Export of internal Abseil changes

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f6fbb03bff276e72123e8590519079e87732ae62 by Abseil Team <absl-team@google.com>:

Replace static absl::Mutex with SpinLock in absl::Cords

to avoid static initializers by absl::Mutex destructors

PiperOrigin-RevId: 370694199

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654b7d9edfdc24f226990b2b46cbf91451a1d92a by Martijn Vels <mvels@google.com>:

Implement global data for CordzInfo in an ODR hardened way

This change puts the global data into a global list structure, and stores a reference to the global list in the handle itself. This hardens the implementation against ODR violations where info pointers are crossing dynamic library boundaries which are privately loaded.

PiperOrigin-RevId: 370673045

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712dba768e66ee2ba85d6010829c617cd2af6ba7 by Martijn Vels <mvels@google.com>:

Intrument Cord::operator= for Cordz

PiperOrigin-RevId: 370659149

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c0b347a2289e151b72680269332e264b8fa989c0 by Matt Kulukundis <kfm@google.com>:

Fix test guards for ABSL_ATTRIBUTE_RETURNS_NONNULL

PiperOrigin-RevId: 370594807

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c2bedaa3472ef223f907de2604f9b9b58852ec5f by Martijn Vels <mvels@google.com>:

Add new Cordz instrumentation on GetAppendRegion.

PiperOrigin-RevId: 370587761

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84fbfcc852697d509f6094482b86e84743a6b331 by Martijn Vels <mvels@google.com>:

Add instrumentation on Cord::Apppend(string_view)

PiperOrigin-RevId: 370576590

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9e077390b8ca2239e1cb7bfbe1d5a04f2fc11d30 by Abseil Team <absl-team@google.com>:

Google-internal changes only.

PiperOrigin-RevId: 370558424

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fb53c149eb2364ea34e3a67235f873866618b8ac by Matt Kulukundis <kfm@google.com>:

Update config.h macros with a few useful helpers to simplify version checking

PiperOrigin-RevId: 370557684

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abf8142e99b9ff7e15f6528a357f1005461950b0 by Martijn Vels <mvels@google.com>:

clang-format cord

PiperOrigin-RevId: 370549371

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e555985eabe63fcf0e980e9c433dd84caffec191 by Martijn Vels <mvels@google.com>:

Add MaybeUntrackCord() function

This function is near identical to the old UntrackCord() but allows info to be null, moving the cord.is_profiled() branch into CordzInfo.

PiperOrigin-RevId: 370528447

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3883538efe4601f7864bda70a50d868bb383c63b by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 370503186

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a9514b65542fde1bc73584e6f3c1c4b3a05f215f by Derek Mauro <dmauro@google.com>:

Add -Winvalid-constexpr to warning options for LLVM

PiperOrigin-RevId: 370455171

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d8a3966de2cf15a2dc28e17e49a3d27d205eca92 by Martijn Vels <mvels@google.com>:

Add naive UniqueGenerator<T, kMaxValues, ...> to avoid flakes from dup random values.

PiperOrigin-RevId: 370179772

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46d0caa1a12b68a5998d4f919e20f0f83b9286f8 by Martijn Vels <mvels@google.com>:

Add new Cordz instrumentation on PrependTree.

PiperOrigin-RevId: 370138969
GitOrigin-RevId: f6fbb03bff276e72123e8590519079e87732ae62
Change-Id: Ifa4c00a5c7b01198ee367a3253bea6b66612135e

1 files changed, 44 insertions, 10 deletions

diff --git a/absl/strings/cord.h b/absl/strings/cord.h
index dd6c3bca..d5a13b34 100644
--- a/absl/strings/cord.h
+++ b/absl/strings/cord.h
@@ -671,6 +671,7 @@ class Cord {
 
  private:
   using CordRep = absl::cord_internal::CordRep;
+  using CordRepFlat = absl::cord_internal::CordRepFlat;
   using CordzInfo = cord_internal::CordzInfo;
   using CordzUpdateScope = cord_internal::CordzUpdateScope;
   using CordzUpdateTracker = cord_internal::CordzUpdateTracker;
@@ -728,12 +729,15 @@ class Cord {
     // Returns non-null iff was holding a pointer
     absl::cord_internal::CordRep* clear();
     // Converts to pointer if necessary.
-    absl::cord_internal::CordRep* force_tree(size_t extra_hint);
     void reduce_size(size_t n);  // REQUIRES: holding data
     void remove_prefix(size_t n);  // REQUIRES: holding data
-    void AppendArray(const char* src_data, size_t src_size);
+    void AppendArray(absl::string_view src, MethodIdentifier method);
     absl::string_view FindFlatStartPiece() const;
 
+    // Creates a CordRepFlat instance from the current inlined data with `extra'
+    // bytes of desired additional capacity.
+    CordRepFlat* MakeFlatWithExtraCapacity(size_t extra);
+
     // Sets the tree value for this instance. `rep` must not be null.
     // Requires the current instance to hold a tree, and a lock to be held on
     // any CordzInfo referenced by this instance. The latter is enforced through
@@ -747,12 +751,22 @@ class Cord {
     // value to a non-inlined (tree / ring) value.
     void EmplaceTree(CordRep* rep, MethodIdentifier method);
 
+    // Commits the change of a newly created, or updated `rep` root value into
+    // this cord. `old_rep` indicates the old (inlined or tree) value of the
+    // cord, and determines if the commit invokes SetTree() or EmplaceTree().
+    void CommitTree(const CordRep* old_rep, CordRep* rep,
+                    const CordzUpdateScope& scope, MethodIdentifier method);
+
     void AppendTreeToInlined(CordRep* tree, MethodIdentifier method);
     void AppendTreeToTree(CordRep* tree, MethodIdentifier method);
     void AppendTree(CordRep* tree, MethodIdentifier method);
-    void PrependTree(absl::cord_internal::CordRep* tree);
-    void GetAppendRegion(char** region, size_t* size, size_t max_length);
-    void GetAppendRegion(char** region, size_t* size);
+    void PrependTreeToInlined(CordRep* tree, MethodIdentifier method);
+    void PrependTreeToTree(CordRep* tree, MethodIdentifier method);
+    void PrependTree(CordRep* tree, MethodIdentifier method);
+
+    template <bool has_length>
+    void GetAppendRegion(char** region, size_t* size, size_t length);
+
     bool IsSame(const InlineRep& other) const {
       return memcmp(&data_, &other.data_, sizeof(data_)) == 0;
     }
@@ -1041,6 +1055,16 @@ inline size_t Cord::InlineRep::size() const {
   return is_tree() ? as_tree()->length : inline_size();
 }
 
+inline cord_internal::CordRepFlat* Cord::InlineRep::MakeFlatWithExtraCapacity(
+    size_t extra) {
+  static_assert(cord_internal::kMinFlatLength >= sizeof(data_), "");
+  size_t len = data_.inline_size();
+  auto* result = CordRepFlat::New(len + extra);
+  result->length = len;
+  memcpy(result->Data(), data_.as_chars(), sizeof(data_));
+  return result;
+}
+
 inline void Cord::InlineRep::EmplaceTree(CordRep* rep,
                                          MethodIdentifier method) {
   data_.make_tree(rep);
@@ -1055,10 +1079,20 @@ inline void Cord::InlineRep::SetTree(CordRep* rep,
   scope.SetCordRep(rep);
 }
 
+inline void Cord::InlineRep::CommitTree(const CordRep* old_rep, CordRep* rep,
+                                        const CordzUpdateScope& scope,
+                                        MethodIdentifier method) {
+  if (old_rep) {
+    SetTree(rep, scope);
+  } else {
+    EmplaceTree(rep, method);
+  }
+}
+
 inline void Cord::InlineRep::set_tree(absl::cord_internal::CordRep* rep) {
   if (rep == nullptr) {
-    if (ABSL_PREDICT_FALSE(is_profiled())) {
-      absl::cord_internal::CordzInfo::UntrackCord(cordz_info());
+    if (data_.is_tree()) {
+      CordzInfo::MaybeUntrackCord(data_.cordz_info());
     }
     ResetToEmpty();
   } else {
@@ -1086,8 +1120,8 @@ inline void Cord::InlineRep::replace_tree(absl::cord_internal::CordRep* rep) {
 }
 
 inline absl::cord_internal::CordRep* Cord::InlineRep::clear() {
-  if (ABSL_PREDICT_FALSE(is_profiled())) {
-    absl::cord_internal::CordzInfo::UntrackCord(cordz_info());
+  if (is_tree()) {
+    CordzInfo::MaybeUntrackCord(cordz_info());
   }
   absl::cord_internal::CordRep* result = tree();
   ResetToEmpty();
@@ -1180,7 +1214,7 @@ inline absl::string_view Cord::Flatten() {
 }
 
 inline void Cord::Append(absl::string_view src) {
-  contents_.AppendArray(src.data(), src.size());
+  contents_.AppendArray(src, CordzUpdateTracker::kAppendString);
 }
 
 extern template void Cord::Append(std::string&& src);