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low_level_alloc_test.cc (5608B)


      1 // Copyright 2017 The Abseil Authors.
      2 //
      3 // Licensed under the Apache License, Version 2.0 (the "License");
      4 // you may not use this file except in compliance with the License.
      5 // You may obtain a copy of the License at
      6 //
      7 //      https://www.apache.org/licenses/LICENSE-2.0
      8 //
      9 // Unless required by applicable law or agreed to in writing, software
     10 // distributed under the License is distributed on an "AS IS" BASIS,
     11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 // See the License for the specific language governing permissions and
     13 // limitations under the License.
     14 
     15 #include "absl/base/internal/low_level_alloc.h"
     16 
     17 #include <stdint.h>
     18 #include <stdio.h>
     19 #include <stdlib.h>
     20 #include <thread>  // NOLINT(build/c++11)
     21 #include <unordered_map>
     22 #include <utility>
     23 
     24 #ifdef __EMSCRIPTEN__
     25 #include <emscripten.h>
     26 #endif
     27 
     28 #include "absl/container/node_hash_map.h"
     29 
     30 namespace absl {
     31 ABSL_NAMESPACE_BEGIN
     32 namespace base_internal {
     33 namespace {
     34 
     35 // This test doesn't use gtest since it needs to test that everything
     36 // works before main().
     37 #define TEST_ASSERT(x)                                           \
     38  if (!(x)) {                                                    \
     39    printf("TEST_ASSERT(%s) FAILED ON LINE %d\n", #x, __LINE__); \
     40    abort();                                                     \
     41  }
     42 
     43 // a block of memory obtained from the allocator
     44 struct BlockDesc {
     45  char *ptr;      // pointer to memory
     46  int len;        // number of bytes
     47  int fill;       // filled with data starting with this
     48 };
     49 
     50 // Check that the pattern placed in the block d
     51 // by RandomizeBlockDesc is still there.
     52 static void CheckBlockDesc(const BlockDesc &d) {
     53  for (int i = 0; i != d.len; i++) {
     54    TEST_ASSERT((d.ptr[i] & 0xff) == ((d.fill + i) & 0xff));
     55  }
     56 }
     57 
     58 // Fill the block "*d" with a pattern
     59 // starting with a random byte.
     60 static void RandomizeBlockDesc(BlockDesc *d) {
     61  d->fill = rand() & 0xff;
     62  for (int i = 0; i != d->len; i++) {
     63    d->ptr[i] = (d->fill + i) & 0xff;
     64  }
     65 }
     66 
     67 // Use to indicate to the malloc hooks that
     68 // this calls is from LowLevelAlloc.
     69 static bool using_low_level_alloc = false;
     70 
     71 // n times, toss a coin, and based on the outcome
     72 // either allocate a new block or deallocate an old block.
     73 // New blocks are placed in a std::unordered_map with a random key
     74 // and initialized with RandomizeBlockDesc().
     75 // If keys conflict, the older block is freed.
     76 // Old blocks are always checked with CheckBlockDesc()
     77 // before being freed.  At the end of the run,
     78 // all remaining allocated blocks are freed.
     79 // If use_new_arena is true, use a fresh arena, and then delete it.
     80 // If call_malloc_hook is true and user_arena is true,
     81 // allocations and deallocations are reported via the MallocHook
     82 // interface.
     83 static void Test(bool use_new_arena, bool call_malloc_hook, int n) {
     84  typedef absl::node_hash_map<int, BlockDesc> AllocMap;
     85  AllocMap allocated;
     86  AllocMap::iterator it;
     87  BlockDesc block_desc;
     88  int rnd;
     89  LowLevelAlloc::Arena *arena = nullptr;
     90  if (use_new_arena) {
     91    int32_t flags = call_malloc_hook ? LowLevelAlloc::kCallMallocHook : 0;
     92    arena = LowLevelAlloc::NewArena(flags);
     93  }
     94  for (int i = 0; i != n; i++) {
     95    if (i != 0 && i % 10000 == 0) {
     96      printf(".");
     97      fflush(stdout);
     98    }
     99 
    100    switch (rand() & 1) {      // toss a coin
    101    case 0:     // coin came up heads: add a block
    102      using_low_level_alloc = true;
    103      block_desc.len = rand() & 0x3fff;
    104      block_desc.ptr = reinterpret_cast<char *>(
    105          arena == nullptr
    106              ? LowLevelAlloc::Alloc(block_desc.len)
    107              : LowLevelAlloc::AllocWithArena(block_desc.len, arena));
    108      using_low_level_alloc = false;
    109      RandomizeBlockDesc(&block_desc);
    110      rnd = rand();
    111      it = allocated.find(rnd);
    112      if (it != allocated.end()) {
    113        CheckBlockDesc(it->second);
    114        using_low_level_alloc = true;
    115        LowLevelAlloc::Free(it->second.ptr);
    116        using_low_level_alloc = false;
    117        it->second = block_desc;
    118      } else {
    119        allocated[rnd] = block_desc;
    120      }
    121      break;
    122    case 1:     // coin came up tails: remove a block
    123      it = allocated.begin();
    124      if (it != allocated.end()) {
    125        CheckBlockDesc(it->second);
    126        using_low_level_alloc = true;
    127        LowLevelAlloc::Free(it->second.ptr);
    128        using_low_level_alloc = false;
    129        allocated.erase(it);
    130      }
    131      break;
    132    }
    133  }
    134  // remove all remaining blocks
    135  while ((it = allocated.begin()) != allocated.end()) {
    136    CheckBlockDesc(it->second);
    137    using_low_level_alloc = true;
    138    LowLevelAlloc::Free(it->second.ptr);
    139    using_low_level_alloc = false;
    140    allocated.erase(it);
    141  }
    142  if (use_new_arena) {
    143    TEST_ASSERT(LowLevelAlloc::DeleteArena(arena));
    144  }
    145 }
    146 
    147 // LowLevelAlloc is designed to be safe to call before main().
    148 static struct BeforeMain {
    149  BeforeMain() {
    150    Test(false, false, 50000);
    151    Test(true, false, 50000);
    152    Test(true, true, 50000);
    153  }
    154 } before_main;
    155 
    156 }  // namespace
    157 }  // namespace base_internal
    158 ABSL_NAMESPACE_END
    159 }  // namespace absl
    160 
    161 int main(int argc, char *argv[]) {
    162  // The actual test runs in the global constructor of `before_main`.
    163  printf("PASS\n");
    164 #ifdef __EMSCRIPTEN__
    165  // clang-format off
    166 // This is JS here. Don't try to format it.
    167    MAIN_THREAD_EM_ASM({
    168      if (ENVIRONMENT_IS_WEB) {
    169        if (typeof TEST_FINISH === 'function') {
    170          TEST_FINISH($0);
    171        } else {
    172          console.error('Attempted to exit with status ' + $0);
    173          console.error('But TEST_FINSIHED is not a function.');
    174        }
    175      }
    176    }, 0);
    177 // clang-format on
    178 #endif
    179  return 0;
    180 }