{ "number": 35598, "repo": "bitcoin/bitcoin", "url": "https://github.com/bitcoin/bitcoin/pull/35598", "title": "test: cover feeThreshold = MAX_MONEY in interface_ipc_mining.py", "author": "Sjors", "author_association": "MEMBER", "created_at": "2026-06-24T19:35:34Z", "updated_at": "2026-08-28T12:53:40Z", "age_days": 84, "draft": false, "labels": [ "Tests" ], "milestone": null, "base": "master", "head_sha": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec", "head_ref": "2026/06/max-money", "head_repo": "Sjors/bitcoin", "head_history": [ { "t": "2026-06-26T12:56:35Z", "sha": "bd1771fc0cd248438e87b028b096f59ffc976d18" }, { "t": "2026-07-02T11:54:44Z", "sha": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0" }, { "t": "2026-08-28T12:53:26Z", "sha": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec" } ], "additions": 27, "deletions": 11, "changed_files": 2, "commit_count": 1, "size_bucket": "S", "mergeable_state": "blocked", "bot": { "drahtbot": { "present": true, "reviews": { "approach_ack": [ { "login": "jeanpablojp", "url": "https://github.com/bitcoin/bitcoin/pull/35598#pullrequestreview-5040791065" } ], "stale_ack": [ { "login": "enirox001", "url": "https://github.com/bitcoin/bitcoin/pull/35598#pullrequestreview-5049908342" } ] }, "conflicts": [] } }, "acks_parsed": { "enirox001": { "kind": "ack", "hash": null, "t": "2026-08-28T09:44:44Z", "stale": true }, "jeanpablojp": { "kind": "approach_ack", "hash": null, "t": "2026-08-27T12:33:12Z", "stale": false } }, "acks_tally": { "ack": 0, "stale_ack": 1, "concept_ack": 0, "approach_ack": 1, "nack": 0, "concept_nack": 0, "approach_nack": 0 }, "reviews": { "approved": 0, "changes_requested": 0, "distinct_reviewers": [ "davidgumberg", "enirox001", "jeanpablojp" ] }, "signals": { "needs_rebase": false, "ci_failed": false, "mergeable_state": "blocked", "last_author_activity": "2026-08-28T12:53:32Z", "last_reviewer_activity": "2026-08-28T09:46:40Z", "last_reviewer": "enirox001", "author_silent_days": 20, "waiting_on_author_days": 0, "days_since_update": 20 }, "refs": { "mentioned": [ 33922 ], "depends_on": [], "fixes": [], "linked_issues": [], "references": [ { "number": 33922, "type": "pull", "state": "open", "merged": false, "merged_at": null, "title": "mining: add getMemoryLoad() and track template non-mempool memory footprint" } ], "conflicts": [] }, "stack": { "shares_commits_with": [], "based_on": [], "base_for": [] }, "review_paths": [ "test/functional/interface_ipc_mining.py" ], "body": "This adds coverage for when [BlockWaitOptions](https://github.com/bitcoin/bitcoin/blob/master/src/node/mining_types.h#L94-L113)'s `feeThreshold` is set to `MAX_MONEY`. In other words, when the IPC client is only interested in tip updates, not in fee increases.\n\nThis tested ended up in #33922 at some point https://github.com/bitcoin/bitcoin/pull/33922#issuecomment-3674495132, but doesn't really belong there.", "commits": [ { "sha": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec", "date": "2026-08-28T12:51:10Z", "message": "test: cover feeThreshold = MAX_MONEY\n\nCo-authored-by: David Gumberg " } ], "timeline": [ { "t": "2026-06-26T11:55:37Z", "kind": "review_comment", "who": "enirox001", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "4f74b7302f9261831c43065e1876bff937a9b0b7", "in_reply_to": null, "text": "In 4f74b73 (_test: cover feeThreshold = MAX_MONEY_)\n\nWould be nice if there were a comment explaining the assertion here. Something like\n\n```\nIf waitNext had returned for the fee increase instead of the tip update,\nthis template would include the mempool transaction.\n```" }, { "t": "2026-06-26T11:55:43Z", "kind": "review", "who": "enirox001", "assoc": "CONTRIBUTOR", "state": "COMMENTED", "commit": "4f74b7302f9261831c43065e1876bff937a9b0b7", "text": "ACK 4f74b73\n\n_Mostly_ reviewing this in isolation, as I have not looked at #33922 in depth, it makes sense that this should be a PR on its own\n\nThe change updates the functional test to explicitly ignore mempool fee increases while waiting for a tip update, then restores the lower fee threshold for subsequent checks.\n\nThese changes look good to me. Left a minor non-blocking suggestion below," }, { "t": "2026-06-26T12:56:35Z", "kind": "force_push", "who": "Sjors", "commit": "bd1771fc0cd248438e87b028b096f59ffc976d18" }, { "t": "2026-06-26T12:56:52Z", "kind": "comment", "who": "Sjors", "assoc": "MEMBER", "text": "Added the suggested comment.\n\n[quoted text omitted]\nIt's unrelated. That PR is about memory tracking and management, this test is about adding coverages to pre-existing `waitNext()` behavior. The PR touches the same test file, so it was easy to add. But now that I'm considering alternative approaches for #33922, the test becomes a distraction - and it might be a long time before it lands." }, { "t": "2026-07-02T00:21:50Z", "kind": "review_comment", "who": "davidgumberg", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "bd1771fc0cd248438e87b028b096f59ffc976d18", "in_reply_to": null, "text": "https://github.com/bitcoin/bitcoin/pull/35598/changes/bd1771fc0cd248438e87b028b096f59ffc976d18 (_test: cover feeThreshold = MAX_MONEY_)\n\n---\n\nThe test still passes with `waitoptions.feeThreshold = 1`\n\nThat is because `WaitAndCreateNewBlock()` checks for a tip update immediately and then goes to sleep waiting for a tip update, only waking up 1 second after being called or at the timeout deadline before checking for a fee-based update:\n\nhttps://github.com/bitcoin/bitcoin/blob/a8823c099618559fdf6116fe17c9afd311e88890/src/node/miner.cpp#L452-L460\n\nand `wait_and_do` only sleeps for 0.1s:\n\nhttps://github.com/bitcoin/bitcoin/blob/a8823c099618559fdf6116fe17c9afd311e88890/test/functional/test_framework/ipc_util.py#L59-L67\n\nso the fee check never even has a chance, since `WaitAndCreateNewBlock()` is still asleep waiting for a new tip when `wait_and_do` produces one, returns, and the fee check has never even had a chance..\n\nTo fix it, easier shown than explained I think:\n\n```diff\n- waitoptions.timeout = self.default_ipc_timeout\n+\n+ # Temporarily increase the timeout to allow a fee ticks (1s) to\n+ # happen before the deadline\n+ waitoptions.timeout = 2000\n # Ignore fee increases, wait only for the tip update\n waitoptions.feeThreshold = MAX_MONEY\n self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0])\n template2 = await wait_and_do(\n mining_wait_next_template(template, stack, ctx, waitoptions),\n # This mines the transaction, so it won't be in the next template\n- lambda: self.generate(self.nodes[0], 1))\n+ lambda: self.generate(self.nodes[0], 1),\n+ sleep_time=1.1)\n```\n[quoted text omitted]\n\nand adding an arg to `wait_and_do`:\n\n```diff\n--- a/test/functional/test_framework/ipc_util.py\n+++ b/test/functional/test_framework/ipc_util.py\n@@ -45,7 +45,7 @@ async def destroying(obj, ctx):\n await obj.destroy(ctx)\n\n-async def wait_and_do(wait_fn, do_fn):\n+async def wait_and_do(wait_fn, do_fn, sleep_time=0.1):\n \"\"\"Call wait_fn, then sleep, then call do_fn in a parallel task. Wait for\n both tasks to complete.\"\"\"\n wait_started = asyncio.Event()\n@@ -58,7 +58,7 @@ async def wait_and_do(wait_fn, do_fn):\n\n async def do():\n await wait_started.wait()\n- await asyncio.sleep(0.1)\n+ await asyncio.sleep(sleep_time)\n # Let do_fn be either a callable or an awaitable object\n if inspect.isawaitable(do_fn):\n await do_fn\n```" }, { "t": "2026-07-02T00:25:44Z", "kind": "review_comment", "who": "davidgumberg", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec", "in_reply_to": null, "text": "https://github.com/bitcoin/bitcoin/pull/35598/changes/bd1771fc0cd248438e87b028b096f59ffc976d18 (_test: cover feeThreshold = MAX_MONEY_)\n\n---\n\n(see comment above: https://github.com/bitcoin/bitcoin/pull/35598/changes/bd1771fc0cd248438e87b028b096f59ffc976d18#r3509745119)\n\nShould probably add a transaction here to check in another way that MAX_MONEY works to prevent fee-based template updates:\n\n```diff\n@@ -280,9 +284,14 @@ class IPCMiningTest(BitcoinTestFramework):\n assert_equal(len(block2.vtx), 1)\n\n self.log.debug(\"Wait for another, but time out\")\n+ # Temporarily decrease the timeout since we want to hit the\n+ # deadline and perform a fee check and see what happens.\n+ waitoptions.timeout = 100\n+ self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0])\n template3 = await mining_wait_next_template(template2, stack, ctx, waitoptions)\n assert template3 is None\n\n+ waitoptions.timeout = self.default_ipc_timeout\n self.log.debug(\"Wait for another, get one after increase in fees in the mempool\")\n waitoptions.feeThreshold = 1\n template4 = await wait_and_do(\n@@ -290,14 +299,14 @@ class IPCMiningTest(BitcoinTestFramework):\n lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))\n assert template4 is not None\n block3 = await mining_get_block(template4, ctx)\n- assert_equal(len(block3.vtx), 2)\n+ assert_equal(len(block3.vtx), 3)\n\n self.log.debug(\"Wait again, this should return the same template, since the fee threshold is zero\")\n waitoptions.feeThreshold = 0\n template5 = await mining_wait_next_template(template4, stack, ctx, waitoptions)\n assert template5 is not None\n block4 = await mining_get_block(template5, ctx)\n- assert_equal(len(block4.vtx), 2)\n+ assert_equal(len(block4.vtx), 3)\n waitoptions.feeThreshold = 1\n\n self.log.debug(\"Wait for another, get one after increase in fees in the mempool\")\n@@ -306,7 +315,7 @@ class IPCMiningTest(BitcoinTestFramework):\n lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))\n assert template6 is not None\n block4 = await mining_get_block(template6, ctx)\n- assert_equal(len(block4.vtx), 3)\n+ assert_equal(len(block4.vtx), 4)\n\n self.log.debug(\"Wait for another, but time out, since the fee threshold is set now\")\n template7 = await mining_wait_next_template(template6, stack, ctx, waitoptions)\n```" }, { "t": "2026-07-02T11:54:44Z", "kind": "force_push", "who": "Sjors", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0" }, { "t": "2026-07-02T11:54:47Z", "kind": "review_comment", "who": "Sjors", "assoc": "MEMBER", "path": "test/functional/interface_ipc_mining.py", "commit": "bd1771fc0cd248438e87b028b096f59ffc976d18", "in_reply_to": 3509745119, "text": "Ah oops. The counter intuitive thing here is that `waitNext()` will ignore fee changes in the first second. This might change with cluster mempool when we get rid of the internal tick mechanism, see https://github.com/bitcoin/bitcoin/pull/35581. But the adjusted test should continue to work.\n\nTook your suggestion with some adjustments." }, { "t": "2026-07-02T11:55:08Z", "kind": "review_comment", "who": "Sjors", "assoc": "MEMBER", "path": "test/functional/interface_ipc_mining.py", "commit": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec", "in_reply_to": 3509756746, "text": "Also taken" }, { "t": "2026-07-02T11:55:31Z", "kind": "comment", "who": "Sjors", "assoc": "MEMBER", "text": "Turns out it was a a good idea to make this a separate PR. Fixed https://github.com/bitcoin/bitcoin/pull/35598#discussion_r3509745119" }, { "t": "2026-08-27T12:33:12Z", "kind": "review", "who": "jeanpablojp", "assoc": "CONTRIBUTOR", "state": "COMMENTED", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0", "text": "Approach ACK\n\nLeft two comments." }, { "t": "2026-08-27T12:33:12Z", "kind": "review_comment", "who": "jeanpablojp", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0", "in_reply_to": null, "text": "Nit, feel free to ignore. With `feeThreshold` at MAX_MONEY the fee block in `WaitAndCreateNewBlock` is skipped, so nothing is checked at the deadline either. The assert is right, the comment isn't." }, { "t": "2026-08-27T12:33:12Z", "kind": "review_comment", "who": "jeanpablojp", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0", "in_reply_to": null, "text": "`mining_types.h` describes MAX_MONEY as an optimization, and no fee delta can reach it, so the MAX_MONEY half of that guard only exists to skip building the template. Dropping it, and the `Assume` it makes true, leaves the test green in both release and debug builds. With the wrap below it fails. What do you think about covering that here too?\n\n```suggestion\n # MAX_MONEY is documented as an optimization, so waitNext()\n # should not build a template at all here.\n with self.nodes[0].assert_debug_log(expected_msgs=[], unexpected_msgs=[\"CreateNewBlock()\"]):\n template3 = await mining_wait_next_template(template2, stack, ctx, waitoptions)\n```" }, { "t": "2026-08-28T09:44:44Z", "kind": "review", "who": "enirox001", "assoc": "CONTRIBUTOR", "state": "COMMENTED", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0", "text": "reACK https://github.com/bitcoin/bitcoin/pull/35598/changes/0de7c2bf7912d5632c33195b7764e06c46e5f7b0\n\nChanges look good to me. It is useful to have this coverage, and it makes sense as a standalone pr. Left non-blocking comment" }, { "t": "2026-08-28T09:46:40Z", "kind": "review_comment", "who": "enirox001", "assoc": "CONTRIBUTOR", "path": "test/functional/interface_ipc_mining.py", "commit": "0de7c2bf7912d5632c33195b7764e06c46e5f7b0", "in_reply_to": null, "text": "In https://github.com/bitcoin/bitcoin/pull/35598/changes/0de7c2bf7912d5632c33195b7764e06c46e5f7b0: _test: cover feeThreshold = MAX_MONEY_\n\nnon_blocking nit\n\nLooking at this again, my understanding is that the transaction added above is intentionally kept in the mempool to verify that `feeThreshold = MAX_MONEY` ignores a fee increase and still times out. That part makes sense.\n\nAfter the timeout, however, that transaction remains in the mempool and is not included in `template2`. Therefore, once `feeThreshold` is changed to 1, it already satisfies the threshold before this second wait starts. `waitNext` is allowed to return without waiting for the transaction added by this lambda.\n\nVerified this by delaying the lambda\n\n```diff --git a/test/functional/interface_ipc_mining.py b/test/functional/interface_ipc_mining.py\nindex 85a7b8bf11..fe5b861614 100755\n--- a/test/functional/interface_ipc_mining.py\n+++ b/test/functional/interface_ipc_mining.py\n@@ -299,7 +299,8 @@ class IPCMiningTest(BitcoinTestFramework):\n waitoptions.feeThreshold = 1\n template4 = await wait_and_do(\n mining_wait_next_template(template2, stack, ctx, waitoptions),\n- lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))\n+ lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]),\n+ sleep_time=1.1 * self.options.timeout_factor)\n assert template4 is not None\n block3 = await mining_get_block(template4, ctx)\n assert_equal(len(block3.vtx), 3)\n```\n\nThe test fails when asserting the transaction count because it only contains 2 transactions. Would it be clearer to consume the existing fee increase directly here?\n\n```diff --git a/test/functional/interface_ipc_mining.py b/test/functional/interface_ipc_mining.py\nindex 85a7b8bf11..57c1b60b98 100755\n--- a/test/functional/interface_ipc_mining.py\n+++ b/test/functional/interface_ipc_mining.py\n@@ -295,21 +295,19 @@ class IPCMiningTest(BitcoinTestFramework):\n assert template3 is None\n\n waitoptions.timeout = self.default_ipc_timeout\n- self.log.debug(\"Wait for another, get one after increase in fees in the mempool\")\n+ self.log.debug(\"Wait for another, get one for the fees already in the mempool\")\n waitoptions.feeThreshold = 1\n- template4 = await wait_and_do(\n- mining_wait_next_template(template2, stack, ctx, waitoptions),\n- lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))\n+ template4 = await mining_wait_next_template(template2, stack, ctx, waitoptions)\n assert template4 is not None\n block3 = await mining_get_block(template4, ctx)\n- assert_equal(len(block3.vtx), 3)\n+ assert_equal(len(block3.vtx), 2)\n\n self.log.debug(\"Wait again, this should return the same template, since the fee threshold is zero\")\n waitoptions.feeThreshold = 0\n template5 = await mining_wait_next_template(template4, stack, ctx, waitoptions)\n assert template5 is not None\n block4 = await mining_get_block(template5, ctx)\n- assert_equal(len(block4.vtx), 3)\n+ assert_equal(len(block4.vtx), 2)\n waitoptions.feeThreshold = 1\n\n self.log.debug(\"Wait for another, get one after increase in fees in the mempool\")\n@@ -318,7 +316,7 @@ class IPCMiningTest(BitcoinTestFramework):\n lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))\n assert template6 is not None\n block4 = await mining_get_block(template6, ctx)\n- assert_equal(len(block4.vtx), 4)\n+ assert_equal(len(block4.vtx), 3)\n\n self.log.debug(\"Wait for another, but time out, since the fee threshold is set now\")\n template7 = await mining_wait_next_template(template6, stack, ctx, waitoptions)\n```\n\nLater on `template6` would still test adding a transaction while `waitNext` is active, verifying that a new template is returned" }, { "t": "2026-08-28T12:53:26Z", "kind": "force_push", "who": "Sjors", "commit": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec" }, { "t": "2026-08-28T12:53:32Z", "kind": "comment", "who": "Sjors", "assoc": "MEMBER", "text": "Rebased just in case, and addressed feedback from @jeanpablojp and @enirox001." } ], "labels_log": [ { "t": "2026-06-24T19:35:38Z", "action": "labeled", "label": "Tests", "who": "DrahtBot" } ], "state_log": [], "text_chars": 13150, "text_tokens_estimate": 3287, "changed_paths": [ "test/functional/interface_ipc_mining.py", "test/functional/test_framework/ipc_util.py" ], "files": [ { "path": "test/functional/interface_ipc_mining.py", "add": 25, "del": 9 }, { "path": "test/functional/test_framework/ipc_util.py", "add": 2, "del": 2 } ], "test_lines": 38, "git": { "head": "8fb2dbc0d6e788da43c8e471b6e8027b03b8b6ec", "head_matches_backup": true, "base": "05e49b342faa1412266951429c135e9f5daa30c2", "commits": [ { "sha": "8fb2dbc0d6", "subject": "test: cover feeThreshold = MAX_MONEY", "files": 2, "add": 27, "del": 11 } ], "patch_truncated": false }, "input_hash": "a322375c31944556", "extracted_at": "2026-09-17T16:15:31+00:00" }