Commit Graph

24 Commits

Author SHA1 Message Date
Sam McCall 6d4eb46d0c [clangd] workspace/symbol should be async, it reads from the index.
Summary:
To enable this, TUScheduler has to provide a way to run async tasks without
needing a preamble or AST!

Reviewers: ilya-biryukov

Subscribers: javed.absar, ioeric, MaskRay, jkorous, arphaman, jfb, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D53644

llvm-svn: 345268
2018-10-25 14:19:14 +00:00
Fangrui Song 847bd33166 [clangd] Fix TUScheduler typos
llvm-svn: 342198
2018-09-14 00:56:11 +00:00
Sam McCall 046557bc03 [clangd] Some nitpicking around the new split (preamble/main) dynamic index
Summary:
- DynamicIndex doesn't implement ParsingCallbacks, to make its role clearer.
  ParsingCallbacks is a separate object owned by the receiving TUScheduler.
  (I tried to get rid of the "index-like-object that doesn't implement index"
  but it was too messy).
- Clarified(?) docs around DynamicIndex - fewer details up front, more details
  inside.
- Exposed dynamic index from ClangdServer for memory monitoring and more
  direct testing of its contents (actual tests not added here, wanted to get
  this out for review)
- Removed a redundant and sligthly confusing filename param in a callback

Reviewers: ilya-biryukov

Subscribers: javed.absar, ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D51221

llvm-svn: 341325
2018-09-03 16:37:59 +00:00
Sam McCall e6ce8da025 [clangd] Run SignatureHelp using an up-to-date preamble, waiting if needed.
Summary:
After code completion inserts a header, running signature help using the old
preamble will usually fail. So we add support for consistent preamble reads.

Reviewers: ilya-biryukov

Subscribers: javed.absar, ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D51438

llvm-svn: 341076
2018-08-30 15:07:34 +00:00
Eric Liu 25d74e9594 [clangd] Speculative code completion index request before Sema is run.
Summary:
For index-based code completion, send an asynchronous speculative index
request, based on the index request for the last code completion on the same
file and the filter text typed before the cursor, before sema code completion
is invoked. This can reduce the code completion latency (by roughly latency of
sema code completion) if the speculative request is the same as the one
generated for the ongoing code completion from sema. As a sequence of code
completions often have the same scopes and proximity paths etc, this should be
effective for a number of code completions.

Trace with speculative index request:{F6997544}

Reviewers: hokein, ilya-biryukov

Reviewed By: ilya-biryukov

Subscribers: javed.absar, jfb, MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D50962

llvm-svn: 340604
2018-08-24 11:23:56 +00:00
Ilya Biryukov c5e44c1805 [clangd] Add callbacks on parsed AST in addition to parsed preambles
Summary:
Will be used for updating the dynamic index on updates to the open files.
Currently we collect only information coming from the preamble
AST. This has a bunch of limitations:
  - Dynamic index misses important information from the body of the
    file, e.g. locations of definitions.
  - XRefs cannot be collected at all, since we can only obtain full
    information for the current file (preamble is parsed with skipped
    function bodies, therefore not reliable).

This patch only adds the new callback, actually updates to the index
will be done in a follow-up patch.

Reviewers: hokein

Reviewed By: hokein

Subscribers: kadircet, javed.absar, ioeric, MaskRay, jkorous, arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D50847

llvm-svn: 340401
2018-08-22 11:39:16 +00:00
Eric Liu f40819ea2d [clangd] Record the file being processed in a TUScheduler thread in context.
Summary:
This allows implementations like different symbol indexes to know what
the current active file is. For example, some customized index implementation
might decide to only return results for some files.

Reviewers: ilya-biryukov

Reviewed By: ilya-biryukov

Subscribers: javed.absar, MaskRay, jkorous, arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D50446

llvm-svn: 339320
2018-08-09 09:05:45 +00:00
Ilya Biryukov 4a9312079a [clangd] Wait for first preamble before code completion
Summary:
To avoid doing extra work of processing headers in the preamble
mutilple times in parallel.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: javed.absar, ioeric, MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D48940

llvm-svn: 336538
2018-07-09 10:45:33 +00:00
Benjamin Kramer c36c09fe8e [clangd] Replace UniqueFunction with llvm::unique_function.
One implementation of this ought to be enough for everyone.

llvm-svn: 336228
2018-07-03 20:59:33 +00:00
Ilya Biryukov 823b056f58 [clangd] Keep only a limited number of idle ASTs in memory
Summary:
After this commit, clangd will only keep the last 3 accessed ASTs in
memory. Preambles for each of the opened files are still kept in
memory to make completion and AST rebuilds fast.

AST rebuilds are usually fast enough, but having the last ASTs in
memory still considerably improves latency of operations like
findDefinition and documeneHighlight, which are often sent multiple
times a second when moving around the code. So keeping some of the last
accessed ASTs in memory seems like a reasonable tradeoff.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: malaperle, arphaman, klimek, javed.absar, ioeric, MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D47063

llvm-svn: 333737
2018-06-01 10:08:43 +00:00
Ilya Biryukov 6c5e99ed46 [clangd] Build index on preamble changes instead of the AST changes
Summary:
This is more efficient and avoids data races when reading files that
come from the preamble. The staleness can occur when reading a file
from disk that changed after the preamble was built. This can lead to
crashes, e.g. when parsing comments.

We do not to rely on symbols from the main file anyway, since any info
that those provide can always be taken from the AST.

Reviewers: ioeric, sammccall

Reviewed By: ioeric

Subscribers: malaperle, klimek, javed.absar, MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D47272

llvm-svn: 333196
2018-05-24 15:50:15 +00:00
Ilya Biryukov fe3aae2a76 [clangd] Fix indentation in the comment. NFC
llvm-svn: 327539
2018-03-14 17:49:19 +00:00
Ilya Biryukov f1f3d57eb2 [clangd] Don't expose vfs in TUScheduler::runWithPreamble.
Summary:
It was previously an easy way to concurrently access a mutable vfs,
which is a recipe for disaster.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: klimek, jkorous-apple, cfe-commits, ioeric

Differential Revision: https://reviews.llvm.org/D44463

llvm-svn: 327537
2018-03-14 17:46:52 +00:00
Sam McCall a7bb0cc09e [clangd] Remove Tagged and some related APIs from ClangdServer.
Context can do what Tagged was intended to support (snapshot filesystems),
and less intrusively.
getTaggedFileSystem() no longer needs a filename.

Cleanups while here:
 - code-complete now returns errors as Expected, like other functions
 - added an alias Callback<T> for the usual callback function type

llvm-svn: 327344
2018-03-12 23:22:35 +00:00
Ilya Biryukov 71028b83e7 [clangd] Revamp handling of diagnostics.
Summary:
The new implementation attaches notes to diagnostic message and shows
the original diagnostics in the message of the note.

Reviewers: hokein, ioeric, sammccall

Reviewed By: sammccall

Subscribers: klimek, mgorny, cfe-commits, jkorous-apple

Differential Revision: https://reviews.llvm.org/D44142

llvm-svn: 327282
2018-03-12 15:28:22 +00:00
Sam McCall d1e0deb271 [clangd] Debounce streams of updates.
Summary:
Don't actually start building ASTs for new revisions until either:
- 500ms have passed since the last revision, or
- we actually need the revision for something (or to unblock the queue)

In practice, this avoids the "first keystroke results in diagnostics" problem.
This is kind of awkward to test, and the test is pretty bad.
It can be observed nicely by capturing a trace, though.

Reviewers: hokein, ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D43648

llvm-svn: 326546
2018-03-02 08:56:37 +00:00
Sam McCall 568e17f1e6 [clangd] Allow embedders some control over when diagnostics are generated.
Summary:
Through the C++ API, we support for a given snapshot version:
 - Yes: make sure we generate diagnostics for exactly this version
 - Auto: generate eventually-consistent diagnostics for at least this version
 - No: don't generate diagnostics for this version
Eventually auto should be debounced for better UX.

Through LSP, we force diagnostics for initial load (bypassing future debouncing)
and all updates follow the "auto" policy.

This is complicated to implement under the CancellationFlag design, so
rewrote that part to just inspect the queue instead.

It turns out we never pass None to the diagnostics callback, so remove Optional
from the signature. The questionable behavior of not invoking the callback at
all if CppFile::rebuild fails is not changed.

Reviewers: ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D43518

llvm-svn: 325774
2018-02-22 13:11:12 +00:00
Sam McCall c901c5db78 [clangd] Tracing: name worker threads, and enforce naming scheduled async tasks
Summary:
This has a bit of a blast radius, but I think there's enough value in "forcing"
us to give names to these async tasks for debugging. Guessing about what
multithreaded code is doing is so unfun...

The "file" param attached to the tasks may seem to be redundant with the thread
names, but note that thread names are truncated to 15 chars on linux!
We'll be lucky to get the whole basename...

Reviewers: ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D43388

llvm-svn: 325480
2018-02-19 09:56:28 +00:00
Sam McCall 0bb24cd4fa [clangd] Stop exposing Futures from ClangdServer operations.
Summary:
LSP has asynchronous semantics, being able to block on an async operation
completing is unneccesary and leads to tighter coupling with the threading.

In practice only tests depend on this, so we add a general-purpose "block until
idle" function to the scheduler which will work for all operations.

To get this working, fix a latent condition-variable bug in ASTWorker, and make
AsyncTaskRunner const-correct.

Reviewers: ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D43127

llvm-svn: 324990
2018-02-13 08:59:23 +00:00
Ilya Biryukov 7e5ee26d1a Resubmit "[clangd] The new threading implementation"
Initially submitted as r324356 and reverted in r324386.

This change additionally contains a fix to crashes of the buildbots.
The source of the crash was undefined behaviour caused by
std::future<> whose std::promise<> was destroyed without calling
set_value().

llvm-svn: 324575
2018-02-08 07:37:35 +00:00
Ilya Biryukov 3693f5941a Revert "[clangd] The new threading implementation" (r324356)
And the follow-up changes r324361 and r324363.
These changes seem to break two buildbots:
  - http://lab.llvm.org:8011/builders/clang-atom-d525-fedora-rel/builds/14091
  - http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules-2/builds/16001

We will need to investigate what went wrong and resubmit the changes
afterwards.

llvm-svn: 324386
2018-02-06 19:22:40 +00:00
Ilya Biryukov cce8883094 [clangd] The new threading implementation
Summary:
In the new threading model clangd creates one thread per file to manage
the AST and one thread to process each of the incoming requests.
The number of actively running threads is bounded by the semaphore to
avoid overloading the system.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: klimek, mgorny, jkorous-apple, ioeric, hintonda, cfe-commits

Differential Revision: https://reviews.llvm.org/D42573

llvm-svn: 324356
2018-02-06 15:53:42 +00:00
Sam McCall d1a7a37c22 [clangd] Pass Context implicitly using TLS.
Summary:
Instead of passing Context explicitly around, we now have a thread-local
Context object `Context::current()` which is an implicit argument to
every function.
Most manipulation of this should use the WithContextValue helper, which
augments the current Context to add a single KV pair, and restores the
old context on destruction.

Advantages are:
- less boilerplate in functions that just propagate contexts
- reading most code doesn't require understanding context at all, and
  using context as values in fewer places still
- fewer options to pass the "wrong" context when it changes within a
  scope (e.g. when using Span)
- contexts pass through interfaces we can't modify, such as VFS
- propagating contexts across threads was slightly tricky (e.g.
  copy vs move, no move-init in lambdas), and is now encapsulated in
  the threadpool

Disadvantages are all the usual TLS stuff - hidden magic, and
potential for higher memory usage on threads that don't use the
context. (In practice, it's just one pointer)

Reviewers: ilya-biryukov

Subscribers: klimek, jkorous-apple, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D42517

llvm-svn: 323872
2018-01-31 13:40:48 +00:00
Ilya Biryukov 75f1dd9b98 [clangd] Refactored threading in ClangdServer
Summary:
We now provide an abstraction of Scheduler that abstracts threading
and resource management in ClangdServer.
No changes to behavior are intended with an exception of changed error
messages.
This patch is preliminary work to allow a revamped threading
implementation that will move the threading code out of CppFile.

Reviewers: sammccall, bkramer, jkorous-apple

Reviewed By: sammccall

Subscribers: hokein, mgorny, hintonda, ioeric, jkorous-apple, cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D42174

llvm-svn: 323851
2018-01-31 08:51:16 +00:00