Chris Bieneman 9317c64768 Another netbsd build failure...
llvm-svn: 300640
2017-04-19 01:17:29 +00:00

268 lines
7.1 KiB
C++

//===-- 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/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
#if SIGNAL_POLLING_UNSUPPORTED
#ifdef LLVM_ON_WIN32
typedef int sigset_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;
}
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() {
std::vector<int> signals;
m_terminate_request = false;
signals.reserve(m_signals.size());
#if HAVE_SYS_EVENT_H
int queue_id = kqueue();
if (queue_id < 0)
Error("kqueue failed with error %d\n", queue_id);
std::vector<struct kevent> events;
events.reserve(m_read_fds.size() + m_signals.size());
#else
sigset_t sigmask;
std::vector<struct pollfd> read_fds;
read_fds.reserve(m_read_fds.size());
#endif
// run until termination or until we run out of things to listen to
while (!m_terminate_request && (!m_read_fds.empty() || !m_signals.empty())) {
// To avoid problems with callbacks changing the things we're supposed to
// listen to, we
// will store the *real* list of events separately.
signals.clear();
#if HAVE_SYS_EVENT_H
events.resize(m_read_fds.size() + m_signals.size());
int i = 0;
for (auto &fd: m_read_fds) {
EV_SET(&events[i++], fd.first, EVFILT_READ, EV_ADD, 0, 0, 0);
}
for (const auto &sig : m_signals) {
signals.push_back(sig.first);
EV_SET(&events[i++], sig.first, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
}
struct kevent event_list[4];
int num_events =
kevent(queue_id, events.data(), events.size(), event_list, 4, NULL);
if (num_events < 0)
return Error("kevent() failed with error %d\n", num_events);
#else
read_fds.clear();
#if !SIGNAL_POLLING_UNSUPPORTED
if (int ret = pthread_sigmask(SIG_SETMASK, nullptr, &sigmask))
return Error("pthread_sigmask failed with error %d\n", ret);
for (const auto &sig : m_signals) {
signals.push_back(sig.first);
sigdelset(&sigmask, sig.first);
}
#endif
for (const auto &fd : 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);
#endif
for (int sig : signals) {
if (g_signal_flags[sig] == 0)
continue; // No signal
g_signal_flags[sig] = 0;
auto it = m_signals.find(sig);
if (it == m_signals.end())
continue; // Signal must have gotten unregistered in the meantime
it->second.callback(*this); // Do the work
if (m_terminate_request)
return Error();
}
#if HAVE_SYS_EVENT_H
for (int i = 0; i < num_events; ++i) {
auto it = m_read_fds.find(event_list[i].ident);
#else
for (auto fd : read_fds) {
if ((fd.revents & POLLIN) == 0)
continue;
auto it = m_read_fds.find(fd.fd);
#endif
if (it == m_read_fds.end())
continue; // File descriptor must have gotten unregistered in the
// meantime
it->second(*this); // Do the work
if (m_terminate_request)
return Error();
}
}
return Error();
}