/* This should be the alignment size used by malloc(). The size of
the union above is correct, if not optimal, in all known cases. */
-#if defined (i386) || defined (__i386__)
-#define ALIGN_SIZE 4 /* Save some extra memory. */
-#else
#define ALIGN_SIZE sizeof (union align)
-#endif
/* DISCRETE_BLOCKS may be declared as nonzero to prevent
suballocation of blocks. This is useful under memory
return pool;
}
+/* Creates a pool, allocates a block STRUCT_SIZE bytes in
+ length from it, stores the pool's address at offset
+ POOL_MEMBER_OFFSET within the block, and returns the allocated
+ block.
+
+ Meant for use indirectly via pool_create_container(). */
+void *
+pool_create_at_offset (size_t struct_size, size_t pool_member_offset)
+{
+ struct pool *pool;
+ char *struct_;
+
+ assert (struct_size >= sizeof pool);
+ assert (pool_member_offset <= struct_size - sizeof pool);
+
+ pool = pool_create ();
+ struct_ = pool_alloc (pool, struct_size);
+ *(struct pool **) (struct_ + pool_member_offset) = pool;
+ return struct_;
+}
+
/* Destroy the specified pool, including all subpools. */
void
pool_destroy (struct pool *pool)
/* Suballocation routines. */
/* Allocates a memory region AMT bytes in size from POOL and returns a
- pointer to the region's start. */
+ pointer to the region's start.
+ The region is properly aligned for storing any object. */
void *
pool_alloc (struct pool *pool, size_t amt)
{
assert (pool != NULL);
+
+ if (amt == 0)
+ return NULL;
#ifndef DISCRETE_BLOCKS
if (amt <= MAX_SUBALLOC)
return pool_malloc (pool, amt);
}
+/* Allocates a memory region AMT bytes in size from POOL and
+ returns a pointer to the region's start. The region is not
+ necessarily aligned, so it is most suitable for storing
+ strings. */
+void *
+pool_alloc_unaligned (struct pool *pool, size_t amt)
+{
+ assert (pool != NULL);
+
+#ifndef DISCRETE_BLOCKS
+ /* Strings need not be aligned on any boundary, but some
+ operations may be more efficient when they are. However,
+ that's only going to help with reasonably long strings. */
+ if (amt < ALIGN_SIZE)
+ {
+ if (amt == 0)
+ return NULL;
+ else
+ {
+ struct pool_block *const b = pool->blocks;
+
+ if (b->ofs + amt <= BLOCK_SIZE)
+ {
+ void *p = ((char *) b) + b->ofs;
+ b->ofs += amt;
+ return p;
+ }
+ }
+ }
+#endif
+
+ return pool_alloc (pool, amt);
+}
+
/* Allocates a memory region N * S bytes in size from POOL and
returns a pointer to the region's start.
N must be nonnegative, S must be positive.
return block;
}
-/* Duplicates STRING, which has LENGTH characters, within POOL,
- and returns a pointer to the duplicate. LENGTH should not
- include the null terminator, which is always added to the
- duplicate. For use only with strings, because the returned
- pointere may not be aligned properly for other types. */
-char *
-pool_strndup (struct pool *pool, const char *string, size_t length)
+/* Allocates SIZE bytes of unaligned data in POOL, copies BUFFER
+ into it, and returns the new copy. */
+void *
+pool_clone_unaligned (struct pool *pool, const void *buffer, size_t size)
{
- size_t size;
- char *copy;
-
- assert (pool && string);
- size = length + 1;
-
- /* Note that strings need not be aligned on any boundary. */
-#ifndef DISCRETE_BLOCKS
- {
- struct pool_block *const b = pool->blocks;
-
- if (b->ofs + size <= BLOCK_SIZE)
- {
- copy = ((char *) b) + b->ofs;
- b->ofs += size;
- }
- else
- copy = pool_alloc (pool, size);
- }
-#else
- copy = pool_alloc (pool, size);
-#endif
-
- memcpy (copy, string, length);
- copy[length] = '\0';
- return copy;
+ void *block = pool_alloc_unaligned (pool, size);
+ memcpy (block, buffer, size);
+ return block;
}
/* Duplicates null-terminated STRING, within POOL, and returns a
char *
pool_strdup (struct pool *pool, const char *string)
{
- return pool_strndup (pool, string, strlen (string));
+ return pool_clone_unaligned (pool, string, strlen (string) + 1);
}
\f
/* Standard allocation routines. */
return subpool;
}
+/* Makes SUBPOOL a subpool of POOL.
+ SUBPOOL must not already have a parent pool.
+ The subpool will be destroyed automatically when POOL is destroyed.
+ It may also be destroyed explicitly in advance. */
+void
+pool_add_subpool (struct pool *pool, struct pool *subpool)
+{
+ struct pool_gizmo *g;
+
+ assert (pool != NULL);
+ assert (subpool != NULL);
+ assert (subpool->parent == NULL);
+
+ g = pool_alloc (subpool, sizeof *g);
+ g->type = POOL_GIZMO_SUBPOOL;
+ g->p.subpool = subpool;
+ add_gizmo (pool, g);
+
+ subpool->parent = pool;
+}
+
/* Opens file FILENAME with mode MODE and returns a handle to it
if successful or a null pointer if not.
The file will be closed automatically when POOL is destroyed, or it
projects / pspp-builds.git / blobdiff