Tcl_Alloc(3tcl)
Tcl_Alloc(3) Tcl Library Procedures Tcl_Alloc(3)
_________________________________________________________________
NAME
Tcl_Alloc, Tcl_Free, Tcl_Realloc, Tcl_AttemptAlloc,
Tcl_AttemptRealloc, ckalloc, ckfree, ckrealloc, attemptckal-
loc, attemptckrealloc - allocate or free heap memory
SYNOPSIS
#include <tcl.h>
char *
Tcl_Alloc(size)
void
Tcl_Free(ptr)
char *
Tcl_Realloc(ptr, size)
char *
Tcl_AttemptAlloc(size)
char *
Tcl_AttemptRealloc(ptr, size)
char *
ckalloc(size)
void
ckfree(ptr)
char *
ckrealloc(ptr, size)
char *
attemptckalloc(size)
char *
attemptckrealloc(ptr, size)
ARGUMENTS
unsigned int size (in) Size in bytes of the memory block
to allocate.
char *ptr (in) Pointer to memory block to free or
realloc.
_________________________________________________________________
DESCRIPTION
These procedures provide a platform and compiler independent
interface for memory allocation. Programs that need to
Tcl Last change: 7.5 1
Tcl_Alloc(3) Tcl Library Procedures Tcl_Alloc(3)
transfer ownership of memory blocks between Tcl and other
modules should use these routines rather than the native
malloc() and free() routines provided by the C run-time
library.
Tcl_Alloc returns a pointer to a block of at least size
bytes suitably aligned for any use.
Tcl_Free makes the space referred to by ptr available for
further allocation.
Tcl_Realloc changes the size of the block pointed to by ptr
to size bytes and returns a pointer to the new block. The
contents will be unchanged up to the lesser of the new and
old sizes. The returned location may be different from ptr.
If ptr is NULL, this is equivalent to calling Tcl_Alloc with
just the size argument.
Tcl_AttemptAlloc and Tcl_AttemptRealloc are identical in
function to Tcl_Alloc and Tcl_Realloc, except that
Tcl_AttemptAlloc and Tcl_AttemptRealloc will not cause the
Tcl interpreter to panic if the memory allocation fails. If
the allocation fails, these functions will return NULL.
Note that on some platforms, but not all, attempting to
allocate a zero-sized block of memory will also cause these
functions to return NULL.
The procedures ckalloc, ckfree, ckrealloc, attemptckalloc,
and attemptckrealloc are implemented as macros. Normally,
they are synonyms for the corresponding procedures docu-
mented on this page. When Tcl and all modules calling Tcl
are compiled with TCL_MEM_DEBUG defined, however, these mac-
ros are redefined to be special debugging versions of these
procedures. To support Tcl's memory debugging within a
module, use the macros rather than direct calls to
Tcl_Alloc, etc.
KEYWORDS
alloc, allocation, free, malloc, memory, realloc,
TCL_MEM_DEBUG
Tcl Last change: 7.5 2
Man(1) output converted with
man2html