Class: Rclrb::WaitSet

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

Overview

This class is use to Wait for events.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ WaitSet

Returns a new instance of WaitSet.



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# File 'lib/rclrb/wait_set.rb', line 5

def initialize
  @subscriptions = []
  @services = []
  @clients = []
  @timers = []
end

Class Method Details

.wait_for(what, timeout = -1,, &block) ⇒ Object

Wait for an event on ẃhat, every timeout evaluate block and if the value returned is true, then exit the function otherwise continue waiting.



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# File 'lib/rclrb/wait_set.rb', line 14

def WaitSet.wait_for what, timeout = -1, &block
  ws = WaitSet.new
  ws.add what
  until block.call
    ws.wait timeout
  end
end

Instance Method Details

#add(what) ⇒ Object

Add an item (Subscription, Service…) to the wait set



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# File 'lib/rclrb/wait_set.rb', line 23

def add(what)
  if what.kind_of? Subscription
    @subscriptions.append what
  elsif what.kind_of? Service
    @services.append what
  elsif what.kind_of? Client
    @clients.append what
  elsif what.kind_of? Timer
    @timers.append what
  end
end

#wait(timeout = -1)) ⇒ Object

Wait until timeout or an event occured in one of the item added with add. If timeout is equalt to -1, this function will block until an event occured or indefinitely.



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# File 'lib/rclrb/wait_set.rb', line 37

def wait(timeout = -1)
  ws = CApi.rcl_get_zero_initialized_wait_set
  CApi.handle_result CApi.rcl_wait_set_init(ws, @subscriptions.size, 1, @timers.size, @clients.size, @services.size, 0, Rclrb.rcl_context, Rclrb.rcl_allocator)
  begin
    @subscriptions.each() { |x| CApi.handle_result CApi.rcl_wait_set_add_subscription(ws, x.subscription_handle, nil)}
    CApi.handle_result CApi.rcl_wait_set_add_guard_condition(ws, Rclrb.rcl_signal_guard_condition.guard_condition_handle, nil)
    @services.each() { |x| CApi.handle_result CApi.rcl_wait_set_add_service(ws, x.service_handle, nil)}
    @clients.each() { |x| CApi.handle_result CApi.rcl_wait_set_add_client(ws, x.client_handle, nil)}
    @timers.each() { |x| CApi.handle_result CApi.rcl_wait_set_add_timer(ws, x.timer_handle, nil)}
    # Wait has to run in a seperate thread to allow for signals to work
    status = nil
    t = Thread.new do
      status = CApi.rcl_wait(ws, timeout)
    end
    t.join
    if status != CApi::RCL_RET_OK and status != CApi::RCL_RET_TIMEOUT
      CApi.handle_result status
    end
  rescue RclError
    CApi.handle_result CApi.rcl_wait_set_fini(ws)
    raise
  end
  CApi.handle_result CApi.rcl_wait_set_fini(ws)
end