sig) {
+      auto it = m_signals.find(sig);
+      if (it != m_signals.end())
+        it->second.callback(*this); // Do the work
+    });
+    if (m_terminate_request)
+      return Error();
+
+    impl->ForEachReadFD([&](int fd) {
+      auto it = m_read_fds.find(fd);
+      if (it != m_read_fds.end())
+        it->second(*this); // Do the work
+    });
+    if (m_terminate_request)
+      return Error();
+  }
+  return Error();
+}
diff --git a/source/Host/common/Socket.cpp b/source/Host/common/Socket.cpp
index 2a665ddacb64f..d73b5d0ad0732 100644
--- a/source/Host/common/Socket.cpp
+++ b/source/Host/common/Socket.cpp
@@ -18,6 +18,8 @@
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/RegularExpression.h"
 
+#include "llvm/ADT/STLExtras.h"
+
 #ifndef LLDB_DISABLE_POSIX
 #include "lldb/Host/posix/DomainSocket.h"
 
@@ -67,9 +69,11 @@ bool IsInterrupted() {
 }
 }
 
-Socket::Socket(NativeSocket socket, SocketProtocol protocol, bool should_close)
+Socket::Socket(SocketProtocol protocol, bool should_close,
+               bool child_processes_inherit)
     : IOObject(eFDTypeSocket, should_close), m_protocol(protocol),
-      m_socket(socket) {}
+      m_socket(kInvalidSocketValue),
+      m_child_processes_inherit(child_processes_inherit) {}
 
 Socket::~Socket() { Close(); }
 
@@ -81,14 +85,17 @@ std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,
   std::unique_ptr<Socket> socket_up;
   switch (protocol) {
   case ProtocolTcp:
-    socket_up.reset(new TCPSocket(child_processes_inherit, error));
+    socket_up =
+        llvm::make_unique<TCPSocket>(true, child_processes_inherit);
     break;
   case ProtocolUdp:
-    socket_up.reset(new UDPSocket(child_processes_inherit, error));
+    socket_up =
+        llvm::make_unique<UDPSocket>(true, child_processes_inherit);
     break;
   case ProtocolUnixDomain:
 #ifndef LLDB_DISABLE_POSIX
-    socket_up.reset(new DomainSocket(child_processes_inherit, error));
+    socket_up =
+        llvm::make_unique<DomainSocket>(true, child_processes_inherit);
 #else
     error.SetErrorString(
         "Unix domain sockets are not supported on this platform.");
@@ -96,7 +103,8 @@ std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,
     break;
   case ProtocolUnixAbstract:
 #ifdef __linux__
-    socket_up.reset(new AbstractSocket(child_processes_inherit, error));
+    socket_up =
+        llvm::make_unique<AbstractSocket>(child_processes_inherit);
 #else
     error.SetErrorString(
         "Abstract domain sockets are not supported on this platform.");
@@ -145,7 +153,7 @@ Error Socket::TcpListen(llvm::StringRef host_and_port,
     return error;
 
   std::unique_ptr<TCPSocket> listen_socket(
-      new TCPSocket(child_processes_inherit, error));
+      new TCPSocket(true, child_processes_inherit));
   if (error.Fail())
     return error;
 
@@ -208,7 +216,7 @@ Error Socket::UnixDomainAccept(llvm::StringRef name,
   if (error.Fail())
     return error;
 
-  error = listen_socket->Accept(name, child_processes_inherit, socket);
+  error = listen_socket->Accept(socket);
   return error;
 }
 
@@ -240,18 +248,22 @@ Error Socket::UnixAbstractAccept(llvm::StringRef name,
   if (error.Fail())
     return error;
 
-  error = listen_socket->Accept(name, child_processes_inherit, socket);
+  error = listen_socket->Accept(socket);
   return error;
 }
 
 bool Socket::DecodeHostAndPort(llvm::StringRef host_and_port,
                                std::string &host_str, std::string &port_str,
                                int32_t &port, Error *error_ptr) {
-  static RegularExpression g_regex(llvm::StringRef("([^:]+):([0-9]+)"));
+  static RegularExpression g_regex(
+      llvm::StringRef("([^:]+|\\[[0-9a-fA-F:]+.*\\]):([0-9]+)"));
   RegularExpression::Match regex_match(2);
   if (g_regex.Execute(host_and_port, &regex_match)) {
     if (regex_match.GetMatchAtIndex(host_and_port.data(), 1, host_str) &&
         regex_match.GetMatchAtIndex(host_and_port.data(), 2, port_str)) {
+      // IPv6 addresses are wrapped in [] when specified with ports
+      if (host_str.front() == '[' && host_str.back() == ']')
+        host_str = host_str.substr(1, host_str.size() - 2);
       bool ok = false;
       port = StringConvert::ToUInt32(port_str.c_str(), UINT32_MAX, 10, &ok);
       if (ok && port <= UINT16_MAX) {
@@ -404,12 +416,12 @@ NativeSocket Socket::CreateSocket(const int domain, const int type,
                                   const int protocol,
                                   bool child_processes_inherit, Error &error) {
   error.Clear();
-  auto socketType = type;
+  auto socket_type = type;
 #ifdef SOCK_CLOEXEC
   if (!child_processes_inherit)
-    socketType |= SOCK_CLOEXEC;
+    socket_type |= SOCK_CLOEXEC;
 #endif
-  auto sock = ::socket(domain, socketType, protocol);
+  auto sock = ::socket(domain, socket_type, protocol);
   if (sock == kInvalidSocketValue)
     SetLastError(error);
 
diff --git a/source/Host/common/SocketAddress.cpp b/source/Host/common/SocketAddress.cpp
index b41cef6ca2ebd..440ae5d9027fd 100644
--- a/source/Host/common/SocketAddress.cpp
+++ b/source/Host/common/SocketAddress.cpp
@@ -6,6 +6,12 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// Note: This file is used on Darwin by debugserver, so it needs to remain as
+//       self contained as possible, and devoid of references to LLVM unless 
+//       there is compelling reason.
+//
+//===----------------------------------------------------------------------===//
 
 #if defined(_MSC_VER)
 #define _WINSOCK_DEPRECATED_NO_WARNINGS
@@ -227,7 +233,8 @@ bool SocketAddress::getaddrinfo(const char *host, const char *service,
                                 int ai_flags) {
   Clear();
 
-  auto addresses = GetAddressInfo(host, service, ai_family, ai_socktype, ai_protocol, ai_flags);
+  auto addresses = GetAddressInfo(host, service, ai_family, ai_socktype,
+                                  ai_protocol, ai_flags);
   if (!addresses.empty())
     *this = addresses[0];
   return IsValid();
diff --git a/source/Host/common/TCPSocket.cpp b/source/Host/common/TCPSocket.cpp
index 9a009280a9045..55db4bb0c4562 100644
--- a/source/Host/common/TCPSocket.cpp
+++ b/source/Host/common/TCPSocket.cpp
@@ -14,30 +14,57 @@
 #include "lldb/Host/common/TCPSocket.h"
 
 #include "lldb/Host/Config.h"
+#include "lldb/Host/MainLoop.h"
 #include "lldb/Utility/Log.h"
 
+#include "llvm/Config/llvm-config.h"
+#include "llvm/Support/raw_ostream.h"
+
 #ifndef LLDB_DISABLE_POSIX
 #include <arpa/inet.h>
 #include <netinet/tcp.h>
 #include <sys/socket.h>
 #endif
 
+#if defined(LLVM_ON_WIN32)
+#include <winsock2.h>
+#endif
+
+#ifdef LLVM_ON_WIN32
+#define CLOSE_SOCKET closesocket
+typedef const char *set_socket_option_arg_type;
+#else
+#define CLOSE_SOCKET ::close
+typedef const void *set_socket_option_arg_type;
+#endif
+
 using namespace lldb;
 using namespace lldb_private;
 
 namespace {
-
-const int kDomain = AF_INET;
 const int kType = SOCK_STREAM;
 }
 
-TCPSocket::TCPSocket(NativeSocket socket, bool should_close)
-    : Socket(socket, ProtocolTcp, should_close) {}
+TCPSocket::TCPSocket(bool should_close, bool child_processes_inherit)
+    : Socket(ProtocolTcp, should_close, child_processes_inherit) {}
 
-TCPSocket::TCPSocket(bool child_processes_inherit, Error &error)
-    : TCPSocket(CreateSocket(kDomain, kType, IPPROTO_TCP,
-                             child_processes_inherit, error),
-                true) {}
+TCPSocket::TCPSocket(NativeSocket socket, const TCPSocket &listen_socket)
+    : Socket(ProtocolTcp, listen_socket.m_should_close_fd,
+             listen_socket.m_child_processes_inherit) {
+  m_socket = socket;
+}
+
+TCPSocket::TCPSocket(NativeSocket socket, bool should_close,
+                     bool child_processes_inherit)
+    : Socket(ProtocolTcp, should_close, child_processes_inherit) {
+  m_socket = socket;
+}
+
+TCPSocket::~TCPSocket() { CloseListenSockets(); }
+
+bool TCPSocket::IsValid() const {
+  return m_socket != kInvalidSocketValue || m_listen_sockets.size() != 0;
+}
 
 // Return the port number that is being used by the socket.
 uint16_t TCPSocket::GetLocalPortNumber() const {
@@ -46,6 +73,12 @@ uint16_t TCPSocket::GetLocalPortNumber() const {
     socklen_t sock_addr_len = sock_addr.GetMaxLength();
     if (::getsockname(m_socket, sock_addr, &sock_addr_len) == 0)
       return sock_addr.GetPort();
+  } else if (!m_listen_sockets.empty()) {
+    SocketAddress sock_addr;
+    socklen_t sock_addr_len = sock_addr.GetMaxLength();
+    if (::getsockname(m_listen_sockets.begin()->first, sock_addr,
+                      &sock_addr_len) == 0)
+      return sock_addr.GetPort();
   }
   return 0;
 }
@@ -84,9 +117,18 @@ std::string TCPSocket::GetRemoteIPAddress() const {
   return "";
 }
 
+Error TCPSocket::CreateSocket(int domain) {
+  Error error;
+  if (IsValid())
+    error = Close();
+  if (error.Fail())
+    return error;
+  m_socket = Socket::CreateSocket(domain, kType, IPPROTO_TCP,
+                                  m_child_processes_inherit, error);
+  return error;
+}
+
 Error TCPSocket::Connect(llvm::StringRef name) {
-  if (m_socket == kInvalidSocketValue)
-    return Error("Invalid socket");
 
   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
   if (log)
@@ -99,146 +141,140 @@ Error TCPSocket::Connect(llvm::StringRef name) {
   if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
     return error;
 
-  struct sockaddr_in sa;
-  ::memset(&sa, 0, sizeof(sa));
-  sa.sin_family = kDomain;
-  sa.sin_port = htons(port);
-
-  int inet_pton_result = ::inet_pton(kDomain, host_str.c_str(), &sa.sin_addr);
-
-  if (inet_pton_result <= 0) {
-    struct hostent *host_entry = gethostbyname(host_str.c_str());
-    if (host_entry)
-      host_str = ::inet_ntoa(*(struct in_addr *)*host_entry->h_addr_list);
-    inet_pton_result = ::inet_pton(kDomain, host_str.c_str(), &sa.sin_addr);
-    if (inet_pton_result <= 0) {
-      if (inet_pton_result == -1)
-        SetLastError(error);
-      else
-        error.SetErrorStringWithFormat("invalid host string: '%s'",
-                                       host_str.c_str());
+  auto addresses = lldb_private::SocketAddress::GetAddressInfo(
+      host_str.c_str(), NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
+  for (auto address : addresses) {
+    error = CreateSocket(address.GetFamily());
+    if (error.Fail())
+      continue;
 
-      return error;
+    address.SetPort(port);
+
+    if (-1 == ::connect(GetNativeSocket(), &address.sockaddr(),
+                        address.GetLength())) {
+      CLOSE_SOCKET(GetNativeSocket());
+      continue;
     }
-  }
 
-  if (-1 ==
-      ::connect(GetNativeSocket(), (const struct sockaddr *)&sa, sizeof(sa))) {
-    SetLastError(error);
+    SetOptionNoDelay();
+
+    error.Clear();
     return error;
   }
 
-  // Keep our TCP packets coming without any delays.
-  SetOptionNoDelay();
-  error.Clear();
+  error.SetErrorString("Failed to connect port");
   return error;
 }
 
 Error TCPSocket::Listen(llvm::StringRef name, int backlog) {
-  Error error;
-
-  // enable local address reuse
-  SetOptionReuseAddress();
-
   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
   if (log)
     log->Printf("TCPSocket::%s (%s)", __FUNCTION__, name.data());
 
+  Error error;
   std::string host_str;
   std::string port_str;
   int32_t port = INT32_MIN;
   if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
     return error;
 
-  SocketAddress bind_addr;
+  if (host_str == "*")
+    host_str = "0.0.0.0";
+  auto addresses = lldb_private::SocketAddress::GetAddressInfo(
+      host_str.c_str(), NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
+  for (auto address : addresses) {
+    int fd = Socket::CreateSocket(address.GetFamily(), kType, IPPROTO_TCP,
+                                  m_child_processes_inherit, error);
+    if (error.Fail()) {
+      error.Clear();
+      continue;
+    }
 
-  // Only bind to the loopback address if we are expecting a connection from
-  // localhost to avoid any firewall issues.
-  const bool bind_addr_success = (host_str == "127.0.0.1")
-                                     ? bind_addr.SetToLocalhost(kDomain, port)
-                                     : bind_addr.SetToAnyAddress(kDomain, port);
+    // enable local address reuse
+    int option_value = 1;
+    set_socket_option_arg_type option_value_p =
+        reinterpret_cast<set_socket_option_arg_type>(&option_value);
+    ::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, option_value_p,
+                 sizeof(option_value));
 
-  if (!bind_addr_success) {
-    error.SetErrorString("Failed to bind port");
-    return error;
-  }
+    address.SetPort(port);
+
+    int err = ::bind(fd, &address.sockaddr(), address.GetLength());
+    if (-1 != err)
+      err = ::listen(fd, backlog);
 
-  int err = ::bind(GetNativeSocket(), bind_addr, bind_addr.GetLength());
-  if (err != -1)
-    err = ::listen(GetNativeSocket(), backlog);
+    if (-1 == err) {
+      CLOSE_SOCKET(fd);
+      continue;
+    }
 
-  if (err == -1)
-    SetLastError(error);
+    if (port == 0) {
+      socklen_t sa_len = address.GetLength();
+      if (getsockname(fd, &address.sockaddr(), &sa_len) == 0)
+        port = address.GetPort();
+    }
+    m_listen_sockets[fd] = address;
+  }
 
+  if (m_listen_sockets.size() == 0)
+    error.SetErrorString("Failed to connect port");
   return error;
 }
 
-Error TCPSocket::Accept(llvm::StringRef name, bool child_processes_inherit,
-                        Socket *&conn_socket) {
+void TCPSocket::CloseListenSockets() {
+  for (auto socket : m_listen_sockets)
+  CLOSE_SOCKET(socket.first);
+  m_listen_sockets.clear();
+}
+
+Error TCPSocket::Accept(Socket *&conn_socket) {
   Error error;
-  std::string host_str;
-  std::string port_str;
-  int32_t port;
-  if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
+  if (m_listen_sockets.size() == 0) {
+    error.SetErrorString("No open listening sockets!");
     return error;
+  }
 
-  const sa_family_t family = kDomain;
-  const int socktype = kType;
-  const int protocol = IPPROTO_TCP;
-  SocketAddress listen_addr;
-  if (host_str.empty())
-    listen_addr.SetToLocalhost(family, port);
-  else if (host_str.compare("*") == 0)
-    listen_addr.SetToAnyAddress(family, port);
-  else {
-    if (!listen_addr.getaddrinfo(host_str.c_str(), port_str.c_str(), family,
-                                 socktype, protocol)) {
-      error.SetErrorStringWithFormat("unable to resolve hostname '%s'",
-                                     host_str.c_str());
+  int sock = -1;
+  int listen_sock = -1;
+  lldb_private::SocketAddress AcceptAddr;
+  MainLoop accept_loop;
+  std::vector<MainLoopBase::ReadHandleUP> handles;
+  for (auto socket : m_listen_sockets) {
+    auto fd = socket.first;
+    auto inherit = this->m_child_processes_inherit;
+    auto io_sp = IOObjectSP(new TCPSocket(socket.first, false, inherit));
+    handles.emplace_back(accept_loop.RegisterReadObject(
+        io_sp, [fd, inherit, &sock, &AcceptAddr, &error,
+                        &listen_sock](MainLoopBase &loop) {
+          socklen_t sa_len = AcceptAddr.GetMaxLength();
+          sock = AcceptSocket(fd, &AcceptAddr.sockaddr(), &sa_len, inherit,
+                              error);
+          listen_sock = fd;
+          loop.RequestTermination();
+        }, error));
+    if (error.Fail())
       return error;
-    }
   }
 
   bool accept_connection = false;
   std::unique_ptr<TCPSocket> accepted_socket;
-
   // Loop until we are happy with our connection
   while (!accept_connection) {
-    struct sockaddr_in accept_addr;
-    ::memset(&accept_addr, 0, sizeof accept_addr);
-#if !(defined(__linux__) || defined(_WIN32))
-    accept_addr.sin_len = sizeof accept_addr;
-#endif
-    socklen_t accept_addr_len = sizeof accept_addr;
-
-    int sock = AcceptSocket(GetNativeSocket(), (struct sockaddr *)&accept_addr,
-                            &accept_addr_len, child_processes_inherit, error);
-
+    accept_loop.Run();
+    
     if (error.Fail())
-      break;
-
-    bool is_same_addr = true;
-#if !(defined(__linux__) || (defined(_WIN32)))
-    is_same_addr = (accept_addr_len == listen_addr.sockaddr_in().sin_len);
-#endif
-    if (is_same_addr)
-      is_same_addr = (accept_addr.sin_addr.s_addr ==
-                      listen_addr.sockaddr_in().sin_addr.s_addr);
-
-    if (is_same_addr ||
-        (listen_addr.sockaddr_in().sin_addr.s_addr == INADDR_ANY)) {
-      accept_connection = true;
-      accepted_socket.reset(new TCPSocket(sock, true));
-    } else {
-      const uint8_t *accept_ip = (const uint8_t *)&accept_addr.sin_addr.s_addr;
-      const uint8_t *listen_ip =
-          (const uint8_t *)&listen_addr.sockaddr_in().sin_addr.s_addr;
-      ::fprintf(stderr, "error: rejecting incoming connection from %u.%u.%u.%u "
-                        "(expecting %u.%u.%u.%u)\n",
-                accept_ip[0], accept_ip[1], accept_ip[2], accept_ip[3],
-                listen_ip[0], listen_ip[1], listen_ip[2], listen_ip[3]);
-      accepted_socket.reset();
+        return error;
+
+    lldb_private::SocketAddress &AddrIn = m_listen_sockets[listen_sock];
+    if (!AddrIn.IsAnyAddr() && AcceptAddr != AddrIn) {
+      CLOSE_SOCKET(sock);
+      llvm::errs() << llvm::formatv(
+          "error: rejecting incoming connection from {0} (expecting {1})",
+          AcceptAddr.GetIPAddress(), AddrIn.GetIPAddress());
+      continue;
     }
+    accept_connection = true;
+    accepted_socket.reset(new TCPSocket(sock, *this));
   }
 
   if (!accepted_socket)
diff --git a/source/Host/common/UDPSocket.cpp b/source/Host/common/UDPSocket.cpp
index 7ca62e7496ba0..a32657aab0a66 100644
--- a/source/Host/common/UDPSocket.cpp
+++ b/source/Host/common/UDPSocket.cpp
@@ -28,13 +28,16 @@ const int kDomain = AF_INET;
 const int kType = SOCK_DGRAM;
 
 static const char *g_not_supported_error = "Not supported";
-}
+} // namespace
 
-UDPSocket::UDPSocket(NativeSocket socket) : Socket(socket, ProtocolUdp, true) {}
+UDPSocket::UDPSocket(bool should_close, bool child_processes_inherit)
+    : Socket(ProtocolUdp, should_close, child_processes_inherit) {}
 
-UDPSocket::UDPSocket(bool child_processes_inherit, Error &error)
-    : UDPSocket(
-          CreateSocket(kDomain, kType, 0, child_processes_inherit, error)) {}
+UDPSocket::UDPSocket(NativeSocket socket, const UDPSocket &listen_socket)
+    : Socket(ProtocolUdp, listen_socket.m_should_close_fd,
+             listen_socket.m_child_processes_inherit) {
+  m_socket = socket;
+}
 
 size_t UDPSocket::Send(const void *buf, const size_t num_bytes) {
   return ::sendto(m_socket, static_cast<const char *>(buf), num_bytes, 0,
@@ -42,27 +45,14 @@ size_t UDPSocket::Send(const void *buf, const size_t num_bytes) {
 }
 
 Error UDPSocket::Connect(llvm::StringRef name) {
-  return Error("%s", g_not_supported_error);
-}
-
-Error UDPSocket::Listen(llvm::StringRef name, int backlog) {
-  return Error("%s", g_not_supported_error);
-}
-
-Error UDPSocket::Accept(llvm::StringRef name, bool child_processes_inherit,
-                        Socket *&socket) {
-  return Error("%s", g_not_supported_error);
-}
-
-Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
-                         Socket *&socket) {
-  std::unique_ptr<UDPSocket> final_socket;
-
   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
   if (log)
     log->Printf("UDPSocket::%s (host/port = %s)", __FUNCTION__, name.data());
 
   Error error;
+  if (error.Fail())
+    return error;
+
   std::string host_str;
   std::string port_str;
   int32_t port = INT32_MIN;
@@ -94,12 +84,11 @@ Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
   for (struct addrinfo *service_info_ptr = service_info_list;
        service_info_ptr != nullptr;
        service_info_ptr = service_info_ptr->ai_next) {
-    auto send_fd = CreateSocket(
+    m_socket = Socket::CreateSocket(
         service_info_ptr->ai_family, service_info_ptr->ai_socktype,
-        service_info_ptr->ai_protocol, child_processes_inherit, error);
+        service_info_ptr->ai_protocol, m_child_processes_inherit, error);
     if (error.Success()) {
-      final_socket.reset(new UDPSocket(send_fd));
-      final_socket->m_sockaddr = service_info_ptr;
+      m_sockaddr = service_info_ptr;
       break;
     } else
       continue;
@@ -107,16 +96,17 @@ Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
 
   ::freeaddrinfo(service_info_list);
 
-  if (!final_socket)
+  if (IsValid())
     return error;
 
   SocketAddress bind_addr;
 
   // Only bind to the loopback address if we are expecting a connection from
   // localhost to avoid any firewall issues.
-  const bool bind_addr_success = (host_str == "127.0.0.1" || host_str == "localhost")
-                                     ? bind_addr.SetToLocalhost(kDomain, port)
-                                     : bind_addr.SetToAnyAddress(kDomain, port);
+  const bool bind_addr_success =
+      (host_str == "127.0.0.1" || host_str == "localhost")
+          ? bind_addr.SetToLocalhost(kDomain, port)
+          : bind_addr.SetToAnyAddress(kDomain, port);
 
   if (!bind_addr_success) {
     error.SetErrorString("Failed to get hostspec to bind for");
@@ -125,13 +115,37 @@ Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
 
   bind_addr.SetPort(0); // Let the source port # be determined dynamically
 
-  err = ::bind(final_socket->GetNativeSocket(), bind_addr, bind_addr.GetLength());
-
-  struct sockaddr_in source_info;
-  socklen_t address_len = sizeof (struct sockaddr_in);
-  err = ::getsockname(final_socket->GetNativeSocket(), (struct sockaddr *) &source_info, &address_len);
+  err = ::bind(m_socket, bind_addr, bind_addr.GetLength());
 
-  socket = final_socket.release();
   error.Clear();
   return error;
 }
+
+Error UDPSocket::Listen(llvm::StringRef name, int backlog) {
+  return Error("%s", g_not_supported_error);
+}
+
+Error UDPSocket::Accept(Socket *&socket) {
+  return Error("%s", g_not_supported_error);
+}
+
+Error UDPSocket::CreateSocket() {
+  Error error;
+  if (IsValid())
+    error = Close();
+  if (error.Fail())
+    return error;
+  m_socket =
+      Socket::CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
+  return error;
+}
+
+Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
+                         Socket *&socket) {
+  std::unique_ptr<UDPSocket> final_socket(
+      new UDPSocket(true, child_processes_inherit));
+  Error error = final_socket->Connect(name);
+  if (!error.Fail())
+    socket = final_socket.release();
+  return error;
+}