Initial self-hosting commit

This is the initial version of our tool that is able to
build itself. In can be bootstrapped by

  ./bin/bootstrap.py

Co-authored-by: Oliver Reiche <oliver.reiche@huawei.com>
Co-authored-by: Victor Moreno <victor.moreno1@huawei.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/buildtool/multithreading/task.hpp b/src/buildtool/multithreading/task.hpp
new file mode 100644
index 00000000..49eb20a9
--- /dev/null
+++ b/src/buildtool/multithreading/task.hpp
@@ -0,0 +1,38 @@
+#ifndef INCLUDED_SRC_BUILDTOOL_MULTITHREADING_TASK_HPP
+#define INCLUDED_SRC_BUILDTOOL_MULTITHREADING_TASK_HPP
+
+#include <functional>
+#include <type_traits>
+
+class Task {
+  public:
+    using TaskFunc = std::function<void()>;
+
+    Task() noexcept = default;
+
+    // NOLINTNEXTLINE(modernize-pass-by-value)
+    explicit Task(TaskFunc const& function) noexcept : f_{function} {}
+    explicit Task(TaskFunc&& function) noexcept : f_{std::move(function)} {}
+
+    void operator()() { f_(); }
+
+    // To be able to discern whether the internal f_ has been set or not,
+    // allowing us to write code such as:
+    /*
+    Task t;
+    while (!t) {
+        t = TryGetTaskFromQueue(); // (*)
+    }
+    t(); // (**)
+    */
+    // (*) does `return Task();` or `return {};` if queue is empty or locked)
+    // (**) we can now surely execute the task (and be sure it won't throw any
+    // exception) (for the sake of the example, imagine we are sure that the
+    // queue wasn't empty, otherwise this would be an infinite loop)
+    explicit operator bool() const noexcept { return f_.operator bool(); }
+
+  private:
+    TaskFunc f_{};
+};
+
+#endif  // INCLUDED_SRC_BUILDTOOL_MULTITHREADING_TASK_HPP