[finagle-core] Fix for DeadlineFilter takes rejectWithdrawal regardle…

…ss of passed Deadline

Problem
DeadlineFilter takes rejectWithdrawal regardless of passed Deadline
#936

Solution
Withdraw tokens only if the deadline has passed

Closes #936

Differential Revision: https://phabricator.twitter.biz/D1120240

CHANGELOG.rst

@@ -7,6 +7,11 @@ Note that ``PHAB_ID=#`` and ``RB_ID=#`` correspond to associated messages in com
 Unreleased
 ----------
 
+Bug Fixes
+~~~~~~~~~~
+
+* finagle-core: Fix for DeadlineFilter takes rejectWithdrawal regardless of passed Deadline. ``PHAB_ID=D1120240``
+
 23.11.0
 -------
 

finagle-core/src/main/scala/com/twitter/finagle/service/DeadlineFilter.scala

@@ -280,9 +280,6 @@ class DeadlineFilter[Req, Rep](
 
         val now = Time.now
         val difference: Duration = deadline - now
-        val reject = rejectBucket.tryGet(rejectWithdrawal)
-
-        trace(tracing, deadline, difference, reject)
 
         // If the difference is negative, we've exceeded the deadline
         if (difference.inMillis < 0l) {
@@ -291,6 +288,8 @@ class DeadlineFilter[Req, Rep](
           expiredTimeStat.add(exceeded.inMillis)
 
           // There are enough tokens to reject the request
+          val reject = rejectBucket.tryGet(rejectWithdrawal)
+          trace(tracing, deadline, difference, reject)
           if (reject) {
             rejectedCounter.incr()
             if (isDarkMode)
@@ -304,6 +303,7 @@ class DeadlineFilter[Req, Rep](
             service(request)
           }
         } else {
+          trace(tracing, deadline, difference, false)
           rejectBucket.put(serviceDeposit)
           val remaining = difference
           remainingTimeStat.add(remaining.inMillis)