Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 251 insertions, 0 deletions

diff --git a/js/src/vm/PropMap-inl.h b/js/src/vm/PropMap-inl.h
new file mode 100644
index 0000000000..f45e1abb4e
--- /dev/null
+++ b/js/src/vm/PropMap-inl.h
@@ -0,0 +1,251 @@
+/* -*- 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/. */
+
+#ifndef vm_PropMap_inl_h
+#define vm_PropMap_inl_h
+
+#include "vm/PropMap.h"
+
+#include "gc/Cell.h"
+#include "gc/Zone.h"
+#include "vm/JSContext.h"
+
+#include "gc/GCContext-inl.h"
+
+namespace js {
+
+inline AutoKeepPropMapTables::AutoKeepPropMapTables(JSContext* cx)
+    : cx_(cx), prev_(cx->zone()->keepPropMapTables()) {
+  cx->zone()->setKeepPropMapTables(true);
+}
+
+inline AutoKeepPropMapTables::~AutoKeepPropMapTables() {
+  cx_->zone()->setKeepPropMapTables(prev_);
+}
+
+// static
+MOZ_ALWAYS_INLINE PropMap* PropMap::lookupLinear(uint32_t mapLength,
+                                                 PropertyKey key,
+                                                 uint32_t* index) {
+  MOZ_ASSERT(mapLength > 0);
+  MOZ_ASSERT(mapLength <= Capacity);
+
+  // This function is very hot, so we use a macro to manually unroll the lookups
+  // below. Some compilers are able to unroll the equivalent loops, but they're
+  // not very consistent about this. The code below results in reasonable code
+  // with all compilers we tested.
+
+  static_assert(PropMap::Capacity == 8,
+                "Code below needs to change when capacity changes");
+
+#define LOOKUP_KEY(idx)                        \
+  if (mapLength > idx && getKey(idx) == key) { \
+    *index = idx;                              \
+    return this;                               \
+  }
+  LOOKUP_KEY(0);
+  LOOKUP_KEY(1);
+  LOOKUP_KEY(2);
+  LOOKUP_KEY(3);
+  LOOKUP_KEY(4);
+  LOOKUP_KEY(5);
+  LOOKUP_KEY(6);
+  LOOKUP_KEY(7);
+#undef LOOKUP_KEY
+
+  PropMap* map = this;
+  while (map->hasPrevious()) {
+    map = map->asLinked()->previous();
+#define LOOKUP_KEY(idx)          \
+  if (map->getKey(idx) == key) { \
+    *index = idx;                \
+    return map;                  \
+  }
+    LOOKUP_KEY(0);
+    LOOKUP_KEY(1);
+    LOOKUP_KEY(2);
+    LOOKUP_KEY(3);
+    LOOKUP_KEY(4);
+    LOOKUP_KEY(5);
+    LOOKUP_KEY(6);
+    LOOKUP_KEY(7);
+#undef LOOKUP_INDEX
+  }
+
+  return nullptr;
+}
+
+MOZ_ALWAYS_INLINE PropMap* PropMapTable::lookup(PropMap* map,
+                                                uint32_t mapLength,
+                                                PropertyKey key,
+                                                uint32_t* index) {
+  JS::AutoCheckCannotGC nogc;
+  MOZ_ASSERT(map->asLinked()->maybeTable(nogc) == this);
+
+  PropMapAndIndex entry;
+  if (lookupInCache(key, &entry)) {
+    if (entry.isNone()) {
+      return nullptr;
+    }
+  } else {
+    auto p = lookupRaw(key);
+    addToCache(key, p);
+    if (!p) {
+      return nullptr;
+    }
+    entry = *p;
+  }
+
+  // For the last map, only properties in [0, mapLength) are part of the object.
+  if (entry.map() == map && entry.index() >= mapLength) {
+    return nullptr;
+  }
+
+  *index = entry.index();
+  return entry.map();
+}
+
+// static
+MOZ_ALWAYS_INLINE PropMap* PropMap::lookupPure(uint32_t mapLength,
+                                               PropertyKey key,
+                                               uint32_t* index) {
+  if (canHaveTable()) {
+    JS::AutoCheckCannotGC nogc;
+    if (PropMapTable* table = asLinked()->maybeTable(nogc)) {
+      return table->lookup(this, mapLength, key, index);
+    }
+  }
+
+  return lookupLinear(mapLength, key, index);
+}
+
+// static
+MOZ_ALWAYS_INLINE PropMap* PropMap::lookup(JSContext* cx, uint32_t mapLength,
+                                           PropertyKey key, uint32_t* index) {
+  if (canHaveTable()) {
+    JS::AutoCheckCannotGC nogc;
+    if (PropMapTable* table = asLinked()->ensureTable(cx, nogc);
+        MOZ_LIKELY(table)) {
+      return table->lookup(this, mapLength, key, index);
+    }
+    // OOM. Do a linear lookup.
+    cx->recoverFromOutOfMemory();
+  }
+
+  return lookupLinear(mapLength, key, index);
+}
+
+// static
+inline void SharedPropMap::getPrevious(MutableHandle<SharedPropMap*> map,
+                                       uint32_t* mapLength) {
+  // Update the map/mapLength pointers to "remove" the last property. In most
+  // cases we can simply decrement *mapLength, but if *mapLength is 1 we have to
+  // either start at the previous map or set map/mapLength to nullptr/zero
+  // (if there is just one property).
+
+  MOZ_ASSERT(map);
+  MOZ_ASSERT(*mapLength > 0);
+
+  if (*mapLength > 1) {
+    *mapLength -= 1;
+    return;
+  }
+
+  if (map->hasPrevious()) {
+    map.set(map->asNormal()->previous());
+    *mapLength = PropMap::Capacity;
+    return;
+  }
+
+  map.set(nullptr);
+  *mapLength = 0;
+}
+
+// static
+inline bool PropMap::lookupForRemove(JSContext* cx, PropMap* map,
+                                     uint32_t mapLength, PropertyKey key,
+                                     const AutoKeepPropMapTables& keep,
+                                     PropMap** propMap, uint32_t* propIndex,
+                                     PropMapTable** table,
+                                     PropMapTable::Ptr* ptr) {
+  if (map->isDictionary()) {
+    *table = map->asLinked()->ensureTable(cx, keep);
+    if (!*table) {
+      return false;
+    }
+    *ptr = (*table)->lookupRaw(key);
+    *propMap = *ptr ? (*ptr)->map() : nullptr;
+    *propIndex = *ptr ? (*ptr)->index() : 0;
+    return true;
+  }
+
+  *table = nullptr;
+  *propMap = map->lookup(cx, mapLength, key, propIndex);
+  return true;
+}
+
+MOZ_ALWAYS_INLINE bool SharedPropMap::shouldConvertToDictionaryForAdd() const {
+  if (MOZ_LIKELY(numPreviousMaps() < NumPrevMapsConsiderDictionary)) {
+    return false;
+  }
+  if (numPreviousMaps() >= NumPrevMapsAlwaysDictionary) {
+    return true;
+  }
+
+  // More heuristics: if one of the last two maps has had a dictionary
+  // conversion before, or is branchy (indicated by parent != previous), convert
+  // to dictionary.
+  const SharedPropMap* curMap = this;
+  for (size_t i = 0; i < 2; i++) {
+    if (curMap->hadDictionaryConversion()) {
+      return true;
+    }
+    if (curMap->treeDataRef().parent.map() != curMap->asNormal()->previous()) {
+      return true;
+    }
+    curMap = curMap->asNormal()->previous();
+  }
+  return false;
+}
+
+inline void SharedPropMap::sweep(JS::GCContext* gcx) {
+  // We detach the child from the parent if the parent is reachable.
+  //
+  // This test depends on PropMap arenas not being freed until after we finish
+  // incrementally sweeping them. If that were not the case the parent pointer
+  // could point to a marked cell that had been deallocated and then
+  // reallocated, since allocating a cell in a zone that is being marked will
+  // set the mark bit for that cell.
+
+  MOZ_ASSERT(zone()->isGCSweeping());
+  MOZ_ASSERT_IF(hasPrevious(), asLinked()->previous()->zone() == zone());
+
+  SharedPropMapAndIndex parent = treeDataRef().parent;
+  if (!parent.isNone() && TenuredThingIsMarkedAny(parent.map())) {
+    parent.map()->removeChild(gcx, this);
+  }
+}
+
+inline void SharedPropMap::finalize(JS::GCContext* gcx) {
+  if (canHaveTable() && asLinked()->hasTable()) {
+    asLinked()->purgeTable(gcx);
+  }
+  if (hasChildrenSet()) {
+    SharedChildrenPtr& childrenRef = treeDataRef().children;
+    gcx->delete_(this, childrenRef.toChildrenSet(), MemoryUse::PropMapChildren);
+    childrenRef.setNone();
+  }
+}
+
+inline void DictionaryPropMap::finalize(JS::GCContext* gcx) {
+  if (asLinked()->hasTable()) {
+    asLinked()->purgeTable(gcx);
+  }
+}
+
+}  // namespace js
+
+#endif /* vm_PropMap_inl_h */