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

86 lines
2.1 KiB
C++

#include "Threading.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/Threading.h"
#include <thread>
namespace clang {
namespace clangd {
void Notification::notify() {
{
std::lock_guard<std::mutex> Lock(Mu);
Notified = true;
}
CV.notify_all();
}
void Notification::wait() const {
std::unique_lock<std::mutex> Lock(Mu);
CV.wait(Lock, [this] { return Notified; });
}
Semaphore::Semaphore(std::size_t MaxLocks) : FreeSlots(MaxLocks) {}
void Semaphore::lock() {
std::unique_lock<std::mutex> Lock(Mutex);
SlotsChanged.wait(Lock, [&]() { return FreeSlots > 0; });
--FreeSlots;
}
void Semaphore::unlock() {
std::unique_lock<std::mutex> Lock(Mutex);
++FreeSlots;
Lock.unlock();
SlotsChanged.notify_one();
}
AsyncTaskRunner::~AsyncTaskRunner() { wait(); }
bool AsyncTaskRunner::wait(Deadline D) const {
std::unique_lock<std::mutex> Lock(Mutex);
return clangd::wait(Lock, TasksReachedZero, D,
[&] { return InFlightTasks == 0; });
}
void AsyncTaskRunner::runAsync(llvm::Twine Name,
UniqueFunction<void()> Action) {
{
std::lock_guard<std::mutex> Lock(Mutex);
++InFlightTasks;
}
auto CleanupTask = llvm::make_scope_exit([this]() {
std::lock_guard<std::mutex> Lock(Mutex);
int NewTasksCnt = --InFlightTasks;
if (NewTasksCnt == 0) {
// Note: we can't unlock here because we don't want the object to be
// destroyed before we notify.
TasksReachedZero.notify_one();
}
});
std::thread(
[](std::string Name, decltype(Action) Action, decltype(CleanupTask)) {
llvm::set_thread_name(Name);
Action();
// Make sure function stored by Action is destroyed before CleanupTask
// is run.
Action = nullptr;
},
Name.str(), std::move(Action), std::move(CleanupTask))
.detach();
}
Deadline timeoutSeconds(llvm::Optional<double> Seconds) {
using namespace std::chrono;
if (!Seconds)
return llvm::None;
return steady_clock::now() +
duration_cast<steady_clock::duration>(duration<double>(*Seconds));
}
} // namespace clangd
} // namespace clang