[all-commits] [llvm/llvm-project] 6149e5: [ThreadPool] Support returning futures with results.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6149e57dc1313d32c85524f8009a1249e0b8f4d1
      https://github.com/llvm/llvm-project/commit/6149e57dc1313d32c85524f8009a1249e0b8f4d1
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2021-11-22 (Mon, 22 Nov 2021)

  Changed paths:
    M llvm/include/llvm/Support/ThreadPool.h
    M llvm/lib/Support/ThreadPool.cpp
    M llvm/unittests/Support/ThreadPool.cpp

  Log Message:
  -----------
  [ThreadPool] Support returning futures with results.

This patch adjusts ThreadPool::async to return futures that wrap
the result type of the passed in callable.

To do so, ThreadPool::asyncImpl first creates a shared promise. The
result of the promise is set in a new callable that first executes the
task. The callable is added to the task queue.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D114183