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path: root/src/vppinfra/cuckoo_template.c
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# Copyright (c) 2018 Cisco and/or its affiliates.
# 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:
#
#     http://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.

cmake_minimum_required(VERSION 3.10)

set(CMAKE_C_COMPILER_NAMES
  clang-13
  clang-12
  clang-11
  clang-10
  clang-9
  gcc-10
  gcc-9
  cc
)

project(vpp C)

if(CMAKE_VERSION VERSION_LESS 3.12)
  macro(add_compile_definitions defs)
    foreach(d ${defs})
      add_compile_options(-D${d})
    endforeach()
  endmacro()
endif()

if(NOT DEFINED CMAKE_INSTALL_LIBDIR AND EXISTS "/etc/debian_version")
  set(CMAKE_INSTALL_LIBDIR "lib/${CMAKE_LIBRARY_ARCHITECTURE}")
endif()

include(CheckCCompilerFlag)
include(CheckIPOSupported)
include(GNUInstallDirs)
include(cmake/misc.cmake)
include(cmake/cpu.cmake)
include(cmake/ccache.cmake)

##############################################################################
# VPP Version
##############################################################################
execute_process(
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
  COMMAND scripts/version
  OUTPUT_VARIABLE VPP_VERSION
  OUTPUT_STRIP_TRAILING_WHITESPACE
)
string(REPLACE "-" ";" VPP_LIB_VERSION ${VPP_VERSION})
list(GET VPP_LIB_VERSION 0 VPP_LIB_VERSION)

##############################################################################
# cross compiling
##############################################################################
if(CMAKE_CROSSCOMPILING)
  set(CMAKE_IGNORE_PATH
    /usr/lib/${CMAKE_HOST_SYSTEM_PROCESSOR}-linux-gnu/
    /usr/lib/${CMAKE_HOST_SYSTEM_PROCESSOR}-linux-gnu/lib/
  )
endif()
set(CMAKE_C_COMPILER_TARGET ${CMAKE_SYSTEM_PROCESSOR}-linux-gnu)

##############################################################################
# build config
##############################################################################
check_c_compiler_flag("-Wno-address-of-packed-member"
		      compiler_flag_no_address_of_packed_member)
set(VPP_RUNTIME_DIR ${CMAKE_INSTALL_BINDIR} CACHE STRING "Relative runtime directory path")
set(VPP_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR} CACHE STRING "Relative library directory path")

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/${VPP_RUNTIME_DIR})
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/${VPP_LIBRARY_DIR})
set(VPP_BINARY_DIR ${CMAKE_BINARY_DIR}/CMakeFiles)
set(PYENV PYTHONPYCACHEPREFIX=${CMAKE_BINARY_DIR}/CMakeFile/__pycache__)

if (CMAKE_BUILD_TYPE)
  add_compile_options(-g -fPIC -Werror -Wall)
endif()

if (compiler_flag_no_address_of_packed_member)
  add_compile_options(-Wno-address-of-packed-member)
endif()

string(TOLOWER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_LC)
string(TOUPPER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_UC)

set(CMAKE_C_FLAGS_RELEASE "")
set(CMAKE_C_FLAGS_DEBUG "")

if (${CMAKE_BUILD_TYPE_LC} MATCHES "release")
  add_compile_options(-O3 -fstack-protector -fno-common)
  add_compile_definitions(_FORTIFY_SOURCE=2)
  set(CMAKE_EXE_LINKER_FLAGS_RELEASE "-pie")
elseif (${CMAKE_BUILD_TYPE_LC} MATCHES "debug")
  add_compile_options(-O0 -fstack-protector -fno-common)
  add_compile_definitions(CLIB_DEBUG)
elseif (${CMAKE_BUILD_TYPE_LC} MATCHES "coverity")
  add_compile_options(-O0)
  add_compile_definitions(__COVERITY__)
elseif (${CMAKE_BUILD_TYPE_LC} MATCHES "gcov")
  add_compile_options(-O0 -fprofile-arcs -ftest-coverage)
  add_compile_definitions(CLIB_DEBUG CLIB_GCOV)
endif()

set(BUILD_TYPES release debug coverity gcov)
string(REPLACE ";" " " BUILD_TYPES_STR "${BUILD_TYPES}")
set_property(CACHE CMAKE_BUILD_TYPE PROPERTY
	     HELPSTRING "Build type - valid options are: ${BUILD_TYPES_STR}")

##############################################################################
# link time optimizations
##############################################################################
if (CMAKE_BUILD_TYPE_UC STREQUAL "RELEASE")
  check_ipo_supported(RESULT _result)
  if (_result)
    option(VPP_USE_LTO "Link time optimization of release binaries" ON)
  endif()
endif()

if(VPP_USE_LTO)
  check_c_compiler_flag("-Wno-stringop-overflow"
		        compiler_flag_no_stringop_overflow)
endif()
##############################################################################
# sanitizers
##############################################################################

option(VPP_ENABLE_SANITIZE_ADDR "Enable Address Sanitizer" OFF)
set(VPP_SANITIZE_ADDR_OPTIONS
  "unmap_shadow_on_exit=1:disable_coredump=0:abort_on_error=1:detect_leaks=0"
  CACHE
  STRING "Address sanitizer arguments"
)

if (VPP_ENABLE_SANITIZE_ADDR)
  add_compile_options(-fsanitize=address)
  add_compile_definitions(CLIB_SANITIZE_ADDR)
  set(CMAKE_EXE_LINKER_FLAGS "-fsanitize=address ${CMAKE_EXE_LINKER_FLAGS}")
  set(CMAKE_SHARED_LINKER_FLAGS "-fsanitize=address ${CMAKE_SHARED_LINKER_FLAGS}")
endif (VPP_ENABLE_SANITIZE_ADDR)

##############################################################################
# trajectory trace
##############################################################################

option(VPP_ENABLE_TRAJECTORY_TRACE "Build vpp with trajectory tracing enabled" OFF)
if(VPP_ENABLE_TRAJECTORY_TRACE)
  add_compile_definitions(VLIB_BUFFER_TRACE_TRAJECTORY=1)
endif()

##############################################################################
# unittest with clang ode coverage
##############################################################################

if("${CMAKE_VERSION}" VERSION_GREATER_EQUAL "3.13" AND "${CMAKE_C_COMPILER_ID}" MATCHES "(Apple)?[Cc]lang")
  option(VPP_BUILD_TESTS_WITH_COVERAGE "Build unit tests with code coverage" OFF)
endif()

##############################################################################
# install config
##############################################################################
option(VPP_SET_RPATH "Set rpath for resulting binaries and libraries." ON)
if(VPP_SET_RPATH)
  set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/${VPP_LIBRARY_DIR}")
endif()
set(CMAKE_INSTALL_MESSAGE NEVER)

include_directories (
	${CMAKE_SOURCE_DIR}
	${VPP_BINARY_DIR}
)
set(CMAKE_INSTALL_DEFAULT_COMPONENT_NAME "vpp")

set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)

include(cmake/syscall.cmake)
include(cmake/api.cmake)
include(cmake/library.cmake)
include(cmake/exec.cmake)
include(cmake/plugin.cmake)

##############################################################################
# subdirs - order matters
##############################################################################
option(VPP_HOST_TOOLS_ONLY "Build only host tools" OFF)
if(VPP_HOST_TOOLS_ONLY)
  set(SUBDIRS tools/vppapigen cmake)
elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
  find_package(OpenSSL)
  set(SUBDIRS
    vppinfra svm vlib vlibmemory vlibapi vnet vpp vat vat2 vcl vpp-api
    plugins tools/vppapigen tools/g2 tools/perftool cmake pkg
    tools/appimage
  )
elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
  set(SUBDIRS vppinfra)
else()
  message(FATAL_ERROR "Unsupported system: ${CMAKE_SYSTEM_NAME}")
endif()

foreach(DIR ${SUBDIRS})
  add_subdirectory(${DIR} ${VPP_BINARY_DIR}/${DIR})
endforeach()

##############################################################################
# detect if we are inside git repo and add configure dependency
##############################################################################
execute_process(
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
  COMMAND git rev-parse --show-toplevel
  OUTPUT_VARIABLE VPP_GIT_TOPLEVEL_DIR
  OUTPUT_STRIP_TRAILING_WHITESPACE
  ERROR_QUIET
)

if (VPP_GIT_TOPLEVEL_DIR)
  set_property(
    DIRECTORY APPEND PROPERTY
    CMAKE_CONFIGURE_DEPENDS ${VPP_GIT_TOPLEVEL_DIR}/.git/index
  )
endif()

##############################################################################
# custom targets
##############################################################################

add_custom_target(run
  COMMAND ./${VPP_RUNTIME_DIR}/vpp -c startup.conf
  COMMENT "Starting VPP..."
  USES_TERMINAL
)

add_custom_target(debug
  COMMAND gdb --args ./${VPP_RUNTIME_DIR}/vpp -c startup.conf
  COMMENT "Starting VPP in the debugger..."
  USES_TERMINAL
)

add_custom_target(config
  COMMAND ccmake ${CMAKE_BINARY_DIR}
  COMMENT "Starting Configuration TUI..."
  USES_TERMINAL
)

foreach(bt ${BUILD_TYPES})
  add_custom_target(set-build-type-${bt}
    COMMAND cmake -DCMAKE_BUILD_TYPE:STRING=${bt} .
    COMMENT "Changing build type to ${bt}"
    USES_TERMINAL
  )
endforeach()

mark_as_advanced(CLEAR
  CMAKE_C_FLAGS
  CMAKE_C_COMPILER
  CMAKE_EXPORT_COMPILE_COMMANDS
  CMAKE_INSTALL_PREFIX
  CMAKE_LINKER
  CMAKE_SHARED_LINKER_FLAGS
  CMAKE_VERBOSE_MAKEFILE
)

##############################################################################
# print configuration
##############################################################################
message(STATUS "Configuration:")
pr("VPP version" ${VPP_VERSION})
pr("VPP library version" ${VPP_LIB_VERSION})
pr("GIT toplevel dir" ${VPP_GIT_TOPLEVEL_DIR})
pr("Build type" ${CMAKE_BUILD_TYPE})
pr("C compiler" ${CMAKE_C_COMPILER})
pr("C flags" ${CMAKE_C_FLAGS}${CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE_UC}})
pr("Linker flags (apps)" ${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_EXE_LINKER_FLAGS_${CMAKE_BUILD_TYPE_UC}})
pr("Linker flags (libs)" ${CMAKE_SHARED_LINKER_FLAGS} ${CMAKE_SHARED_LINKER_FLAGS_${CMAKE_BUILD_TYPE_UC}})
pr("Host processor" ${CMAKE_HOST_SYSTEM_PROCESSOR})
pr("Target processor" ${CMAKE_SYSTEM_PROCESSOR})
pr("Prefix path" ${CMAKE_PREFIX_PATH})
pr("Install prefix" ${CMAKE_INSTALL_PREFIX})
pr("Library dir" ${VPP_LIBRARY_DIR})
'#n875'>875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * 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:
 *
 *     http://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.
 */

/*
 * cuckoo hash implementation based on paper
 * 'Algorithmic Improvements for Fast Concurrent Cuckoo Hashing'
 * by Xiaozhou Li, David G. Andersen, Michael Kaminsky, Michael J. Freedman
 * and their libcuckoo implementation (https://github.com/efficient/libcuckoo)
 */

#include <vppinfra/vec.h>
#include <vppinfra/cuckoo_template.h>

int CV (clib_cuckoo_search) (CVT (clib_cuckoo) * h,
			     CVT (clib_cuckoo_kv) * search_v,
			     CVT (clib_cuckoo_kv) * return_v)
{
  CVT (clib_cuckoo_kv) tmp = *search_v;
  int rv = CV (clib_cuckoo_search_inline) (h, &tmp);
  if (CLIB_CUCKOO_ERROR_SUCCESS == rv)
    {
      *return_v = tmp;
    }
  return rv;
}

static
CVT (clib_cuckoo_bucket) *
CV (clib_cuckoo_bucket_at_index) (CVT (clib_cuckoo) * h, uword bucket)
{
  return vec_elt_at_index (h->buckets, bucket);
}

static uword CV (clib_cuckoo_get_nbuckets) (CVT (clib_cuckoo) * h)
{
  return vec_len (h->buckets);
}

static inline uword
CV (clib_cuckoo_elt_in_bucket_to_offset) (CVT (clib_cuckoo_bucket) * b,
					  CVT (clib_cuckoo_kv) * e)
{
  ASSERT (e >= b->elts);
  ASSERT (e <= &b->elts[sizeof (b->elts) / sizeof (b->elts[0]) - 1]);
  return e - b->elts;
}

u8 *CV (format_cuckoo_elt) (u8 * s, va_list * args)
{
  CVT (clib_cuckoo_kv) * elt = va_arg (*args, CVT (clib_cuckoo_kv) *);
  unsigned reduced_hash = va_arg (*args, unsigned);
  if (CV (clib_cuckoo_kv_is_free) (elt))
    {
      s = format (s, "[ -- empty -- ]");
    }
  else
    {
      s = format (s, "[%U, reduced hash: %u]", CV (format_cuckoo_kvp), elt,
		  reduced_hash);
    }
  return s;
}

u8 *CV (format_cuckoo_bucket) (u8 * s, va_list * args)
{
  CVT (clib_cuckoo_bucket) * bucket =
    va_arg (*args, CVT (clib_cuckoo_bucket) *);
  int i = 0;

  /* *INDENT-OFF* */
  clib_cuckoo_bucket_foreach_idx (i)
  {
    CVT (clib_cuckoo_kv) *elt = bucket->elts + i;
    s = format (s, "bucket %p, offset %d: %U\n", bucket, i,
                CV (format_cuckoo_elt), elt, bucket->reduced_hashes[i]);
  }
  /* *INDENT-ON* */
  clib_cuckoo_bucket_aux_t aux = bucket->aux;
  s = format (s, "version: %lld, use count: %d\n",
	      clib_cuckoo_bucket_aux_get_version (aux),
	      clib_cuckoo_bucket_aux_get_use_count (aux));
  return s;
}

#if CLIB_CUCKOO_DEBUG
static void CV (clib_cuckoo_deep_self_check) (CVT (clib_cuckoo) * h)
{
  CVT (clib_cuckoo_bucket) * bucket;
  uword bucket_idx = 0;
  /* *INDENT-OFF* */
  clib_cuckoo_foreach_bucket (bucket, h)
  {
    int i = 0;
    int used = 0;
    clib_cuckoo_bucket_foreach_idx (i)
    {
      CVT (clib_cuckoo_kv) *elt = bucket->elts + i;
      if (!CV (clib_cuckoo_kv_is_free) (elt))
        {
          u64 hash = CV (clib_cuckoo_hash) (elt);
          clib_cuckoo_lookup_info_t lookup = CV (clib_cuckoo_calc_lookup) (
              CV (clib_cuckoo_get_snapshot) (h), hash);
          CVT (clib_cuckoo_kv) kv = *elt;
          int rv = CV (clib_cuckoo_search) (h, &kv, &kv);
          if (CLIB_CUCKOO_ERROR_SUCCESS != rv)
            {
              CLIB_CUCKOO_DBG ("Search for elt `%U' failed!",
                               CV (format_cuckoo_elt), elt,
                               bucket->reduced_hashes[i]);
              CLIB_CUCKOO_DBG ("%U", CV (format_cuckoo), h, 1);
            }
          ASSERT (aux.bucket1 == bucket_idx || aux.bucket2 == bucket_idx);
          ASSERT (CLIB_CUCKOO_ERROR_SUCCESS == rv);
          ++used;
        }
    }
    clib_cuckoo_bucket_aux_t aux = bucket->aux;
    ASSERT (used == clib_cuckoo_bucket_aux_get_use_count (aux));
    ++bucket_idx;
  }
  /* *INDENT-ON* */
  // CLIB_CUCKOO_DBG ("Deep self check passed: %U", CV (format_cuckoo), h);
}

#define CLIB_CUCKOO_DEEP_SELF_CHECK(h) CV (clib_cuckoo_deep_self_check) (h)
#define CLIB_CUCKOO_ASSERT_BUCKET_SORTED(b)                                 \
  do                                                                        \
    {                                                                       \
      int i;                                                                \
      int min_free = CLIB_CUCKOO_KVP_PER_BUCKET;                            \
      int max_used = 0;                                                     \
      clib_cuckoo_bucket_foreach_idx (i)                                    \
      {                                                                     \
        if (!CV (clib_cuckoo_kv_is_free) (b->elts + i))                     \
          {                                                                 \
            max_used = i;                                                   \
          }                                                                 \
        if (CV (clib_cuckoo_kv_is_free) (b->elts +                          \
                                         (CLIB_CUCKOO_KVP_PER_BUCKET - i))) \
          {                                                                 \
            min_free = i;                                                   \
          }                                                                 \
      }                                                                     \
      ASSERT (min_free > max_used);                                         \
    }                                                                       \
  while (0)

#else
#define CLIB_CUCKOO_DEEP_SELF_CHECK(h)
#define CLIB_CUCKOO_ASSERT_BUCKET_SORTED(b)
#endif

void CV (clib_cuckoo_init) (CVT (clib_cuckoo) * h, const char *name,
			    uword nbuckets,
			    void (*garbage_callback) (CVT (clib_cuckoo) *,
						      void *),
			    void *garbage_ctx)
{
  uword log2_nbuckets = max_log2 (nbuckets);
  nbuckets = 1ULL << (log2_nbuckets);
  CLIB_CUCKOO_DBG ("New cuckoo, adjusted nbuckets %wu", nbuckets);
  CVT (clib_cuckoo_bucket) * buckets = NULL;
  vec_validate_aligned (buckets, nbuckets - 1, CLIB_CACHE_LINE_BYTES);
  ASSERT (nbuckets == vec_len (buckets));
  h->buckets = buckets;
  clib_spinlock_init (&h->writer_lock);
  /* mark all elements free ... */
  CVT (clib_cuckoo_bucket) * bucket;
  /* *INDENT-OFF* */
  clib_cuckoo_foreach_bucket (
      bucket, h, { clib_memset (bucket->elts, 0xff, sizeof (bucket->elts)); });
  /* *INDENT-ON* */
  h->name = name;
  h->garbage_callback = garbage_callback;
  h->garbage_ctx = garbage_ctx;
}

void CV (clib_cuckoo_free) (CVT (clib_cuckoo) * h)
{
  clib_memset (h, 0, sizeof (*h));
}

static clib_cuckoo_bucket_aux_t
CV (clib_cuckoo_bucket_version_bump_and_lock) (CVT (clib_cuckoo_bucket) * b)
{
  clib_cuckoo_bucket_aux_t aux = b->aux;
  u64 version = clib_cuckoo_bucket_aux_get_version (aux);
  u8 use_count = clib_cuckoo_bucket_aux_get_use_count (aux);
  u8 writer_flag = clib_cuckoo_bucket_aux_get_writer_flag (aux);
  ASSERT (0 == writer_flag);
  aux = clib_cuckoo_bucket_aux_pack (version + 1, use_count, 1);
  b->aux = aux;
  return aux;
}

static void CV (clib_cuckoo_bucket_unlock) (CVT (clib_cuckoo_bucket) * b,
					    clib_cuckoo_bucket_aux_t aux)
{
  u64 version = clib_cuckoo_bucket_aux_get_version (aux);
  u8 use_count = clib_cuckoo_bucket_aux_get_use_count (aux);
  u8 writer_flag = clib_cuckoo_bucket_aux_get_writer_flag (aux);
  ASSERT (1 == writer_flag);
  aux = clib_cuckoo_bucket_aux_pack (version, use_count, 0);
  b->aux = aux;
}

#define CLIB_CUCKOO_DEBUG_PATH (1)
#define CLIB_CUCKOO_DEBUG_PATH_DETAIL (0)

#if CLIB_CUCKOO_DEBUG && CLIB_CUCKOO_DEBUG_PATH
static u8 *CV (format_cuckoo_path) (u8 * s, va_list * args);
#endif

static clib_cuckoo_path_t *CV (clib_cuckoo_path_get) (CVT (clib_cuckoo) * h)
{
  clib_cuckoo_path_t *path;
  pool_get (h->paths, path);
  clib_memset (path, 0, sizeof (*path));
#if CLIB_CUCKOO_DEBUG_PATH_DETAIL
  CLIB_CUCKOO_DBG ("Get path @%lu", (long unsigned) (path - h->paths));
#endif
  return path;
}

static void CV (clib_cuckoo_path_put) (CVT (clib_cuckoo) * h, uword path_idx)
{
  clib_cuckoo_path_t *path = pool_elt_at_index (h->paths, path_idx);
#if CLIB_CUCKOO_DEBUG_PATH_DETAIL
  CLIB_CUCKOO_DBG ("Put path @%lu", (long unsigned) (path - h->paths));
#endif
  pool_put (h->paths, path);
}

static clib_cuckoo_path_t *CV (clib_cuckoo_path_begin) (CVT (clib_cuckoo) * h,
							uword bucket,
							uword next_offset)
{
  ASSERT (next_offset < CLIB_CUCKOO_KVP_PER_BUCKET);
  clib_cuckoo_path_t *new_path = CV (clib_cuckoo_path_get) (h);
  new_path->length = 1;
  new_path->data = next_offset;
  new_path->start = bucket;
  new_path->bucket = bucket;
#if CLIB_CUCKOO_DEBUG_PATH
  CLIB_CUCKOO_DBG ("Create new path @%wu, length: %u data: %llu bucket: %wu "
		   "next-offset: %wu",
		   new_path - h->paths, new_path->length,
		   (long long unsigned) new_path->data, new_path->bucket,
		   next_offset);
#endif
  return new_path;
}

/**
 * create a new path based on existing path extended by adding a bucket
 * and offset
 */
static uword CV (clib_cuckoo_path_extend) (CVT (clib_cuckoo) * h,
					   uword path_idx, uword bucket,
					   unsigned offset)
{
  ASSERT (offset < CLIB_CUCKOO_KVP_PER_BUCKET);
  clib_cuckoo_path_t *new_path = CV (clib_cuckoo_path_get) (h);
  uword new_path_idx = new_path - h->paths;
  clib_cuckoo_path_t *path = pool_elt_at_index (h->paths, path_idx);
  new_path->start = path->start;
  new_path->length = path->length + 1;
  new_path->data = (path->data << CLIB_CUCKOO_LOG2_KVP_PER_BUCKET) + offset;
  new_path->bucket = bucket;
#if CLIB_CUCKOO_DEBUG_PATH
  CLIB_CUCKOO_DBG ("Extend path @%wu, new path @%wu, %U", path_idx,
		   new_path_idx, CV (format_cuckoo_path), h, new_path_idx);
#endif
  return new_path_idx;
}

/** return the offset of the last element in the path */
static uword CV (clib_cuckoo_path_peek_offset) (const clib_cuckoo_path_t *
						path)
{
  ASSERT (path->length > 0);
  uword mask = (1 << CLIB_CUCKOO_LOG2_KVP_PER_BUCKET) - 1;
  uword offset = path->data & mask;
  return offset;
}

static
CVT (clib_cuckoo_kv) *
CV (clib_cuckoo_bucket_find_empty) (CVT (clib_cuckoo_bucket) * bucket)
{
  clib_cuckoo_bucket_aux_t aux = bucket->aux;
  u8 use_count = clib_cuckoo_bucket_aux_get_use_count (aux);
  if (use_count < CLIB_CUCKOO_KVP_PER_BUCKET)
    {
      return bucket->elts + use_count;
    }
  return NULL;
}

/**
 * walk the cuckoo path two ways,
 * first backwards, extracting offsets,
 * then forward, extracting buckets
 *
 * buckets and offsets are arrays filled with elements extracted from path
 * the arrays must be able to contain CLIB_CUCKOO_BFS_MAX_PATH_LENGTH elements
 */
static void
clib_cuckoo_path_walk (CVT (clib_cuckoo) * h, uword path_idx,
		       uword * buckets, uword * offsets)
{
  clib_cuckoo_path_t *path = pool_elt_at_index (h->paths, path_idx);
  ASSERT (path->length > 0);
  u64 data = path->data;
  uword mask = (1 << CLIB_CUCKOO_LOG2_KVP_PER_BUCKET) - 1;
  uword i;
  for (i = path->length; i > 0; --i)
    {
      uword offset = data & mask;
      offsets[i - 1] = offset;
      data >>= CLIB_CUCKOO_LOG2_KVP_PER_BUCKET;
    }
  buckets[0] = path->start;
  for (i = 1; i < path->length; ++i)
    {
      CVT (clib_cuckoo_bucket) * b =
	CV (clib_cuckoo_bucket_at_index) (h, buckets[i - 1]);
      buckets[i] =
	clib_cuckoo_get_other_bucket (CV (clib_cuckoo_get_nbuckets) (h),
				      buckets[i - 1],
				      b->reduced_hashes[offsets[i - 1]]);
    }
}

#if CLIB_CUCKOO_DEBUG && CLIB_CUCKOO_DEBUG_PATH
static u8 *CV (format_cuckoo_path) (u8 * s, va_list * args)
{
  CVT (clib_cuckoo) * h = va_arg (*args, CVT (clib_cuckoo) *);
  uword path_idx = va_arg (*args, uword);
  clib_cuckoo_path_t *p = pool_elt_at_index (h->paths, path_idx);
  uword buckets[CLIB_CUCKOO_BFS_MAX_PATH_LENGTH];
  uword offsets[CLIB_CUCKOO_BFS_MAX_PATH_LENGTH];
  clib_cuckoo_path_walk (h, path_idx, buckets, offsets);
  s = format (s, "length %u: ", p->length);
  for (uword i = p->length - 1; i > 0; --i)
    {
      s = format (s, "%wu[%wu]->", buckets[i], offsets[i]);
    }
  if (p->length)
    {
      s = format (s, "%wu[%wu]", buckets[0], offsets[0]);
    }
  return s;
}
#endif

/*
 * perform breadth-first search in the cuckoo hash, finding the closest
 * empty slot, i.e. one which requires minimum swaps to move it
 * to one of the buckets provided
 */
static int CV (clib_cuckoo_find_empty_slot_bfs) (CVT (clib_cuckoo) * h,
						 clib_cuckoo_lookup_info_t *
						 lookup, uword * path_idx_out,
						 uword * found_bucket,
						 CVT (clib_cuckoo_kv) *
						 *found_elt)
{
  uword *tail;
  ASSERT (!vec_len (h->bfs_search_queue));
  clib_cuckoo_path_t *tmp;
  pool_flush (tmp, h->paths,);
  int rv = CLIB_CUCKOO_ERROR_AGAIN;
  int counter = 0;
  /* start by creating paths starting in each of the buckets ... */
  vec_add2 (h->bfs_search_queue, tail, CLIB_CUCKOO_KVP_PER_BUCKET);
  int i;
  for (i = 0; i < CLIB_CUCKOO_KVP_PER_BUCKET; ++i)
    {
      clib_cuckoo_path_t *path =
	CV (clib_cuckoo_path_begin) (h, lookup->bucket1, i);
      tail[i] = path - h->paths;
    }
  if (lookup->bucket1 != lookup->bucket2)
    {
      vec_add2 (h->bfs_search_queue, tail, CLIB_CUCKOO_KVP_PER_BUCKET);
      for (i = 0; i < CLIB_CUCKOO_KVP_PER_BUCKET; ++i)
	{
	  clib_cuckoo_path_t *path =
	    CV (clib_cuckoo_path_begin) (h, lookup->bucket2, i);
	  tail[i] = path - h->paths;
	}
    }
  while (1)
    {
      if (counter >= CLIB_CUCKOO_BFS_MAX_STEPS)
	{
#if CLIB_CUCKOO_DEBUG_COUNTERS
	  ++h->steps_exceeded;
#endif
	  break;
	}
      if (counter >= vec_len (h->bfs_search_queue))
	{
#if CLIB_CUCKOO_DEBUG_COUNTERS
	  ++h->bfs_queue_emptied;
#endif
	  break;
	}
      const uword path_idx = vec_elt (h->bfs_search_queue, counter);
      const clib_cuckoo_path_t *path = pool_elt_at_index (h->paths, path_idx);
#if CLIB_CUCKOO_DEBUG_PATH
      CLIB_CUCKOO_DBG ("Examine path @%wu: %U", path_idx,
		       CV (format_cuckoo_path), h, path_idx);
#endif
      /* TODO prefetch ? */
      /* search the alternative bucket for free space */
      int offset = CV (clib_cuckoo_path_peek_offset) (path);
      CVT (clib_cuckoo_bucket) * bucket =
	CV (clib_cuckoo_bucket_at_index) (h, path->bucket);
      uword other_bucket =
	clib_cuckoo_get_other_bucket (CV (clib_cuckoo_get_nbuckets) (h),
				      path->bucket,
				      bucket->reduced_hashes[offset]);
      CLIB_CUCKOO_DBG
	("Path ends in bucket %wu, offset #%wu, other bucket is %wu",
	 path->bucket, CV (clib_cuckoo_path_peek_offset) (path),
	 other_bucket);
      if (path->bucket != other_bucket)
	{
	  if ((*found_elt =
	       CV (clib_cuckoo_bucket_find_empty) (CV
						   (clib_cuckoo_bucket_at_index)
						   (h, other_bucket))))
	    {
	      /* found empty element */
	      *found_bucket = other_bucket;
	      *path_idx_out = path_idx;
	      rv = CLIB_CUCKOO_ERROR_SUCCESS;
#if CLIB_CUCKOO_DEBUG_PATH
	      CLIB_CUCKOO_DBG ("Bucket with empty slot:\n%U",
			       CV (format_cuckoo_bucket),
			       CV (clib_cuckoo_bucket_at_index) (h,
								 other_bucket));
#endif
	      goto out;
	    }
	  /* extend the current path with possible next buckets and add to
	   * queue */
	  if (path->length < CLIB_CUCKOO_BFS_MAX_PATH_LENGTH &&
	      vec_len (h->bfs_search_queue) < CLIB_CUCKOO_BFS_MAX_STEPS)
	    {
	      uword *tail;
	      vec_add2 (h->bfs_search_queue, tail,
			CLIB_CUCKOO_KVP_PER_BUCKET);
	      for (i = 0; i < CLIB_CUCKOO_KVP_PER_BUCKET; ++i)
		{
		  uword new_path_idx =
		    CV (clib_cuckoo_path_extend) (h, path_idx, other_bucket,
						  i);
		  tail[i] = new_path_idx;
		}
	    }
	}
      else
	{
	  CLIB_CUCKOO_DBG ("Discard path @%wu, loop detected", path_idx);
	}
      /* done with this path - put back to pool for later reuse */
      CV (clib_cuckoo_path_put) (h, path_idx);
      ++counter;
    }
out:
  vec_reset_length (h->bfs_search_queue);
  return rv;
}

static void CV (clib_cuckoo_swap_elts_in_bucket) (CVT (clib_cuckoo_bucket) *
						  b, uword e1, uword e2)
{
  CVT (clib_cuckoo_kv) kv;
  clib_memcpy (&kv, b->elts + e1, sizeof (kv));
  clib_memcpy (b->elts + e1, b->elts + e2, sizeof (kv));
  clib_memcpy (b->elts + e2, &kv, sizeof (kv));
  u8 reduced_hash = b->reduced_hashes[e1];
  b->reduced_hashes[e1] = b->reduced_hashes[e2];
  b->reduced_hashes[e2] = reduced_hash;
}

static void CV (clib_cuckoo_bucket_tidy) (CVT (clib_cuckoo_bucket) * b)
{
  int i = 0;
  int j = CLIB_CUCKOO_KVP_PER_BUCKET - 1;
  while (i != j)
    {
      int min_free = i;
      int max_used = j;
      while (!CV (clib_cuckoo_kv_is_free) (&b->elts[min_free]))
	{
	  ++min_free;
	}
      while (CV (clib_cuckoo_kv_is_free) (&b->elts[max_used]))
	{
	  --max_used;
	}
      if (min_free < max_used)
	{
	  CV (clib_cuckoo_swap_elts_in_bucket) (b, min_free, max_used);
	  i = min_free + 1;
	  j = max_used - 1;
	}
      else
	{
	  break;
	}
    }
}

static void CV (clib_cuckoo_free_locked_elt) (CVT (clib_cuckoo_kv) * elt)
{
  /*
   * FIXME - improve performance by getting rid of this clib_memset - make all
   * functions in this file not rely on clib_cuckoo_kv_is_free but instead
   * take use_count into account */
  clib_memset (elt, 0xff, sizeof (*elt));
}

static void CV (clib_cuckoo_free_elt_in_bucket) (CVT (clib_cuckoo_bucket) * b,
						 CVT (clib_cuckoo_kv) * elt)
{
  clib_cuckoo_bucket_aux_t aux =
    CV (clib_cuckoo_bucket_version_bump_and_lock) (b);
  int use_count = clib_cuckoo_bucket_aux_get_use_count (aux);
  int offset = elt - b->elts;
  ASSERT (offset < use_count);
  CV (clib_cuckoo_free_locked_elt) (elt);
  if (offset != use_count - 1)
    {
      CV (clib_cuckoo_bucket_tidy) (b);
    }
  aux = clib_cuckoo_bucket_aux_set_use_count (aux, use_count - 1);
  CV (clib_cuckoo_bucket_unlock) (b, aux);
}

static void CV (clib_cuckoo_set_locked_elt) (CVT (clib_cuckoo_bucket) * b,
					     CVT (clib_cuckoo_kv) * elt,
					     CVT (clib_cuckoo_kv) * kvp,
					     u8 reduced_hash)
{
  int offset = CV (clib_cuckoo_elt_in_bucket_to_offset) (b, elt);
  clib_memcpy (elt, kvp, sizeof (*elt));
  b->reduced_hashes[offset] = reduced_hash;
  CLIB_CUCKOO_DBG ("Set bucket %p, offset %d, %U", b, offset,
		   CV (format_cuckoo_elt), elt, b->reduced_hashes[offset]);
}

static void CV (clib_cuckoo_set_elt) (CVT (clib_cuckoo_bucket) * b,
				      CVT (clib_cuckoo_kv) * elt,
				      CVT (clib_cuckoo_kv) * kvp,
				      u8 reduced_hash)
{
  clib_cuckoo_bucket_aux_t aux =
    CV (clib_cuckoo_bucket_version_bump_and_lock) (b);
  CV (clib_cuckoo_set_locked_elt) (b, elt, kvp, reduced_hash);
  CV (clib_cuckoo_bucket_unlock) (b, aux);
}

static int CV (clib_cuckoo_add_slow) (CVT (clib_cuckoo) * h,
				      CVT (clib_cuckoo_kv) * kvp,
				      clib_cuckoo_lookup_info_t * lookup,
				      u8 reduced_hash)
{
  uword path_idx;
  uword empty_bucket_idx;
  CVT (clib_cuckoo_kv) * empty_elt;
  int rv = CV (clib_cuckoo_find_empty_slot_bfs) (h, lookup, &path_idx,
						 &empty_bucket_idx,
						 &empty_elt);
  if (CLIB_CUCKOO_ERROR_SUCCESS == rv)
    {
      uword buckets[CLIB_CUCKOO_BFS_MAX_PATH_LENGTH];
      uword offsets[CLIB_CUCKOO_BFS_MAX_PATH_LENGTH];
      clib_cuckoo_path_walk (h, path_idx, buckets, offsets);
      /*
       * walk back the path, moving the free element forward to one of our
       * buckets ...
       */
      clib_cuckoo_path_t *path = pool_elt_at_index (h->paths, path_idx);
      CVT (clib_cuckoo_bucket) * empty_bucket =
	CV (clib_cuckoo_bucket_at_index) (h, empty_bucket_idx);
      int i;
      for (i = path->length - 1; i >= 0; --i)
	{
	  /* copy the key-value in path to the bucket with empty element */
	  CVT (clib_cuckoo_bucket) * b =
	    CV (clib_cuckoo_bucket_at_index) (h, buckets[i]);
	  CVT (clib_cuckoo_kv) * elt = b->elts + offsets[i];
	  clib_cuckoo_bucket_aux_t empty_aux =
	    CV (clib_cuckoo_bucket_version_bump_and_lock) (empty_bucket);
	  CV (clib_cuckoo_set_locked_elt)
	    (empty_bucket, empty_elt, elt, b->reduced_hashes[elt - b->elts]);
	  if (i == path->length - 1)
	    {
	      /* we only need to increase the use count for the bucket with
	       * free element - all other buckets' use counts won't change */
	      empty_aux = clib_cuckoo_bucket_aux_set_use_count (empty_aux,
								clib_cuckoo_bucket_aux_get_use_count
								(empty_aux) +
								1);
	    }
	  CV (clib_cuckoo_bucket_unlock) (empty_bucket, empty_aux);
	  /*
	   * the element now exists in both places - in the previously empty
	   * element and in its original bucket - we can now safely overwrite
	   * the element in the original bucket with previous element in path
	   * without loosing data (and we don't need to modify the use count)
	   */
	  empty_bucket = b;
	  empty_elt = elt;
	}
      /* now we have a place to put the kvp in ... */
      CV (clib_cuckoo_set_elt) (empty_bucket, empty_elt, kvp, reduced_hash);
      CLIB_CUCKOO_DBG ("Slow insert success, bucket: %p\n%U", empty_bucket,
		       CV (format_cuckoo_bucket), empty_bucket);
#if CLIB_CUCKOO_DEBUG_COUNTERS
      ++h->slow_adds;
#endif
    }
  return rv;
}

static int CV (clib_cuckoo_add_fast) (CVT (clib_cuckoo) * h,
				      clib_cuckoo_lookup_info_t * lookup,
				      CVT (clib_cuckoo_kv) * kvp,
				      u8 reduced_hash)
{
  CVT (clib_cuckoo_kv) * elt;
  CVT (clib_cuckoo_bucket) * bucket1 =
    CV (clib_cuckoo_bucket_at_index) (h, lookup->bucket1);
  if ((elt = CV (clib_cuckoo_bucket_find_empty) (bucket1)))
    {
      clib_cuckoo_bucket_aux_t aux =
	CV (clib_cuckoo_bucket_version_bump_and_lock) (bucket1);
      CV (clib_cuckoo_set_locked_elt) (bucket1, elt, kvp, reduced_hash);
      aux =
	clib_cuckoo_bucket_aux_set_use_count (aux,
					      clib_cuckoo_bucket_aux_get_use_count
					      (aux) + 1);
      CV (clib_cuckoo_bucket_unlock) (bucket1, aux);
#if CLIB_CUCKOO_DEBUG_COUNTERS
      ++h->fast_adds;
#endif
      return CLIB_CUCKOO_ERROR_SUCCESS;
    }
  CVT (clib_cuckoo_bucket) * bucket2 =
    CV (clib_cuckoo_bucket_at_index) (h, lookup->bucket2);
  if ((elt =
       CV (clib_cuckoo_bucket_find_empty) (CV (clib_cuckoo_bucket_at_index)
					   (h, lookup->bucket2))))
    {
      clib_cuckoo_bucket_aux_t aux =
	CV (clib_cuckoo_bucket_version_bump_and_lock) (bucket2);
      CV (clib_cuckoo_set_locked_elt) (bucket2, elt, kvp, reduced_hash);
      aux =
	clib_cuckoo_bucket_aux_set_use_count (aux,
					      clib_cuckoo_bucket_aux_get_use_count
					      (aux) + 1);
      CV (clib_cuckoo_bucket_unlock) (bucket2, aux);
#if CLIB_CUCKOO_DEBUG_COUNTERS
      ++h->fast_adds;
#endif
      return CLIB_CUCKOO_ERROR_SUCCESS;
    }
  return CLIB_CUCKOO_ERROR_AGAIN;
}

/**
 * perform garbage collection
 *
 * this function assumes there is no other thread touching the cuckoo hash,
 * not even a reader, it's meant to be called from main thread
 * in a stop-the-world situation
 */
void CV (clib_cuckoo_garbage_collect) (CVT (clib_cuckoo) * h)
{
  CLIB_MEMORY_BARRIER ();
  CVT (clib_cuckoo_bucket) * *b;
  /* *INDENT-OFF* */
  vec_foreach (b, h->to_be_freed)
  {
    if (*b == h->buckets)
      {
        continue;
      }
#if CLIB_CUCKOO_DEBUG_GC
    fformat (stdout, "gc: free %p\n", *b);
#endif
    vec_free (*b);
  }
  /* *INDENT-ON* */
  vec_free (h->to_be_freed);
  CLIB_MEMORY_BARRIER ();
}

/**
 * expand and rehash a cuckoo hash
 *
 * 1. double the size of the hash table
 * 2. move items to new locations derived from the new size
 */
static void CV (clib_cuckoo_rehash) (CVT (clib_cuckoo) * h)
{
  CVT (clib_cuckoo_bucket) * old = h->buckets;
  uword old_nbuckets = vec_len (old);
  uword new_nbuckets = 2 * old_nbuckets;
  CVT (clib_cuckoo_bucket) * new =
    vec_dup_aligned (old, CLIB_CACHE_LINE_BYTES);
  /* allocate space */
  vec_validate_aligned (new, new_nbuckets - 1, CLIB_CACHE_LINE_BYTES);
  ASSERT (new_nbuckets == vec_len (new));
  /* store old pointer in to-be-freed list */
  vec_add1 (h->to_be_freed, old);
  /* mark new elements as free */
  CVT (clib_cuckoo_bucket) * bucket;
  for (bucket = new + old_nbuckets; bucket < vec_end (new); ++bucket)
    {
      clib_memset (bucket->elts, 0xff, sizeof (bucket->elts));
    }
  /*
   * this for loop manipulates the new (unseen) memory, so no locks
   * are required here
   */
  uword old_bucket_idx;
  for (old_bucket_idx = 0; old_bucket_idx < old_nbuckets; ++old_bucket_idx)
    {
      /* items in old bucket might be moved to new bucket */
      uword new_bucket_idx = old_bucket_idx + old_nbuckets;
      CVT (clib_cuckoo_bucket) * old_bucket = new + old_bucket_idx;
      CVT (clib_cuckoo_bucket) * new_bucket = new + new_bucket_idx;
      int i = 0;
      int moved = 0;
      clib_cuckoo_bucket_aux_t aux = old_bucket->aux;
      for (i = 0; i < clib_cuckoo_bucket_aux_get_use_count (aux); ++i)
	{
	  CVT (clib_cuckoo_kv) * elt = old_bucket->elts + i;
	  u64 hash = CV (clib_cuckoo_hash) (elt);
	  clib_cuckoo_lookup_info_t old_lookup =
	    CV (clib_cuckoo_calc_lookup) (old, hash);
	  clib_cuckoo_lookup_info_t new_lookup =
	    CV (clib_cuckoo_calc_lookup) (new, hash);
	  if ((old_bucket_idx == old_lookup.bucket1 &&
	       new_bucket_idx == new_lookup.bucket1) ||
	      (old_bucket_idx == old_lookup.bucket2 &&
	       new_bucket_idx == new_lookup.bucket2))
	    {
	      /* move the item to new bucket */
	      CVT (clib_cuckoo_kv) * empty_elt = new_bucket->elts + moved;
	      ASSERT (empty_elt);
	      CV (clib_cuckoo_set_locked_elt)
		(new_bucket, empty_elt, elt, old_bucket->reduced_hashes[i]);
	      CV (clib_cuckoo_free_locked_elt) (elt);
	      ++moved;
	    }
	}
      if (moved)
	{
	  CV (clib_cuckoo_bucket_tidy) (old_bucket);
	  aux =
	    clib_cuckoo_bucket_aux_set_use_count (aux,
						  clib_cuckoo_bucket_aux_get_use_count
						  (aux) - moved);
	  old_bucket->aux = aux;
	  aux = new_bucket->aux;
	  aux =
	    clib_cuckoo_bucket_aux_set_use_count (aux,
						  clib_cuckoo_bucket_aux_get_use_count
						  (aux) + moved);
	  new_bucket->aux = aux;
	}
    }
  h->buckets = new;
#if CLIB_CUCKOO_DEBUG_COUNTERS
  ++h->rehashes;
#endif
  h->garbage_callback (h, h->garbage_ctx);
}

static int CV (clib_cuckoo_bucket_search_internal) (CVT (clib_cuckoo) * h,
						    uword bucket,
						    CVT (clib_cuckoo_kv) *
						    kvp,
						    CVT (clib_cuckoo_kv) *
						    *found)
{
  CVT (clib_cuckoo_bucket) * b = CV (clib_cuckoo_bucket_at_index) (h, bucket);
  int i;
  /* *INDENT-OFF* */
  clib_cuckoo_bucket_foreach_idx_unrolled (i, {
    CVT (clib_cuckoo_kv) *elt = &b->elts[i];
    if (CV (clib_cuckoo_key_compare) (elt->key, kvp->key))
      {
        *found = elt;
        return CLIB_CUCKOO_ERROR_SUCCESS;
      }
  });
  /* *INDENT-ON* */
  return CLIB_CUCKOO_ERROR_NOT_FOUND;
}

int CV (clib_cuckoo_add_del) (CVT (clib_cuckoo) * h,
			      CVT (clib_cuckoo_kv) * kvp, int is_add)
{
  CLIB_CUCKOO_DBG ("%s %U", is_add ? "Add" : "Del", CV (format_cuckoo_kvp),
		   kvp);
  clib_cuckoo_lookup_info_t lookup;
  u64 hash = CV (clib_cuckoo_hash) (kvp);
  clib_spinlock_lock (&h->writer_lock);
  u8 reduced_hash = clib_cuckoo_reduce_hash (hash);
restart:
  lookup = CV (clib_cuckoo_calc_lookup) (h->buckets, hash);
  CVT (clib_cuckoo_bucket) * b =
    CV (clib_cuckoo_bucket_at_index) (h, lookup.bucket1);
  CVT (clib_cuckoo_kv) * found;
  int rv =
    CV (clib_cuckoo_bucket_search_internal) (h, lookup.bucket1, kvp, &found);
  if (CLIB_CUCKOO_ERROR_SUCCESS != rv)
    {
      ASSERT (CLIB_CUCKOO_ERROR_NOT_FOUND == rv);
      b = CV (clib_cuckoo_bucket_at_index) (h, lookup.bucket2);
      rv = CV (clib_cuckoo_bucket_search_internal) (h, lookup.bucket2, kvp,
						    &found);
    }
  if (CLIB_CUCKOO_ERROR_SUCCESS == rv)
    {
      if (is_add)
	{
	  /* prevent readers reading this bucket while we switch the values */
	  clib_cuckoo_bucket_aux_t aux =
	    CV (clib_cuckoo_bucket_version_bump_and_lock) (b);
	  clib_memcpy (&found->value, &kvp->value, sizeof (found->value));
	  CLIB_CUCKOO_DBG ("Replaced existing %U", CV (format_cuckoo_elt),
			   found, b->reduced_hashes[found - b->elts]);
	  CV (clib_cuckoo_bucket_unlock) (b, aux);
	}
      else
	{
	  CV (clib_cuckoo_free_elt_in_bucket) (b, found);
	}
      rv = CLIB_CUCKOO_ERROR_SUCCESS;
      CLIB_CUCKOO_DEEP_SELF_CHECK (h);
      goto unlock;
    }
  if (!is_add)
    {
      CLIB_CUCKOO_DBG ("%U not present in table", CV (format_cuckoo_kvp),
		       kvp);
      rv = CLIB_CUCKOO_ERROR_NOT_FOUND;
      goto unlock;
    }
  /* from this point on, it's add code only */
  ASSERT (CLIB_CUCKOO_ERROR_NOT_FOUND == rv);
  /* fast path: try to search for unoccupied slot in one of the buckets */
  rv = CV (clib_cuckoo_add_fast) (h, &lookup, kvp, reduced_hash);
  CLIB_CUCKOO_DEEP_SELF_CHECK (h);
  if (CLIB_CUCKOO_ERROR_SUCCESS != rv)
    {
    CLIB_CUCKOO_DBG ("Fast insert failed, bucket 1: %wu, bucket 2: %wu\n%U%U", aux.bucket1, aux.bucket2, CV (format_cuckoo_bucket), CV (clib_cuckoo_bucindent: Standaindent: Standard input: 903: Error: Unmatched 'else' rd input: 865: Error:Unmatched 'else' ket_at_index) (h, aux.bucket1),
		       CV (format_cuckoo_bucket),
		       CV (clib_cuckoo_bucket_at_index) (h, aux.bucket2));
      /* slow path */
      rv = CV (clib_cuckoo_add_slow) (h, kvp, &lookup, reduced_hash);
      CLIB_CUCKOO_DEEP_SELF_CHECK (h);
      if (CLIB_CUCKOO_ERROR_SUCCESS != rv)
	{
	  CLIB_CUCKOO_DBG ("Slow insert failed, rehash required:\n%U",
			   CV (format_cuckoo), h, 1);
	  /* ultra slow path */
	  CV (clib_cuckoo_rehash) (h);
	  CLIB_CUCKOO_DEEP_SELF_CHECK (h);
	  CLIB_CUCKOO_DBG ("Restarting add after rehash...");
	  goto restart;
	}
    }
unlock:
  clib_spinlock_unlock (&h->writer_lock);
  return rv;
}

u8 *CV (format_cuckoo) (u8 * s, va_list * args)
{
  CVT (clib_cuckoo) * h = va_arg (*args, CVT (clib_cuckoo) *);
  int verbose = va_arg (*args, int);

  s = format (s, "Hash table %s\n", h->name ? h->name : "(unnamed)");

  uword free = 0;
  uword used = 0;
  uword use_count_total = 0;
  float load_factor;
  CVT (clib_cuckoo_bucket) * b;
  /* *INDENT-OFF* */
  clib_cuckoo_foreach_bucket (b, h, {
    if (verbose)
      {
        s = format (s, "%U", CV (format_cuckoo_bucket), b);
      }
    int i;
    clib_cuckoo_bucket_foreach_idx (i)
    {
      CVT (clib_cuckoo_kv) *elt = &b->elts[i];
      if (CV (clib_cuckoo_kv_is_free) (elt))
        {
          ++free;
        }
      else
        {
          ++used;
        }
    }
    clib_cuckoo_bucket_aux_t aux = b->aux;
    use_count_total += clib_cuckoo_bucket_aux_get_use_count (aux);
  });
  /* *INDENT-ON* */
  s = format (s, "Used slots: %wu\n", used);
  s = format (s, "Use count total: %wu\n", use_count_total);
  s = format (s, "Free slots: %wu\n", free);
  if (free + used != 0)
    load_factor = ((float) used) / ((float) (free + used));
  else
    load_factor = 0.0;
  s = format (s, "Load factor: %.2f\n", load_factor);
#if CLIB_CUCKOO_DEBUG_COUNTERS
  s = format (s, "BFS attempts limited by max steps: %lld\n",
	      h->steps_exceeded);
  s = format (s, "BFS cutoffs due to empty queue: %lld\n",
	      h->bfs_queue_emptied);
  s = format (s, "Fast adds: %lld\n", h->fast_adds);
  s = format (s, "Slow adds: %lld\n", h->slow_adds);
  s = format (s, "Rehashes: %lld\n", h->rehashes);
#endif
  return s;
}

float CV (clib_cuckoo_calculate_load_factor) (CVT (clib_cuckoo) * h)
{
  uword nonfree = 0;
  uword all = 0;
  CVT (clib_cuckoo_bucket) * bucket;
  /* *INDENT-OFF* */
  clib_cuckoo_foreach_bucket (bucket, h, {
    int i;
    clib_cuckoo_bucket_foreach_idx (i)
    {
      CVT (clib_cuckoo_kv) *elt = bucket->elts + i;
      ++all;
      if (!CV (clib_cuckoo_kv_is_free) (elt))
        {
          ++nonfree;
        }
    }
  });
  /* *INDENT-ON* */
  if (all)
    return (float) nonfree / (float) all;
  else
    return 0.0;
}

/** @endcond */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */