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