FFI testing

foo.rb

require "ffi"

class TimeValue < FFI::Struct 
  layout :seconds,      :int,
         :microseconds, :int
end

#struct task_basic_info
#{
#       integer_t      suspend_count;
#       vm_size_t       virtual_size;
#       vm_size_t      resident_size;
#       time_value_t       user_time;
#       time_value_t     system_time;
#       policy_t              policy;
#};

#struct task_basic_info_64 {
#        integer_t       suspend_count;  /* suspend count for task */
#        mach_vm_size_t  virtual_size;   /* virtual memory size (bytes) */
#        mach_vm_size_t  resident_size;  /* resident memory size (bytes) */
#        time_value_t    user_time;      /* total user run time for
#                                           terminated threads */
#        time_value_t    system_time;    /* total system run time for
#                                           terminated threads */
#	policy_t	policy;		/* default policy for new threads */
#};


class TaskBasicInfo < FFI::Struct
  layout :suspend_count,  :int,
         :virtual_size,   :uint64,
         :resident_size,  :uint64,
         :user_time,      TimeValue,
         :system_time,    TimeValue,
         :policy,         :int
end
#  class TaskBasicInfo < FFI::Struct
#    layout(
#           :suspend_count, integer_t,
#           :virtual_size, vm_size_t,
#           :resident_size, vm_size_t,
#           :user_time, time_value_t,
#           :system_time, time_value_t,
#           :policy, policy_t
#    )
#  end
TASK_BASIC_INFO = 5

module LibSystem
  extend FFI::Library

  lib = ffi_lib '/usr/lib/libSystem.dylib'
  attach_function :mach_task_self, [], :uint64
  attach_function :task_for_pid, [:uint64, :uint, :pointer], :uint
  #attach_function :task_info, [:uint, :int, :pointer, :pointer], :uint
  attach_function :task_info, [:uint64, :uint, :pointer, :pointer], :uint
end

module Foo
  extend FFI::Library

  lib = ffi_lib '/Users/bethanym/development/mikbe/rbmu/CPUThrottle/foo.dylib'
  attach_function :mach_task_self, [], :uint
  attach_function :sample, [:int32, :pointer, :pointer, :pointer], :int
end


user_time = FFI::MemoryPointer.new(8, 1, true) 
system_time = FFI::MemoryPointer.new(8, 1, true) 
percent = FFI::MemoryPointer.new(8, 1, true) 

puts me = Foo.mach_task_self
puts Foo.sample(me, user_time, system_time, percent)




#KB64 = 64 * 1024 * 1024
#PID = 14433
#task_info_out = FFI::MemoryPointer.new TaskBasicInfo.size, 2, true
#task_info_out_count = FFI::MemoryPointer.new(KB64.size, 1, true)
#task_pointer = FFI::MemoryPointer.new(KB64.size, 1, true) 
#puts "this task"
#puts (this_task = LibSystem.mach_task_self)
#puts "task for pid: (5 == failure)"
#puts LibSystem.task_for_pid(this_task, PID, task_pointer)
#puts task = task_pointer.get_uint(0)
#puts "Get task info: (should be 0)"
#puts LibSystem.task_info this_task, TASK_BASIC_INFO, task_info_out, task_info_out_count
#task_info = TaskBasicInfo.new task_info_out
#puts task_info[:resident_size]