text: // Copyright 2019 The TCMalloc 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 "tcmalloc/cpu_cache.h"
  
  #include <stdlib.h>
  #include <string.h>
  
  #include <algorithm>
  #include <atomic>
  
  #include "absl/base/dynamic_annotations.h"
  #include "absl/base/macros.h"
  #include "absl/base/thread_annotations.h"
  #include "absl/container/fixed_array.h"
  #include "tcmalloc/arena.h"
  #include "tcmalloc/common.h"
  #include "tcmalloc/internal/logging.h"
  #include "tcmalloc/internal_malloc_extension.h"
  #include "tcmalloc/parameters.h"
  #include "tcmalloc/static_vars.h"
  #include "tcmalloc/transfer_cache.h"
  
  GOOGLE_MALLOC_SECTION_BEGIN
  namespace tcmalloc {
  namespace tcmalloc_internal {
  
  static void ActivatePerCPUCaches() {
    if (tcmalloc::tcmalloc_internal::Static::CPUCacheActive()) {
      // Already active.
      return;
    }
  
    if (Parameters::per_cpu_caches() && subtle::percpu::IsFast()) {
      Static::InitIfNecessary();
      Static::cpu_cache().Activate();
      Static::ActivateCPUCache();
      // no need for this thread cache anymore, I guess.
      ThreadCache::BecomeIdle();
      // If there's a problem with this code, let's notice it right away:
      ::operator delete(::operator new(1));
    }
  }
  
  class PerCPUInitializer {
   public:
    PerCPUInitializer() {
     ActivatePerCPUCaches();
    }
  };
  static PerCPUInitializer module_enter_exit;
  
  }  // namespace tcmalloc_internal
  }  // namespace tcmalloc
  GOOGLE_MALLOC_SECTION_END
  
  extern "C" void TCMalloc_Internal_ForceCpuCacheActivation() {
    tcmalloc::tcmalloc_internal::ActivatePerCPUCaches();
  }
  
  extern "C" bool MallocExtension_Internal_GetPerCpuCachesActive() {
    return tcmalloc::tcmalloc_internal::Static::CPUCacheActive();
  }
  
  extern "C" int32_t MallocExtension_Internal_GetMaxPerCpuCacheSize() {
    return tcmalloc::tcmalloc_internal::Parameters::max_per_cpu_cache_size();
  }
  
  extern "C" void MallocExtension_Internal_SetMaxPerCpuCacheSize(int32_t value) {
    tcmalloc::tcmalloc_internal::Parameters::set_max_per_cpu_cache_size(value);
  }
  