/ 
Hypersonic-0.11
/ Hypersonic::Event::Select

NAME

Hypersonic::Event::Select - select() event backend (universal)

SYNOPSIS

use Hypersonic::Event;

my $backend = Hypersonic::Event->backend('select');
# $backend is 'Hypersonic::Event::Select'

DESCRIPTION

Hypersonic::Event::Select is the select()-based event backend for Hypersonic. It provides universal compatibility across all platforms including Windows, making it the fallback of last resort.

select() is the oldest and most portable event notification mechanism, but also the slowest due to O(n) scanning and FD_SETSIZE limitations.

METHODS

name

my $name = Hypersonic::Event::Select->name;  # 'select'

Returns the backend name.

available

if (Hypersonic::Event::Select->available) { ... }

Always returns true - select() is available on all systems.

includes

Returns the C #include directives needed for select. On Windows, includes winsock2.h; on Unix, includes sys/select.h.

defines

Returns the C #define directives for select configuration, including FD_SETSIZE.

event_struct

my $struct = Hypersonic::Event::Select->event_struct;  # 'fd_set'

Returns 'fd_set' (note: not used as an array like other backends).

extra_ldflags

my $flags = Hypersonic::Event::Select->extra_ldflags;

Returns '-lws2_32' on Windows, empty string otherwise.

gen_create($builder, $listen_fd_var)

Generates C code to initialize the master fd_set and add the listen socket. On Windows, also generates WSAStartup() call.

gen_add($builder, $loop_var, $fd_var)

Generates C code to add a file descriptor to the master fd_set and update max_fd.

gen_del($builder, $loop_var, $fd_var)

Generates C code to remove a file descriptor from the master fd_set.

gen_wait($builder, $loop_var, $events_var, $count_var, $timeout_var)

Generates C code to copy the master fd_set (select modifies it) and call select() with a timeout.

gen_get_fd($builder, $events_var, $index_var, $fd_var)

Generates C code to check FD_ISSET for each potential fd, skipping those without events.

gen_cleanup($builder)

Generates C code for cleanup. On Windows, calls WSACleanup().

LIMITATIONS

  • FD_SETSIZE limit (typically 1024 on Unix, 64 on Windows)

  • O(n) scanning of all file descriptors on each call

  • Must copy fd_set on each iteration (select modifies it)

  • Slower than poll(), epoll, or kqueue

WINDOWS SUPPORT

On Windows, this backend uses Winsock2 (ws2_32.lib). It automatically calls WSAStartup() during initialization and WSACleanup() during shutdown.

WHEN TO USE

  • Windows compatibility is required

  • Very old Unix systems without poll()

  • Testing on systems where other backends fail

  • Low-concurrency scenarios (< 100 connections)

AVAILABILITY

All systems: Linux, macOS, BSD, Windows, Solaris, AIX, HP-UX, etc.

SEE ALSO

Hypersonic::Event, Hypersonic::Event::Role, Hypersonic::Event::Poll

AUTHOR

LNATION <email@lnation.org>

LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.