From: Charles Nutter Date: 2012-02-20T05:19:34+09:00 Subject: [ruby-core:42744] [ruby-trunk - Feature #5138] Add nonblocking IO that does not use exceptions for EOF and EWOULDBLOCK Issue #5138 has been updated by Charles Nutter. Worth pointing out that the cost of allocating an exception every time could be blunted by always raising the *same* exception object. This avoids the backtrace, construction cost, *and* mixin overhead in one shot, provided you're ok with the backtrace being meaningless. FWIW, even all these tricks can't make an exception-based version as fast as one that simply returns nil. Modifying IO#read_nonblock in JRuby to return nil on a zero-length read improves the above benchmark 2-3x. ---------------------------------------- Feature #5138: Add nonblocking IO that does not use exceptions for EOF and EWOULDBLOCK https://bugs.ruby-lang.org/issues/5138 Author: Yehuda Katz Status: Open Priority: Normal Assignee: Yukihiro Matsumoto Category: core Target version: 1.9.4 The current Ruby I/O classes have non-blocking methods (read_nonblock and write_nonblock). These methods will never block, and if they would block, they raise an exception instead (IO::WaitReadable or IO::WaitWritable). In addition, if the IO is at EOF, they raise an EOFError. These exceptions are raised repeatedly in virtually every use of the non-blocking methods. This patch adds a pair of methods (try_read_nonblock and try_write_nonblock) that have the same semantics as the existing methods, but they return Symbols instead of raising exceptions for these routine cases: * :read_would_block * :write_would_block * :eof The patch contains updates for IO, StringIO, and OpenSSL. The updates are fully documented and tested. -- http://bugs.ruby-lang.org/