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Diffstat (limited to 'dom/heapsnapshot/HeapSnapshot.h')
| -rw-r--r-- | dom/heapsnapshot/HeapSnapshot.h | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/dom/heapsnapshot/HeapSnapshot.h b/dom/heapsnapshot/HeapSnapshot.h new file mode 100644 index 000000000..12dfa4c2b --- /dev/null +++ b/dom/heapsnapshot/HeapSnapshot.h @@ -0,0 +1,224 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* 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 mozilla_devtools_HeapSnapshot__ +#define mozilla_devtools_HeapSnapshot__ + +#include "js/HashTable.h" +#include "mozilla/ErrorResult.h" +#include "mozilla/devtools/DeserializedNode.h" +#include "mozilla/dom/BindingDeclarations.h" +#include "mozilla/dom/Nullable.h" +#include "mozilla/HashFunctions.h" +#include "mozilla/Maybe.h" +#include "mozilla/RefCounted.h" +#include "mozilla/RefPtr.h" +#include "mozilla/TimeStamp.h" +#include "mozilla/UniquePtr.h" + +#include "CoreDump.pb.h" +#include "nsCOMPtr.h" +#include "nsCRTGlue.h" +#include "nsCycleCollectionParticipant.h" +#include "nsISupports.h" +#include "nsWrapperCache.h" +#include "nsXPCOM.h" + +namespace mozilla { +namespace devtools { + +class DominatorTree; + +struct NSFreePolicy { + void operator()(void* ptr) { + NS_Free(ptr); + } +}; + +using UniqueTwoByteString = UniquePtr<char16_t[], NSFreePolicy>; +using UniqueOneByteString = UniquePtr<char[], NSFreePolicy>; + +class HeapSnapshot final : public nsISupports + , public nsWrapperCache +{ + friend struct DeserializedNode; + friend struct DeserializedEdge; + friend struct DeserializedStackFrame; + friend class JS::ubi::Concrete<JS::ubi::DeserializedNode>; + + explicit HeapSnapshot(JSContext* cx, nsISupports* aParent) + : timestamp(Nothing()) + , rootId(0) + , nodes(cx) + , frames(cx) + , mParent(aParent) + { + MOZ_ASSERT(aParent); + }; + + // Initialize this HeapSnapshot from the given buffer that contains a + // serialized core dump. Do NOT take ownership of the buffer, only borrow it + // for the duration of the call. Return false on failure. + bool init(JSContext* cx, const uint8_t* buffer, uint32_t size); + + using NodeIdSet = js::HashSet<NodeId>; + + // Save the given `protobuf::Node` message in this `HeapSnapshot` as a + // `DeserializedNode`. + bool saveNode(const protobuf::Node& node, NodeIdSet& edgeReferents); + + // Save the given `protobuf::StackFrame` message in this `HeapSnapshot` as a + // `DeserializedStackFrame`. The saved stack frame's id is returned via the + // out parameter. + bool saveStackFrame(const protobuf::StackFrame& frame, + StackFrameId& outFrameId); + +public: + // The maximum number of stack frames that we will serialize into a core + // dump. This helps prevent over-recursion in the protobuf library when + // deserializing stacks. + static const size_t MAX_STACK_DEPTH = 60; + +private: + // If present, a timestamp in the same units that `PR_Now` gives. + Maybe<uint64_t> timestamp; + + // The id of the root node for this deserialized heap graph. + NodeId rootId; + + // The set of nodes in this deserialized heap graph, keyed by id. + using NodeSet = js::HashSet<DeserializedNode, DeserializedNode::HashPolicy>; + NodeSet nodes; + + // The set of stack frames in this deserialized heap graph, keyed by id. + using FrameSet = js::HashSet<DeserializedStackFrame, + DeserializedStackFrame::HashPolicy>; + FrameSet frames; + + Vector<UniqueTwoByteString> internedTwoByteStrings; + Vector<UniqueOneByteString> internedOneByteStrings; + + using StringOrRef = Variant<const std::string*, uint64_t>; + + template<typename CharT, + typename InternedStringSet> + const CharT* getOrInternString(InternedStringSet& internedStrings, + Maybe<StringOrRef>& maybeStrOrRef); + +protected: + nsCOMPtr<nsISupports> mParent; + + virtual ~HeapSnapshot() { } + +public: + // Create a `HeapSnapshot` from the given buffer that contains a serialized + // core dump. Do NOT take ownership of the buffer, only borrow it for the + // duration of the call. + static already_AddRefed<HeapSnapshot> Create(JSContext* cx, + dom::GlobalObject& global, + const uint8_t* buffer, + uint32_t size, + ErrorResult& rv); + + // Creates the `$TEMP_DIR/XXXXXX-XXX.fxsnapshot` core dump file that heap + // snapshots are serialized into. + static already_AddRefed<nsIFile> CreateUniqueCoreDumpFile(ErrorResult& rv, + const TimeStamp& now, + nsAString& outFilePath); + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(HeapSnapshot) + MOZ_DECLARE_REFCOUNTED_TYPENAME(HeapSnapshot) + + nsISupports* GetParentObject() const { return mParent; } + + virtual JSObject* WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) override; + + const char16_t* borrowUniqueString(const char16_t* duplicateString, + size_t length); + + // Get the root node of this heap snapshot's graph. + JS::ubi::Node getRoot() { + MOZ_ASSERT(nodes.initialized()); + auto p = nodes.lookup(rootId); + MOZ_ASSERT(p); + const DeserializedNode& node = *p; + return JS::ubi::Node(const_cast<DeserializedNode*>(&node)); + } + + Maybe<JS::ubi::Node> getNodeById(JS::ubi::Node::Id nodeId) { + auto p = nodes.lookup(nodeId); + if (!p) + return Nothing(); + return Some(JS::ubi::Node(const_cast<DeserializedNode*>(&*p))); + } + + void TakeCensus(JSContext* cx, JS::HandleObject options, + JS::MutableHandleValue rval, ErrorResult& rv); + + void DescribeNode(JSContext* cx, JS::HandleObject breakdown, uint64_t nodeId, + JS::MutableHandleValue rval, ErrorResult& rv); + + already_AddRefed<DominatorTree> ComputeDominatorTree(ErrorResult& rv); + + void ComputeShortestPaths(JSContext*cx, uint64_t start, + const dom::Sequence<uint64_t>& targets, + uint64_t maxNumPaths, + JS::MutableHandleObject results, + ErrorResult& rv); + + dom::Nullable<uint64_t> GetCreationTime() { + static const uint64_t maxTime = uint64_t(1) << 53; + if (timestamp.isSome() && timestamp.ref() <= maxTime) { + return dom::Nullable<uint64_t>(timestamp.ref()); + } + + return dom::Nullable<uint64_t>(); + } +}; + +// A `CoreDumpWriter` is given the data we wish to save in a core dump and +// serializes it to disk, or memory, or a socket, etc. +class CoreDumpWriter +{ +public: + virtual ~CoreDumpWriter() { }; + + // Write the given bits of metadata we would like to associate with this core + // dump. + virtual bool writeMetadata(uint64_t timestamp) = 0; + + enum EdgePolicy : bool { + INCLUDE_EDGES = true, + EXCLUDE_EDGES = false + }; + + // Write the given `JS::ubi::Node` to the core dump. The given `EdgePolicy` + // dictates whether its outgoing edges should also be written to the core + // dump, or excluded. + virtual bool writeNode(const JS::ubi::Node& node, + EdgePolicy includeEdges) = 0; +}; + +// Serialize the heap graph as seen from `node` with the given `CoreDumpWriter`. +// If `wantNames` is true, capture edge names. If `zones` is non-null, only +// capture the sub-graph within the zone set, otherwise capture the whole heap +// graph. Returns false on failure. +bool +WriteHeapGraph(JSContext* cx, + const JS::ubi::Node& node, + CoreDumpWriter& writer, + bool wantNames, + JS::CompartmentSet* compartments, + JS::AutoCheckCannotGC& noGC); + +// Get the mozilla::MallocSizeOf for the current thread's JSRuntime. +MallocSizeOf GetCurrentThreadDebuggerMallocSizeOf(); + +} // namespace devtools +} // namespace mozilla + +#endif // mozilla_devtools_HeapSnapshot__ |