Files
arena-allocator/test/test_arena.c
2025-06-20 22:27:20 +02:00

154 lines
4.3 KiB
C

#include "arena.h"
#include "knob.h"
#include <signal.h>
#include <stdio.h> // fprintf
#include <stdlib.h> // exit, EXIT_FAILURE
#include <string.h> // memset
#include <sys/wait.h> // waitpid
#include <unistd.h> // sysconf
int main()
{
size_t page_size = sysconf(_SC_PAGE_SIZE);
if (page_size == -1) {
perror("sysconf");
exit(EXIT_FAILURE);
}
/*
* test arena from arena_new();
* ===============================
*/
{
fprintf(stderr, "creating new arena with arena_new()\n ");
arena_t a = arena_new();
if (arena_new_failed(&a)) {
fprintf(stderr, "arena_new failed\n");
exit(EXIT_FAILURE);
}
fprintf(stderr, "OK\n");
fprintf(stderr, "attempting many small allocations\n ");
for (int i = 0; i < page_size * 8; i++) {
char* s = arena_alloc(&a, 4 * sizeof *s);
if (!s) {
fprintf(stderr, "arena_alloc failed\n");
exit(EXIT_FAILURE);
}
memset(s, 'a', 4);
}
fprintf(stderr, "OK\n");
fprintf(stderr, "testing allocations of cap * 3 + 123\n ");
for (int i = 0; i < 2; i++) {
size_t n = a.cap * 3 + 123;
volatile char* s = arena_alloc(&a, n);
if (!s) {
fprintf(stderr, "arena_alloc failed\n");
exit(EXIT_FAILURE);
}
}
fprintf(stderr, "OK\n");
fprintf(stderr, "calling arena_delete() on arena from arena_new()\n ");
int ok = arena_delete(&a);
if (ok == -1) {
fprintf(stderr, "arena_delete failed\n");
exit(EXIT_FAILURE);
}
fprintf(stderr, "OK\n");
}
/*
* test arena made by arena_attach();
* ===============================
*/
{
fprintf(stderr, "creating new arena with arena_attach() and malloc()\n ");
char* p = malloc(page_size);
if (!p) {
perror("malloc");
exit(EXIT_FAILURE);
}
arena_t a = arena_attach(p, page_size);
fprintf(stderr, "OK\n");
bool failed = false;
fprintf(stderr, "try to grow more than the buffer size (should fail)\n ");
int i;
for (i=0; i < page_size + 1; i++) {
char* s = arena_alloc(&a, 8);
if (!s) {
failed = true;
break;
}
}
if (!failed) {
fprintf(stderr, "allocation was supposed to fail, but didn't\n");
exit(EXIT_FAILURE);
} else if (i != page_size / KNOB_ALIGNMENT ) {
fprintf(stderr, "allocation failed after %d allocations, but should fail after %d!\n", i, page_size/sizeof(void*));
exit(EXIT_FAILURE);
}
fprintf(stderr, "OK\n");
fprintf(stderr, "deleting an arena not made with arena_new (should fail)\n ");
int ok = arena_delete(&a);
if (ok != -1) {
fprintf(stderr, "arena_delete was supposed to fail, but didn't\n");
exit(EXIT_FAILURE);
}
fprintf(stderr, "OK\n");
free(arena_detatch(a));
}
/*
* test the memory protection
* ===============================
*/
{
fprintf(stderr, "attempting to access memory beyond arena cap (should sigsegv)\n ");
pid_t p;
switch (p = fork()) {
case -1: /* error */
perror("fork()");
exit(EXIT_FAILURE);
case 0: /* child */
arena_t a = arena_new();
if (arena_new_failed(&a)) {
fprintf(stderr, "arena_new failed\n");
exit(EXIT_FAILURE);
}
char* s = arena_alloc(&a, 12345);
if (!s) {
fprintf(stderr, "arena_alloc failed\n");
exit(EXIT_FAILURE);
}
// should sigsegv
a.data[a.cap] = 1;
exit(EXIT_SUCCESS);
}
int status;
int ok = waitpid(p, &status, 0);
if (!ok) {
perror("waitpid");
}
if (!( WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV)) {
fprintf(stderr, "allocating beyond arena cap succeeded when it shouldn't!\n");
exit(EXIT_FAILURE);
}
fprintf(stderr, "OK\n");
}
return EXIT_SUCCESS;
}