diff options
Diffstat (limited to 'deps/v8/src/compiler/node-marker.h')
| -rw-r--r-- | deps/v8/src/compiler/node-marker.h | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/deps/v8/src/compiler/node-marker.h b/deps/v8/src/compiler/node-marker.h index 5ef2063f18..84666d5f07 100644 --- a/deps/v8/src/compiler/node-marker.h +++ b/deps/v8/src/compiler/node-marker.h @@ -42,9 +42,22 @@ class NodeMarkerBase { DISALLOW_COPY_AND_ASSIGN(NodeMarkerBase); }; - -// A NodeMarker uses monotonically increasing marks to assign local "states" -// to nodes. Only one NodeMarker per graph is valid at a given time. +// A NodeMarker assigns a local "state" to every node of a graph in constant +// memory. Only one NodeMarker per graph is valid at a given time, that is, +// after you create a NodeMarker you should no longer use NodeMarkers that +// were created earlier. Internally, the local state is stored in the Node +// structure. +// +// When you initialize a NodeMarker, all the local states are conceptually +// set to State(0) in constant time. +// +// In its current implementation, in debug mode NodeMarker will try to +// (efficiently) detect invalid use of an older NodeMarker. Namely, if you get +// or set a node with a NodeMarker, and then get or set that node +// with an older NodeMarker you will get a crash. +// +// GraphReducer uses a NodeMarker, so individual Reducers cannot use a +// NodeMarker. template <typename State> class NodeMarker : public NodeMarkerBase { public: |