Class: TinyDTLS::SessionManager

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

Overview

This class is used to manage established tinydtls sessions. It stores instances of the TinyDTLS::Session class.

While memory allocated for sessions is automatically freed by tinydtls, if it receive an alert from the peer associated with that session, memory isn’t freed if the peer doesn’t send an alert. Therefore this class starts a background thread automatically freeing memory associated with sessions which haven’t been used since a specified duration.

Constant Summary collapse

DEFAULT_TIMEOUT =

Default timeout for the cleanup thread in seconds.

(5 * 60).freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context, timeout = DEFAULT_TIMEOUT) ⇒ SessionManager

Creates a new instance of this class. A tinydtls ‘context_t` pointer is required to free sessions in the background thread.

Memory for sessions created using #[] needs to be explicitly freed by calling #close as soons as this class instance is no longer needed.



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# File 'lib/tinydtls/session_manager.rb', line 25

def initialize(context, timeout = DEFAULT_TIMEOUT)
  @store = {}
  @mutex = Mutex.new

  @timeout = timeout
  @context = context

  start_thread
end

Instance Attribute Details

#timeout ⇒ Object (readonly)

Timeout used by the cleanup thread. If a session hasn’t been used within ‘timeout * 2` seconds it will be freed automatically.



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# File 'lib/tinydtls/session_manager.rb', line 17

def timeout
  @timeout
end

Instance Method Details

#[](addrinfo, &f) ⇒ Object

Retrieve a session from the session manager.



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# File 'lib/tinydtls/session_manager.rb', line 36

def [](addrinfo, &f)
  unless addrinfo.is_a? Addrinfo
    raise TypeError
  end

  key = addrinfo.getnameinfo
  @mutex.synchronize do
    if @store.has_key? key
      sess, _ = @store[key]
    else
      sess = Session.new(addrinfo)
      @store[key] = [sess, true]
    end

    f.call(sess)
  end
end

#close ⇒ Object

Kills the background thread. All established sessions are closed as well, see Session#close.



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# File 'lib/tinydtls/session_manager.rb', line 56

def close
  @mutex.synchronize do
    @thread.kill
    @store.each_value do |value|
      sess, _ = value
      sess.close(@context)
    end
  end
end