Bug 1612799 - Make UniqueJSONStrings a FailureLatch - r=canaltinova

Differential Revision: https://phabricator.services.mozilla.com/D155652

mozglue/baseprofiler/core/ProfileBufferEntry.cpp

@@ -232,7 +232,8 @@ bool UniqueStacks::FrameKey::NormalFrameData::operator==(
 }
 
 UniqueStacks::UniqueStacks()
-    : mUniqueStrings(MakeUnique<UniqueJSONStrings>()),
+    : mUniqueStrings(MakeUnique<UniqueJSONStrings>(
+          FailureLatchInfallibleSource::Singleton())),
       mFrameTableWriter(FailureLatchInfallibleSource::Singleton()),
       mStackTableWriter(FailureLatchInfallibleSource::Singleton()) {
   mFrameTableWriter.StartBareList();

mozglue/baseprofiler/core/ProfileJSONWriter.cpp

@@ -8,16 +8,26 @@
 
 namespace mozilla::baseprofiler {
 
-UniqueJSONStrings::UniqueJSONStrings()
+UniqueJSONStrings::UniqueJSONStrings(FailureLatch& aFailureLatch)
-    : mStringTableWriter(FailureLatchInfallibleSource::Singleton()) {
+    : mStringTableWriter(aFailureLatch) {
   mStringTableWriter.StartBareList();
 }
 
-UniqueJSONStrings::UniqueJSONStrings(const UniqueJSONStrings& aOther,
+UniqueJSONStrings::UniqueJSONStrings(FailureLatch& aFailureLatch,
+                                     const UniqueJSONStrings& aOther,
                                      ProgressLogger aProgressLogger)
-    : mStringTableWriter(FailureLatchInfallibleSource::Singleton()) {
+    : mStringTableWriter(aFailureLatch) {
   using namespace mozilla::literals::ProportionValue_literals;  // For `10_pc`.
 
+  if (mStringTableWriter.Failed()) {
+    return;
+  }
+
+  if (const char* failure = aOther.GetFailure(); failure) {
+    mStringTableWriter.SetFailure(failure);
+    return;
+  }
+
   mStringTableWriter.StartBareList();
   uint32_t count = aOther.mStringHashToIndexMap.count();
   if (count != 0) {

mozglue/baseprofiler/public/BaseProfileJSONWriter.h

@@ -524,13 +524,14 @@ class JSONSchemaWriter {
 // and later, `u.SpliceStringTableElements(w)` (inside a JSON array), will
 // output the corresponding indexed list of unique strings:
 // `["a", "b"]`
-class UniqueJSONStrings {
+class UniqueJSONStrings final : public FailureLatch {
  public:
   // Start an empty list of unique strings.
-  MFBT_API UniqueJSONStrings();
+  MFBT_API explicit UniqueJSONStrings(FailureLatch& aFailureLatch);
 
   // Start with a copy of the strings from another list.
-  MFBT_API UniqueJSONStrings(const UniqueJSONStrings& aOther,
+  MFBT_API UniqueJSONStrings(FailureLatch& aFailureLatch,
+                             const UniqueJSONStrings& aOther,
                              ProgressLogger aProgressLogger);
 
   MFBT_API ~UniqueJSONStrings();
@@ -552,6 +553,12 @@ class UniqueJSONStrings {
   // once, and then this UniqueStrings shouldn't be used anymore.
   MFBT_API void SpliceStringTableElements(SpliceableJSONWriter& aWriter);
 
+  FAILURELATCH_IMPL_PROXY(mStringTableWriter)
+
+  void ChangeFailureLatchAndForwardState(FailureLatch& aFailureLatch) {
+    mStringTableWriter.ChangeFailureLatchAndForwardState(aFailureLatch);
+  }
+
  private:
   // If `aStr` is already listed, return its index.
   // Otherwise add it to the list and return the new index.

mozglue/tests/TestBaseProfiler.cpp

@@ -5126,9 +5126,20 @@ static void VerifyUniqueStringContents(
                      &mozilla::FailureLatchInfallibleSource::Singleton());
 
   // By default use a local UniqueJSONStrings, otherwise use the one provided.
-  mozilla::baseprofiler::UniqueJSONStrings localUniqueStrings;
+  mozilla::baseprofiler::UniqueJSONStrings localUniqueStrings{
+      FailureLatchInfallibleSource::Singleton()};
+  MOZ_RELEASE_ASSERT(!localUniqueStrings.Fallible());
+  MOZ_RELEASE_ASSERT(!localUniqueStrings.Failed());
+  MOZ_RELEASE_ASSERT(!localUniqueStrings.GetFailure());
+  MOZ_RELEASE_ASSERT(&localUniqueStrings.SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(&std::as_const(localUniqueStrings).SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+
   mozilla::baseprofiler::UniqueJSONStrings& uniqueStrings =
       aUniqueStringsOrNull ? *aUniqueStringsOrNull : localUniqueStrings;
+  MOZ_RELEASE_ASSERT(!uniqueStrings.Failed());
+  MOZ_RELEASE_ASSERT(!uniqueStrings.GetFailure());
 
   writer.Start();
   {
@@ -5142,6 +5153,9 @@ static void VerifyUniqueStringContents(
   }
   writer.End();
 
+  MOZ_RELEASE_ASSERT(!uniqueStrings.Failed());
+  MOZ_RELEASE_ASSERT(!uniqueStrings.GetFailure());
+
   MOZ_RELEASE_ASSERT(!writer.ChunkedWriteFunc().Failed());
   MOZ_RELEASE_ASSERT(!writer.ChunkedWriteFunc().GetFailure());
 
@@ -5243,7 +5257,7 @@ void TestUniqueJSONStrings() {
 
   // Unique string table with pre-existing data.
   {
-    UJS ujs;
+    UJS ujs{FailureLatchInfallibleSource::Singleton()};
     {
       SCJW writer{FailureLatchInfallibleSource::Singleton()};
       ujs.WriteElement(writer, "external0");
@@ -5261,14 +5275,15 @@ void TestUniqueJSONStrings() {
 
   // Unique string table with pre-existing data from another table.
   {
-    UJS ujs;
+    UJS ujs{FailureLatchInfallibleSource::Singleton()};
     {
       SCJW writer{FailureLatchInfallibleSource::Singleton()};
       ujs.WriteElement(writer, "external0");
       ujs.WriteElement(writer, "external1");
       ujs.WriteElement(writer, "external0");
     }
-    UJS ujsCopy(ujs, mozilla::ProgressLogger{});
+    UJS ujsCopy(FailureLatchInfallibleSource::Singleton(), ujs,
+                mozilla::ProgressLogger{});
     VerifyUniqueStringContents(
         [](SCJW& aWriter, UJS& aUniqueStrings) {
           aUniqueStrings.WriteElement(aWriter, "string0");
@@ -5329,7 +5344,8 @@ void PrintMarkers(const mozilla::ProfileChunkedBuffer& aBuffer) {
       mozilla::MakeUnique<mozilla::baseprofiler::OStreamJSONWriteFunc>(
           std::cout),
       FailureLatchInfallibleSource::Singleton());
-  mozilla::baseprofiler::UniqueJSONStrings uniqueStrings;
+  mozilla::baseprofiler::UniqueJSONStrings uniqueStrings{
+      FailureLatchInfallibleSource::Singleton()};
   writer.SetUniqueStrings(uniqueStrings);
   writer.Start();
   {

tools/profiler/core/ProfileBufferEntry.cpp

@@ -268,7 +268,7 @@ JITFrameInfoForBufferRange JITFrameInfoForBufferRange::Clone() const {
 JITFrameInfo::JITFrameInfo(const JITFrameInfo& aOther,
                            mozilla::ProgressLogger aProgressLogger)
     : mUniqueStrings(MakeUnique<UniqueJSONStrings>(
-          *aOther.mUniqueStrings,
+          FailureLatchInfallibleSource::Singleton(), *aOther.mUniqueStrings,
           aProgressLogger.CreateSubLoggerFromTo(
               0_pc, "Creating JIT frame info unique strings...", 49_pc,
               "Created JIT frame info unique strings"))) {

tools/profiler/core/ProfileBufferEntry.h

@@ -143,7 +143,9 @@ struct JITFrameInfoForBufferRange final {
 // ranges.
 class JITFrameInfo final {
  public:
-  JITFrameInfo() : mUniqueStrings(mozilla::MakeUnique<UniqueJSONStrings>()) {}
+  JITFrameInfo()
+      : mUniqueStrings(mozilla::MakeUnique<UniqueJSONStrings>(
+            mozilla::FailureLatchInfallibleSource::Singleton())) {}
 
   MOZ_IMPLICIT JITFrameInfo(const JITFrameInfo& aOther,
                             mozilla::ProgressLogger aProgressLogger);