stopping connection on Linux does not close the socket, which can create problem when re-starting the connection

This commit is contained in:
Benjamin Sergeant
2018-11-01 17:02:49 -07:00
parent 9c81eeace0
commit cf0045a483
5 changed files with 26 additions and 59 deletions

View File

@ -32,22 +32,7 @@
#include <sys/types.h>
#include <algorithm>
//
// Linux/Android has a special type of virtual files. select(2) will react
// when reading/writing to those files, unlike closing sockets.
//
// https://linux.die.net/man/2/eventfd
//
// eventfd was added in Linux kernel 2.x, and our oldest Android (Kitkat 4.4)
// is on Kernel 3.x
//
// cf Android/Kernel table here
// https://android.stackexchange.com/questions/51651/which-android-runs-which-linux-kernel
//
#ifdef __linux__
# include <sys/eventfd.h>
#endif
#include <iostream>
// Android needs extra headers for TCP_NODELAY and IPPROTO_TCP
#ifdef ANDROID
@ -58,22 +43,14 @@
namespace ix
{
Socket::Socket() :
_sockfd(-1),
_eventfd(-1)
_sockfd(-1)
{
#ifdef __linux__
_eventfd = eventfd(0, 0);
assert(_eventfd != -1 && "Panic - eventfd not functioning on this platform");
#endif
}
Socket::~Socket()
{
close();
#ifdef __linux__
::close(_eventfd);
#endif
}
bool Socket::connectToAddress(const struct addrinfo *address,
@ -180,36 +157,20 @@ namespace ix
FD_SET(_sockfd, &rfds);
#ifdef __linux__
FD_SET(_eventfd, &rfds);
FD_SET(_eventfd.getFd(), &rfds);
#endif
int sockfd = _sockfd;
int nfds = (std::max)(sockfd, _eventfd);
int nfds = (std::max)(sockfd, _eventfd.getFd());
select(nfds + 1, &rfds, nullptr, nullptr, nullptr);
onPollCallback();
}
void Socket::wakeUpFromPollApple()
{
close(); // All OS but Linux will wake up select
// when closing the file descriptor watched by select
}
void Socket::wakeUpFromPollLinux()
{
std::string str("\n"); // this will wake up the thread blocked on select
const void* buf = reinterpret_cast<const void*>(str.c_str());
write(_eventfd, buf, str.size());
}
void Socket::wakeUpFromPoll()
{
#ifdef __APPLE__
wakeUpFromPollApple();
#elif defined(__linux__)
wakeUpFromPollLinux();
#endif
// this will wake up the thread blocked on select, only needed on Linux
_eventfd.notify();
}
bool Socket::connect(const std::string& host,
@ -218,12 +179,7 @@ namespace ix
{
std::lock_guard<std::mutex> lock(_socketMutex);
#ifdef __linux__
if (_eventfd == -1)
{
return false; // impossible to use this socket if eventfd is broken
}
#endif
if (!_eventfd.clear()) return false;
_sockfd = Socket::hostname_connect(host, port, errMsg);
return _sockfd != -1;