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#include "utils/platform/unix/interface.h"
#include "utils/platform/platform.h"
#include <functional>
#include <thread>
#include <array>
#include <cstring>
#include <csignal>
#include <ctime>
#include <unistd.h>
#include <fcntl.h>
#include <sys/event.h>
#include <iostream>
namespace TangoTest::platform
{
std::vector<std::string> default_env()
{
return {"PATH="};
}
namespace unix
{
struct FileWatcher::Impl
{
explicit Impl(const char *filename)
{
// Create a kqueue that allows us to watch file events.
if((kernel_queue = kqueue()) < 0)
{
throw_strerror("Could not open a kernel queue.");
}
// Open a file that we want to watch via the kqueue events.
const auto fd{open(filename, O_EVTONLY)};
if(fd <= 0)
{
throw_strerror("Could not open file \"", filename, "\".");
}
else
{
event_fd = fd;
}
// Tell the kqueue event set what we want to monitor.
wanted_events = NOTE_WRITE;
EV_SET64(&(events_to_monitor[0]), event_fd, EVFILT_VNODE, EV_ADD | EV_CLEAR, wanted_events, 0, 0, 0, 0);
if(::pipe(watched_fds) != 0)
{
throw_strerror("Could not open a pipe for communication with the "
"testing framework.");
}
}
void start_watching()
{
stop_thread = false;
event_thread = std::thread(&FileWatcher::Impl::thread_run, this);
}
void thread_run()
{
struct timespec timeout
{
};
while(!stop_thread)
{
// Always reset the timeout to 0.1s.
timeout.tv_sec = 0;
timeout.tv_nsec = 100'000'000;
// Wait until a kqueue event that we want happens. This call
// will time out after timeout seconds.
const int event_count{kevent64(kernel_queue,
&(events_to_monitor[0]),
number_of_watched_files,
&(event_data[0]),
number_of_watched_files,
KEVENT_FLAG_NONE,
&timeout)};
if((event_count < 0) || (event_data[0].flags == EV_ERROR))
{
// An error occurred.
throw_strerror("An error occurred (event count=", event_count, ").");
break;
}
if(event_count)
{
::write(watched_fds[1], "\0", 1);
}
};
}
void stop_watching_thread()
{
stop_thread = true;
if(event_thread.joinable())
{
event_thread.join();
}
}
void stop_watching()
{
stop_watching_thread();
::close(kernel_queue);
const int fd{event_fd};
event_fd = -1;
::close(fd);
const int fds[2]{watched_fds[0], watched_fds[1]};
watched_fds[0] = watched_fds[1] = -1;
::close(fds[1]);
::close(fds[0]);
}
~Impl()
{
stop_watching();
}
const std::size_t number_of_watched_files{1};
int event_fd{-1};
int watched_fds[2]{-1, -1};
int kernel_queue{-1};
bool stop_thread{true};
std::thread event_thread;
std::array<struct kevent64_s, 1> events_to_monitor{};
std::array<struct kevent64_s, 1> event_data{};
struct timespec timeout
{
1, 0
};
unsigned int wanted_events;
};
FileWatcher::FileWatcher(const char *filename) :
m_pimpl{std::make_unique<FileWatcher::Impl>(filename)}
{
}
FileWatcher::~FileWatcher() { }
int FileWatcher::get_file_descriptor()
{
return m_pimpl->watched_fds[0];
}
void FileWatcher::start_watching()
{
m_pimpl->start_watching();
}
void FileWatcher::stop_watching()
{
m_pimpl->stop_watching();
}
void FileWatcher::cleanup_in_child()
{
m_pimpl.reset(nullptr);
}
void FileWatcher::pop_event()
{
char foo;
::read(m_pimpl->watched_fds[0], &foo, 1);
}
// There is no equivalent of prctl(PR_SET_PDEATHSIG). It is not worth the
// effort to implement something that mimics it. The tests works without it.
void kill_self_on_parent_death([[maybe_unused]] pid_t ppid) { }
} // namespace unix
} // namespace TangoTest::platform
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