[HBASE-17331] Avoid busy waiting in ThrottledInputStream

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Release Note: For each read(), old ThrottledInputStream sleeps/wakes/checks for many times for controlling the throughput. After this patch, ThrottledInputStream sleeps/wakes/checks only once. So we can reduce CPU usage.
• Assignee: Chia-Ping Tsai
• Reporter: Chia-Ping Tsai
• Created: 17/Dec/16 12:34
• Updated: 21/Dec/16 01:42
• Resolved: 18/Dec/16 16:15

Description

ThrottledInputStream.java

// We can calculate the precise sleep time instead of busy waiting
  private void throttle() throws IOException {
    while (getBytesPerSec() > maxBytesPerSec) {
      try {
        Thread.sleep(SLEEP_DURATION_MS);
        totalSleepTime += SLEEP_DURATION_MS;
      } catch (InterruptedException e) {
        throw new IOException("Thread aborted", e);
      }
    }
  }