1 files changed, 161 insertions, 0 deletions
diff --git a/js/src/gc/PrivateIterators-inl.h b/js/src/gc/PrivateIterators-inl.h
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index 0000000000..e6013c3e94
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+++ b/js/src/gc/PrivateIterators-inl.h
@@ -0,0 +1,161 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * GC-internal iterators for various data structures.
+ */
+
+#ifndef gc_PrivateIterators_inl_h
+#define gc_PrivateIterators_inl_h
+
+#include "gc/PublicIterators.h"
+
+#include "gc/GC-inl.h"
+
+namespace js::gc {
+
+class ArenaCellIterUnderGC : public ArenaCellIter {
+ public:
+  explicit ArenaCellIterUnderGC(Arena* arena) : ArenaCellIter(arena) {
+    MOZ_ASSERT(CurrentThreadIsPerformingGC());
+  }
+};
+
+class ArenaCellIterUnderFinalize : public ArenaCellIter {
+ public:
+  explicit ArenaCellIterUnderFinalize(Arena* arena) : ArenaCellIter(arena) {
+    MOZ_ASSERT(CurrentThreadIsGCFinalizing());
+  }
+};
+
+class GrayObjectIter : public ZoneAllCellIter<js::gc::TenuredCell> {
+ public:
+  explicit GrayObjectIter(JS::Zone* zone, AllocKind kind) {
+    initForTenuredIteration(zone, kind);
+  }
+
+  JSObject* get() const {
+    return ZoneAllCellIter<js::gc::TenuredCell>::get<JSObject>();
+  }
+  operator JSObject*() const { return get(); }
+  JSObject* operator->() const { return get(); }
+};
+
+class GCZonesIter {
+  AllZonesIter zone;
+
+ public:
+  explicit GCZonesIter(GCRuntime* gc) : zone(gc) {
+    MOZ_ASSERT(gc->heapState() != JS::HeapState::Idle);
+    if (!done() && !zone->wasGCStarted()) {
+      next();
+    }
+  }
+  explicit GCZonesIter(JSRuntime* rt) : GCZonesIter(&rt->gc) {}
+
+  bool done() const { return zone.done(); }
+
+  void next() {
+    MOZ_ASSERT(!done());
+    do {
+      zone.next();
+    } while (!zone.done() && !zone->wasGCStarted());
+  }
+
+  JS::Zone* get() const {
+    MOZ_ASSERT(!done());
+    return zone;
+  }
+
+  operator JS::Zone*() const { return get(); }
+  JS::Zone* operator->() const { return get(); }
+};
+
+using GCCompartmentsIter =
+    CompartmentsOrRealmsIterT<GCZonesIter, CompartmentsInZoneIter>;
+using GCRealmsIter = CompartmentsOrRealmsIterT<GCZonesIter, RealmsInZoneIter>;
+
+/* Iterates over all zones in the current sweep group. */
+class SweepGroupZonesIter {
+  JS::Zone* current;
+
+ public:
+  explicit SweepGroupZonesIter(GCRuntime* gc)
+      : current(gc->getCurrentSweepGroup()) {
+    MOZ_ASSERT(CurrentThreadIsPerformingGC());
+  }
+  explicit SweepGroupZonesIter(JSRuntime* rt) : SweepGroupZonesIter(&rt->gc) {}
+
+  bool done() const { return !current; }
+
+  void next() {
+    MOZ_ASSERT(!done());
+    current = current->nextNodeInGroup();
+  }
+
+  JS::Zone* get() const {
+    MOZ_ASSERT(!done());
+    return current;
+  }
+
+  operator JS::Zone*() const { return get(); }
+  JS::Zone* operator->() const { return get(); }
+};
+
+using SweepGroupCompartmentsIter =
+    CompartmentsOrRealmsIterT<SweepGroupZonesIter, CompartmentsInZoneIter>;
+using SweepGroupRealmsIter =
+    CompartmentsOrRealmsIterT<SweepGroupZonesIter, RealmsInZoneIter>;
+
+// Iterate the free cells in an arena. See also ArenaCellIter which iterates
+// the allocated cells.
+class ArenaFreeCellIter {
+  Arena* arena;
+  size_t thingSize;
+  FreeSpan span;
+  uint_fast16_t thing;
+
+ public:
+  explicit ArenaFreeCellIter(Arena* arena)
+      : arena(arena),
+        thingSize(arena->getThingSize()),
+        span(*arena->getFirstFreeSpan()),
+        thing(span.first) {
+    MOZ_ASSERT(arena);
+    MOZ_ASSERT(thing < ArenaSize);
+  }
+
+  bool done() const {
+    MOZ_ASSERT(thing < ArenaSize);
+    return !thing;
+  }
+
+  TenuredCell* get() const {
+    MOZ_ASSERT(!done());
+    return reinterpret_cast<TenuredCell*>(uintptr_t(arena) + thing);
+  }
+
+  void next() {
+    MOZ_ASSERT(!done());
+    MOZ_ASSERT(thing >= span.first && thing <= span.last);
+
+    if (thing == span.last) {
+      span = *span.nextSpan(arena);
+      thing = span.first;
+    } else {
+      thing += thingSize;
+    }
+
+    MOZ_ASSERT(thing < ArenaSize);
+  }
+
+  operator TenuredCell*() const { return get(); }
+  TenuredCell* operator->() const { return get(); }
+};
+
+}  // namespace js::gc
+
+#endif  // gc_PrivateIterators_inl_h