llvm-project/clang-tools-extra/clangd/Threading.cpp

62 lines
1.7 KiB
C++

#include "Threading.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/Threading.h"
namespace clang {
namespace clangd {
ThreadPool::ThreadPool(unsigned AsyncThreadsCount)
: RunSynchronously(AsyncThreadsCount == 0) {
if (RunSynchronously) {
// Don't start the worker thread if we're running synchronously
return;
}
Workers.reserve(AsyncThreadsCount);
for (unsigned I = 0; I < AsyncThreadsCount; ++I) {
Workers.push_back(std::thread([this, I]() {
llvm::set_thread_name(llvm::formatv("scheduler/{0}", I));
while (true) {
UniqueFunction<void()> Request;
// Pick request from the queue
{
std::unique_lock<std::mutex> Lock(Mutex);
// Wait for more requests.
RequestCV.wait(Lock,
[this] { return !RequestQueue.empty() || Done; });
if (RequestQueue.empty()) {
assert(Done);
return;
}
// We process requests starting from the front of the queue. Users of
// ThreadPool have a way to prioritise their requests by putting
// them to the either side of the queue (using either addToEnd or
// addToFront).
Request = std::move(RequestQueue.front());
RequestQueue.pop_front();
} // unlock Mutex
Request();
}
}));
}
}
ThreadPool::~ThreadPool() {
if (RunSynchronously)
return; // no worker thread is running in that case
{
std::lock_guard<std::mutex> Lock(Mutex);
// Wake up the worker thread
Done = true;
} // unlock Mutex
RequestCV.notify_all();
for (auto &Worker : Workers)
Worker.join();
}
} // namespace clangd
} // namespace clang