Add xmalloc(), xcalloc() functions.

[pintos-anon] / src / threads / malloc.c

diff --git a/src/threads/malloc.c b/src/threads/malloc.c
index 0cb5f9d997def46ce1570b40eb5d9e1195216f3c..9c83e3d438f780199166c3c92aa0893aa842f98f 100644 (file)
--- a/src/threads/malloc.c
+++ b/src/threads/malloc.c
@@ -153,6 +153,19 @@ malloc (size_t size)
   return b;
 }
 
+/* Obtains and returns a new block of at least SIZE bytes.
+   Panics if memory is not available.  It is unacceptable for the
+   kernel to panic in normal operation, so this function should
+   only be used during kernel initialization. */
+void *
+xmalloc (size_t size) 
+{
+  void *p = malloc (size);
+  if (p == NULL && size > 0)
+    PANIC ("memory exhausted");
+  return p;
+}
+
 /* Allocates and return A times B bytes initialized to zeroes.
    Returns a null pointer if memory is not available. */
 void *
@@ -161,7 +174,7 @@ calloc (size_t a, size_t b)
   void *p;
   size_t size;
 
-  /* Calculate block size. */
+  /* Calculate block size and make sure it fits in size_t. */
   size = a * b;
   if (size < a || size < b)
     return NULL;
@@ -174,6 +187,19 @@ calloc (size_t a, size_t b)
   return p;
 }
 
+/* Allocates and return A times B bytes initialized to zeroes.
+   Panics if memory is not available.  It is unacceptable for the
+   kernel to panic in normal operation, so this function should
+   only be used during kernel initialization. */
+void *
+xcalloc (size_t a, size_t b) 
+{
+  void *p = calloc (a, b);
+  if (p == NULL && a > 0 && b > 0)
+    PANIC ("memory exhausted");
+  return p;
+}
+
 /* Frees block P, which must have been previously allocated with
    malloc() or calloc(). */
 void