@kha The runtime folder includes what is needed to link a
standalone Lean program. It is still contains some unnecessary files.
We will be able to remove them after we release Lean4.
This commit allows us to build Lean without the pthread dependency.
It is also useful if we want to implement multi-threading on top of Boost.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
We need support for recursive locks. The main user of this class is
the environment object. This commit adds a test that demonstrates that
the shared_lock of the environment object may be recursively requested.
Before this fix, the Lean was deadlocking in this example.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
