https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66803
Bug ID: 66803
Summary: std::this_thread::sleep_for gets interrupted by
signals.
Product: gcc
Version: 5.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: adam at mizerski dot pl
Target Milestone: ---
Created attachment 35930
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35930&action=edit
preprocessed source
#include <chrono>
#include <iostream>
#include <thread>
#include <csignal>
void signal_handler(int) {}
int main()
{
using namespace std::chrono_literals;
std::signal(SIGUSR1, signal_handler);
const auto start = std::chrono::high_resolution_clock::now();
std::this_thread::sleep_for(5s);
const auto end = std::chrono::high_resolution_clock::now();
std::cout << "Waited " <<
std::chrono::duration_cast<std::chrono::seconds>(end-start).count() << " s\n";
return 0;
}
Compilation command: g++-5.1 -save-temps -std=c++14 test_cpp.cpp -o test_cpp
-O2 -Wall -Wextra -pedantic -pthread
Preprocessed source in attachment.
Testing command line: ./test_cpp & sleep 2 && kill -USR1 $!
Expected result: std::this_thread::sleep_for(5s); sleeps for 5 seconds.
Actual result: std::this_thread::sleep_for(5s); sleeps for 2 seconds.
The behavior of std::this_thread::sleep_for seems similar to sleep from
unistd.h - it gets interrupted by signal handler. But
std::this_thread::sleep_for unlike sleep has no way to report if it was
interrupted or time left to sleep. C++14 standard (N3797) in 30.3.2 says that
sleep_for should sleep specified amount of time and nothing about any
interrupts.
The same source compiled with "clang++ -std=c++14 -stdlib=libc++ -lc++abi
test_cpp.cpp -o test_cpp -O2" (with clang version 3.5.0) behaves as expected.
$ g++-5.1 -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/5.1.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /usr/src/gcc/configure --disable-multilib
--enable-languages=c,c++
Thread model: posix
gcc version 5.1.0 (GCC)
