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