Environment

• jruby 9.0.5.0 (2.2.3) 2016-01-26 7bee00d Java HotSpot(TM) 64-Bit Server VM 25.72-b15 on 1.8.0_72-b15 +jit [darwin-x86_64]
• Darwin veritas.local 15.4.0 Darwin Kernel Version 15.4.0: Fri Feb 26 22:08:05 PST 2016; root:xnu-3248.40.184~3/RELEASE_X86_64 x86_64
• Rails app running puma: https://github.com/cdonadeo/puma_big_response_test

Expected Behavior

Long strings passed to UNIXSocket#write writes the data and returns the number of bytes written.

Actual Behavior

#write writes a subset of the data and raises an exception: #<SystemCallError: Unknown error - >}. The amount of data varies but I've seen 8192 show up not-randomly, almost like there was a 8k buffer somewhere.

The git repo linked to above shows the behavior. The exception in question is raise inside #fast_write. Changing the code to use #write instead of #syswrite does not change the behavior.