tests/util_allocator.cpp

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 */

#include "util_allocator.h"

void *cx_malloc_testing(void *d, size_t n) {
    auto data = reinterpret_cast<CxTestingAllocator *>(d);
    void *ptr = malloc(n);
    data->alloc_total++;
    if (ptr == nullptr) {
        data->alloc_failed++;
    } else {
        data->tracked.insert(ptr);
    }
    return ptr;
}

void *cx_realloc_testing(void *d, void *mem, size_t n) {
    auto data = reinterpret_cast<CxTestingAllocator *>(d);
    void *ptr = realloc(mem, n);
    if (ptr == mem) {
        return ptr;
    } else {
        data->alloc_total++;
        if (ptr == nullptr) {
            data->alloc_failed++;
        } else {
            data->free_total++;
            if (data->tracked.erase(mem) == 0) {
                data->free_failed++;
            }
            data->tracked.insert(ptr);
        }
        return ptr;
    }
}

void *cx_calloc_testing(void *d, size_t nelem, size_t n) {
    auto data = reinterpret_cast<CxTestingAllocator *>(d);
    void *ptr = calloc(nelem, n);
    data->alloc_total++;
    if (ptr == nullptr) {
        data->alloc_failed++;
    } else {
        data->tracked.insert(ptr);
    }
    return ptr;
}

void cx_free_testing(void *d, void *mem) {
    auto data = reinterpret_cast<CxTestingAllocator *>(d);
    data->free_total++;
    if (data->tracked.erase(mem) == 0) {
        data->free_failed++;
        // do not even attempt to free mem, because it is likely to segfault
    } else {
        free(mem);
    }
}

cx_allocator_class cx_testing_allocator_class = {
        cx_malloc_testing,
        cx_realloc_testing,
        cx_calloc_testing,
        cx_free_testing
};

CxTestingAllocator::CxTestingAllocator() : CxAllocator() {
    cl = &cx_testing_allocator_class;
    data = this;
}

bool CxTestingAllocator::used() const {
    return alloc_total > 0;
}

bool CxTestingAllocator::verify() const {
    return tracked.empty() && alloc_failed == 0 && free_failed == 0 && alloc_total == free_total;
}

// SELF-TEST

#include <gtest/gtest.h>

TEST(TestingAllocator, ExpectFree) {
    CxTestingAllocator allocator;

    ASSERT_TRUE(allocator.verify());
    EXPECT_FALSE(allocator.used());
    auto ptr = cxMalloc(&allocator, 16);
    EXPECT_TRUE(allocator.used());
    ASSERT_NE(ptr, nullptr);
    EXPECT_FALSE(allocator.verify());

    cxFree(&allocator, ptr);
    EXPECT_TRUE(allocator.verify());
}

TEST(TestingAllocator, DetectDoubleFree) {
    CxTestingAllocator allocator;

    ASSERT_TRUE(allocator.verify());
    auto ptr = cxMalloc(&allocator, 16);
    ASSERT_NE(ptr, nullptr);

    cxFree(&allocator, ptr);
    EXPECT_TRUE(allocator.verify());
    ASSERT_NO_FATAL_FAILURE(cxFree(&allocator, ptr));
    EXPECT_FALSE(allocator.verify());
}

TEST(TestingAllocator, FreeUntracked) {
    CxTestingAllocator allocator;

    auto ptr = malloc(16);
    ASSERT_TRUE(allocator.verify());
    ASSERT_NO_FATAL_FAILURE(cxFree(&allocator, ptr));
    EXPECT_FALSE(allocator.verify());
    ASSERT_NO_FATAL_FAILURE(free(ptr));
}

TEST(TestingAllocator, FullLifecycleWithRealloc) {
    CxTestingAllocator allocator;
    ASSERT_TRUE(allocator.verify());
    auto ptr = cxMalloc(&allocator, 16);
    ASSERT_NE(ptr, nullptr);
    EXPECT_EQ(allocator.tracked.size(), 1);
    ptr = cxRealloc(&allocator, ptr, 256);
    ASSERT_NE(ptr, nullptr);
    EXPECT_EQ(allocator.tracked.size(), 1);
    cxFree(&allocator, ptr);
    EXPECT_TRUE(allocator.verify());
}

TEST(TestingAllocator, CallocInitializes) {
    CxTestingAllocator allocator;
    const char zeros[16] = {0};
    auto ptr = cxCalloc(&allocator, 16, 1);
    EXPECT_EQ(memcmp(ptr, zeros, 16), 0);
    cxFree(&allocator, ptr);
    EXPECT_TRUE(allocator.verify());
}