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authorVincent Ambo <mail@tazj.in>2022-02-07T23·05+0300
committerclbot <clbot@tvl.fyi>2022-02-07T23·09+0000
commit5aa5d282eac56a21e74611c1cdbaa97bb5db2dca (patch)
tree8cc5dce8157a1470ff76719dd15d65f648a05522 /third_party/abseil_cpp/absl/random/internal/pool_urbg.cc
parenta25675804c4f429fab5ee5201fe25e89865dfd13 (diff)
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>
Diffstat (limited to 'third_party/abseil_cpp/absl/random/internal/pool_urbg.cc')
-rw-r--r--third_party/abseil_cpp/absl/random/internal/pool_urbg.cc254
1 files changed, 0 insertions, 254 deletions
diff --git a/third_party/abseil_cpp/absl/random/internal/pool_urbg.cc b/third_party/abseil_cpp/absl/random/internal/pool_urbg.cc
deleted file mode 100644
index 5bee530770eb..000000000000
--- a/third_party/abseil_cpp/absl/random/internal/pool_urbg.cc
+++ /dev/null
@@ -1,254 +0,0 @@
-// Copyright 2017 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.
-
-#include "absl/random/internal/pool_urbg.h"
-
-#include <algorithm>
-#include <atomic>
-#include <cstdint>
-#include <cstring>
-#include <iterator>
-
-#include "absl/base/attributes.h"
-#include "absl/base/call_once.h"
-#include "absl/base/config.h"
-#include "absl/base/internal/endian.h"
-#include "absl/base/internal/raw_logging.h"
-#include "absl/base/internal/spinlock.h"
-#include "absl/base/internal/sysinfo.h"
-#include "absl/base/internal/unaligned_access.h"
-#include "absl/base/optimization.h"
-#include "absl/random/internal/randen.h"
-#include "absl/random/internal/seed_material.h"
-#include "absl/random/seed_gen_exception.h"
-
-using absl::base_internal::SpinLock;
-using absl::base_internal::SpinLockHolder;
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace random_internal {
-namespace {
-
-// RandenPoolEntry is a thread-safe pseudorandom bit generator, implementing a
-// single generator within a RandenPool<T>. It is an internal implementation
-// detail, and does not aim to conform to [rand.req.urng].
-//
-// NOTE: There are alignment issues when used on ARM, for instance.
-// See the allocation code in PoolAlignedAlloc().
-class RandenPoolEntry {
- public:
-  static constexpr size_t kState = RandenTraits::kStateBytes / sizeof(uint32_t);
-  static constexpr size_t kCapacity =
-      RandenTraits::kCapacityBytes / sizeof(uint32_t);
-
-  void Init(absl::Span<const uint32_t> data) {
-    SpinLockHolder l(&mu_);  // Always uncontested.
-    std::copy(data.begin(), data.end(), std::begin(state_));
-    next_ = kState;
-  }
-
-  // Copy bytes into out.
-  void Fill(uint8_t* out, size_t bytes) ABSL_LOCKS_EXCLUDED(mu_);
-
-  // Returns random bits from the buffer in units of T.
-  template <typename T>
-  inline T Generate() ABSL_LOCKS_EXCLUDED(mu_);
-
-  inline void MaybeRefill() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-    if (next_ >= kState) {
-      next_ = kCapacity;
-      impl_.Generate(state_);
-    }
-  }
-
- private:
-  // Randen URBG state.
-  uint32_t state_[kState] ABSL_GUARDED_BY(mu_);  // First to satisfy alignment.
-  SpinLock mu_;
-  const Randen impl_;
-  size_t next_ ABSL_GUARDED_BY(mu_);
-};
-
-template <>
-inline uint8_t RandenPoolEntry::Generate<uint8_t>() {
-  SpinLockHolder l(&mu_);
-  MaybeRefill();
-  return static_cast<uint8_t>(state_[next_++]);
-}
-
-template <>
-inline uint16_t RandenPoolEntry::Generate<uint16_t>() {
-  SpinLockHolder l(&mu_);
-  MaybeRefill();
-  return static_cast<uint16_t>(state_[next_++]);
-}
-
-template <>
-inline uint32_t RandenPoolEntry::Generate<uint32_t>() {
-  SpinLockHolder l(&mu_);
-  MaybeRefill();
-  return state_[next_++];
-}
-
-template <>
-inline uint64_t RandenPoolEntry::Generate<uint64_t>() {
-  SpinLockHolder l(&mu_);
-  if (next_ >= kState - 1) {
-    next_ = kCapacity;
-    impl_.Generate(state_);
-  }
-  auto p = state_ + next_;
-  next_ += 2;
-
-  uint64_t result;
-  std::memcpy(&result, p, sizeof(result));
-  return result;
-}
-
-void RandenPoolEntry::Fill(uint8_t* out, size_t bytes) {
-  SpinLockHolder l(&mu_);
-  while (bytes > 0) {
-    MaybeRefill();
-    size_t remaining = (kState - next_) * sizeof(state_[0]);
-    size_t to_copy = std::min(bytes, remaining);
-    std::memcpy(out, &state_[next_], to_copy);
-    out += to_copy;
-    bytes -= to_copy;
-    next_ += (to_copy + sizeof(state_[0]) - 1) / sizeof(state_[0]);
-  }
-}
-
-// Number of pooled urbg entries.
-static constexpr int kPoolSize = 8;
-
-// Shared pool entries.
-static absl::once_flag pool_once;
-ABSL_CACHELINE_ALIGNED static RandenPoolEntry* shared_pools[kPoolSize];
-
-// Returns an id in the range [0 ... kPoolSize), which indexes into the
-// pool of random engines.
-//
-// Each thread to access the pool is assigned a sequential ID (without reuse)
-// from the pool-id space; the id is cached in a thread_local variable.
-// This id is assigned based on the arrival-order of the thread to the
-// GetPoolID call; this has no binary, CL, or runtime stability because
-// on subsequent runs the order within the same program may be significantly
-// different. However, as other thread IDs are not assigned sequentially,
-// this is not expected to matter.
-int GetPoolID() {
-  static_assert(kPoolSize >= 1,
-                "At least one urbg instance is required for PoolURBG");
-
-  ABSL_CONST_INIT static std::atomic<int64_t> sequence{0};
-
-#ifdef ABSL_HAVE_THREAD_LOCAL
-  static thread_local int my_pool_id = -1;
-  if (ABSL_PREDICT_FALSE(my_pool_id < 0)) {
-    my_pool_id = (sequence++ % kPoolSize);
-  }
-  return my_pool_id;
-#else
-  static pthread_key_t tid_key = [] {
-    pthread_key_t tmp_key;
-    int err = pthread_key_create(&tmp_key, nullptr);
-    if (err) {
-      ABSL_RAW_LOG(FATAL, "pthread_key_create failed with %d", err);
-    }
-    return tmp_key;
-  }();
-
-  // Store the value in the pthread_{get/set}specific. However an uninitialized
-  // value is 0, so add +1 to distinguish from the null value.
-  intptr_t my_pool_id =
-      reinterpret_cast<intptr_t>(pthread_getspecific(tid_key));
-  if (ABSL_PREDICT_FALSE(my_pool_id == 0)) {
-    // No allocated ID, allocate the next value, cache it, and return.
-    my_pool_id = (sequence++ % kPoolSize) + 1;
-    int err = pthread_setspecific(tid_key, reinterpret_cast<void*>(my_pool_id));
-    if (err) {
-      ABSL_RAW_LOG(FATAL, "pthread_setspecific failed with %d", err);
-    }
-  }
-  return my_pool_id - 1;
-#endif
-}
-
-// Allocate a RandenPoolEntry with at least 32-byte alignment, which is required
-// by ARM platform code.
-RandenPoolEntry* PoolAlignedAlloc() {
-  constexpr size_t kAlignment =
-      ABSL_CACHELINE_SIZE > 32 ? ABSL_CACHELINE_SIZE : 32;
-
-  // Not all the platforms that we build for have std::aligned_alloc, however
-  // since we never free these objects, we can over allocate and munge the
-  // pointers to the correct alignment.
-  void* memory = std::malloc(sizeof(RandenPoolEntry) + kAlignment);
-  auto x = reinterpret_cast<intptr_t>(memory);
-  auto y = x % kAlignment;
-  void* aligned =
-      (y == 0) ? memory : reinterpret_cast<void*>(x + kAlignment - y);
-  return new (aligned) RandenPoolEntry();
-}
-
-// Allocate and initialize kPoolSize objects of type RandenPoolEntry.
-//
-// The initialization strategy is to initialize one object directly from
-// OS entropy, then to use that object to seed all of the individual
-// pool instances.
-void InitPoolURBG() {
-  static constexpr size_t kSeedSize =
-      RandenTraits::kStateBytes / sizeof(uint32_t);
-  // Read the seed data from OS entropy once.
-  uint32_t seed_material[kPoolSize * kSeedSize];
-  if (!random_internal::ReadSeedMaterialFromOSEntropy(
-          absl::MakeSpan(seed_material))) {
-    random_internal::ThrowSeedGenException();
-  }
-  for (int i = 0; i < kPoolSize; i++) {
-    shared_pools[i] = PoolAlignedAlloc();
-    shared_pools[i]->Init(
-        absl::MakeSpan(&seed_material[i * kSeedSize], kSeedSize));
-  }
-}
-
-// Returns the pool entry for the current thread.
-RandenPoolEntry* GetPoolForCurrentThread() {
-  absl::call_once(pool_once, InitPoolURBG);
-  return shared_pools[GetPoolID()];
-}
-
-}  // namespace
-
-template <typename T>
-typename RandenPool<T>::result_type RandenPool<T>::Generate() {
-  auto* pool = GetPoolForCurrentThread();
-  return pool->Generate<T>();
-}
-
-template <typename T>
-void RandenPool<T>::Fill(absl::Span<result_type> data) {
-  auto* pool = GetPoolForCurrentThread();
-  pool->Fill(reinterpret_cast<uint8_t*>(data.data()),
-             data.size() * sizeof(result_type));
-}
-
-template class RandenPool<uint8_t>;
-template class RandenPool<uint16_t>;
-template class RandenPool<uint32_t>;
-template class RandenPool<uint64_t>;
-
-}  // namespace random_internal
-ABSL_NAMESPACE_END
-}  // namespace absl