[SPARK-4715] ShuffleMemoryManager.tryToAcquire may return a negative value

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.1.2, 1.2.0
• Component/s: Spark Core
• Target Version/s: 1.1.2, 1.2.0
• Assignee: Shixiong Zhu
• Reporter: Shixiong Zhu
• Created: 03/Dec/14 07:58
• Updated: 03/Dec/14 20:21
• Resolved: 03/Dec/14 20:21

Description

Here is a unit test to demonstrate it:

  test("threads should not be granted a negative size") {
    val manager = new ShuffleMemoryManager(1000L)
    manager.tryToAcquire(700L)

    val latch = new CountDownLatch(1)
    startThread("t1") {
       manager.tryToAcquire(300L)
      latch.countDown()
    }
    latch.await() // Wait until `t1` calls `tryToAcquire`

    val granted = manager.tryToAcquire(300L)
    assert(0 === granted, "granted is negative")
  }

It outputs "0 did not equal -200 granted is negative"

Issue Links

• links to: [Github] Pull Request #3575 (zsxwing)