Timer for switch debouncing

ISR: (pseudo code)
{
   static uint8_t last_key_state = released;
   static uint8_t debounced_key = released;  // this may be a public variable if used else where
   uint8_t key = read_key_state();

   if (if key == pressed && last_key_state == pressed && debounced_key == released)  // checks on a debounced ON_edge
   {
      debounced_key = pressed;    // now debounced key = ON
      out_pin = 3;  // sets counter for 3 x 10ms timeout
   }

   if (last_key_state  == released && key == released)   // checks if key is released
   {
      debounced_key = released;   // now it is debounced released
   }

   last_key_state = key;   // just to memorize state for next run
   if (out_pin > 0)   // checks whether output should be ON
   {
      pin = ON;  // set pin ON
      out_pin--;  // decrement counter
   }
   else  // pin should be OFF
   {
      pin = OFF;  // set pin OFF
   }
}