Tcl_Alloc(3) Tcl Library Procedures Tcl_Alloc(3)______________________________________________________________________________NAME
Tcl_Alloc, Tcl_Free, Tcl_Realloc, Tcl_AttemptAlloc, Tcl_AttemptRealloc,
ckalloc, ckfree, ckrealloc, attemptckalloc, 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
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 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 allo‐
cation.
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 syn‐
onyms for the corresponding procedures documented on this page. When
Tcl and all modules calling Tcl are compiled with TCL_MEM_DEBUG
defined, however, these macros 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 7.5 Tcl_Alloc(3)
