bridge.py causes high CPU load on AR9331

The polling of bridge.py consumes about 90% of the CPU (AR9331) on my ArduinoYun.
A quick-fix for this issue can be time.sleep(0.01), which brings down the value to about 30%.

The adopted version of bridge.py:

...
pr = packet.PacketReader(cp)
start_time = time.time()
with cbreak():
  #while time.time() - start_time < 100:
  while True:
    res = pr.process()
    if res == False:
      break
    time.sleep(0.01)

[cmaglie]

pr.process() already stops itself when there is no serial traffic (on a "select" with a timeout of 50ms):
https://github.com/arduino/YunBridge/blob/master/bridge/packet.py#L113

When idle (no requests from the 32u4) the bridge should use very little CPU time.
Maybe is your sketch that is continously querying the bridge?

You are right, it is a bug in the sketch.
However, the sketch is an official example from [1], which is also distributed with the IDE.
I provide an optimized version of the example sketch in this comment.

Wish: It would be nice to have a method called readLine(), which covers such a case.

_Official version:_

void loop() {
  if (Console.available() > 0) {
    char c = Console.read(); // read the next char received
    // look for the newline character, this is the last character in the string
    if (c == '\n') {
      //print text with the name received
      Console.print("Hi ");
      Console.print(name);
      Console.println("! Nice to meet you!");
      Console.println();
      // Ask again for name and clear the old name
      Console.println("Hi, what's your name?");
      name = "";  // clear the name string
    } 
    else {       // if the buffer is empty Cosole.read() returns -1
      name += c; // append the read char from Console to the name string
    }
  }
}

_Proposal for an optimized version:_

void loop() {
  if (Console.available() > 0) {
    char c = Console.read(); // read the next char received
    // look for the newline character, this is the last character in the string
    if (c == '\n') {
      //print text with the name received
      Console.print("Hi ");
      Console.print(name);
      Console.println("! Nice to meet you!");
      Console.println();
      // Ask again for name and clear the old name
      Console.println("Hi, what's your name?");
      name = "";  // clear the name string
    } 
    else {       // if the buffer is empty Console.read() returns -1
      name += c; // append the read char from Console to the name string
    }
  } else {
    delay(100);
  }
}

[1] http://arduino.cc/en/Tutorial/ConsoleRead

[ffissore]

@sealytics next arduino ide nightly build will feature your proposed change. Tomorrow it will available at http://arduino.cc/en/Main/Software#toc4 Thank you very much