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//===-- rusage.cpp --------------------------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "klee/KDAlloc/kdalloc.h"
#include "gtest/gtest.h"
#include <vector>
#include <sys/resource.h>
// This test is disabled for asan and msan because they create additional page
// faults
#if !defined(__has_feature) || \
(!__has_feature(memory_sanitizer) && !__has_feature(address_sanitizer))
std::size_t write_to_allocations(std::vector<void *> &allocations) {
struct rusage ru;
getrusage(RUSAGE_SELF, &ru);
auto initial = ru.ru_minflt;
for (auto p : allocations) {
auto pp = static_cast<char *>(p);
*pp = 1;
}
getrusage(RUSAGE_SELF, &ru);
return ru.ru_minflt - initial;
}
TEST(KDAllocTest, Rusage) {
// initialize a factory and an associated allocator (using the location "0"
// gives an OS-assigned location)
klee::kdalloc::AllocatorFactory factory(static_cast<std::size_t>(1) << 30,
0); // 1 GB
klee::kdalloc::Allocator allocator = factory.makeAllocator();
std::vector<void *> allocations;
for (std::size_t i = 0; i < 1000; ++i) {
allocations.emplace_back(allocator.allocate(16));
}
// When writing to allocations we should have at least one page fault per
// object, but may have more due to unrelated behavior (e.g., swapping). In
// the hopes that such interference is relatively rare, we try a few times to
// encounter a perfect run, where the number of page faults matches the number
// of allocated objects exactly.
constexpr std::size_t tries = 100;
for (std::size_t i = 0; i < tries; ++i) {
auto pageFaults = write_to_allocations(allocations);
if (pageFaults == allocations.size()) {
// we have a perfect match
return;
}
ASSERT_GE(pageFaults, allocations.size())
<< "There should be at least as many page faults as allocated objects";
factory.getMapping().clear();
}
FAIL()
<< "No single try out of " << tries
<< " yielded a perfect match between page faults and allocated objects";
}
#endif
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