path: root/ext/socket
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authornormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-04-19 01:08:16 (GMT)
committernormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-04-19 01:08:16 (GMT)
commitc32fc82d0ed8bcf0d6e4de8518bbb7bd808a69b8 (patch)
treea92b3b9275d623968562e7e984375e80a67ff8b8 /ext/socket
parent0013fdaaa5145f2003d96b6e54a5f16f16f3678b (diff)
socket: avoid fcntl for read/write_nonblock on Linux
On platforms where MSG_DONTWAIT works reliably on all sockets (so far, I know of Linux), we can avoid fcntl syscalls and implement IO#write_nonblock and IO#read_nonblock in terms of the socket-specific send and recv family of syscalls. This avoids side effects on the socket, and also encourages generic code to be written in cases where IO wrappers like OpenSSL::SSL::SSLSocket are used. Perhaps in the future, side-effect-free non-blocking I/O can be standard on all files and OSes: * ext/socket/lib/socket.rb (read_nonblock, write_nonblock): Linux-specific wrapper without side effects [ruby-core:80780] [Feature #13362] * test/socket/test_basicsocket.rb (test_read_write_nonblock): new test git-svn-id: svn+ssh:// b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'ext/socket')
1 files changed, 18 insertions, 0 deletions
diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index de5eda3..8127009 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -442,6 +442,24 @@ class BasicSocket < IO
scm_rights: false, exception: true)
__recvmsg_nonblock(dlen, flags, clen, scm_rights, exception)
+ # Linux-specific optimizations to avoid fcntl for IO#read_nonblock
+ # and IO#write_nonblock using MSG_DONTWAIT
+ # Do other platforms suport MSG_DONTWAIT reliably?
+ if RUBY_PLATFORM =~ /linux/ && Socket.const_defined?(:MSG_DONTWAIT)
+ def read_nonblock(len, str = nil, exception: true) # :nodoc:
+ case rv = __recv_nonblock(len, 0, str, exception)
+ when '' # recv_nonblock returns empty string on EOF
+ exception ? raise(EOFError, 'end of file reached') : nil
+ else
+ rv
+ end
+ end
+ def write_nonblock(buf, exception: true) # :nodoc:
+ __sendmsg_nonblock(buf, 0, nil, nil, exception)
+ end
+ end
class Socket < BasicSocket