src/google/protobuf/arena_config.h

// Protocol Buffers - Google's data interchange format
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#ifndef GOOGLE_PROTOBUF_ARENA_CONFIG_H__
#define GOOGLE_PROTOBUF_ARENA_CONFIG_H__

#include <atomic>
#include <cstddef>

// Must be included last.
#include "google/protobuf/port_def.inc"

namespace google {
namespace protobuf {
namespace internal {
namespace arena_config_internal {

// We use an atomic here only for correctness so that we can read/write
// concurrently. We don't have memory order requirements so we use relaxed
// memory ordering.
PROTOBUF_EXPORT extern std::atomic<size_t> default_arena_max_block_size;

}  // namespace arena_config_internal

// The default value to use for DefaultArenaMaxBlockSize when
// SetDefaultArenaMaxBlockSize hasn't been called.
PROTOBUF_EXPORT extern const size_t kDefaultDefaultArenaMaxBlockSize;

// The default value to use for arena max block size when no value is provided
// in ArenaOptions.
inline size_t GetDefaultArenaMaxBlockSize() {
  return arena_config_internal::default_arena_max_block_size.load(
      std::memory_order_relaxed);
}
inline void SetDefaultArenaMaxBlockSize(size_t default_arena_max_block_size) {
  return arena_config_internal::default_arena_max_block_size.store(
      default_arena_max_block_size, std::memory_order_relaxed);
}

}  // namespace internal
}  // namespace protobuf
}  // namespace google

#include "google/protobuf/port_undef.inc"

#endif  // GOOGLE_PROTOBUF_ARENA_CONFIG_H__