chore(3p/abseil_cpp): unvendor abseil_cpp r/3786

we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 321 deletions

diff --git a/third_party/abseil_cpp/absl/container/internal/hashtablez_sampler.h b/third_party/abseil_cpp/absl/container/internal/hashtablez_sampler.h
deleted file mode 100644
index 394348da58f5..000000000000
--- a/third_party/abseil_cpp/absl/container/internal/hashtablez_sampler.h
+++ /dev/null
@@ -1,321 +0,0 @@
-// Copyright 2018 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// -----------------------------------------------------------------------------
-// File: hashtablez_sampler.h
-// -----------------------------------------------------------------------------
-//
-// This header file defines the API for a low level library to sample hashtables
-// and collect runtime statistics about them.
-//
-// `HashtablezSampler` controls the lifecycle of `HashtablezInfo` objects which
-// store information about a single sample.
-//
-// `Record*` methods store information into samples.
-// `Sample()` and `Unsample()` make use of a single global sampler with
-// properties controlled by the flags hashtablez_enabled,
-// hashtablez_sample_rate, and hashtablez_max_samples.
-//
-// WARNING
-//
-// Using this sampling API may cause sampled Swiss tables to use the global
-// allocator (operator `new`) in addition to any custom allocator.  If you
-// are using a table in an unusual circumstance where allocation or calling a
-// linux syscall is unacceptable, this could interfere.
-//
-// This utility is internal-only. Use at your own risk.
-
-#ifndef ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
-#define ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
-
-#include <atomic>
-#include <functional>
-#include <memory>
-#include <vector>
-
-#include "absl/base/internal/per_thread_tls.h"
-#include "absl/base/optimization.h"
-#include "absl/container/internal/have_sse.h"
-#include "absl/synchronization/mutex.h"
-#include "absl/utility/utility.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace container_internal {
-
-// Stores information about a sampled hashtable.  All mutations to this *must*
-// be made through `Record*` functions below.  All reads from this *must* only
-// occur in the callback to `HashtablezSampler::Iterate`.
-struct HashtablezInfo {
-  // Constructs the object but does not fill in any fields.
-  HashtablezInfo();
-  ~HashtablezInfo();
-  HashtablezInfo(const HashtablezInfo&) = delete;
-  HashtablezInfo& operator=(const HashtablezInfo&) = delete;
-
-  // Puts the object into a clean state, fills in the logically `const` members,
-  // blocking for any readers that are currently sampling the object.
-  void PrepareForSampling() ABSL_EXCLUSIVE_LOCKS_REQUIRED(init_mu);
-
-  // These fields are mutated by the various Record* APIs and need to be
-  // thread-safe.
-  std::atomic<size_t> capacity;
-  std::atomic<size_t> size;
-  std::atomic<size_t> num_erases;
-  std::atomic<size_t> num_rehashes;
-  std::atomic<size_t> max_probe_length;
-  std::atomic<size_t> total_probe_length;
-  std::atomic<size_t> hashes_bitwise_or;
-  std::atomic<size_t> hashes_bitwise_and;
-
-  // `HashtablezSampler` maintains intrusive linked lists for all samples.  See
-  // comments on `HashtablezSampler::all_` for details on these.  `init_mu`
-  // guards the ability to restore the sample to a pristine state.  This
-  // prevents races with sampling and resurrecting an object.
-  absl::Mutex init_mu;
-  HashtablezInfo* next;
-  HashtablezInfo* dead ABSL_GUARDED_BY(init_mu);
-
-  // All of the fields below are set by `PrepareForSampling`, they must not be
-  // mutated in `Record*` functions.  They are logically `const` in that sense.
-  // These are guarded by init_mu, but that is not externalized to clients, who
-  // can only read them during `HashtablezSampler::Iterate` which will hold the
-  // lock.
-  static constexpr int kMaxStackDepth = 64;
-  absl::Time create_time;
-  int32_t depth;
-  void* stack[kMaxStackDepth];
-};
-
-inline void RecordRehashSlow(HashtablezInfo* info, size_t total_probe_length) {
-#if ABSL_INTERNAL_RAW_HASH_SET_HAVE_SSE2
-  total_probe_length /= 16;
-#else
-  total_probe_length /= 8;
-#endif
-  info->total_probe_length.store(total_probe_length, std::memory_order_relaxed);
-  info->num_erases.store(0, std::memory_order_relaxed);
-  // There is only one concurrent writer, so `load` then `store` is sufficient
-  // instead of using `fetch_add`.
-  info->num_rehashes.store(
-      1 + info->num_rehashes.load(std::memory_order_relaxed),
-      std::memory_order_relaxed);
-}
-
-inline void RecordStorageChangedSlow(HashtablezInfo* info, size_t size,
-                                     size_t capacity) {
-  info->size.store(size, std::memory_order_relaxed);
-  info->capacity.store(capacity, std::memory_order_relaxed);
-  if (size == 0) {
-    // This is a clear, reset the total/num_erases too.
-    info->total_probe_length.store(0, std::memory_order_relaxed);
-    info->num_erases.store(0, std::memory_order_relaxed);
-  }
-}
-
-void RecordInsertSlow(HashtablezInfo* info, size_t hash,
-                      size_t distance_from_desired);
-
-inline void RecordEraseSlow(HashtablezInfo* info) {
-  info->size.fetch_sub(1, std::memory_order_relaxed);
-  // There is only one concurrent writer, so `load` then `store` is sufficient
-  // instead of using `fetch_add`.
-  info->num_erases.store(
-      1 + info->num_erases.load(std::memory_order_relaxed),
-      std::memory_order_relaxed);
-}
-
-HashtablezInfo* SampleSlow(int64_t* next_sample);
-void UnsampleSlow(HashtablezInfo* info);
-
-#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-#error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set
-#endif  // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-
-#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-class HashtablezInfoHandle {
- public:
-  explicit HashtablezInfoHandle() : info_(nullptr) {}
-  explicit HashtablezInfoHandle(HashtablezInfo* info) : info_(info) {}
-  ~HashtablezInfoHandle() {
-    if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
-    UnsampleSlow(info_);
-  }
-
-  HashtablezInfoHandle(const HashtablezInfoHandle&) = delete;
-  HashtablezInfoHandle& operator=(const HashtablezInfoHandle&) = delete;
-
-  HashtablezInfoHandle(HashtablezInfoHandle&& o) noexcept
-      : info_(absl::exchange(o.info_, nullptr)) {}
-  HashtablezInfoHandle& operator=(HashtablezInfoHandle&& o) noexcept {
-    if (ABSL_PREDICT_FALSE(info_ != nullptr)) {
-      UnsampleSlow(info_);
-    }
-    info_ = absl::exchange(o.info_, nullptr);
-    return *this;
-  }
-
-  inline void RecordStorageChanged(size_t size, size_t capacity) {
-    if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
-    RecordStorageChangedSlow(info_, size, capacity);
-  }
-
-  inline void RecordRehash(size_t total_probe_length) {
-    if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
-    RecordRehashSlow(info_, total_probe_length);
-  }
-
-  inline void RecordInsert(size_t hash, size_t distance_from_desired) {
-    if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
-    RecordInsertSlow(info_, hash, distance_from_desired);
-  }
-
-  inline void RecordErase() {
-    if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
-    RecordEraseSlow(info_);
-  }
-
-  friend inline void swap(HashtablezInfoHandle& lhs,
-                          HashtablezInfoHandle& rhs) {
-    std::swap(lhs.info_, rhs.info_);
-  }
-
- private:
-  friend class HashtablezInfoHandlePeer;
-  HashtablezInfo* info_;
-};
-#else
-// Ensure that when Hashtablez is turned off at compile time, HashtablezInfo can
-// be removed by the linker, in order to reduce the binary size.
-class HashtablezInfoHandle {
- public:
-  explicit HashtablezInfoHandle() = default;
-  explicit HashtablezInfoHandle(std::nullptr_t) {}
-
-  inline void RecordStorageChanged(size_t /*size*/, size_t /*capacity*/) {}
-  inline void RecordRehash(size_t /*total_probe_length*/) {}
-  inline void RecordInsert(size_t /*hash*/, size_t /*distance_from_desired*/) {}
-  inline void RecordErase() {}
-
-  friend inline void swap(HashtablezInfoHandle& /*lhs*/,
-                          HashtablezInfoHandle& /*rhs*/) {}
-};
-#endif  // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-
-#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample;
-#endif  // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-
-// Returns an RAII sampling handle that manages registration and unregistation
-// with the global sampler.
-inline HashtablezInfoHandle Sample() {
-#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
-  if (ABSL_PREDICT_TRUE(--global_next_sample > 0)) {
-    return HashtablezInfoHandle(nullptr);
-  }
-  return HashtablezInfoHandle(SampleSlow(&global_next_sample));
-#else
-  return HashtablezInfoHandle(nullptr);
-#endif  // !ABSL_PER_THREAD_TLS
-}
-
-// Holds samples and their associated stack traces with a soft limit of
-// `SetHashtablezMaxSamples()`.
-//
-// Thread safe.
-class HashtablezSampler {
- public:
-  // Returns a global Sampler.
-  static HashtablezSampler& Global();
-
-  HashtablezSampler();
-  ~HashtablezSampler();
-
-  // Registers for sampling.  Returns an opaque registration info.
-  HashtablezInfo* Register();
-
-  // Unregisters the sample.
-  void Unregister(HashtablezInfo* sample);
-
-  // The dispose callback will be called on all samples the moment they are
-  // being unregistered. Only affects samples that are unregistered after the
-  // callback has been set.
-  // Returns the previous callback.
-  using DisposeCallback = void (*)(const HashtablezInfo&);
-  DisposeCallback SetDisposeCallback(DisposeCallback f);
-
-  // Iterates over all the registered `StackInfo`s.  Returning the number of
-  // samples that have been dropped.
-  int64_t Iterate(const std::function<void(const HashtablezInfo& stack)>& f);
-
- private:
-  void PushNew(HashtablezInfo* sample);
-  void PushDead(HashtablezInfo* sample);
-  HashtablezInfo* PopDead();
-
-  std::atomic<size_t> dropped_samples_;
-  std::atomic<size_t> size_estimate_;
-
-  // Intrusive lock free linked lists for tracking samples.
-  //
-  // `all_` records all samples (they are never removed from this list) and is
-  // terminated with a `nullptr`.
-  //
-  // `graveyard_.dead` is a circular linked list.  When it is empty,
-  // `graveyard_.dead == &graveyard`.  The list is circular so that
-  // every item on it (even the last) has a non-null dead pointer.  This allows
-  // `Iterate` to determine if a given sample is live or dead using only
-  // information on the sample itself.
-  //
-  // For example, nodes [A, B, C, D, E] with [A, C, E] alive and [B, D] dead
-  // looks like this (G is the Graveyard):
-  //
-  //           +---+    +---+    +---+    +---+    +---+
-  //    all -->| A |--->| B |--->| C |--->| D |--->| E |
-  //           |   |    |   |    |   |    |   |    |   |
-  //   +---+   |   | +->|   |-+  |   | +->|   |-+  |   |
-  //   | G |   +---+ |  +---+ |  +---+ |  +---+ |  +---+
-  //   |   |         |        |        |        |
-  //   |   | --------+        +--------+        |
-  //   +---+                                    |
-  //     ^                                      |
-  //     +--------------------------------------+
-  //
-  std::atomic<HashtablezInfo*> all_;
-  HashtablezInfo graveyard_;
-
-  std::atomic<DisposeCallback> dispose_;
-};
-
-// Enables or disables sampling for Swiss tables.
-void SetHashtablezEnabled(bool enabled);
-
-// Sets the rate at which Swiss tables will be sampled.
-void SetHashtablezSampleParameter(int32_t rate);
-
-// Sets a soft max for the number of samples that will be kept.
-void SetHashtablezMaxSamples(int32_t max);
-
-// Configuration override.
-// This allows process-wide sampling without depending on order of
-// initialization of static storage duration objects.
-// The definition of this constant is weak, which allows us to inject a
-// different value for it at link time.
-extern "C" bool AbslContainerInternalSampleEverything();
-
-}  // namespace container_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_