1 files changed, 77 insertions, 0 deletions
diff --git a/mozglue/baseprofiler/core/PageInformation.h b/mozglue/baseprofiler/core/PageInformation.h
new file mode 100644
index 0000000000..41808877b3
--- /dev/null
+++ b/mozglue/baseprofiler/core/PageInformation.h
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 2; 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 PageInformation_h
+#define PageInformation_h
+
+#include "mozilla/Atomics.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/MemoryReporting.h"
+
+#include <string>
+
+namespace mozilla {
+namespace baseprofiler {
+
+class SpliceableJSONWriter;
+
+// This class contains information that's relevant to a single page only
+// while the page information is important and registered with the profiler,
+// but regardless of whether the profiler is running. All accesses to it are
+// protected by the profiler state lock.
+// When the page gets unregistered, we keep the profiler buffer position
+// to determine if we are still using this page. If not, we unregister
+// it in the next page registration.
+class PageInformation final {
+ public:
+  PageInformation(uint64_t aTabID, uint64_t aInnerWindowID,
+                  const std::string& aUrl, uint64_t aEmbedderInnerWindowID);
+
+  // Using hand-rolled ref-counting, because RefCounted.h macros don't produce
+  // the same code between mozglue and libxul, see bug 1536656.
+  MFBT_API void AddRef() const { ++mRefCnt; }
+  MFBT_API void Release() const {
+    MOZ_ASSERT(int32_t(mRefCnt) > 0);
+    if (--mRefCnt) {
+      delete this;
+    }
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
+  bool Equals(PageInformation* aOtherPageInfo) const;
+  void StreamJSON(SpliceableJSONWriter& aWriter) const;
+
+  uint64_t InnerWindowID() const { return mInnerWindowID; }
+  uint64_t TabID() const { return mTabID; }
+  const std::string& Url() const { return mUrl; }
+  uint64_t EmbedderInnerWindowID() const { return mEmbedderInnerWindowID; }
+
+  Maybe<uint64_t> BufferPositionWhenUnregistered() const {
+    return mBufferPositionWhenUnregistered;
+  }
+
+  void NotifyUnregistered(uint64_t aBufferPosition) {
+    mBufferPositionWhenUnregistered = Some(aBufferPosition);
+  }
+
+ private:
+  const uint64_t mTabID;
+  const uint64_t mInnerWindowID;
+  const std::string mUrl;
+  const uint64_t mEmbedderInnerWindowID;
+
+  // Holds the buffer position when page is unregistered.
+  // It's used to determine if we still use this page in the profiler or
+  // not.
+  Maybe<uint64_t> mBufferPositionWhenUnregistered;
+
+  mutable Atomic<int32_t, MemoryOrdering::ReleaseAcquire> mRefCnt;
+};
+
+}  // namespace baseprofiler
+}  // namespace mozilla
+
+#endif  // PageInformation_h