1 files changed, 89 insertions, 0 deletions
diff --git a/tools/profiler/core/ProfileBuffer.cpp b/tools/profiler/core/ProfileBuffer.cpp
new file mode 100644
index 000000000..a4b91d8fc
--- /dev/null
+++ b/tools/profiler/core/ProfileBuffer.cpp
@@ -0,0 +1,89 @@
+/* -*- 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/. */
+
+#include "ProfileBuffer.h"
+
+ProfileBuffer::ProfileBuffer(int aEntrySize)
+  : mEntries(MakeUnique<ProfileEntry[]>(aEntrySize))
+  , mWritePos(0)
+  , mReadPos(0)
+  , mEntrySize(aEntrySize)
+  , mGeneration(0)
+{
+}
+
+ProfileBuffer::~ProfileBuffer()
+{
+  while (mStoredMarkers.peek()) {
+    delete mStoredMarkers.popHead();
+  }
+}
+
+// Called from signal, call only reentrant functions
+void ProfileBuffer::addTag(const ProfileEntry& aTag)
+{
+  mEntries[mWritePos++] = aTag;
+  if (mWritePos == mEntrySize) {
+    // Wrapping around may result in things referenced in the buffer (e.g.,
+    // JIT code addresses and markers) being incorrectly collected.
+    MOZ_ASSERT(mGeneration != UINT32_MAX);
+    mGeneration++;
+    mWritePos = 0;
+  }
+  if (mWritePos == mReadPos) {
+    // Keep one slot open.
+    mEntries[mReadPos] = ProfileEntry();
+    mReadPos = (mReadPos + 1) % mEntrySize;
+  }
+}
+
+void ProfileBuffer::addStoredMarker(ProfilerMarker *aStoredMarker) {
+  aStoredMarker->SetGeneration(mGeneration);
+  mStoredMarkers.insert(aStoredMarker);
+}
+
+void ProfileBuffer::deleteExpiredStoredMarkers() {
+  // Delete markers of samples that have been overwritten due to circular
+  // buffer wraparound.
+  uint32_t generation = mGeneration;
+  while (mStoredMarkers.peek() &&
+         mStoredMarkers.peek()->HasExpired(generation)) {
+    delete mStoredMarkers.popHead();
+  }
+}
+
+void ProfileBuffer::reset() {
+  mGeneration += 2;
+  mReadPos = mWritePos = 0;
+}
+
+#define DYNAMIC_MAX_STRING 8192
+
+char* ProfileBuffer::processDynamicTag(int readPos,
+                                       int* tagsConsumed, char* tagBuff)
+{
+  int readAheadPos = (readPos + 1) % mEntrySize;
+  int tagBuffPos = 0;
+
+  // Read the string stored in mTagData until the null character is seen
+  bool seenNullByte = false;
+  while (readAheadPos != mWritePos && !seenNullByte) {
+    (*tagsConsumed)++;
+    ProfileEntry readAheadEntry = mEntries[readAheadPos];
+    for (size_t pos = 0; pos < sizeof(void*); pos++) {
+      tagBuff[tagBuffPos] = readAheadEntry.mTagChars[pos];
+      if (tagBuff[tagBuffPos] == '\0' || tagBuffPos == DYNAMIC_MAX_STRING-2) {
+        seenNullByte = true;
+        break;
+      }
+      tagBuffPos++;
+    }
+    if (!seenNullByte)
+      readAheadPos = (readAheadPos + 1) % mEntrySize;
+  }
+  return tagBuff;
+}
+
+