1 = socket_dontwait - socket methods using MSG_DONTWAIT and more
3 This library is a drop-in replacement that reimplements several IO
4 methods with replacements using MSG_DONTWAIT for BasicSocket. This
5 allows us to avoid unnecessary system calls and GVL bouncing.
7 We've reimplemented the +readpartial+, +read_nonblock+,
8 +write_nonblock+, +read+ and +write+ instance methods normally inherited
9 from the IO class directly into BasicSocket with socket-specific system
12 This library is only intended for Ruby 1.9 and will not build with other
13 versions of Ruby. This only supports operating systems with complete
14 support of the non-POSIX MSG_DONTWAIT flag for send(2) and recv(2)
15 syscalls on stream sockets.
17 This library is fully-supported and stable on GNU/Linux 2.6+. It is
18 experimental and unsupported on other systems unless someone steps
19 forward to support them. Some operating systems have incomplete/broken
20 support for the MSG_DONTWAIT flag on various types of stream sockets.
24 * Avoid use of fcntl(2) to set O_NONBLOCK in favor of MSG_DONTWAIT when
25 using non-blocking I/O. We _unset_ O_NONBLOCK if we need to block
26 and release the GVL instead of relying on select(2).
28 * Avoids select(2) entirely in favor of blocking I/O when the
29 GVL is released. This allows using file descriptor numbers higher
30 than 1023 without overflowing select(2) buffers or relying on malloc()
31 to allocate large fdsets.
33 * BasicSocket#read uses recv(2) with MSG_WAITALL to avoid extra system
34 calls for larger reads.
36 * Thread and signal-safe, releases the GVL for all blocking operations
37 and retries if system calls are interrupted.
39 * Includes a 1.9.1-specific workaround to preserve errno after reacquiring
41 {fixed}[http://redmine.ruby-lang.org/repositories/diff/ruby-19?rev=27401]
42 in newer versions of Ruby.
44 * Falls back to line-buffered IO if needed (not recommended).
48 * We ignore taint/$SAFE checks, we'll support it if there's demand,
49 but we doubt there is...
51 * Does not support 1.9 encoding filters. 1.9 defaults all sockets to
52 Encoding::BINARY anyways, so this should not be noticeable to code
53 that leaves socket encodings untouched.
55 * Does not support write buffering in userspace. Ruby defaults all
56 sockets to "IO#sync = true", anyways so this does not affect code
57 that leaves the default setting untouched.
59 * Avoid using line-buffered IO on sockets (IO#gets, IO#each_line),
60 nearly all of the features of this library are cancelled out when
61 the line-buffering fallback is used.
65 If you're using a packaged Ruby distribution, make sure you have a C
66 compiler and the matching Ruby development libraries and headers.
67 You need Ruby 1.9 to install socket_dontwait. Previous versions of
68 Ruby will NOT be supported.
72 gem install socket_dontwait
74 Otherwise grab the latest tarball from:
76 http://bogomips.org/socket_dontwait/files/
78 Unpack it, and run "ruby setup.rb"
82 You can get the latest source via git from the following locations:
84 git://git.bogomips.org/socket_dontwait.git
85 git://repo.or.cz/socket_dontwait.git (mirror)
87 You may browse the code from the web and download the latest snapshot
90 * http://git.bogomips.org/cgit/socket_dontwait.git (cgit)
91 * http://repo.or.cz/w/socket_dontwait.git (gitweb)
93 Inline patches (from "git format-patch") to the mailing list are
94 preferred because they allow code review and comments in the reply to
97 We will adhere to mostly the same conventions for patch submissions as
98 git itself. See the Documentation/SubmittingPatches document
99 distributed with git on on patch submission guidelines to follow. Just
100 don't email the git mailing list or maintainer with socket_dontwait
103 == Contact/Bug Reports/Feedback/Patches/Pull-Requests
105 This was originally created for the Rainbows! project (but may be used by
106 others), so we'll reuse their mailing list at
107 {rainbows-talk@rubyforge.org}[mailto:rainbows-talk@rubyforge.org].