1 files changed, 324 insertions, 0 deletions
diff --git a/tools/memory-profiler/MemoryProfiler.cpp b/tools/memory-profiler/MemoryProfiler.cpp
new file mode 100644
index 000000000..c2b8cbd1d
--- /dev/null
+++ b/tools/memory-profiler/MemoryProfiler.cpp
@@ -0,0 +1,324 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=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/. */
+
+#include "MemoryProfiler.h"
+
+#include <cmath>
+#include <cstdlib>
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Move.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtr.h"
+
+#include "GCHeapProfilerImpl.h"
+#include "GeckoProfiler.h"
+#include "NativeProfilerImpl.h"
+#include "UncensoredAllocator.h"
+#include "js/TypeDecls.h"
+#include "jsfriendapi.h"
+#include "nsIDOMClassInfo.h"
+#include "nsIGlobalObject.h"
+#include "prtime.h"
+#include "xpcprivate.h"
+
+namespace mozilla {
+
+#define MEMORY_PROFILER_SAMPLE_SIZE 65536
+#define BACKTRACE_BUFFER_SIZE 16384
+
+ProfilerImpl::ProfilerImpl()
+  : mSampleSize(MEMORY_PROFILER_SAMPLE_SIZE)
+{
+  mLog1minusP = std::log(1.0 - 1.0 / mSampleSize);
+  mRemainingBytes = std::floor(std::log(1.0 - DRandom()) / mLog1minusP);
+}
+
+nsTArray<nsCString>
+ProfilerImpl::GetStacktrace()
+{
+  nsTArray<nsCString> trace;
+  auto output = MakeUnique<char[]>(BACKTRACE_BUFFER_SIZE);
+
+  profiler_get_backtrace_noalloc(output.get(), BACKTRACE_BUFFER_SIZE);
+  for (const char* p = output.get(); *p; p += strlen(p) + 1) {
+    trace.AppendElement()->Assign(p);
+  }
+
+  return trace;
+}
+
+// Generate a random number in [0, 1).
+double
+ProfilerImpl::DRandom()
+{
+  return double(((uint64_t(std::rand()) & ((1 << 26) - 1)) << 27) +
+                (uint64_t(std::rand()) & ((1 << 27) - 1)))
+    / (uint64_t(1) << 53);
+}
+
+size_t
+ProfilerImpl::AddBytesSampled(uint32_t aBytes)
+{
+  size_t nSamples = 0;
+  while (mRemainingBytes <= aBytes) {
+    mRemainingBytes += std::floor(std::log(1.0 - DRandom()) / mLog1minusP);
+    nSamples++;
+  }
+  mRemainingBytes -= aBytes;
+  return nSamples;
+}
+
+NS_IMPL_ISUPPORTS(MemoryProfiler, nsIMemoryProfiler)
+
+PRLock* MemoryProfiler::sLock;
+uint32_t MemoryProfiler::sProfileContextCount;
+StaticAutoPtr<NativeProfilerImpl> MemoryProfiler::sNativeProfiler;
+StaticAutoPtr<JSContextProfilerMap> MemoryProfiler::sJSContextProfilerMap;
+TimeStamp MemoryProfiler::sStartTime;
+
+void
+MemoryProfiler::InitOnce()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  static bool initialized = false;
+
+  if (!initialized) {
+    MallocHook::Initialize();
+    sLock = PR_NewLock();
+    sProfileContextCount = 0;
+    sJSContextProfilerMap = new JSContextProfilerMap();
+    ClearOnShutdown(&sJSContextProfilerMap);
+    ClearOnShutdown(&sNativeProfiler);
+    std::srand(PR_Now());
+    bool ignored;
+    sStartTime = TimeStamp::ProcessCreation(ignored);
+    initialized = true;
+  }
+}
+
+NS_IMETHODIMP
+MemoryProfiler::StartProfiler()
+{
+  InitOnce();
+  AutoUseUncensoredAllocator ua;
+  AutoMPLock lock(sLock);
+  JSContext* context = XPCJSContext::Get()->Context();
+  ProfilerForJSContext profiler;
+  if (!sJSContextProfilerMap->Get(context, &profiler) ||
+      !profiler.mEnabled) {
+    if (sProfileContextCount == 0) {
+      js::EnableContextProfilingStack(context, true);
+      if (!sNativeProfiler) {
+        sNativeProfiler = new NativeProfilerImpl();
+      }
+      MemProfiler::SetNativeProfiler(sNativeProfiler);
+    }
+    GCHeapProfilerImpl* gp = new GCHeapProfilerImpl();
+    profiler.mEnabled = true;
+    profiler.mProfiler = gp;
+    sJSContextProfilerMap->Put(context, profiler);
+    MemProfiler::GetMemProfiler(context)->start(gp);
+    if (sProfileContextCount == 0) {
+      MallocHook::Enable(sNativeProfiler);
+    }
+    sProfileContextCount++;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+MemoryProfiler::StopProfiler()
+{
+  InitOnce();
+  AutoUseUncensoredAllocator ua;
+  AutoMPLock lock(sLock);
+  JSContext* context = XPCJSContext::Get()->Context();
+  ProfilerForJSContext profiler;
+  if (sJSContextProfilerMap->Get(context, &profiler) &&
+      profiler.mEnabled) {
+    MemProfiler::GetMemProfiler(context)->stop();
+    if (--sProfileContextCount == 0) {
+      MallocHook::Disable();
+      MemProfiler::SetNativeProfiler(nullptr);
+      js::EnableContextProfilingStack(context, false);
+    }
+    profiler.mEnabled = false;
+    sJSContextProfilerMap->Put(context, profiler);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+MemoryProfiler::ResetProfiler()
+{
+  InitOnce();
+  AutoUseUncensoredAllocator ua;
+  AutoMPLock lock(sLock);
+  JSContext* context = XPCJSContext::Get()->Context();
+  ProfilerForJSContext profiler;
+  if (!sJSContextProfilerMap->Get(context, &profiler) ||
+      !profiler.mEnabled) {
+    delete profiler.mProfiler;
+    profiler.mProfiler = nullptr;
+    sJSContextProfilerMap->Put(context, profiler);
+  }
+  if (sProfileContextCount == 0) {
+    sNativeProfiler = nullptr;
+  }
+  return NS_OK;
+}
+
+struct MergedTraces
+{
+  nsTArray<nsCString> mNames;
+  nsTArray<TrieNode> mTraces;
+  nsTArray<AllocEvent> mEvents;
+};
+
+// Merge events and corresponding traces and names.
+static MergedTraces
+MergeResults(const nsTArray<nsCString>& names0,
+             const nsTArray<TrieNode>& traces0,
+             const nsTArray<AllocEvent>& events0,
+             const nsTArray<nsCString>& names1,
+             const nsTArray<TrieNode>& traces1,
+             const nsTArray<AllocEvent>& events1)
+{
+  NodeIndexMap<nsCStringHashKey, nsCString> names;
+  NodeIndexMap<nsGenericHashKey<TrieNode>, TrieNode> traces;
+  nsTArray<AllocEvent> events;
+
+  nsTArray<size_t> names1Tonames0(names1.Length());
+  nsTArray<size_t> traces1Totraces0(traces1.Length());
+
+  // Merge names.
+  for (auto& i: names0) {
+    names.Insert(i);
+  }
+  for (auto& i: names1) {
+    names1Tonames0.AppendElement(names.Insert(i));
+  }
+
+  // Merge traces. Note that traces1[i].parentIdx < i for all i > 0.
+  for (auto& i: traces0) {
+    traces.Insert(i);
+  }
+  traces1Totraces0.AppendElement(0);
+  for (size_t i = 1; i < traces1.Length(); i++) {
+    TrieNode node = traces1[i];
+    node.parentIdx = traces1Totraces0[node.parentIdx];
+    node.nameIdx = names1Tonames0[node.nameIdx];
+    traces1Totraces0.AppendElement(traces.Insert(node));
+  }
+
+  // Merge the events according to timestamps.
+  auto p0 = events0.begin();
+  auto p1 = events1.begin();
+
+  while (p0 != events0.end() && p1 != events1.end()) {
+    if (p0->mTimestamp < p1->mTimestamp) {
+      events.AppendElement(*p0++);
+    } else {
+      events.AppendElement(*p1++);
+      events.LastElement().mTraceIdx =
+        traces1Totraces0[events.LastElement().mTraceIdx];
+    }
+  }
+
+  while (p0 != events0.end()) {
+    events.AppendElement(*p0++);
+  }
+
+  while (p1 != events1.end()) {
+    events.AppendElement(*p1++);
+    events.LastElement().mTraceIdx =
+      traces1Totraces0[events.LastElement().mTraceIdx];
+  }
+
+  return MergedTraces{names.Serialize(), traces.Serialize(), Move(events)};
+}
+
+NS_IMETHODIMP
+MemoryProfiler::GetResults(JSContext* cx, JS::MutableHandle<JS::Value> aResult)
+{
+  InitOnce();
+  AutoUseUncensoredAllocator ua;
+  AutoMPLock lock(sLock);
+  JSContext* context = XPCJSContext::Get()->Context();
+  // Getting results when the profiler is running is not allowed.
+  if (sProfileContextCount > 0) {
+    return NS_OK;
+  }
+  // Return immediately when native profiler does not exist.
+  if (!sNativeProfiler) {
+    return NS_OK;
+  }
+  // Return immediately when there's no result in current context.
+  ProfilerForJSContext profiler;
+  if (!sJSContextProfilerMap->Get(context, &profiler) ||
+      !profiler.mProfiler) {
+    return NS_OK;
+  }
+  GCHeapProfilerImpl* gp = profiler.mProfiler;
+
+  auto results = MergeResults(gp->GetNames(), gp->GetTraces(), gp->GetEvents(),
+                              sNativeProfiler->GetNames(),
+                              sNativeProfiler->GetTraces(),
+                              sNativeProfiler->GetEvents());
+  const nsTArray<nsCString>& names = results.mNames;
+  const nsTArray<TrieNode>& traces = results.mTraces;
+  const nsTArray<AllocEvent>& events = results.mEvents;
+
+  JS::RootedObject jsnames(cx, JS_NewArrayObject(cx, names.Length()));
+  JS::RootedObject jstraces(cx, JS_NewArrayObject(cx, traces.Length()));
+  JS::RootedObject jsevents(cx, JS_NewArrayObject(cx, events.Length()));
+
+  for (size_t i = 0; i < names.Length(); i++) {
+    JS::RootedString name(cx, JS_NewStringCopyZ(cx, names[i].get()));
+    JS_SetElement(cx, jsnames, i, name);
+  }
+
+  for (size_t i = 0; i < traces.Length(); i++) {
+    JS::RootedObject tn(cx, JS_NewPlainObject(cx));
+    JS::RootedValue nameIdx(cx, JS_NumberValue(traces[i].nameIdx));
+    JS::RootedValue parentIdx(cx, JS_NumberValue(traces[i].parentIdx));
+    JS_SetProperty(cx, tn, "nameIdx", nameIdx);
+    JS_SetProperty(cx, tn, "parentIdx", parentIdx);
+    JS_SetElement(cx, jstraces, i, tn);
+  }
+
+  int i = 0;
+  for (auto ent: events) {
+    if (ent.mSize == 0) {
+      continue;
+    }
+    MOZ_ASSERT(!sStartTime.IsNull());
+    double time = (ent.mTimestamp - sStartTime).ToMilliseconds();
+    JS::RootedObject tn(cx, JS_NewPlainObject(cx));
+    JS::RootedValue size(cx, JS_NumberValue(ent.mSize));
+    JS::RootedValue traceIdx(cx, JS_NumberValue(ent.mTraceIdx));
+    JS::RootedValue timestamp(cx, JS_NumberValue(time));
+    JS_SetProperty(cx, tn, "size", size);
+    JS_SetProperty(cx, tn, "traceIdx", traceIdx);
+    JS_SetProperty(cx, tn, "timestamp", timestamp);
+    JS_SetElement(cx, jsevents, i++, tn);
+  }
+  JS_SetArrayLength(cx, jsevents, i);
+
+  JS::RootedObject result(cx, JS_NewPlainObject(cx));
+  JS::RootedValue objnames(cx, ObjectOrNullValue(jsnames));
+  JS_SetProperty(cx, result, "names", objnames);
+  JS::RootedValue objtraces(cx, ObjectOrNullValue(jstraces));
+  JS_SetProperty(cx, result, "traces", objtraces);
+  JS::RootedValue objevents(cx, ObjectOrNullValue(jsevents));
+  JS_SetProperty(cx, result, "events", objevents);
+  aResult.setObject(*result);
+  return NS_OK;
+}
+
+} // namespace mozilla