Commit Graph

4 Commits

Author SHA1 Message Date
Ilya Biryukov 0c904861e6 [clangd] Fixed a bug in the new threading implementation.
This should fix the buildbots.

llvm-svn: 324363
2018-02-06 17:22:58 +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