Utils: add WorkQueueThread

Straightforward queue for arbitrary work.

FEXCore/Source/Utils/WorkQueueThread.cpp

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: MIT
+#include <FEXCore/Utils/WorkQueueThread.h>
+#include <FEXCore/Utils/LogManager.h>
+
+namespace FEXCore {
+
+WorkQueueThread::WorkQueueThread() {
+  Thread = FEXCore::Threads::Thread::Create(ThreadEntry, this);
+}
+
+WorkQueueThread::~WorkQueueThread() {
+  {
+    std::unique_lock lk {Mutex};
+    Stop = true;
+  }
+  CV.notify_one();
+
+  if (Thread && Thread->joinable()) {
+    Thread->join(nullptr);
+  }
+}
+
+void WorkQueueThread::QueueWork(fextl::unique_ptr<WorkItem> Work) {
+  {
+    std::unique_lock lk {Mutex};
+    Queue.push_back(std::move(Work));
+  }
+  CV.notify_one();
+}
+
+void WorkQueueThread::ThreadProc() {
+  while (true) {
+    fextl::unique_ptr<WorkItem> Work;
+    {
+      std::unique_lock lk {Mutex};
+      while (!(Stop || !Queue.empty())) {
+        CV.wait(lk);
+      }
+      if (Queue.empty()) {
+        // nothing to do? must be stopping
+        LOGMAN_THROW_A_FMT(Stop, "WorkQueueThread wakes up empty but no Stop?");
+        return;
+      }
+
+      Work = std::move(Queue.front());
+      Queue.pop_front();
+    }
+
+    Work->Run();
+    // Work is destroyed here
+  }
+}
+
+} // namespace FEXCore