1 files changed, 172 insertions, 0 deletions
diff --git a/js/src/gc/Nursery-inl.h b/js/src/gc/Nursery-inl.h
new file mode 100644
index 0000000000..48f25a536e
--- /dev/null
+++ b/js/src/gc/Nursery-inl.h
@@ -0,0 +1,172 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=4 sw=2 et tw=80 ft=cpp:
+ *
+ * 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/. */
+
+#ifndef gc_Nursery_inl_h
+#define gc_Nursery_inl_h
+
+#include "gc/Nursery.h"
+
+#include "gc/RelocationOverlay.h"
+#include "js/TracingAPI.h"
+#include "vm/JSContext.h"
+#include "vm/Runtime.h"
+
+#include "vm/JSContext-inl.h"
+
+inline JSRuntime* js::Nursery::runtime() const { return gc->rt; }
+
+template <typename T>
+bool js::Nursery::isInside(const SharedMem<T>& p) const {
+  return isInside(p.unwrap(/*safe - used for value in comparison above*/));
+}
+
+MOZ_ALWAYS_INLINE /* static */ bool js::Nursery::getForwardedPointer(
+    js::gc::Cell** ref) {
+  js::gc::Cell* cell = (*ref);
+  MOZ_ASSERT(IsInsideNursery(cell));
+  if (!cell->isForwarded()) {
+    return false;
+  }
+  const gc::RelocationOverlay* overlay = gc::RelocationOverlay::fromCell(cell);
+  *ref = overlay->forwardingAddress();
+  return true;
+}
+
+inline void js::Nursery::maybeSetForwardingPointer(JSTracer* trc, void* oldData,
+                                                   void* newData, bool direct) {
+  if (trc->isTenuringTracer()) {
+    setForwardingPointerWhileTenuring(oldData, newData, direct);
+  }
+}
+
+inline void js::Nursery::setForwardingPointerWhileTenuring(void* oldData,
+                                                           void* newData,
+                                                           bool direct) {
+  if (isInside(oldData)) {
+    setForwardingPointer(oldData, newData, direct);
+  }
+}
+
+inline void js::Nursery::setSlotsForwardingPointer(HeapSlot* oldSlots,
+                                                   HeapSlot* newSlots,
+                                                   uint32_t nslots) {
+  // Slot arrays always have enough space for a forwarding pointer, since the
+  // number of slots is never zero.
+  MOZ_ASSERT(nslots > 0);
+  setDirectForwardingPointer(oldSlots, newSlots);
+}
+
+inline void js::Nursery::setElementsForwardingPointer(ObjectElements* oldHeader,
+                                                      ObjectElements* newHeader,
+                                                      uint32_t capacity) {
+  // Only use a direct forwarding pointer if there is enough space for one.
+  setForwardingPointer(oldHeader->elements(), newHeader->elements(),
+                       capacity > 0);
+}
+
+inline void js::Nursery::setForwardingPointer(void* oldData, void* newData,
+                                              bool direct) {
+  if (direct) {
+    setDirectForwardingPointer(oldData, newData);
+    return;
+  }
+
+  setIndirectForwardingPointer(oldData, newData);
+}
+
+inline void js::Nursery::setDirectForwardingPointer(void* oldData,
+                                                    void* newData) {
+  MOZ_ASSERT(isInside(oldData));
+  MOZ_ASSERT(!isInside(newData));
+
+  new (oldData) BufferRelocationOverlay{newData};
+}
+
+namespace js {
+
+// The allocation methods below will not run the garbage collector. If the
+// nursery cannot accomodate the allocation, the malloc heap will be used
+// instead.
+
+template <typename T>
+static inline T* AllocateObjectBuffer(JSContext* cx, uint32_t count) {
+  size_t nbytes = RoundUp(count * sizeof(T), sizeof(Value));
+  auto* buffer =
+      static_cast<T*>(cx->nursery().allocateBuffer(cx->zone(), nbytes));
+  if (!buffer) {
+    ReportOutOfMemory(cx);
+  }
+  return buffer;
+}
+
+template <typename T>
+static inline T* AllocateObjectBuffer(JSContext* cx, JSObject* obj,
+                                      uint32_t count) {
+  MOZ_ASSERT(cx->isMainThreadContext());
+
+  size_t nbytes = RoundUp(count * sizeof(T), sizeof(Value));
+  auto* buffer =
+      static_cast<T*>(cx->nursery().allocateBuffer(cx->zone(), obj, nbytes));
+  if (!buffer) {
+    ReportOutOfMemory(cx);
+  }
+  return buffer;
+}
+
+// If this returns null then the old buffer will be left alone.
+template <typename T>
+static inline T* ReallocateObjectBuffer(JSContext* cx, JSObject* obj,
+                                        T* oldBuffer, uint32_t oldCount,
+                                        uint32_t newCount) {
+  MOZ_ASSERT(cx->isMainThreadContext());
+
+  T* buffer = static_cast<T*>(cx->nursery().reallocateBuffer(
+      obj->zone(), obj, oldBuffer, oldCount * sizeof(T), newCount * sizeof(T)));
+  if (!buffer) {
+    ReportOutOfMemory(cx);
+  }
+
+  return buffer;
+}
+
+static inline JS::BigInt::Digit* AllocateBigIntDigits(JSContext* cx,
+                                                      JS::BigInt* bi,
+                                                      uint32_t length) {
+  MOZ_ASSERT(cx->isMainThreadContext());
+
+  size_t nbytes = RoundUp(length * sizeof(JS::BigInt::Digit), sizeof(Value));
+  auto* digits =
+      static_cast<JS::BigInt::Digit*>(cx->nursery().allocateBuffer(bi, nbytes));
+  if (!digits) {
+    ReportOutOfMemory(cx);
+  }
+
+  return digits;
+}
+
+static inline JS::BigInt::Digit* ReallocateBigIntDigits(
+    JSContext* cx, JS::BigInt* bi, JS::BigInt::Digit* oldDigits,
+    uint32_t oldLength, uint32_t newLength) {
+  MOZ_ASSERT(cx->isMainThreadContext());
+
+  size_t oldBytes =
+      RoundUp(oldLength * sizeof(JS::BigInt::Digit), sizeof(Value));
+  size_t newBytes =
+      RoundUp(newLength * sizeof(JS::BigInt::Digit), sizeof(Value));
+
+  auto* digits = static_cast<JS::BigInt::Digit*>(cx->nursery().reallocateBuffer(
+      bi->zone(), bi, oldDigits, oldBytes, newBytes));
+  if (!digits) {
+    ReportOutOfMemory(cx);
+  }
+
+  return digits;
+}
+
+}  // namespace js
+
+#endif /* gc_Nursery_inl_h */