#include "xalloc.h"
-#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
/* If non NULL, call this function when memory is exhausted. */
void (*xalloc_fail_func) (void) = 0;
-/* Return true if array of N objects, each of size S, cannot exist due
- to arithmetic overflow. S must be nonzero. */
-
-static inline bool
-array_size_overflow (size_t n, size_t s)
-{
- return SIZE_MAX / s < n;
-}
-
/* If XALLOC_FAIL_FUNC is NULL, or does return, display this message
before exiting when memory is exhausted. Goes through gettext. */
char const xalloc_msg_memory_exhausted[] = N_("memory exhausted");
/* Allocate an array of N objects, each with S bytes of memory,
dynamically, with error checking. S must be nonzero. */
-inline void *
-xnmalloc (size_t n, size_t s)
+static inline void *
+xnmalloc_inline (size_t n, size_t s)
{
void *p;
- if (array_size_overflow (n, s) || ! (p = malloc (n * s)))
+ if (xalloc_oversized (n, s) || ! (p = malloc (n * s)))
xalloc_die ();
return p;
}
+void *
+xnmalloc (size_t n, size_t s)
+{
+ return xnmalloc_inline (n, s);
+}
+
/* Allocate N bytes of memory dynamically, with error checking. */
void *
xmalloc (size_t n)
{
- return xnmalloc (n, 1);
+ return xnmalloc_inline (n, 1);
}
/* Change the size of an allocated block of memory P to an array of N
objects each of S bytes, with error checking. S must be nonzero. */
-inline void *
-xnrealloc (void *p, size_t n, size_t s)
+static inline void *
+xnrealloc_inline (void *p, size_t n, size_t s)
{
- if (array_size_overflow (n, s) || ! (p = realloc (p, n * s)))
+ if (xalloc_oversized (n, s) || ! (p = realloc (p, n * s)))
xalloc_die ();
return p;
}
+void *
+xnrealloc (void *p, size_t n, size_t s)
+{
+ return xnrealloc_inline (p, n, s);
+}
+
/* Change the size of an allocated block of memory P to N bytes,
with error checking. */
void *
xrealloc (void *p, size_t n)
{
- return xnrealloc (p, n, 1);
+ return xnrealloc_inline (p, n, 1);
+}
+
+
+/* If P is null, allocate a block of at least *PN such objects;
+ otherwise, reallocate P so that it contains more than *PN objects
+ each of S bytes. *PN must be nonzero unless P is null, and S must
+ be nonzero. Set *PN to the new number of objects, and return the
+ pointer to the new block. *PN is never set to zero, and the
+ returned pointer is never null.
+
+ Repeated reallocations are guaranteed to make progress, either by
+ allocating an initial block with a nonzero size, or by allocating a
+ larger block.
+
+ In the following implementation, nonzero sizes are doubled so that
+ repeated reallocations have O(N log N) overall cost rather than
+ O(N**2) cost, but the specification for this function does not
+ guarantee that sizes are doubled.
+
+ Here is an example of use:
+
+ int *p = NULL;
+ size_t used = 0;
+ size_t allocated = 0;
+
+ void
+ append_int (int value)
+ {
+ if (used == allocated)
+ p = x2nrealloc (p, &allocated, sizeof *p);
+ p[used++] = value;
+ }
+
+ This causes x2nrealloc to allocate a block of some nonzero size the
+ first time it is called.
+
+ To have finer-grained control over the initial size, set *PN to a
+ nonzero value before calling this function with P == NULL. For
+ example:
+
+ int *p = NULL;
+ size_t used = 0;
+ size_t allocated = 0;
+ size_t allocated1 = 1000;
+
+ void
+ append_int (int value)
+ {
+ if (used == allocated)
+ {
+ p = x2nrealloc (p, &allocated1, sizeof *p);
+ allocated = allocated1;
+ }
+ p[used++] = value;
+ }
+
+ */
+
+static inline void *
+x2nrealloc_inline (void *p, size_t *pn, size_t s)
+{
+ size_t n = *pn;
+
+ if (! p)
+ {
+ if (! n)
+ {
+ /* The approximate size to use for initial small allocation
+ requests, when the invoking code specifies an old size of
+ zero. 64 bytes is the largest "small" request for the
+ GNU C library malloc. */
+ enum { DEFAULT_MXFAST = 64 };
+
+ n = DEFAULT_MXFAST / s;
+ n += !n;
+ }
+ }
+ else
+ {
+ if (SIZE_MAX / 2 / s < n)
+ xalloc_die ();
+ n *= 2;
+ }
+
+ *pn = n;
+ return xrealloc (p, n * s);
+}
+
+void *
+x2nrealloc (void *p, size_t *pn, size_t s)
+{
+ return x2nrealloc_inline (p, pn, s);
+}
+
+/* If P is null, allocate a block of at least *PN bytes; otherwise,
+ reallocate P so that it contains more than *PN bytes. *PN must be
+ nonzero unless P is null. Set *PN to the new block's size, and
+ return the pointer to the new block. *PN is never set to zero, and
+ the returned pointer is never null. */
+
+void *
+x2realloc (void *p, size_t *pn)
+{
+ return x2nrealloc_inline (p, pn, 1);
}
/* Allocate S bytes of zeroed memory dynamically, with error checking.
void *p;
/* Test for overflow, since some calloc implementations don't have
proper overflow checks. */
- if (array_size_overflow (n, s) || ! (p = calloc (n, s)))
+ if (xalloc_oversized (n, s) || ! (p = calloc (n, s)))
xalloc_die ();
return p;
}