compiler-rt/test/tsan/large_malloc_meta.cpp

   1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
   2
   3 // UNSUPPORTED: ios
   4
   5 #include "test.h"
   6 #include <sys/mman.h>
   7
   8 // Test for previously unbounded memory consumption for large mallocs.
   9 // Code allocates a large memory block (that is handled by LargeMmapAllocator),
  10 // and forces allocation of meta shadow for the block. Then freed the block.
  11 // But meta shadow was not unmapped. Then code occupies the virtual memory
  12 // range of the block with something else (that does not need meta shadow).
  13 // And repeats. As the result meta shadow growed infinitely.
  14 // This program used to consume >2GB. Now it consumes <50MB.
  15
  16 int main() {
  17   for (int i = 0; i < 1000; i++) {
  18     const int kSize = 1 << 20;
  19     const int kPageSize = 4 << 10;
  20     volatile int *p = new int[kSize];
  21     for (int j = 0; j < kSize; j += kPageSize / sizeof(*p))
  22       __atomic_store_n(&p[i], 1, __ATOMIC_RELEASE);
  23     delete[] p;
  24     mmap(0, kSize * sizeof(*p) + kPageSize, PROT_NONE, MAP_PRIVATE | MAP_ANON,
  25         -1, 0);
  26   }
  27   fprintf(stderr, "DONE\n");
  28   return 0;
  29 }
  30
  31 // CHECK: DONE