5 Commits (ed4462cc78afd2065bbf5bd79728852b65b9ad7f)

Author	SHA1	Message	Date
fanquake	a7261da479	Merge bitcoin/bitcoin#27831: test: handle failed `assert_equal()` assertions in bcc callback functions ... 61f4b9b7ad Manage exceptions in bcc callback functions (virtu) Pull request description: Address #27380 (and similar future issues) by handling failed `assert_equal()` assertions in bcc callback functions ### Problem Exceptions are not propagated in ctype callback functions used by bcc. This means an AssertionError exception raised by `assert_equal()` to signal a failed assertion is not getting caught and properly logged. Instead, the error is logged to stdout and execution of the callback stops. The current workaround to check whether all `assert_equal()` assertions in a callback succeeded is to increment a success counter after the assertions (which only gets incremented if none exception is raised and stops execution). Then, outside the callback, the success counter can be used to check whether a callback executed successfully. One issue with the described workaround is that when an exception occurs, there is no way of telling which of the `assert_equal()` statements caused the exception; moreover, there is no way of inspecting how the pieces of data that got compared in `assert_equal()` differed (often a crucial clue when debugging what went wrong). This problem is happening in #27380: Sporadically, in the `mempool:rejected` test, execution does not reach the end of the callback function and the success counter is not incremented. Thus, the test fails when comparing the counter to its expected value of one. Without knowing which of the asserts failed any why it failed, this issue is hard to debug. ### Solution Two fixes come to mind. The first involves having the callback function make event data accessible outside the callback and inspecting the event using `assert_equal()` outside the callback. This solution still requires a counter in the callback in order to tell whether a callback was actually executed or if instead the call to perf_buffer_poll() timed out. The second fix entails wrapping all relevant `assert_equal()` statements inside callback functions into try-catch blocks and manually logging AssertionErrors. While not as elegant in terms of design, this approach can be more pragmatic for more complex tests (e.g., ones involving multiple events, events of different types, or the order of events). The solution proposed here is to select the most pragmatic fix on a case-by-case basis: Tests in `interface_usdt_net.py`, `interface_usdt_mempool.py` and `interface_usdt_validation.py` have been refactored to use the first approach, while the second approach was chosen for `interface_usdt_utxocache.py` (partly to provide a reference for the second approach, but mainly because the utxocache tests are the most intricate tests, and refactoring them to use the first approach would negatively impact their readability). Lastly, `interface_usdt_coinselection.py` was kept unchanged because it does not use `assert_equal()` statements inside callback functions. ACKs for top commit: 0xB10C: Reviewed the changes since my last review. ACK 61f4b9b7ad. I've tested that the combined log contains both exceptions by modifying `interface_usdt_utxocache.py`. willcl-ark: utACK 61f4b9b stickies-v: utACK 61f4b9b7a Tree-SHA512: 85cdaabf370d4f09a9eab6af9ce7c796cd9d08cb91f38f021f71adda34c5f643331022dd09cadb95be2185dad6016c95cbb8942e41e4fbd566a49bf431c5141a	1 year ago
virtu	61f4b9b7ad	Manage exceptions in bcc callback functions ... Exceptions are not propagated in ctype callback functions used by bcc. This means an AssertionError exception raised by check_equal() to signal a failed assertion is not getting caught and properly logged. Instead, the error is logged to stdout and execution of the handler stops. The current workaround to check whether all check_equal() assertions in a callback succeeded is to increment a success counter after the assertions (which only gets incremented if none exception is raised and stops execution). Then, outside the callback, the success counter can be used to check whether a callback executed successfully. One issue with the described workaround is that when an exception occurs, there is no way of telling which of the check_equal() statements caused the exception; moreover, there is no way of inspecting how the pieces of data that got compared in check_equal() differed (often a crucial clue when debugging what went wrong). Two fixes to this problem come to mind. The first involves having the callback function make event data accessible outside the callback and inspecting the event using check_equal() outside the callback. This solution still requires a counter in the callback to tell whether a callback was actually executed or if instead the call to perf_buffer_poll() timed out. The second fix entails wrapping all relevant check_equal() statements inside callback functions into try-catch blocks and manually logging AssertionErrors. While not as elegant in terms of design, this approach can be more pragmatic for more complex tests (e.g., ones involving multiple events, events of different types, or the order of events). The solution proposed here is to select the most pragmatic fix on a case-by-case basis: Tests in interface_usdt_net.py, interface_usdt_mempool.py and interface_usdt_validation.py have been refactored to use the first approach, while the second approach was chosen for interface_usdt_utxocache.py (partly to provide a reference for the second approach, but mainly because the utxocache tests are the most intricate tests, and refactoring them to use the first approach would negatively impact their readability). Lastly, interface_usdt_coinselection.py was kept unchanged because it does not use check_equal() statements inside callback functions.	1 year ago
Hennadii Stepanov	d2f6d2a95a	Use `int32_t` type for most transaction size/weight values ... This change gets rid of a few casts and makes the following commit diff smaller.	1 year ago
brunoerg	a951c34f17	test: fix `interface_usdt_mempool` by mining a block after each test ... Co-authored-by: josibake <josibake@protonmail.com>	1 year ago
virtu	4b7aec2951	Add mempool tracepoints ... Tracepoints for added, removed, replaced, and rejected transactions. The removal reason is passed as string instead of a numeric value, since the benefits of not having to maintain a redundant enum-string mapping seem to outweigh the small cost of string generation. The reject reason is passed as string as well, although here the string does not have to be generated but is readily available. So far, tracepoint PRs typically included two demo scripts: a naive bpftrace script to show raw tracepoint data and a bcc script for a more refined view. However, as some of the ongoing changes to bpftrace introduce a certain degree of unreliability (running some of the existing bpftrace scripts was not possible with standard kernels and bpftrace packages on latest stable Ubuntu, Debian, and NixOS), this PR includes only a single bcc script that fuses the functionality of former bpftrace and bcc scripts.	2 years ago