src/third_party/llvm-project/compiler-rt/test/asan/TestCases/Linux/release_to_os_test.cc

// Tests ASAN_OPTIONS=allocator_release_to_os=1

// RUN: %clangxx_asan -std=c++11 %s -o %t
// RUN: %env_asan_opts=allocator_release_to_os_interval_ms=0 %run %t 2>&1 | FileCheck %s --check-prefix=RELEASE
// RUN: %env_asan_opts=allocator_release_to_os_interval_ms=-1 %run %t 2>&1 | FileCheck %s --check-prefix=NO_RELEASE
// RUN: %env_asan_opts=allocator_release_to_os_interval_ms=-1 %run %t force 2>&1 | FileCheck %s --check-prefix=FORCE_RELEASE

// REQUIRES: x86_64-target-arch

#include <algorithm>
#include <assert.h>
#include <random>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sanitizer/allocator_interface.h>
#include <sanitizer/asan_interface.h>

void MallocReleaseStress() {
  const size_t kNumChunks = 10000;
  const size_t kAllocSize = 100;
  const size_t kNumIter = 100;
  uintptr_t *chunks[kNumChunks] = {0};
  std::mt19937 r;

  for (size_t iter = 0; iter < kNumIter; iter++) {
    std::shuffle(chunks, chunks + kNumChunks, r);
    size_t to_replace = rand() % kNumChunks;
    for (size_t i = 0; i < kNumChunks; i++) {
      if (chunks[i])
        assert(chunks[i][0] == (uintptr_t)chunks[i]);
      if (i < to_replace) {
        delete [] chunks[i];
        chunks[i] = new uintptr_t[kAllocSize];
        chunks[i][0] = (uintptr_t)chunks[i];
      }
    }
  }
  for (auto p : chunks)
    delete[] p;
}

int main(int argc, char **argv) {
  MallocReleaseStress();
  if (argc > 1 && !strcmp("force", argv[1]))
    __sanitizer_purge_allocator();
  __asan_print_accumulated_stats();
}

// RELEASE: mapped:{{.*}}releases: {{[1-9]}}
// NO_RELEASE: mapped:{{.*}}releases: 0
// FORCE_RELEASE: mapped:{{.*}}releases: {{[1-9]}}