Investigating some of the biggest slow downs during tests, the biggest
offender is 'wait_for_stopped' requiring a negative assertion around the
'stopped' event.
It currently waits for a negative predicate to fail before continuing.
This means it must wait for the full DEFAULT_TIMEOUT (50s) before the
test is allowed to continue.
To mitigate this, I added a new `collect_events` helper that will wait
for the given event to occur with the DEFAULT_TIMEOUT, then wait for a
quiet period (0.25s) before returning.
This greatly reduces the amount of idle waiting during tests.
Additionally, looking a the performance of individual test files,
`TestDAP_launch` is the slowest overall test. No individual test is that
slow, but the fact it has so many tests in the same file results in the
test harness waiting for that one file to finish.
To mitigate that, I split `TestDAP_launch` into individual test files
that run in parallel, reducing the runtime locally from over 2mins to
~5s.
In https://github.com/llvm/llvm-project/pull/170523 it was pointed out
that the spec does specifically specify that launch/attach should not
respond until configurationDone is handled.
This means we do need to support async request handlers. To better align
with the spec, I've added a new `lldb_dap::AsyncRequestHandler`. This is
an additional handler type that allows us to respond at a later point.
Additionally, I refactored `launch` and `attach` to only respond once
the `configurationDone` is complete, specifically during the `PostRun`
operation of the `configurationDone` handler.
I merged some of the common behavior between `RequestHandler` and
`AsyncRequestHandler` into their common `BaseRequestHandler`.
The flow should now be:
```
<-> initialize request / response
--> launch/attach request
<-- event initialized
... optionally ...
<-> setBreakpoints request / response
<-> setFunctionBreakpoints request / response
<-> setExceptionBreakpoints request / response
<-> setInstructionBreakpoints request / response
... finally ...
<-> configurationDone request / response
<-- launch/attach response
```
---------
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>
This is more straight forward refactor of the startup sequence that
reverts parts of ba29e60f9a2222bd5e883579bb78db13fc5a7588. Unlike my
previous attempt, I ended up removing the pending request queue and not
including an `AsyncReqeustHandler` because I don't think we actually
need that at the moment.
The key is that during the startup flow there are 2 parallel operations
happening in the DAP that have different triggers.
* The `initialize` request is sent and once the response is received the
`launch` or `attach` is sent.
* When the `initialized` event is recieved the `setBreakpionts` and
other config requests are made followed by the `configurationDone`
event.
I moved the `initialized` event back to happen in the `PostRun` of the
`launch` or `attach` request handlers. This ensures that we have a valid
target by the time the configuration calls are made. I added also added
a few extra validations that to the `configurationeDone` handler to
ensure we're in an expected state.
I've also fixed up the tests to match the new flow. With the other
additional test fixes in 087a5d2ec7897cd99d3787820711fec76a8e1792 I
think we've narrowed down the main source of test instability that
motivated the startup sequence change.
Adding an assert that the 'continue' request succeeds caused a number of
tests to fail. This showed a number of tests that were not specifying if
they should be stopped or not at key points in the test. This is likely
contributing to these tests being flaky since the debugger is not in the
expected state.
Additionally, I spent a little time trying to improve the readability of
the dap_server.py and lldbdap_testcase.py.
Both spellings are considered correct and acceptable, with adapter being
more common in American English. Given that DAP stands for Debug Adapter
Protocol (with an e) let's go with that as the canonical spelling.
The don't currently work (and they're also not particularly useful,
since all of the remote stuff happens inside lldb).
This saves us from annotating tests one by one.
This uses [teyit](https://pypi.org/project/teyit/) to modernize asserts,
as recommended by the [unittest release
notes](https://docs.python.org/3.12/whatsnew/3.12.html#id3).
For example, `assertTrue(a == b)` is replaced with `assertEqual(a, b)`.
This produces better error messages, e.g. `error: unexpectedly found 1
and 2 to be different` instead of `error: False`.
assertEquals is a deprecated alias for assertEqual and has been removed
in Python 3.12. This wasn't an issue previously because we used a
vendored version of the unittest module. Now that we use the built-in
version this gets updated together with the Python version used to run
the test suite.
Rename lldb-vscode to lldb-dap. This change is largely mechanical. The
following substitutions cover the majority of the changes in this
commit:
s/VSCODE/DAP/
s/VSCode/DAP/
s/vscode/dap/
s/g_vsc/g_dap/
Discourse RFC:
https://discourse.llvm.org/t/rfc-rename-lldb-vscode-to-lldb-dap/74075/
