From 6b46af52aa86780783e2dad5c41ae0f05124575c Mon Sep 17 00:00:00 2001
From: Ole Kristian Morud <ole.morud@gmail.com>
Date: Mon, 15 Jan 2024 16:33:17 +0100
Subject: [PATCH] Update tests

Add test for arena_attach
---
 src/CMakeLists.txt  |   4 +-
 test/CMakeLists.txt |   6 ++-
 test/README         |   6 +++
 test/test_arena.c   | 108 ++++++++++++++++++++++++++++++++------------
 4 files changed, 92 insertions(+), 32 deletions(-)
 create mode 100644 test/README

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index d9ca6e3..aaa5d09 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,4 @@
 
-add_library(arena_allocator arena.c)
+add_library(arena arena.c)
 
-target_include_directories(arena_allocator PUBLIC ../include)
+target_include_directories(arena PUBLIC ../include)
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index fd5e1e6..74f75c4 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,4 +1,6 @@
 
-add_executable(arena_allocator_test test_arena.c ../src/arena.c)
+include_directories(${CMAKE_SOURCE_DIR}/include)
 
-target_include_directories(arena_allocator_test PUBLIC ../include)
+add_executable(test_arena test_arena.c)
+
+target_link_libraries(test_arena arena)
diff --git a/test/README b/test/README
new file mode 100644
index 0000000..5ee62ce
--- /dev/null
+++ b/test/README
@@ -0,0 +1,6 @@
+
+run compiled test in conjunction with other tools, e.g.
+
+/usr/bin/time strace -e trace=\!write ./test/test_arena
+
+ 
diff --git a/test/test_arena.c b/test/test_arena.c
index ed07b63..54e8ea3 100644
--- a/test/test_arena.c
+++ b/test/test_arena.c
@@ -1,53 +1,105 @@
 
 #include "arena.h"
+#include "knob.h"
+
 #include <stdlib.h> // exit(), EXIT_FAILURE
 #include <string.h> // memset
 #include <stdio.h>  // fprintf
 #include <unistd.h> // sysconf
 
+
+
 int main()
 {
+    // calling print functions early makes my strace output more readable
+    printf("\n");
+    fprintf(stderr, "\n");
 
-    printf(".");
-
-    arena_t a = arena_new();
-    if (arena_new_failed(&a)) {
-        fprintf(stderr, "\narena_new failed");
-        exit(EXIT_FAILURE);
-    }
-
-    size_t size = sysconf(_SC_PAGE_SIZE);
-    if (size == -1) {
+    size_t page_size = sysconf(_SC_PAGE_SIZE);
+    if (page_size == -1) {
         perror("sysconf");
         exit(EXIT_FAILURE);
     }
 
-    // test many small allocations
-    for (int i = 0; i < size * 8; i++) {
-        char* s = arena_alloc(&a, 4 * sizeof *s);
-        if (!s) {
-            fprintf(stderr, "\narena_alloc failed");
+    /*
+     * test arena from arena_new();
+     * ===============================
+     */
+    {
+        write(STDERR_FILENO, "\n\n", 2);
+        arena_t a = arena_new();
+        if (arena_new_failed(&a)) {
+            fprintf(stderr, "arena_new failed\n");
             exit(EXIT_FAILURE);
         }
-        memset(s, 'a', 4);
-    }
 
-    // test a few allocations above the cap*2
-    for (int i = 0; i < 2; i++) {
-        size_t n = a.cap * 3 + 123;
-        printf("allocating %d bytes\n", n);
-        volatile char* s = arena_alloc(&a, n);
-        if (!s) {
-            fprintf(stderr, "\narena_alloc failed");
+        // test many small allocations
+        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);
+        }
+
+        // test a few allocations above the cap*2
+        for (int i = 0; i < 2; i++) {
+            size_t n = a.cap * 3 + 123;
+            printf("allocating %d bytes\n", n);
+            volatile char* s = arena_alloc(&a, n);
+            if (!s) {
+                fprintf(stderr, "arena_alloc failed\n");
+                exit(EXIT_FAILURE);
+            }
+        }
+
+        int ok = arena_delete(&a);
+        if (ok == -1) {
+            fprintf(stderr, "arena_delete failed\n");
             exit(EXIT_FAILURE);
         }
     }
 
-    int ok = arena_delete(&a);
-    if (ok == -1) {
-        fprintf(stderr, "arena_delete failed");
-        exit(EXIT_FAILURE);
+    /*
+     * test arena made by arena_attach();
+     * ===============================
+     */
+    {
+        write(STDERR_FILENO, "\n\n", 2);
+        char* p = malloc(page_size);
+        arena_t a = arena_attach(p, page_size);
+
+        bool failed = false;
+
+        // attempt to grow more than the buffer size
+        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, should instead fail after %d. Bad!\n", i, page_size/sizeof(void*));
+            exit(EXIT_FAILURE);
+        } else {
+            fprintf(stderr, "arena from arena_attach failed after %d allocations, good!", i);
+        }
+
+        // deleting an arena not made with arena_new should fail
+        int ok = arena_delete(&a);
+        if (ok != -1) {
+            fprintf(stderr, "arena_delete was supposed to fail, but didn't\n");
+            exit(EXIT_FAILURE);
+        }
     }
+
     
     return EXIT_SUCCESS;
 }