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, 9 insertions, 6 deletions

diff --git a/absl/strings/internal/cordz_handle.cc b/absl/strings/internal/cordz_handle.cc
index 22d07978..5297ec8e 100644
--- a/absl/strings/internal/cordz_handle.cc
+++ b/absl/strings/internal/cordz_handle.cc
@@ -16,16 +16,19 @@
 #include <atomic>
 
 #include "absl/base/internal/raw_logging.h"  // For ABSL_RAW_CHECK
+#include "absl/base/internal/spinlock.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace cord_internal {
 
+using ::absl::base_internal::SpinLockHolder;
+
 ABSL_CONST_INIT CordzHandle::Queue CordzHandle::global_queue_(absl::kConstInit);
 
 CordzHandle::CordzHandle(bool is_snapshot) : is_snapshot_(is_snapshot) {
   if (is_snapshot) {
-    MutexLock lock(&queue_->mutex);
+    SpinLockHolder lock(&queue_->mutex);
     CordzHandle* dq_tail = queue_->dq_tail.load(std::memory_order_acquire);
     if (dq_tail != nullptr) {
       dq_prev_ = dq_tail;
@@ -40,7 +43,7 @@ CordzHandle::~CordzHandle() {
   if (is_snapshot_) {
     std::vector<CordzHandle*> to_delete;
     {
-      absl::MutexLock lock(&queue_->mutex);
+      SpinLockHolder lock(&queue_->mutex);
       CordzHandle* next = dq_next_;
       if (dq_prev_ == nullptr) {
         // We were head of the queue, delete every CordzHandle until we reach
@@ -70,7 +73,7 @@ void CordzHandle::Delete(CordzHandle* handle) {
     handle->ODRCheck();
     Queue* const queue = handle->queue_;
     if (!handle->is_snapshot_ && !queue->IsEmpty()) {
-      MutexLock lock(&queue->mutex);
+      SpinLockHolder lock(&queue->mutex);
       CordzHandle* dq_tail = queue->dq_tail.load(std::memory_order_acquire);
       if (dq_tail != nullptr) {
         handle->dq_prev_ = dq_tail;
@@ -85,7 +88,7 @@ void CordzHandle::Delete(CordzHandle* handle) {
 
 std::vector<const CordzHandle*> CordzHandle::DiagnosticsGetDeleteQueue() {
   std::vector<const CordzHandle*> handles;
-  MutexLock lock(&global_queue_.mutex);
+  SpinLockHolder lock(&global_queue_.mutex);
   CordzHandle* dq_tail = global_queue_.dq_tail.load(std::memory_order_acquire);
   for (const CordzHandle* p = dq_tail; p; p = p->dq_prev_) {
     handles.push_back(p);
@@ -100,7 +103,7 @@ bool CordzHandle::DiagnosticsHandleIsSafeToInspect(
   if (handle == nullptr) return true;
   if (handle->is_snapshot_) return false;
   bool snapshot_found = false;
-  MutexLock lock(&queue_->mutex);
+  SpinLockHolder lock(&queue_->mutex);
   for (const CordzHandle* p = queue_->dq_tail; p; p = p->dq_prev_) {
     if (p == handle) return !snapshot_found;
     if (p == this) snapshot_found = true;
@@ -117,7 +120,7 @@ CordzHandle::DiagnosticsGetSafeToInspectDeletedHandles() {
     return handles;
   }
 
-  MutexLock lock(&queue_->mutex);
+  SpinLockHolder lock(&queue_->mutex);
   for (const CordzHandle* p = dq_next_; p != nullptr; p = p->dq_next_) {
     if (!p->is_snapshot()) {
       handles.push_back(p);