ref: efd1615c5741a6898853fefc24b1cbcb734e5477
dir: /man/10/malloc/
.TH MALLOC 10.2 .SH NAME malloc, mallocz, smalloc, free, realloc, calloc \- kernel memory allocators .SH SYNOPSIS .ta \w'\fLvoid* 'u .B void* malloc(ulong size) .PP .B void* mallocz(ulong size, int clr) .PP .B void* smalloc(ulong size) .PP .B void* realloc(void *p, ulong size) .PP .B void* calloc(ulong n, ulong szelem) .PP .B void free(void *p) .SH DESCRIPTION These functions allocate memory from the .B mainmem memory pool. All but .I smalloc (which sleeps) may safely be called by interrupt handlers. .PP .I Malloc returns a pointer to a block of at least .I size bytes, initialised to zero. The result is aligned on a 32-bit boundary. .I Mallocz is similar, but only clears the memory if .I clr is non-zero. .PP .I Smalloc returns a pointer to a block of .I size bytes, initialised to zero. If the memory is not immediately available, .I smalloc retries every 100 milliseconds until the memory is acquired. .PP .I Calloc returns a pointer to a block of memory of at least .I "n*szelem" bytes, initialised to zero. .PP .I Realloc changes the size of the block pointed to by .I p to .I size bytes, if possible without moving the data, and returns a pointer to the block. The contents are unchanged up to the lesser of old and new sizes, and any new space allocated is initialised to zero. If .I p is a null pointer, .I realloc returns the equivalent of .BR "malloc(size)" . .PP The argument to .I free is a pointer to a block of memory allocated by one of the routines above, which is returned to the allocation pool, or a null pointer, which is ignored. .SH DIAGNOSTICS All functions except .I smalloc return a null pointer if space is unavailable. .SH SEE ALSO .IR xalloc (10.2)