File Descriptors

References

• http://man7.org/linux/man-pages/man2/socket.2.html
• http://man7.org/linux/man-pages/man2/listen.2.html

Select

• On Linux, select supports a maximum of 1024 connections
• On Windows, some historic notes suggest 64 (per thread) is the maximum, but I think this is obsolete (winsock vs winsock2)

References

• How to use `select properly: https://stackoverflow.com/questions/32711521/how-to-use-select-on-sockets-properly

Poll

References

• http://man7.org/linux/man-pages/man2/poll.2.html

EPoll

References

• 500,000 connection limit out-of-the-box: https://stackoverflow.com/questions/28735700/what-is-the-maximum-number-of-sockets-that-epoll-can-handle
• Blocking and Non-Blocking: https://eklitzke.org/blocking-io-nonblocking-io-and-epoll
• EPoll Explained: https://medium.com/@copyconstruct/the-method-to-epolls-madness-d9d2d6378642
• epoll_create: https://linux.die.net/man/2/epoll_create
• epoll_wait: http://man7.org/linux/man-pages/man2/epoll_wait.2.html
• epoll_ctl: http://man7.org/linux/man-pages/man2/epoll_ctl.2.html

KQueue

BSD/Apple specific.

References

• Apple documentation: https://developer.apple.com/library/assets/wp/documentation/Darwin/Conceptual/FSEvents_ProgGuide/KernelQueues/KernelQueues.html

Compared

References

• Comparison: https://www.ulduzsoft.com/2014/01/select-poll-epoll-practical-difference-for-system-architects/
• The C10k Problem: http://www.kegel.com/c10k.html

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ENET

• Homepage: http://enet.bespin.org/
• Docs: http://enet.bespin.org/usergroup0.html

Platform Specific Functions

These functions are found to be defined in unix.c and win32.c. When porting enet to a new platform (or API), these must exist.

Init

Initialization functions. Out-of-the-box neither socket, select or poll need this, but an epoll implementation will.

• intenet_initialize(void)
• voidenet_deinitialize(void)

Misc

Miscaleneous functions. Primarily just time stuff.

• enet_uint32enet_host_random_seed(void)
  • time(NULL);
• enet_uint32enet_time_get(void)
  • gettimeofday
• voidenet_time_set(enet_uint32 newTimeBase)
  • gettimeofday

Address

• intenet_address_set_host_ip(ENetAddress * address, const char * name)
  • inet_pton or inet_aton
  • inet_pton is the modern function. It doesn’t autodetect, but it can be told to encode IPv6 addresses.
• intenet_address_set_host(ENetAddress * address, const char * name)
  • getaddrinfo, freeaddrinfo, gethostbyname_r or gethostbyname
• intenet_address_get_host_ip(const ENetAddress * address, char * name, size_t nameLength)
  • inet_ntop or inet_ntoa
  • inet_ntop is the modern function. It doesn’t autodetect, but it can be told to decode IPv6 addresses.
• intenet_address_get_host(const ENetAddress * address, char * name, size_t nameLength)
  • getnameinfo, gethostbyaddr_r or gethostbyaddr

Socket

• intenet_socket_bind(ENetSocket socket, const ENetAddress * address)
  • bind
• intenet_socket_get_address(ENetSocket socket, ENetAddress * address)
  • getsockname
• intenet_socket_listen(ENetSocket socket, int backlog)
  • listen
• ENetSocketenet_socket_create(ENetSocketType type)
  • socket
• intenet_socket_set_option(ENetSocket socket, ENetSocketOption option, int value)
  • fcntl or ioctl, setsockopt (many)
• intenet_socket_get_option(ENetSocket socket, ENetSocketOption option, int * value)
  • getsockopt
• intenet_socket_connect(ENetSocket socket, const ENetAddress * address)
  • connect
• ENetSocketenet_socket_accept(ENetSocket socket, ENetAddress * address)
  • accept
• intenet_socket_shutdown(ENetSocket socket, ENetSocketShutdown how)
  • shutdown
• voidenet_socket_destroy(ENetSocket socket)
  • close
• intenet_socket_send(ENetSocket socket, const ENetAddress * address, const ENetBuffer * buffers, size_t bufferCount)
  • sendmsg
• intenet_socket_receive(ENetSocket socket, ENetAddress * address, ENetBuffer * buffers, size_t bufferCount)
  • recvmsg
• intenet_socketset_select(ENetSocket maxSocket, ENetSocketSet * readSet, ENetSocketSet * writeSet, enet_uint32 timeout)
  • select
• intenet_socket_wait(ENetSocket socket, enet_uint32 * condition, enet_uint32 timeout)
  • poll or select