We have encountered an instance where the tracepoints were not collected in the same order they were fired (#31951).
Tracepoint ordering is not guaranteed in userspace for a number of reasons.
As this test does not require a strict collection/processing order collect expected and actual events into dicts and compare them.
This will gracefully handle both the number of events, and out-of-order events should they reoccur in the future.
Fixes: #31951
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ACK 693d1e2f54baa0d5e407153f79b2f98385e6b8d9
I successfully ran the changed test a couple of times and the code changes look good to me.
That this behavior works as intended can be tested with this patch:
0diff --git a/test/functional/interface_usdt_utxocache.py b/test/functional/interface_usdt_utxocache.py
1index d4213d5020..94ec23c51a 100755
2--- a/test/functional/interface_usdt_utxocache.py
3+++ b/test/functional/interface_usdt_utxocache.py
4@@ -326,6 +326,7 @@ class UTXOCacheTracepointTest(BitcoinTestFramework):
5 event.is_coinbase
6 )
7
8+ expected_utxocache_adds.reverse()
9 expected_add_keys = {(e["txid"], e["index"], e["height"], e["value"], e["is_coinbase"])
10 for e in expected_utxocache_adds}
11 expected_spent_keys = {(e["txid"], e["index"], e["height"], e["value"], e["is_coinbase"])
315@@ -324,9 +316,26 @@ def handle_utxocache_spent(_, data, __):
316
317 self.log.info(
318 f"check that we successfully traced {EXPECTED_HANDLE_ADD_SUCCESS} adds and {EXPECTED_HANDLE_SPENT_SUCCESS} spent")
319- for expected_utxo, actual_event in zip(expected_utxocache_adds + expected_utxocache_spents,
320- actual_utxocache_adds + actual_utxocache_spents):
321- compare_utxo_with_event(expected_utxo, actual_event)
322+
Good idea. Added a comment in 248fdd88dcf651a0560a3eedfb8af61f38c61400
git range-diff 693d1e2f54baa0d5e407153f79b2f98385e6b8d9...248fdd88dcf651a0560a3eedfb8af61f38c61400
...interface_usdt_utxocache.py
We have encountered an instance where the tracepoints were not collected
in the same order they were fired (#31951).
Tracepoint ordering is not guaranteed in userspace for a number of
reasons.
As this test does not require a strict collection/processing order
collect `expected` and `actual` events into dicts and compare them.
This will gracefully handle both the number of events, and out-of-order
events should they reoccur in the future.