Merge pull request #19153 from azat/async_socket_for_remote-fix-fd-leak

Fix leaking of pipe fd for async_socket_for_remote
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alexey-milovidov 2021-01-16 11:23:55 +03:00 committed by GitHub
commit bf86d3bab8
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5 changed files with 264 additions and 221 deletions

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@ -106,7 +106,7 @@ private:
/// in separate thread.
mutable std::mutex cancel_mutex;
friend class RemoteQueryExecutorReadContext;
friend struct RemoteQueryExecutorRoutine;
};
}

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@ -3,6 +3,7 @@
#include <boost/context/stack_context.hpp>
#include <Common/formatReadable.h>
#include <Common/CurrentMemoryTracker.h>
#include <Common/Exception.h>
#include <sys/time.h>
#include <sys/resource.h>

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@ -0,0 +1,238 @@
#if defined(OS_LINUX)
#include <DataStreams/RemoteQueryExecutorReadContext.h>
#include <Common/Exception.h>
#include <Common/NetException.h>
#include <Client/MultiplexedConnections.h>
#include <sys/epoll.h>
namespace DB
{
struct RemoteQueryExecutorRoutine
{
MultiplexedConnections & connections;
RemoteQueryExecutorReadContext & read_context;
struct ReadCallback
{
RemoteQueryExecutorReadContext & read_context;
Fiber & fiber;
void operator()(Poco::Net::Socket & socket)
{
try
{
read_context.setSocket(socket);
}
catch (DB::Exception & e)
{
e.addMessage(" while reading from socket ({})", socket.peerAddress().toString());
throw;
}
read_context.is_read_in_progress.store(true, std::memory_order_relaxed);
fiber = std::move(fiber).resume();
read_context.is_read_in_progress.store(false, std::memory_order_relaxed);
}
};
Fiber operator()(Fiber && sink) const
{
try
{
while (true)
{
read_context.packet = connections.receivePacketUnlocked(ReadCallback{read_context, sink});
sink = std::move(sink).resume();
}
}
catch (const boost::context::detail::forced_unwind &)
{
/// This exception is thrown by fiber implementation in case if fiber is being deleted but hasn't exited
/// It should not be caught or it will segfault.
/// Other exceptions must be caught
throw;
}
catch (...)
{
read_context.exception = std::current_exception();
}
return std::move(sink);
}
};
namespace ErrorCodes
{
extern const int CANNOT_READ_FROM_SOCKET;
extern const int CANNOT_OPEN_FILE;
extern const int SOCKET_TIMEOUT;
}
RemoteQueryExecutorReadContext::RemoteQueryExecutorReadContext(MultiplexedConnections & connections_)
: connections(connections_)
{
epoll_fd = epoll_create(2);
if (-1 == epoll_fd)
throwFromErrno("Cannot create epoll descriptor", ErrorCodes::CANNOT_OPEN_FILE);
if (-1 == pipe2(pipe_fd, O_NONBLOCK))
throwFromErrno("Cannot create pipe", ErrorCodes::CANNOT_OPEN_FILE);
{
epoll_event socket_event;
socket_event.events = EPOLLIN | EPOLLPRI;
socket_event.data.fd = pipe_fd[0];
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, pipe_fd[0], &socket_event))
throwFromErrno("Cannot add pipe descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
{
epoll_event timer_event;
timer_event.events = EPOLLIN | EPOLLPRI;
timer_event.data.fd = timer.getDescriptor();
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, timer_event.data.fd, &timer_event))
throwFromErrno("Cannot add timer descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
auto routine = RemoteQueryExecutorRoutine{connections, *this};
fiber = boost::context::fiber(std::allocator_arg_t(), stack, std::move(routine));
}
void RemoteQueryExecutorReadContext::setSocket(Poco::Net::Socket & socket)
{
int fd = socket.impl()->sockfd();
if (fd == socket_fd)
return;
epoll_event socket_event;
socket_event.events = EPOLLIN | EPOLLPRI;
socket_event.data.fd = fd;
if (socket_fd != -1)
{
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_DEL, socket_fd, &socket_event))
throwFromErrno("Cannot remove socket descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
socket_fd = fd;
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, socket_fd, &socket_event))
throwFromErrno("Cannot add socket descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
receive_timeout = socket.impl()->getReceiveTimeout();
}
bool RemoteQueryExecutorReadContext::checkTimeout() const
{
try
{
return checkTimeoutImpl();
}
catch (DB::Exception & e)
{
if (last_used_socket)
e.addMessage(" while reading from socket ({})", last_used_socket->peerAddress().toString());
throw;
}
}
bool RemoteQueryExecutorReadContext::checkTimeoutImpl() const
{
epoll_event events[3];
events[0].data.fd = events[1].data.fd = events[2].data.fd = -1;
/// Wait for epoll_fd will not block if it was polled externally.
int num_events = epoll_wait(epoll_fd, events, 3, 0);
if (num_events == -1)
throwFromErrno("Failed to epoll_wait", ErrorCodes::CANNOT_READ_FROM_SOCKET);
bool is_socket_ready = false;
bool is_pipe_alarmed = false;
bool has_timer_alarm = false;
for (int i = 0; i < num_events; ++i)
{
if (events[i].data.fd == socket_fd)
is_socket_ready = true;
if (events[i].data.fd == timer.getDescriptor())
has_timer_alarm = true;
if (events[i].data.fd == pipe_fd[0])
is_pipe_alarmed = true;
}
if (is_pipe_alarmed)
return false;
if (has_timer_alarm && !is_socket_ready)
{
/// Socket receive timeout. Drain it in case or error, or it may be hide by timeout exception.
timer.drain();
throw NetException("Timeout exceeded", ErrorCodes::SOCKET_TIMEOUT);
}
return true;
}
void RemoteQueryExecutorReadContext::setTimer() const
{
/// Did not get packet yet. Init timeout for the next async reading.
timer.reset();
if (receive_timeout.totalMicroseconds())
timer.setRelative(receive_timeout);
}
bool RemoteQueryExecutorReadContext::resumeRoutine()
{
if (is_read_in_progress.load(std::memory_order_relaxed) && !checkTimeout())
return false;
{
std::lock_guard guard(fiber_lock);
if (!fiber)
return false;
fiber = std::move(fiber).resume();
}
if (exception)
std::rethrow_exception(std::move(exception));
return true;
}
void RemoteQueryExecutorReadContext::cancel()
{
std::lock_guard guard(fiber_lock);
/// It is safe to just destroy fiber - we are not in the process of reading from socket.
boost::context::fiber to_destroy = std::move(fiber);
/// Send something to pipe to cancel executor waiting.
uint64_t buf = 0;
while (-1 == write(pipe_fd[1], &buf, sizeof(buf)))
{
if (errno == EAGAIN)
break;
if (errno != EINTR)
throwFromErrno("Cannot write to pipe", ErrorCodes::CANNOT_READ_FROM_SOCKET);
}
}
RemoteQueryExecutorReadContext::~RemoteQueryExecutorReadContext()
{
/// socket_fd is closed by Poco::Net::Socket
if (epoll_fd != -1)
close(epoll_fd);
if (pipe_fd[0] != -1)
close(pipe_fd[0]);
if (pipe_fd[1] != -1)
close(pipe_fd[1]);
}
}
#endif

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@ -2,26 +2,27 @@
#if defined(OS_LINUX)
#include <sys/epoll.h>
#include <mutex>
#include <atomic>
#include <Common/Fiber.h>
#include <Common/FiberStack.h>
#include <Common/TimerDescriptor.h>
#include <Client/Connection.h>
#include <Poco/Timespan.h>
namespace Poco::Net
{
class Socket;
}
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_READ_FROM_SOCKET;
extern const int CANNOT_OPEN_FILE;
extern const int SOCKET_TIMEOUT;
}
class MultiplexedConnections;
class RemoteQueryExecutorReadContext
{
public:
using Self = RemoteQueryExecutorReadContext;
std::atomic_bool is_read_in_progress = false;
Packet packet;
@ -42,224 +43,26 @@ public:
/// We put those descriptors into our own epoll_fd which is used by external executor.
TimerDescriptor timer{CLOCK_MONOTONIC, 0};
int socket_fd = -1;
int epoll_fd;
int pipe_fd[2];
int epoll_fd = -1;
int pipe_fd[2] = { -1, -1 };
explicit RemoteQueryExecutorReadContext(MultiplexedConnections & connections_) : connections(connections_)
{
epoll_fd = epoll_create(2);
if (-1 == epoll_fd)
throwFromErrno("Cannot create epoll descriptor", ErrorCodes::CANNOT_OPEN_FILE);
explicit RemoteQueryExecutorReadContext(MultiplexedConnections & connections_);
~RemoteQueryExecutorReadContext();
if (-1 == pipe2(pipe_fd, O_NONBLOCK))
throwFromErrno("Cannot create pipe", ErrorCodes::CANNOT_OPEN_FILE);
bool checkTimeout() const;
bool checkTimeoutImpl() const;
{
epoll_event socket_event;
socket_event.events = EPOLLIN | EPOLLPRI;
socket_event.data.fd = pipe_fd[0];
void setSocket(Poco::Net::Socket & socket);
void setTimer() const;
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, pipe_fd[0], &socket_event))
throwFromErrno("Cannot add pipe descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
{
epoll_event timer_event;
timer_event.events = EPOLLIN | EPOLLPRI;
timer_event.data.fd = timer.getDescriptor();
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, timer_event.data.fd, &timer_event))
throwFromErrno("Cannot add timer descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
auto routine = Routine{connections, *this};
fiber = boost::context::fiber(std::allocator_arg_t(), stack, std::move(routine));
}
void setSocket(Poco::Net::Socket & socket)
{
int fd = socket.impl()->sockfd();
if (fd == socket_fd)
return;
epoll_event socket_event;
socket_event.events = EPOLLIN | EPOLLPRI;
socket_event.data.fd = fd;
if (socket_fd != -1)
{
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_DEL, socket_fd, &socket_event))
throwFromErrno("Cannot remove socket descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
}
socket_fd = fd;
if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_ADD, socket_fd, &socket_event))
throwFromErrno("Cannot add socket descriptor to epoll", ErrorCodes::CANNOT_OPEN_FILE);
receive_timeout = socket.impl()->getReceiveTimeout();
}
bool checkTimeout() const
{
try
{
return checkTimeoutImpl();
}
catch (DB::Exception & e)
{
if (last_used_socket)
e.addMessage(" while reading from socket ({})", last_used_socket->peerAddress().toString());
throw;
}
}
bool checkTimeoutImpl() const
{
epoll_event events[3];
events[0].data.fd = events[1].data.fd = events[2].data.fd = -1;
/// Wait for epoll_fd will not block if it was polled externally.
int num_events = epoll_wait(epoll_fd, events, 3, 0);
if (num_events == -1)
throwFromErrno("Failed to epoll_wait", ErrorCodes::CANNOT_READ_FROM_SOCKET);
bool is_socket_ready = false;
bool is_pipe_alarmed = false;
bool has_timer_alarm = false;
for (int i = 0; i < num_events; ++i)
{
if (events[i].data.fd == socket_fd)
is_socket_ready = true;
if (events[i].data.fd == timer.getDescriptor())
has_timer_alarm = true;
if (events[i].data.fd == pipe_fd[0])
is_pipe_alarmed = true;
}
if (is_pipe_alarmed)
return false;
if (has_timer_alarm && !is_socket_ready)
{
/// Socket receive timeout. Drain it in case or error, or it may be hide by timeout exception.
timer.drain();
throw NetException("Timeout exceeded", ErrorCodes::SOCKET_TIMEOUT);
}
return true;
}
void setTimer() const
{
/// Did not get packet yet. Init timeout for the next async reading.
timer.reset();
if (receive_timeout.totalMicroseconds())
timer.setRelative(receive_timeout);
}
bool resumeRoutine()
{
if (is_read_in_progress.load(std::memory_order_relaxed) && !checkTimeout())
return false;
{
std::lock_guard guard(fiber_lock);
if (!fiber)
return false;
fiber = std::move(fiber).resume();
}
if (exception)
std::rethrow_exception(std::move(exception));
return true;
}
void cancel()
{
std::lock_guard guard(fiber_lock);
/// It is safe to just destroy fiber - we are not in the process of reading from socket.
boost::context::fiber to_destroy = std::move(fiber);
/// Send something to pipe to cancel executor waiting.
uint64_t buf = 0;
while (-1 == write(pipe_fd[1], &buf, sizeof(buf)))
{
if (errno == EAGAIN)
break;
if (errno != EINTR)
throwFromErrno("Cannot write to pipe", ErrorCodes::CANNOT_READ_FROM_SOCKET);
}
}
~RemoteQueryExecutorReadContext()
{
/// socket_fd is closed by Poco::Net::Socket
/// timer_fd is closed by TimerDescriptor
close(epoll_fd);
}
struct Routine
{
MultiplexedConnections & connections;
Self & read_context;
struct ReadCallback
{
Self & read_context;
Fiber & fiber;
void operator()(Poco::Net::Socket & socket)
{
try
{
read_context.setSocket(socket);
}
catch (DB::Exception & e)
{
e.addMessage(" while reading from socket ({})", socket.peerAddress().toString());
throw;
}
read_context.is_read_in_progress.store(true, std::memory_order_relaxed);
fiber = std::move(fiber).resume();
read_context.is_read_in_progress.store(false, std::memory_order_relaxed);
}
bool resumeRoutine();
void cancel();
};
Fiber operator()(Fiber && sink) const
{
try
{
while (true)
{
read_context.packet = connections.receivePacketUnlocked(ReadCallback{read_context, sink});
sink = std::move(sink).resume();
}
}
catch (const boost::context::detail::forced_unwind &)
{
/// This exception is thrown by fiber implementation in case if fiber is being deleted but hasn't exited
/// It should not be caught or it will segfault.
/// Other exceptions must be caught
throw;
}
catch (...)
{
read_context.exception = std::current_exception();
}
return std::move(sink);
}
};
};
}
#else
namespace DB
{
class RemoteQueryExecutorReadContext

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@ -39,6 +39,7 @@ SRCS(
RemoteBlockInputStream.cpp
RemoteBlockOutputStream.cpp
RemoteQueryExecutor.cpp
RemoteQueryExecutorReadContext.cpp
SizeLimits.cpp
SquashingBlockInputStream.cpp
SquashingBlockOutputStream.cpp