Class: ForkedProcess

Inherits:
Object
  • Object
show all
Defined in:
lib/forked_process.rb

Overview

ForkedProcess exposes a small API for performing a block of code in a forked process, and relaying its output to another block.

Defined Under Namespace

Classes: UnsuccessfulExit

Instance Method Summary collapse

Instance Method Details

#read(&block) ⇒ Object

Public: Define a callback which reads in the output from the forked process.

Yields an IO object opened for reading when ‘run` is invoked. Returns nothing.



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# File 'lib/forked_process.rb', line 22

def read(&block)
  @read_block = block
end

#run ⇒ Object

Public: Fork a process, opening a pipe for IO and yielding the write and read components to the relevant blocks.

Returns nothing.

Raises:



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# File 'lib/forked_process.rb', line 30

def run
  reader, writer = IO.pipe

  pid = fork do
    reader.close
    @write_block.call(writer)
    writer.close
    exit!(0)
  end

  writer.close
  @read_block.call(reader)
  Process.wait(pid)

  raise UnsuccessfulExit unless $CHILD_STATUS.success?
end

#write(&block) ⇒ Object

Public: Define a callback which will be run in a forked process.

Yields an IO object opened for writing when ‘run` is invoked. Returns nothing.



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# File 'lib/forked_process.rb', line 13

def write(&block)
  @write_block = block
end