to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This is failing to compile when LLVM_ENABLE_THREADS is false,
and the fix is not immediately obvious, so reverting while I look
into it.
llvm-svn: 334658
Previously ThreadPool could only queue async "jobs", i.e. work
that was done for its side effects and not for its result. It's
useful occasionally to queue async work that returns a value.
From an API perspective, this is very intuitive. The previous
API just returned a shared_future<void>, so all we need to do is
make it return a shared_future<T>, where T is the type of value
that the operation returns.
Making this work required a little magic, but ultimately it's not
too bad. Instead of keeping a shared queue<packaged_task<void()>>
we just keep a shared queue<unique_ptr<TaskBase>>, where TaskBase
is a class with a pure virtual execute() method, then have a
templated derived class that stores a packaged_task<T()>. Everything
else works out pretty cleanly.
Differential Revision: https://reviews.llvm.org/D48115
llvm-svn: 334643
But now include a check for CPU_COUNT so we still build on 10 year old
versions of glibc.
Original message:
Use sched_getaffinity instead of std:🧵:hardware_concurrency.
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314931
Summary:
This reverts D38481. The change breaks systems with older versions of glibc. It
injects a use of CPU_COUNT() from sched.h without checking to ensure that the
function exists first.
Reviewers:
Subscribers:
llvm-svn: 314922
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314809
By running TSAN on the ThreadPool unit tests it was discovered that the
threads in the pool can pop tasks off the queue at the same time the
"wait" routine is trying to check if the task queue is empty. This patch
fixes this problem by checking for active threads in the waiter before
checking whether the queue is empty.
Patch by Jason Henline.
Differential Revision: http://reviews.llvm.org/D18811
Reviewers: joker.eph, jlebar
llvm-svn: 265618
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
This is a recommit of r255444 ; trying to workaround a bug in the
MSVC 2013 standard library. I think I was hit by:
http://connect.microsoft.com/VisualStudio/feedbackdetail/view/791185/std-packaged-task-t-where-t-is-void-or-a-reference-class-are-not-movable
Recommit of r255589, trying to please g++ as well.
Differential Revision: http://reviews.llvm.org/D15464
From: mehdi_amini <mehdi_amini@91177308-0d34-0410-b5e6-96231b3b80d8>
llvm-svn: 255593
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
This is a recommit of r255444 ; trying to workaround a bug in the
MSVC 2013 standard library. I think I was hit by:
http://connect.microsoft.com/VisualStudio/feedbackdetail/view/791185/std-packaged-task-t-where-t-is-void-or-a-reference-class-are-not-movable
Differential Revision: http://reviews.llvm.org/D15464
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255589
This is a very simple implementation of a thread pool using C++11
thread. It accepts any std::function<void()> for asynchronous
execution. Individual task can be synchronize using the returned
future, or the client can block on the full queue completion.
In case LLVM is configured with Threading disabled, it falls back
to sequential execution using std::async with launch:deferred.
This is intended to support parallelism for ThinLTO processing in
linker plugin, but is generic enough for any other uses.
Differential Revision: http://reviews.llvm.org/D15464
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255444
Chandler Carruth