Port liballoc to userspace

libmsl/alloc/liballoc.h

@@ -0,0 +1,93 @@
+#ifndef _LIBALLOC_H
+#define _LIBALLOC_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define _ALLOC_SKIP_DEFINE
+
+// If we are told to not define our own size_t, then we
+// skip the define.
+#ifndef _ALLOC_SKIP_DEFINE
+
+#ifndef _HAVE_SIZE_T
+#define _HAVE_SIZE_T
+typedef unsigned int size_t;
+#endif
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** This is a boundary tag which is prepended to the
+ * page or section of a page which we have allocated. It is
+ * used to identify valid memory blocks that the
+ * application is trying to free.
+ */
+struct boundary_tag {
+  unsigned int magic;     //< It's a kind of ...
+  unsigned int size;      //< Requested size.
+  unsigned int real_size; //< Actual size.
+  int index;              //< Location in the page table.
+
+  struct boundary_tag* split_left;  //< Linked-list info for broken pages.
+  struct boundary_tag* split_right; //< The same.
+
+  struct boundary_tag* next; //< Linked list info.
+  struct boundary_tag* prev; //< Linked list info.
+};
+
+/** This function is supposed to lock the memory data structures. It
+ * could be as simple as disabling interrupts or acquiring a spinlock.
+ * It's up to you to decide.
+ *
+ * \return 0 if the lock was acquired successfully. Anything else is
+ * failure.
+ */
+extern int liballoc_lock (void);
+
+/** This function unlocks what was previously locked by the liballoc_lock
+ * function.  If it disabled interrupts, it enables interrupts. If it
+ * had acquiried a spinlock, it releases the spinlock. etc.
+ *
+ * \return 0 if the lock was successfully released.
+ */
+extern int liballoc_unlock (void);
+
+/** This is the hook into the local system which allocates pages. It
+ * accepts an integer parameter which is the number of pages
+ * required.  The page size was set up in the liballoc_init function.
+ *
+ * \return NULL if the pages were not allocated.
+ * \return A pointer to the allocated memory.
+ */
+extern void* liballoc_alloc (int);
+
+/** This frees previously allocated memory. The void* parameter passed
+ * to the function is the exact same value returned from a previous
+ * liballoc_alloc call.
+ *
+ * The integer value is the number of pages to free.
+ *
+ * \return 0 if the memory was successfully freed.
+ */
+extern int liballoc_free (void*, int);
+
+void* malloc (size_t);         //< The standard function.
+void* realloc (void*, size_t); //< The standard function.
+void* calloc (size_t, size_t); //< The standard function.
+void free (void*);             //< The standard function.
+
+void liballoc_init (void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif