bsd man page for malloc

MALLOC(3F)																MALLOC(3F)

NAME
       malloc, free, falloc - memory allocator

SYNOPSIS
       subroutine malloc (size, addr)
       integer size, addr

       subroutine free (addr)
       integer addr

       subroutine falloc (nelem, elsize, clean, basevec, addr, offset)
       integer nelem, elsize, clean, addr, offset

DESCRIPTION
       Malloc, falloc  and  free  provide  a general-purpose memory allocation package.  Malloc returns in addr the address of a block of at least
       size bytes beginning on an even-byte boundary.

       Falloc allocates space for an array of nelem elements of size elsize and returns the address of the block in addr.  It zeros the  block	if
       clean  is  1.  It returns in offset an index such that the storage may be addressed as basevec(offset+1) ... basevec(offset+nelem).  Falloc
       gets extra bytes so that after address arithmetic, all the objects so addressed are within the block.

       The argument to free is the address of a block previously allocated by malloc or falloc; this space is made available for  further  alloca-
       tion, but its contents are left undisturbed.  To free blocks allocated by falloc, use addr in calls to free, do not use basevec(offset+1).

       Needless to say, grave disorder will result if the space assigned by mallocorfalloc is overrun or if some random number is handed to free.

DIAGNOSTICS
       Malloc and falloc set addr to 0 if there is no available memory or if the arena has been detectably corrupted by storing outside the bounds
       of a block.

       The following example shows how to obtain memory and use it within a subprogram:

	     integer addr, work(1), offset
		...
	     call falloc ( n, 4, 0, work, addr, offset )
	     do 10 i = 1, n
	     work(offset+i) = ...
       10    continue

       The next example reads in dimension information, allocates space for two arrays and two vectors, and calls subroutine doit to do the compu-
       tations:

	     integer addr, dummy(1), offs
	     read *, k, l, m
	     indm1   = 1
	     indm2   = indm1 + k*l
	     indm3   = indm2 + l*m
	     indsym  = indm3 + k*m
	     lsym = n*(n+1)/2
	     indv  = indsym + lsym
	     indtot = indv + m
	     call falloc ( indtot, 4, 0, dummy, addr, offs )
	     call doit( dummy(indm1+offs), dummy(indm2+offs),
	    .		dummy(indm3+offs), dummy(indsym+offs),
	    .		dummy(indv +offs), m, n, lsym )
	     end
	     subroutine doit( arr1, arr2, arr3, vsym, vec, m, n, lsym )
	     real arr1(k,l), arr2(l,m), arr3(k,m), vsym(lsym), v2(m)
		...

FILES
       /usr/lib/libU77.a

SEE ALSO
       malloc(3)

4.3 Berkeley Distribution					   May 15, 1985 							MALLOC(3F)