ClickHouse/src/Common/Epoll.cpp
2022-12-07 13:32:43 +01:00

86 lines
1.9 KiB
C++

#if defined(OS_LINUX)
#include "Epoll.h"
#include <Common/Exception.h>
#include <unistd.h>
namespace DB
{
namespace ErrorCodes
{
extern const int EPOLL_ERROR;
extern const int LOGICAL_ERROR;
}
Epoll::Epoll() : events_count(0)
{
epoll_fd = epoll_create1(0);
if (epoll_fd == -1)
throwFromErrno("Cannot open epoll descriptor", DB::ErrorCodes::EPOLL_ERROR);
}
Epoll::Epoll(Epoll && other) noexcept : epoll_fd(other.epoll_fd), events_count(other.events_count.load())
{
other.epoll_fd = -1;
}
Epoll & Epoll::operator=(Epoll && other) noexcept
{
epoll_fd = other.epoll_fd;
other.epoll_fd = -1;
events_count.store(other.events_count.load());
return *this;
}
void Epoll::add(int fd, void * ptr)
{
epoll_event event;
event.events = EPOLLIN | EPOLLPRI;
if (ptr)
event.data.ptr = ptr;
else
event.data.fd = fd;
++events_count;
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &event) == -1)
throwFromErrno("Cannot add new descriptor to epoll", DB::ErrorCodes::EPOLL_ERROR);
}
void Epoll::remove(int fd)
{
--events_count;
if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, nullptr) == -1)
throwFromErrno("Cannot remove descriptor from epoll", DB::ErrorCodes::EPOLL_ERROR);
}
size_t Epoll::getManyReady(int max_events, epoll_event * events_out, bool blocking) const
{
if (events_count == 0)
throw Exception("There are no events in epoll", ErrorCodes::LOGICAL_ERROR);
int ready_size;
int timeout = blocking ? -1 : 0;
do
{
ready_size = epoll_wait(epoll_fd, events_out, max_events, timeout);
if (ready_size == -1 && errno != EINTR)
throwFromErrno("Error in epoll_wait", DB::ErrorCodes::EPOLL_ERROR);
}
while (ready_size <= 0 && (ready_size != 0 || blocking));
return ready_size;
}
Epoll::~Epoll()
{
if (epoll_fd != -1)
close(epoll_fd);
}
}
#endif