Make sure we don't work any existing tasks when building in module context

1 files changed, 33 insertions, 0 deletions

diff --git a/libbuild2/scheduler.ixx b/libbuild2/scheduler.ixx
new file mode 100644
index 0000000..f9f0f2e
--- /dev/null
+++ b/libbuild2/scheduler.ixx
@@ -0,0 +1,33 @@
+// file      : libbuild2/scheduler.ixx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+namespace build2
+{
+  inline scheduler::queue_mark::
+  queue_mark (scheduler& s)
+      : tq_ (s.queue ())
+  {
+    if (tq_ != nullptr)
+    {
+      lock ql (tq_->mutex);
+
+      if (tq_->mark != s.task_queue_depth_)
+      {
+        om_ = tq_->mark;
+        tq_->mark = s.task_queue_depth_;
+      }
+      else
+        tq_ = nullptr;
+    }
+  }
+
+  inline scheduler::queue_mark::
+  ~queue_mark ()
+  {
+    if (tq_ != nullptr)
+    {
+      lock ql (tq_->mutex);
+      tq_->mark = tq_->size == 0 ? tq_->tail : om_;
+    }
+  }
+}