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add interrupted bool, to account for spurious wake ups from std::condition_variable::wait_for

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This commit is contained in:
William Woodall 2015-11-03 13:40:59 -08:00
parent 973e38301d
commit dd6aeb2582
1 changed files with 15 additions and 3 deletions
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18
rclcpp/include/rclcpp/utilities.hpp
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@ -45,6 +45,7 @@ rmw_guard_condition_t * g_sigint_guard_cond_handle = \
rmw_create_guard_condition(); rmw_create_guard_condition();
/// Condition variable for timed sleep (see sleep_for). /// Condition variable for timed sleep (see sleep_for).
std::condition_variable g_interrupt_condition_variable; std::condition_variable g_interrupt_condition_variable;
std::atomic<bool> g_is_interrupted = false;
/// Mutex for protecting the global condition variable. /// Mutex for protecting the global condition variable.
std::mutex g_interrupt_mutex; std::mutex g_interrupt_mutex;
@ -95,6 +96,7 @@ signal_handler(int signal_value)
fprintf(stderr, fprintf(stderr,
"[rclcpp::error] failed to trigger guard condition: %s\n", rmw_get_error_string_safe()); "[rclcpp::error] failed to trigger guard condition: %s\n", rmw_get_error_string_safe());
} }
g_is_interrupted.store(true);
g_interrupt_condition_variable.notify_all(); g_interrupt_condition_variable.notify_all();
} }
} // namespace } // namespace
@ -117,6 +119,7 @@ init(int argc, char * argv[])
{ {
(void)argc; (void)argc;
(void)argv; (void)argv;
g_is_interrupted.store(false);
rmw_ret_t status = rmw_init(); rmw_ret_t status = rmw_init();
if (status != RMW_RET_OK) { if (status != RMW_RET_OK) {
// *INDENT-OFF* (prevent uncrustify from making unecessary indents here) // *INDENT-OFF* (prevent uncrustify from making unecessary indents here)
@ -170,6 +173,7 @@ shutdown()
fprintf(stderr, fprintf(stderr,
"[rclcpp::error] failed to trigger guard condition: %s\n", rmw_get_error_string_safe()); "[rclcpp::error] failed to trigger guard condition: %s\n", rmw_get_error_string_safe());
} }
g_is_interrupted.store(true);
g_interrupt_condition_variable.notify_all(); g_interrupt_condition_variable.notify_all();
} }
@ -190,10 +194,18 @@ bool
sleep_for(const std::chrono::nanoseconds & nanoseconds) sleep_for(const std::chrono::nanoseconds & nanoseconds)
{ {
// TODO: determine if posix's nanosleep(2) is more efficient here // TODO: determine if posix's nanosleep(2) is more efficient here
std::unique_lock<std::mutex> lock(::g_interrupt_mutex); std::chrono::nanoseconds time_left = nanoseconds;
auto cvs = ::g_interrupt_condition_variable.wait_for(lock, nanoseconds); {
std::unique_lock<std::mutex> lock(::g_interrupt_mutex);
auto start = std::chrono::steady_clock::now();
::g_interrupt_condition_variable.wait_for(lock, nanoseconds);
time_left -= std::chrono::steady_clock::now() - start;
}
if (time_left > std::chrono::nanoseconds::zero() && !g_is_interrupted) {
return sleep_for(time_left);
}
// Return true if the timeout elapsed successfully, otherwise false. // Return true if the timeout elapsed successfully, otherwise false.
return cvs != std::cv_status::no_timeout; return !g_is_interrupted;
} }
} /* namespace utilities */ } /* namespace utilities */