/*
* $Log$
+ * Revision 1.2 2004/08/04 15:54:18 rasky
+ * Merge da SC: prima versione veramente funzionante
+ *
* Revision 1.1 2004/07/31 16:33:58 rasky
* Spostato lo heap da kern/ a mware/
*
*/
#include "heap.h"
+#include <string.h> // memset()
+#include <drv/kdebug.h> // ASSERT()
/* NOTE: struct size must be a 2's power! */
typedef struct _MemChunk
size_t size;
} MemChunk;
-static REGISTER MemChunk *FreeList; /* Head of the free list */
-static uint8_t Heap[HEAP_SIZE]; /* Heap memory block */
-
+STATIC_ASSERT(IS_POW2(sizeof(MemChunk)));
+#define FREE_FILL_CODE 0xDEAD
+#define ALLOC_FILL_CODE 0xBEEF
-void heap_init(void)
+void heap_init(struct Heap* h, void* memory, size_t size)
{
#ifdef _DEBUG
- int i;
-
- /* Fill the heap with a "DEAD" code to help debugging */
- for (i = 0; i < HEAP_SIZE / sizeof (uint16_t); i++)
- ((uint16_t *)Heap)[i] = MEM_FILL_CODE;
+ memset(memory, FREE_FILL_CODE, size);
#endif
/* Initialize heap with a single big chunk */
- FreeList = (MemChunk *)Heap;
- FreeList->next = NULL;
- FreeList->size = sizeof(Heap);
+ h->FreeList = (MemChunk *)memory;
+ h->FreeList->next = NULL;
+ h->FreeList->size = size;
}
-void *heap_alloc(size_t size)
+void *heap_allocmem(struct Heap* h, size_t size)
{
MemChunk *chunk, *prev;
/* Round size up to the allocation granularity */
size = ROUND2(size, sizeof(MemChunk));
+ /* Handle allocations of 0 bytes */
+ if (!size)
+ size = sizeof(MemChunk);
+
/* Walk on the free list looking for any chunk big enough to
* fit the requested block size.
*/
- for (prev = (MemChunk *)&FreeList, chunk = FreeList;
+ for (prev = (MemChunk *)&h->FreeList, chunk = h->FreeList;
chunk;
prev = chunk, chunk = chunk->next)
{
- if (chunk->size <= size)
+ if (chunk->size >= size)
{
if (chunk->size == size)
{
/* Just remove this chunk from the free list */
prev->next = chunk->next;
+ #ifdef _DEBUG
+ memset(chunk, ALLOC_FILL_CODE, size);
+ #endif
return (void *)chunk;
}
else
{
/* Allocate from the END of an existing chunk */
- prev->size -= size;
- return (void *)(((uint8_t *)prev) + prev->size);
+ chunk->size -= size;
+ #ifdef _DEBUG
+ memset((uint8_t *)chunk + chunk->size, ALLOC_FILL_CODE, size);
+ #endif
+ return (void *)((uint8_t *)chunk + chunk->size);
}
}
}
}
-void heap_free(void *mem, size_t size)
+void heap_freemem(struct Heap* h, void *mem, size_t size)
{
MemChunk *prev;
+ ASSERT(mem);
+
+#ifdef _DEBUG
+ memset(mem, FREE_FILL_CODE, size);
+#endif
+
/* Round size up to the allocation granularity */
size = ROUND2(size, sizeof(MemChunk));
+ /* Handle allocations of 0 bytes */
+ if (!size)
+ size = sizeof(MemChunk);
+
/* Special case: first chunk in the free list */
- if (((uint8_t *)mem) < ((uint8_t *)FreeList))
+ ASSERT((uint8_t*)mem != (uint8_t*)h->FreeList);
+ if (((uint8_t *)mem) < ((uint8_t *)h->FreeList))
{
/* Insert memory block before the current free list head */
prev = (MemChunk *)mem;
- prev->next = FreeList;
+ prev->next = h->FreeList;
prev->size = size;
- FreeList = prev;
+ h->FreeList = prev;
}
else /* Normal case: not the first chunk in the free list */
{
- /* Walk on the free list. Stop at the insertion point */
- prev = FreeList;
- while ((prev->next >= ((MemChunk *)mem)) || (!prev->next))
+ /*
+ * Walk on the free list. Stop at the insertion point (when mem
+ * is between prev and prev->next)
+ */
+ prev = h->FreeList;
+ while (prev->next < (MemChunk *)mem && prev->next)
prev = prev->next;
+ /* Make sure mem is not *within* prev */
+ ASSERT((uint8_t*)mem >= (uint8_t*)prev + prev->size);
+
/* Should it be merged with previous block? */
- if (((uint8_t *)prev) + prev->Size == ((uint8_t *)mem))
+ if (((uint8_t *)prev) + prev->size == ((uint8_t *)mem))
{
/* Yes */
prev->size += size;
}
else /* not merged with previous chunk */
{
+ MemChunk *curr = (MemChunk*)mem;
+
/* insert it after the previous node
* and move the 'prev' pointer forward
* for the following operations
*/
- ((MemChunk *)mem)->next = prev->next;
- prev->next = (MemChunk *)mem;
- prev = (MemChunk *)mem;
+ curr->next = prev->next;
+ curr->size = size;
+ prev->next = curr;
+
+ /* Adjust for the following test */
+ prev = curr;
}
}
{
prev->size += prev->next->size;
prev->next = prev->next->next;
+
+ /* There should be only one merge opportunity, becuase we always merge on free */
+ ASSERT((uint8_t*)prev + prev->size != (uint8_t*)prev->next);
}
}
-#ifdef __POSIX__
+#if CONFIG_HEAP_MALLOC
-/*! ANSI/POSIX-like malloc() implementation based on heap_alloc()/heap_free() */
-void *malloc(size_t size)
+void *heap_malloc(struct Heap* h, size_t size)
{
- void *mem;
+ size_t *mem;
size += sizeof(size_t);
-
- if (mem = heap_alloc(size))
- *((size_t *)mem)++ = size;
+ if ((mem = (size_t*)heap_allocmem(h, size)))
+ *mem++ = size;
return mem;
}
-
-/*! ANSI/POSIX-like calloc() implementation based on heap_alloc()/heap_free() */
-void *calloc(size_t nelem, size_t size)
+void *heap_calloc(struct Heap* h, size_t size)
{
- void *mem, *tmp;
-
- size *= nelem;
+ void *mem;
- if (mem = malloc(size))
- {
- tmp = mem;
- while (size--)
- ((uint8_t *)tmp++) = 0;
- }
+ if ((mem = heap_malloc(h, size)))
+ memset(mem, 0, size);
return mem;
}
-/*! ANSI/POSIX-like free() implementation based on heap_alloc()/heap_free() */
-void free(void *mem)
+void heap_free(struct Heap* h, void *mem_)
{
- ((size_t *)mem)--;
- heap_free(mem, *((size_t *)mem));
+ size_t* mem = (size_t*)mem_;
+ --mem;
+ heap_freemem(h, mem, *mem);
}
-#endif /* __POSIX__ */
+#endif /* CONFIG_HEAP_MALLOC */
* \version $Id$
*
* \author Bernardo Innocenti <bernie@develer.com>
+ *
+ * \todo Heap memory could be defined as an array of MemChunk, and used
+ * in this form also within the implementation. This would probably remove
+ * memory alignment problems, and also some aliasing issues.
+ *
*/
/*
* $Log$
+ * Revision 1.2 2004/08/04 15:54:18 rasky
+ * Merge da SC: prima versione veramente funzionante
+ *
* Revision 1.1 2004/07/31 16:33:58 rasky
* Spostato lo heap da kern/ a mware/
*
*
*/
-#ifndef KERN_HEAP_H
-#define KERN_HEAP_H
+#ifndef MWARE_HEAP_H
+#define MWARE_HEAP_H
+
+#include <compiler.h>
+#include <config.h>
+
+struct _MemChunk;
+
+//! A heap
+struct Heap
+{
+ struct _MemChunk *FreeList; //!< Head of the free list
+};
+
+
+//! Initialize \a heap within the buffer pointed by \a memory which is of \a size bytes
+void heap_init(struct Heap* heap, void* memory, size_t size);
+
+//! Allocate a chunk of memory of \a size bytes from the heap
+void *heap_allocmem(struct Heap* heap, size_t size);
+
+//! Free a chunk of memory of \a size bytes from the heap
+void heap_freemem(struct Heap* heap, void *mem, size_t size);
+
+
+#define HNEW(heap, type) \
+ (type*)heap_allocmem(heap, sizeof(type))
+
+#define HNEWVEC(heap, type, nelem) \
+ (type*)heap_allocmem(heap, sizeof(type) * (nelem))
+
+#define HDELETE(heap, type, mem) \
+ heap_freemem(heap, mem, sizeof(type))
-#include "compiler.h"
+#define HDELETEVEC(heap, type, nelem, mem) \
+ heap_freemem(heap, mem, sizeof(type) * (nelem))
-/* Memory allocation services */
-void heap_init(void);
-void *heap_alloc(size_t size);
-void heap_free(void *mem, size_t size);
+#if CONFIG_HEAP_MALLOC
-#ifdef __POSIX__ /* unused */
-void *malloc(size_t size);
-void *calloc(unsigned int nelem, size_t size);
-void free(void * mem);
-#endif /* __POSIX__ */
+void *heap_malloc(struct Heap* heap, size_t size);
+void *heap_calloc(struct Heap* heap, size_t size);
+void heap_free(struct Heap* heap, void * mem);
-#endif /* KERN_HEAP_H */
+#endif
+#endif /* MWARE_HEAP_H */
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