From b6d200edbe0b6ef6b10fbd87d863766ca567b013 Mon Sep 17 00:00:00 2001
From: Nuutti Varvikko <nvarvikko@gmail.com>
Date: Tue, 7 Sep 2021 15:20:40 +0300
Subject: [PATCH] check memory allocation

---
 game.c  | 18 ++++++++++++------
 game.h  |  2 +-
 snake.c | 13 +++++++++++--
 snake.h |  4 ++--
 4 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/game.c b/game.c
index 6cc4b33..4c1ee1b 100644
--- a/game.c
+++ b/game.c
@@ -23,7 +23,9 @@ int run(void)
     timeout(1000.0 / INPUT_RATE);
 
     generate_apple(ARENA_WIDTH, ARENA_HEIGHT);
-    init_snake();
+    if (!init_snake()) {
+        return QUIT;
+    }
 
     while (true) {
         if (process() == QUIT) {
@@ -56,7 +58,9 @@ int process(void)
             break;
     }
 
-    update();
+    if (!update()) {
+        return QUIT;
+    }
 
     return RUNNING;
 }
@@ -89,7 +93,7 @@ int input(void)
     return RUNNING;
 }
 
-void update(void)
+int update(void)
 { 
     if (!check_win_size()) {
 
@@ -112,7 +116,9 @@ void update(void)
         if (!(state == PAUSE || state == GAME_OVER || state == INTERRUPT)) {
             if (grow_snake_next) {
                 grow_snake_next = 0;
-                grow_snake();
+                if (!grow_snake()) {
+                    return 0;
+                }
             } else {
                 update_snake();
             }
@@ -137,17 +143,17 @@ void update(void)
         draw();
         refresh();
     }
+
+    return 1;
 }
 
 void draw(void)
 {
     draw_arena(ARENA_WIDTH, ARENA_HEIGHT);
 
-    /* print score */
     sprintf(text_buffer, "\n\n  Score: %d", score);
     draw_text(text_buffer);
 
-    // sprintf(text_buffer, "\nr - restart\nq - quit");
     draw_text("\n\n  r - restart\n  q - quit");
 
     if (state == GAME_OVER) {
diff --git a/game.h b/game.h
index 8df00f2..71546f3 100644
--- a/game.h
+++ b/game.h
@@ -28,7 +28,7 @@ enum {
 int run(void);
 int process(void);
 int input(void);
-void update(void);
+int update(void);
 void draw(void);
 
 #endif
diff --git a/snake.c b/snake.c
index ee94208..5a15e63 100644
--- a/snake.c
+++ b/snake.c
@@ -5,7 +5,7 @@
 queue snake;
 int snake_dir;
 
-void init_snake(void)
+int init_snake(void)
 {
     struct node *nodes[SNAKE_MIN_LENGTH];
     int i, x, y;
@@ -15,6 +15,9 @@ void init_snake(void)
 
     for (i = 0; i < SNAKE_MIN_LENGTH; i++) {
         nodes[i] = (struct node *) malloc(sizeof(struct node));
+        if (!nodes[i]) {
+            return 0;
+        }
 
         nodes[i]->x = x + i;
         nodes[i]->y = y;
@@ -23,6 +26,7 @@ void init_snake(void)
     }
 
     snake_dir = RIGHT;
+    return 1;
 }
 
 void empty_snake(void)
@@ -90,10 +94,15 @@ void insert_snake_node(struct node *new)
     }
 }
 
-void grow_snake(void)
+int grow_snake(void)
 {
     struct node *new = (struct node *) malloc(sizeof(struct node));
+    if (!new) {
+        return 0;
+    }
+
     insert_snake_node(new);
+    return 1;
 }
 
 int snake_has_eaten(int apple_x, int apple_y)
diff --git a/snake.h b/snake.h
index e31aae8..13225b1 100644
--- a/snake.h
+++ b/snake.h
@@ -13,11 +13,11 @@ enum direction {
 extern queue snake;
 extern int snake_dir;
 
-void init_snake(void);
+int init_snake(void);
 void empty_snake(void);
 void update_snake(void);
 void turn_snake(int direction, int opposite, int *dir_changed);
-void grow_snake(void);
+int grow_snake(void);
 void insert_snake_node(struct node *new);
 int snake_has_eaten(int apple_x, int apple_y);
 int check_snake_location(int arena_Width, int arena_height);