/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
/* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
* memory starting at 'base'. 'base' should point to a buffer on the stack.
- *
- * An ofpbuf operation that requires reallocating data will assert-fail if this
- * function was used to initialize it.
+ * (Nothing actually relies on 'base' being allocated on the stack. It could
+ * be static or malloc()'d memory. But stack space is the most common use
+ * case.)
*
* 'base' should be appropriately aligned. Using an array of uint32_t or
* uint64_t for the buffer is a reasonable way to ensure appropriate alignment
- * for 32- or 64-bit data.
+ * for 32- or 64-bit data. OFPBUF_STACK_BUFFER is a convenient way to do so.
*
- * (Nothing actually relies on 'base' being allocated on the stack. It could
- * be static or malloc()'d memory. But stack space is the most common use
- * case.) */
+ * An ofpbuf operation that requires reallocating data will assert-fail if this
+ * function was used to initialize it. Thus, one need not call ofpbuf_uninit()
+ * on an ofpbuf initialized by this function (though doing so is harmless),
+ * because it is guaranteed that 'b' does not own any heap-allocated memory. */
void
ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
{
ofpbuf_use__(b, base, allocated, OFPBUF_STACK);
}
+/* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
+ * memory starting at 'base'. 'base' should point to a buffer on the stack.
+ * (Nothing actually relies on 'base' being allocated on the stack. It could
+ * be static or malloc()'d memory. But stack space is the most common usen
+ * case.)
+ *
+ * 'base' should be appropriately aligned. Using an array of uint32_t or
+ * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
+ * for 32- or 64-bit data. OFPBUF_STACK_BUFFER is a convenient way to do so.
+ *
+ * An ofpbuf operation that requires reallocating data will copy the provided
+ * buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
+ * on an ofpbuf initialized by this function, so that if it expanded into the
+ * heap, that memory is freed. */
+void
+ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
+{
+ ofpbuf_use__(b, base, allocated, OFPBUF_STUB);
+}
+
/* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
* 'size' bytes. This is appropriate for an ofpbuf that will be used to
* inspect existing data, without moving it around or reallocating it, and
}
}
+/* Returns a pointer that may be passed to free() to accomplish the same thing
+ * as ofpbuf_uninit(b). The return value is a null pointer if ofpbuf_uninit()
+ * would not free any memory. */
+void *
+ofpbuf_get_uninit_pointer(struct ofpbuf *b)
+{
+ return b && b->source == OFPBUF_MALLOC ? b->base : NULL;
+}
+
/* Frees memory that 'b' points to and allocates a new ofpbuf */
void
ofpbuf_reinit(struct ofpbuf *b, size_t size)
case OFPBUF_STACK:
NOT_REACHED();
+ case OFPBUF_STUB:
+ b->source = OFPBUF_MALLOC;
+ new_base = xmalloc(new_allocated);
+ ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
+ break;
+
default:
NOT_REACHED();
}
/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
enum ofpbuf_source {
OFPBUF_MALLOC, /* Obtained via malloc(). */
- OFPBUF_STACK /* Stack space or static buffer. */
+ OFPBUF_STACK, /* Un-movable stack space or static buffer. */
+ OFPBUF_STUB /* Starts on stack, may expand into heap. */
};
/* Buffer for holding arbitrary data. An ofpbuf is automatically reallocated
void ofpbuf_use(struct ofpbuf *, void *, size_t);
void ofpbuf_use_stack(struct ofpbuf *, void *, size_t);
+void ofpbuf_use_stub(struct ofpbuf *, void *, size_t);
void ofpbuf_use_const(struct ofpbuf *, const void *, size_t);
void ofpbuf_init(struct ofpbuf *, size_t);
void ofpbuf_uninit(struct ofpbuf *);
+void *ofpbuf_get_uninit_pointer(struct ofpbuf *);
void ofpbuf_reinit(struct ofpbuf *, size_t);
struct ofpbuf *ofpbuf_new(size_t);