811_fault_injection.c File Reference

Unit test to verify resource cleanup under memory allocation failures. More...

#include "common/double_tap.h"
#include <infix/infix.h>
#include <stddef.h>
#include <pthread.h>

Include dependency graph for 811_fault_injection.c:

Macros
#define	infix_malloc   test_malloc
#define	infix_calloc   test_calloc
#define	infix_free   test_free
#define	infix_realloc   test_realloc
#define	DBLTAP_IMPLEMENTATION
#define	ALLOCATOR_LOCK()   pthread_mutex_lock(&allocator_mutex)
#define	ALLOCATOR_UNLOCK()   pthread_mutex_unlock(&allocator_mutex)
#define	ALLOCATOR_INIT()   ((void)0)

Functions
void	setup_fault_injector (int fail_after_n_allocs)
void	reset_fault_injector ()
void *	test_malloc (size_t size)
void *	test_calloc (size_t num, size_t size)
void	test_free (void *ptr)
void *	test_realloc (void *ptr, size_t new_size)
void	fault_injection_handler (void)
	subtest ("Leak test for infix_forward_create failures")
	subtest ("Leak test for infix_reverse_create_callback failures")
	subtest ("Leak test for infix_type_from_signature failures")

Variables
static int	allocation_countdown = -1
static int	allocation_counter = 0
static bool	fault_triggered = false
static pthread_mutex_t	allocator_mutex = PTHREAD_MUTEX_INITIALIZER
	TEST

Detailed Description

Unit test to verify resource cleanup under memory allocation failures.

This test uses a fault injection technique to test the library's resilience to memory allocation failures. It overrides the standard malloc and calloc functions with custom versions (test_malloc, test_calloc) that can be configured to fail after a specific number of successful allocations.

The test strategy is as follows:

1. It iterates from N = 0 to a maximum limit.
2. In each iteration N, it configures the custom allocator to fail on the N-th allocation.
3. It then calls a complex infix API function (e.g., infix_forward_create).
4. If the allocation failure was triggered, it asserts that the API function correctly returned an INFIX_ERROR_ALLOCATION_FAILED status.

The most important part of this test is not the assertion itself, but running it under a memory analysis tool like Valgrind or AddressSanitizer (ASan). A "pass" for this test is a clean report from the memory tool, which proves that even when an allocation fails midway through an operation, the infix library correctly cleans up all memory it had allocated up to that point, preventing memory leaks in error paths.

Macro Definition Documentation

ALLOCATOR_INIT

ALLOCATOR_INIT

(

)

((void)0)

ALLOCATOR_LOCK

#define ALLOCATOR_LOCK

(

)

pthread_mutex_lock(&allocator_mutex)

ALLOCATOR_UNLOCK

#define ALLOCATOR_UNLOCK

(

)

pthread_mutex_unlock(&allocator_mutex)

DBLTAP_IMPLEMENTATION

#define DBLTAP_IMPLEMENTATION

infix_calloc

#define infix_calloc   test_calloc

infix_free

#define infix_free   test_free

infix_malloc

#define infix_malloc   test_malloc

infix_realloc

#define infix_realloc   test_realloc

Function Documentation

fault_injection_handler()

void fault_injection_handler

(

void

)

reset_fault_injector()

void reset_fault_injector

(

)

setup_fault_injector()

void setup_fault_injector

(

int

fail_after_n_allocs

)

subtest() [1/3]

subtest

(

"Leak test for infix_forward_create failures"

)

subtest() [2/3]

subtest

(

"Leak test for infix_reverse_create_callback failures"

)

subtest() [3/3]

subtest

(

"Leak test for infix_type_from_signature failures"

)

test_calloc()

void * test_calloc	(	size_t	num,
		size_t	size
	)

test_free()

void test_free

(

void *

ptr

)

test_malloc()

void * test_malloc

(

size_t

size

)

test_realloc()

void * test_realloc	(	void *	ptr,
		size_t	new_size
	)

Variable Documentation

allocation_countdown

int allocation_countdown = -1

static

allocation_counter

int allocation_counter = 0

static

allocator_mutex

pthread_mutex_t allocator_mutex = PTHREAD_MUTEX_INITIALIZER

static

fault_triggered

bool fault_triggered = false

static

TEST

TEST

Initial value:

{
    plan(3)