Shimfs

Crystal binding to rdgarce/imfs with added shared memory support.

This may not work on plateform other than x86_64-linux-gnu and it require a linux kernel supporting mmap flag FIXED_MAP_NOREPLACE.
This shard need GCC to be available to compile the imfs.c file copied from the original repository.

Note imfs/imfs.c is taken from revision 940782b

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     shash:
       github: globoplox/shimfs
   

2. Run shards install

However since I wrote this shards for my own usage, you may be better off just copying the shimfs.cr file and using it as you feel like.
It probably wont be properly maintained nor stay stable.

Usage

require "shimfs"
require "wait_group"

if ARGV.size != 0
  puts "Minion talk"
  name = ARGV[0]
  puts "Minion name: #{name}"
  resource_name = ARGV[1]
  size = ARGV[2].to_i
  address = Pointer(Void).new ARGV[3].to_u64

  shimfs = Shimfs.new size, resource_name, address
    
  io = shimfs.open "hello", "r"
  puts "#{name} read hello: #{io.gets}"
  io.close
else
  puts "Master talk"
  shimfs = Shimfs.new 1024 * 128
  
  io = shimfs.open "hello", "w"
  io.puts "How are you ?"
  io.close

  self_bin = Process.executable_path.not_nil!
  wg = WaitGroup.new 2

  spawn do 
    Process.new(
      self_bin,
      args: ["Minion A", shimfs.resource_name, shimfs.size.to_s, shimfs.address.to_s],
      output: :inherit, error: :inherit
    ).wait

    wg.done
  end

  spawn do 
    Process.new(
      self_bin,
      args: ["Minion B", shimfs.resource_name, shimfs.size.to_s, shimfs.address.to_s],
      output: :inherit, error: :inherit
    ).wait

    wg.done
  end

  wg.wait

  shimfs.close
  
  puts "Master closing without harm"
end