||GC-internal definition of GC cell kinds.
||This flag allows an allocation site to request a specific heap based upon the
estimated lifetime or lifetime requirements of objects allocated from that
||GC-internal definitions of ArenaList and associated heap data structures.
||Provides a delete policy that can be used for objects which have their
lifetime managed by the GC so they can be safely destroyed outside of GC.
This is necessary for example when initializing such an object may fail after
the initial allocation. The partially-initialized object must be destroyed,
but it may not be safe to do so at the current time as the store buffer may
contain pointers into it.
This policy traces GC pointers in the object and clears them, making sure to
trigger barriers while doing so. This will remove any store buffer pointers
into the object and make it safe to delete.
||Finalization registry GC implementation.
||Find the strongly connected components of a graph using Tarjan's algorithm,
and return them in topological order.
Nodes derive from GraphNodeBase and add target edge pointers to
sourceNode.gcGraphEdges to describe the graph:
struct MyGraphNode : public GraphNodeBase<MyGraphNode>
MyGraphNode node1, node2, node3;
node1.gcGraphEdges.put(node2); // Error checking elided.
MyGraphNode* result = finder.getResultsList();
||A JSFreeOp can do one thing: free memory. For convenience, it has delete_
convenience methods that also call destructors.
JSFreeOp is passed to finalizers and other sweep-phase hooks so that we do
not need to pass a JSContext to those hooks.
||JS engine garbage collector API.
||GC-internal enum definitions.
||GC-internal classes for acquiring and releasing the GC lock.
||When the mark stack is full, the GC does not call js::TraceChildren to mark
the reachable "children" of the thing. Rather the thing is put aside and
js::TraceChildren is called later when the mark stack is empty.
To implement such delayed marking of the children with minimal overhead for
the normal case of sufficient stack, we link arenas into a list using
Arena::setNextDelayedMarkingArena(). The head of the list is stored in
GCMarker::delayedMarkingList. GCMarker::delayMarkingChildren() adds arenas
to the list as necessary while markAllDelayedChildren() pops the arenas from
the stack until it is empty.
||This currently does not support multiple runtimes.
||Tracing code is declared within this class, so the class can be a friend of
something and access private details used for tracing.
||Each trace is stored as a 64-bit word with the following format:
56 48 0
| Event type | Optional extra | Optional payload |
||Used to add entries to a js::HashMap or HashSet where the key depends on a GC
thing that may be moved by generational or compacting GC between the call to
lookupForAdd() and relookupOrAdd().
||The minimum cell size ends up as twice the cell alignment because the mark
bitmap contains one bit per CellBytesPerMarkBit bytes (which is equal to
CellAlignBytes) and we need two mark bits per cell.
||Marking and sweeping APIs for use by implementations of different GC cell
||Template types for use in generic code: to use Rooted/Handle/MutableHandle in
cases where GC may occur, or to use mock versions of those types that perform
no rooting or root list manipulation when GC cannot occur.
||System allocation functions generally require the allocation size
to be an integer multiple of the page size of the running process.
||safe - used for value in comparison above
||Key Header text
||GC-internal helper functions for getting the AllocKind used to allocate a
JSObject and related information.
||JS Garbage Collector.
||GC-internal iterators for various data structures.
||Iterators for various data structures.
||GC-internal definition of relocation overlay used while moving cells.
||We may start to collect a zone before its trigger threshold is reached if
GCRuntime::maybeGC() is called for that zone or we start collecting other
zones. These eager threshold factors are not configurable.
||If this fails, then you can either delete this assertion and allow all
larger-numbered reasons to pile up in the last telemetry bucket, or switch
to GC_REASON_3 and bump the max value.
||Number of zones collected in this GC.
||BufferableRef represents an abstract reference for use in the generational
GC's remembered set. Entries in the store buffer that cannot be represented
with the simple pointer-to-a-pointer scheme must derive from this class and
use the generic store buffer interface.
A single BufferableRef entry in the generic buffer can represent many entries
in the remembered set. For example js::OrderedHashTableRef represents all
the incoming edges corresponding to keys in an ordered hash table.
||Callback Tracer Dispatch **********************************************
||Write barrier verification
The next few functions are for write barrier verification.
The VerifyBarriers function is a shorthand. It checks if a verification phase
is currently running. If not, it starts one. Otherwise, it ends the current
phase and starts a new one.
The user can adjust the frequency of verifications, which causes
VerifyBarriers to be a no-op all but one out of N calls. However, if the
|always| parameter is true, it starts a new phase no matter what.
When StartVerifyBarriers is called, a snapshot is taken of all objects in
the GC heap and saved in an explicit graph data structure. Later,
EndVerifyBarriers traverses the heap again. Any pointer values that were in
the snapshot and are no longer found must be marked; otherwise an assertion
triggers. Note that we must not GC in between starting and finishing a
||For unmarked weakmap keys with delegates in a different zone, add a zone
edge to ensure that the delegate zone finishes marking before the key
||Public header for allocating memory associated with GC things.