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Restore old signal handler after shutdown #353

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merged 3 commits into from
Aug 11, 2017
Merged

Restore old signal handler after shutdown #353

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c15db0b
Factor out signal handler swapping
dhood Aug 7, 2017
be985a6
Restore old signal handler on shutdown
dhood Aug 7, 2017
d7b7d74
Factor out guard condition triggering
dhood Aug 11, 2017
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144 changes: 86 additions & 58 deletions rclcpp/src/rclcpp/utilities.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -50,9 +50,79 @@ static std::mutex g_interrupt_mutex;
#ifdef HAS_SIGACTION
static struct sigaction old_action;
#else
static void (* old_signal_handler)(int) = 0;
typedef void (* signal_handler_t)(int);
static signal_handler_t old_signal_handler = 0;
#endif

#ifdef HAS_SIGACTION
struct sigaction
set_sigaction(int signal_value, const struct sigaction & action)
#else
signal_handler_t
set_signal_handler(int signal_value, signal_handler_t signal_handler)
#endif
{
#ifdef HAS_SIGACTION
struct sigaction old_action;
ssize_t ret = sigaction(signal_value, &action, &old_action);
if (ret == -1)
#else
signal_handler_t old_signal_handler = std::signal(signal_value, signal_handler);
// NOLINTNEXTLINE(readability/braces)
if (old_signal_handler == SIG_ERR)
#endif
{
const size_t error_length = 1024;
// NOLINTNEXTLINE(runtime/arrays)
char error_string[error_length];
#ifndef _WIN32
#if (defined(_GNU_SOURCE) && !defined(ANDROID))
char * msg = strerror_r(errno, error_string, error_length);
if (msg != error_string) {
strncpy(error_string, msg, error_length);
msg[error_length - 1] = '\0';
}
#else
int error_status = strerror_r(errno, error_string, error_length);
if (error_status != 0) {
throw std::runtime_error("Failed to get error string for errno: " + std::to_string(errno));
}
#endif
#else
strerror_s(error_string, error_length, errno);
#endif
// *INDENT-OFF* (prevent uncrustify from making unnecessary indents here)
throw std::runtime_error(
std::string("Failed to set SIGINT signal handler: (" + std::to_string(errno) + ")") +
error_string);
// *INDENT-ON*
}

#ifdef HAS_SIGACTION
return old_action;
#else
return old_signal_handler;
#endif
}

void
trigger_interrupt_guard_condition(int signal_value)
{
g_signal_status = signal_value;
{
std::lock_guard<std::mutex> lock(g_sigint_guard_cond_handles_mutex);
for (auto & kv : g_sigint_guard_cond_handles) {
rcl_ret_t status = rcl_trigger_guard_condition(&(kv.second));
if (status != RCL_RET_OK) {
fprintf(stderr,
"[rclcpp::error] failed to trigger guard condition: %s\n", rcl_get_error_string_safe());
}
}
}
g_is_interrupted.store(true);
g_interrupt_condition_variable.notify_all();
}

void
#ifdef HAS_SIGACTION
signal_handler(int signal_value, siginfo_t * siginfo, void * context)
Expand All @@ -62,6 +132,7 @@ signal_handler(int signal_value)
{
// TODO(wjwwood): remove? move to console logging at some point?
printf("signal_handler(%d)\n", signal_value);

#ifdef HAS_SIGACTION
if (old_action.sa_flags & SA_SIGINFO) {
if (old_action.sa_sigaction != NULL) {
Expand All @@ -83,19 +154,8 @@ signal_handler(int signal_value)
old_signal_handler(signal_value);
}
#endif
g_signal_status = signal_value;
{
std::lock_guard<std::mutex> lock(g_sigint_guard_cond_handles_mutex);
for (auto & kv : g_sigint_guard_cond_handles) {
rcl_ret_t status = rcl_trigger_guard_condition(&(kv.second));
if (status != RCL_RET_OK) {
fprintf(stderr,
"[rclcpp::error] failed to trigger guard condition: %s\n", rcl_get_error_string_safe());
}
}
}
g_is_interrupted.store(true);
g_interrupt_condition_variable.notify_all();

trigger_interrupt_guard_condition(signal_value);
}

void
Expand All @@ -114,39 +174,18 @@ rclcpp::utilities::init(int argc, char * argv[])
sigemptyset(&action.sa_mask);
action.sa_sigaction = ::signal_handler;
action.sa_flags = SA_SIGINFO;
ssize_t ret = sigaction(SIGINT, &action, &old_action);
if (ret == -1)
::old_action = set_sigaction(SIGINT, action);
// Register an on_shutdown hook to restore the old action.
rclcpp::utilities::on_shutdown([]() {
set_sigaction(SIGINT, ::old_action);
});
#else
::old_signal_handler = std::signal(SIGINT, ::signal_handler);
// NOLINTNEXTLINE(readability/braces)
if (::old_signal_handler == SIG_ERR)
::old_signal_handler = set_signal_handler(SIGINT, ::signal_handler);
// Register an on_shutdown hook to restore the old signal handler.
rclcpp::utilities::on_shutdown([]() {
set_signal_handler(SIGINT, ::old_signal_handler);
});
#endif
{
const size_t error_length = 1024;
// NOLINTNEXTLINE(runtime/arrays)
char error_string[error_length];
#ifndef _WIN32
#if (defined(_GNU_SOURCE) && !defined(ANDROID))
char * msg = strerror_r(errno, error_string, error_length);
if (msg != error_string) {
strncpy(error_string, msg, error_length);
msg[error_length - 1] = '\0';
}
#else
int error_status = strerror_r(errno, error_string, error_length);
if (error_status != 0) {
throw std::runtime_error("Failed to get error string for errno: " + std::to_string(errno));
}
#endif
#else
strerror_s(error_string, error_length, errno);
#endif
// *INDENT-OFF* (prevent uncrustify from making unnecessary indents here)
throw std::runtime_error(
std::string("Failed to set SIGINT signal handler: (" + std::to_string(errno) + ")") +
error_string);
// *INDENT-ON*
}
}

bool
Expand All @@ -161,19 +200,8 @@ static std::vector<std::function<void(void)>> on_shutdown_callbacks_;
void
rclcpp::utilities::shutdown()
{
g_signal_status = SIGINT;
{
std::lock_guard<std::mutex> lock(g_sigint_guard_cond_handles_mutex);
for (auto & kv : g_sigint_guard_cond_handles) {
if (rcl_trigger_guard_condition(&(kv.second)) != RCL_RET_OK) {
fprintf(stderr,
"[rclcpp::error] failed to trigger sigint guard condition: %s\n",
rcl_get_error_string_safe());
}
}
}
g_is_interrupted.store(true);
g_interrupt_condition_variable.notify_all();
trigger_interrupt_guard_condition(SIGINT);

{
std::lock_guard<std::mutex> lock(on_shutdown_mutex_);
for (auto & on_shutdown_callback : on_shutdown_callbacks_) {
Expand Down