stub: simplify BlockingClientCall infinite blocking (#12217)

Move deadline computation into overloads with finite timeouts. Blocking calls without timeouts now do not have to read the clock.

Author: benjaminp

stub/src/main/java/io/grpc/stub/BlockingClientCall.java

@@ -87,7 +87,7 @@ public final class BlockingClientCall<ReqT, RespT> {
  */
  public RespT read() throws InterruptedException, StatusException {
  try {
- return read(true, 0, TimeUnit.NANOSECONDS);
+ return read(true, 0);
  } catch (TimeoutException e) {
  throw new AssertionError("should never happen", e);
  }
@@ -106,16 +106,14 @@ public RespT read() throws InterruptedException, StatusException {
  */
  public RespT read(long timeout, TimeUnit unit) throws InterruptedException, TimeoutException,
  StatusException {
- return read(false, timeout, unit);
+ long endNanoTime = System.nanoTime() + unit.toNanos(timeout);
+ return read(false, endNanoTime);
  }
 
- private RespT read(boolean waitForever, long timeout, TimeUnit unit)
+ private RespT read(boolean waitForever, long endNanoTime)
  throws InterruptedException, TimeoutException, StatusException {
- long start = System.nanoTime();
- long end = start + unit.toNanos(timeout);
-
  Predicate<BlockingClientCall<ReqT, RespT>> predicate = BlockingClientCall::skipWaitingForRead;
- executor.waitAndDrainWithTimeout(waitForever, end, predicate, this);
+ executor.waitAndDrainWithTimeout(waitForever, endNanoTime, predicate, this);
  RespT bufferedValue = buffer.poll();
 
  if (logger.isLoggable(Level.FINER)) {
@@ -182,7 +180,7 @@ public boolean hasNext() throws InterruptedException, StatusException {
  */
  public boolean write(ReqT request) throws InterruptedException, StatusException {
  try {
- return write(true, request, Integer.MAX_VALUE, TimeUnit.DAYS);
+ return write(true, request, 0);
  } catch (TimeoutException e) {
  throw new RuntimeException(e); // should never happen
  }
@@ -211,21 +209,20 @@ public boolean write(ReqT request) throws InterruptedException, StatusException
  */
  public boolean write(ReqT request, long timeout, TimeUnit unit)
  throws InterruptedException, TimeoutException, StatusException {
- return write(false, request, timeout, unit);
+ long endNanoTime = System.nanoTime() + unit.toNanos(timeout);
+ return write(false, request, endNanoTime);
  }
 
- private boolean write(boolean waitForever, ReqT request, long timeout, TimeUnit unit)
+ private boolean write(boolean waitForever, ReqT request, long endNanoTime)
  throws InterruptedException, TimeoutException, StatusException {
 
  if (writeClosed) {
  throw new IllegalStateException("Writes cannot be done after calling halfClose or cancel");
  }
 
- long end = System.nanoTime() + unit.toNanos(timeout);
-
  Predicate<BlockingClientCall<ReqT, RespT>> predicate =
  (x) -> x.call.isReady() || x.closedStatus != null;
- executor.waitAndDrainWithTimeout(waitForever, end, predicate, this);
+ executor.waitAndDrainWithTimeout(waitForever, endNanoTime, predicate, this);
  Status savedClosedStatus = closedStatus;
  if (savedClosedStatus == null) {
  call.sendMessage(request);