1 files changed, 145 insertions, 0 deletions
diff --git a/js/src/jsalloc.h b/js/src/jsalloc.h
new file mode 100644
index 000000000..7805c5f8c
--- /dev/null
+++ b/js/src/jsalloc.h
@@ -0,0 +1,145 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+/*
+ * JS allocation policies.
+ *
+ * The allocators here are for system memory with lifetimes which are not
+ * managed by the GC. See the comment at the top of vm/MallocProvider.h.
+ */
+
+#ifndef jsalloc_h
+#define jsalloc_h
+
+#include "js/TypeDecls.h"
+#include "js/Utility.h"
+
+extern JS_PUBLIC_API(void) JS_ReportOutOfMemory(JSContext* cx);
+
+namespace js {
+
+enum class AllocFunction {
+    Malloc,
+    Calloc,
+    Realloc
+};
+
+struct ContextFriendFields;
+
+/* Policy for using system memory functions and doing no error reporting. */
+class SystemAllocPolicy
+{
+  public:
+    template <typename T> T* maybe_pod_malloc(size_t numElems) { return js_pod_malloc<T>(numElems); }
+    template <typename T> T* maybe_pod_calloc(size_t numElems) { return js_pod_calloc<T>(numElems); }
+    template <typename T> T* maybe_pod_realloc(T* p, size_t oldSize, size_t newSize) {
+        return js_pod_realloc<T>(p, oldSize, newSize);
+    }
+    template <typename T> T* pod_malloc(size_t numElems) { return maybe_pod_malloc<T>(numElems); }
+    template <typename T> T* pod_calloc(size_t numElems) { return maybe_pod_calloc<T>(numElems); }
+    template <typename T> T* pod_realloc(T* p, size_t oldSize, size_t newSize) {
+        return maybe_pod_realloc<T>(p, oldSize, newSize);
+    }
+    void free_(void* p) { js_free(p); }
+    void reportAllocOverflow() const {}
+    bool checkSimulatedOOM() const {
+        return !js::oom::ShouldFailWithOOM();
+    }
+};
+
+class ExclusiveContext;
+JS_FRIEND_API(void) ReportOutOfMemory(ExclusiveContext* cxArg);
+
+/*
+ * Allocation policy that calls the system memory functions and reports errors
+ * to the context. Since the JSContext given on construction is stored for
+ * the lifetime of the container, this policy may only be used for containers
+ * whose lifetime is a shorter than the given JSContext.
+ *
+ * FIXME bug 647103 - rewrite this in terms of temporary allocation functions,
+ * not the system ones.
+ */
+class TempAllocPolicy
+{
+    ContextFriendFields* const cx_;
+
+    /*
+     * Non-inline helper to call JSRuntime::onOutOfMemory with minimal
+     * code bloat.
+     */
+    JS_FRIEND_API(void*) onOutOfMemory(AllocFunction allocFunc, size_t nbytes,
+                                       void* reallocPtr = nullptr);
+
+    template <typename T>
+    T* onOutOfMemoryTyped(AllocFunction allocFunc, size_t numElems, void* reallocPtr = nullptr) {
+        size_t bytes;
+        if (MOZ_UNLIKELY(!CalculateAllocSize<T>(numElems, &bytes)))
+            return nullptr;
+        return static_cast<T*>(onOutOfMemory(allocFunc, bytes, reallocPtr));
+    }
+
+  public:
+    MOZ_IMPLICIT TempAllocPolicy(JSContext* cx) : cx_((ContextFriendFields*) cx) {} // :(
+    MOZ_IMPLICIT TempAllocPolicy(ContextFriendFields* cx) : cx_(cx) {}
+
+    template <typename T>
+    T* maybe_pod_malloc(size_t numElems) {
+        return js_pod_malloc<T>(numElems);
+    }
+
+    template <typename T>
+    T* maybe_pod_calloc(size_t numElems) {
+        return js_pod_calloc<T>(numElems);
+    }
+
+    template <typename T>
+    T* maybe_pod_realloc(T* prior, size_t oldSize, size_t newSize) {
+        return js_pod_realloc<T>(prior, oldSize, newSize);
+    }
+
+    template <typename T>
+    T* pod_malloc(size_t numElems) {
+        T* p = maybe_pod_malloc<T>(numElems);
+        if (MOZ_UNLIKELY(!p))
+            p = onOutOfMemoryTyped<T>(AllocFunction::Malloc, numElems);
+        return p;
+    }
+
+    template <typename T>
+    T* pod_calloc(size_t numElems) {
+        T* p = maybe_pod_calloc<T>(numElems);
+        if (MOZ_UNLIKELY(!p))
+            p = onOutOfMemoryTyped<T>(AllocFunction::Calloc, numElems);
+        return p;
+    }
+
+    template <typename T>
+    T* pod_realloc(T* prior, size_t oldSize, size_t newSize) {
+        T* p2 = maybe_pod_realloc<T>(prior, oldSize, newSize);
+        if (MOZ_UNLIKELY(!p2))
+            p2 = onOutOfMemoryTyped<T>(AllocFunction::Realloc, newSize, prior);
+        return p2;
+    }
+
+    void free_(void* p) {
+        js_free(p);
+    }
+
+    JS_FRIEND_API(void) reportAllocOverflow() const;
+
+    bool checkSimulatedOOM() const {
+        if (js::oom::ShouldFailWithOOM()) {
+            js::ReportOutOfMemory(reinterpret_cast<ExclusiveContext*>(cx_));
+            return false;
+        }
+
+        return true;
+    }
+};
+
+} /* namespace js */
+
+#endif /* jsalloc_h */