Github user NicoK commented on a diff in the pull request:
https://github.com/apache/flink/pull/4485#discussion_r138891582
--- Diff:
flink-runtime/src/test/java/org/apache/flink/runtime/io/network/buffer/NetworkBufferPoolTest.java
---
@@ -172,44 +178,117 @@ public void testDestroyAll() {
}
}
+ /**
+ * Tests {@link NetworkBufferPool#requestMemorySegments(int)} with the
{@link NetworkBufferPool}
+ * currently containing the number of required free segments.
+ */
@Test
- public void testRequestAndRecycleMemorySegments() throws Exception {
+ public void testRequestMemorySegmentsLessThanTotalBuffers() throws
Exception {
final int numBuffers = 10;
NetworkBufferPool globalPool = new
NetworkBufferPool(numBuffers, 128, MemoryType.HEAP);
- List<MemorySegment> segments = null;
- // request buffers from global pool with illegal argument
+ List<MemorySegment> memorySegments = Collections.emptyList();
try {
- segments = globalPool.requestMemorySegments(0);
- fail("Should throw an IllegalArgumentException");
- } catch (IllegalArgumentException e) {
- assertNull(segments);
+ memorySegments =
globalPool.requestMemorySegments(numBuffers / 2);
+
+ assertEquals(memorySegments.size(), numBuffers / 2);
+ } finally {
+ globalPool.recycleMemorySegments(memorySegments);
assertEquals(globalPool.getNumberOfAvailableMemorySegments(), numBuffers);
}
+ }
- // common case to request buffers less than the total capacity
of global pool
- final int numRequiredBuffers = 8;
- segments = globalPool.requestMemorySegments(numRequiredBuffers);
-
- assertNotNull(segments);
- assertEquals(segments.size(), numRequiredBuffers);
-
- // recycle all the requested buffers to global pool
- globalPool.recycleMemorySegments(segments);
+ /**
+ * Tests {@link NetworkBufferPool#requestMemorySegments(int)} with the
number of required
+ * buffers exceeding the capacity of {@link NetworkBufferPool}.
+ */
+ @Test
+ public void testRequestMemorySegmentsMoreThanTotalBuffers() throws
Exception {
+ final int numBuffers = 10;
- assertEquals(globalPool.getNumberOfAvailableMemorySegments(),
numBuffers);
+ NetworkBufferPool globalPool = new
NetworkBufferPool(numBuffers, 128, MemoryType.HEAP);
- // uncommon case to request buffers exceeding the total
capacity of global pool
+ List<MemorySegment> memorySegments = Collections.emptyList();
try {
- segments = null;
- segments = globalPool.requestMemorySegments(11);
+ memorySegments =
globalPool.requestMemorySegments(numBuffers + 1);
fail("Should throw an IOException");
} catch (IOException e) {
- assertNull(segments);
- // recycle all the requested buffers to global pool
after exception
+ assertEquals(memorySegments.size(), 0);
assertEquals(globalPool.getNumberOfAvailableMemorySegments(), numBuffers);
}
+ }
+ /**
+ * Tests {@link NetworkBufferPool#requestMemorySegments(int)} with the
invalid argument to
+ * cause exception.
+ */
+ @Test
+ public void testRequestMemorySegmentsWithInvalidArgument() throws
Exception {
+ final int numBuffers = 10;
+
+ NetworkBufferPool globalPool = new
NetworkBufferPool(numBuffers, 128, MemoryType.HEAP);
+
+ List<MemorySegment> memorySegments = Collections.emptyList();
+ try {
+ // the number of requested buffers should be larger
than zero
+ memorySegments = globalPool.requestMemorySegments(0);
+ fail("Should throw an IllegalArgumentException");
+ } catch (IllegalArgumentException e) {
+ assertEquals(memorySegments.size(), 0);
+
assertEquals(globalPool.getNumberOfAvailableMemorySegments(), numBuffers);
+ }
+ }
+
+ /**
+ * Tests {@link NetworkBufferPool#requestMemorySegments(int)} with the
{@link NetworkBufferPool}
+ * currently not containing the number of required free segments
(currently occupied by a buffer pool).
+ */
+ @Test
+ public void testRequestMemorySegmentsWithBuffersTaken() throws
IOException, InterruptedException {
+ final int numBuffers = 10;
+
+ NetworkBufferPool networkBufferPool = new
NetworkBufferPool(numBuffers, 128, MemoryType.HEAP);
+
+ final List<Buffer> buffers = new ArrayList<>(numBuffers);
+ List<MemorySegment> memorySegments = Collections.emptyList();
+ Thread bufferRecycler = null;
+ BufferPool lbp1 = null;
+ try {
+ lbp1 = networkBufferPool.createBufferPool(numBuffers /
2, numBuffers);
+
+ // take all buffers (more than the minimum required)
+ for (int i = 0; i < numBuffers; ++i) {
+ Buffer buffer = lbp1.requestBuffer();
+ buffers.add(buffer);
+ assertNotNull(buffer);
+ }
+
+ // if requestMemorySegments() blocks, this will make
sure that enough buffers are freed
+ // eventually for it to continue
+ bufferRecycler = new Thread(() -> {
+ try {
+ Thread.sleep(10000);
--- End diff --
Waiting 10s here will increase the probability of us reaching the desired
(blocking) code but also makes the test wait quite long. How about the
following instead?
```
// requestMemorySegments() below will and wait for
buffers
// this will make sure that enough buffers are freed
eventually for it to continue
final OneShotLatch isRunning = new OneShotLatch();
bufferRecycler = new Thread(() -> {
try {
isRunning.trigger();
Thread.sleep(100);
} catch (InterruptedException ignored) {
}
for (Buffer buffer : buffers) {
buffer.recycle();
}
});
bufferRecycler.start();
// take more buffers than are freely available at the
moment via requestMemorySegments()
isRunning.await();
memorySegments =
networkBufferPool.requestMemorySegments(numBuffers / 2);
```
That makes is more likely than my original variant which was only waiting
100ms but does not increase the test time too much.
---
