Initial commit

1 files changed, 80 insertions, 0 deletions

diff --git a/sys/libc/csalloc.c b/sys/libc/csalloc.c
new file mode 100644
index 00000000..823c0bca
--- /dev/null
+++ b/sys/libc/csalloc.c
@@ -0,0 +1,80 @@
+/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+*/
+
+#define	import_spp
+#define	import_libc
+#define	import_xnames
+#include <iraf.h>
+
+/*
+** CSALLOC -- Dynamic memory allocation on the SPP stack.
+**
+**			c_smark (&sp)
+**			c_sfree (sp)
+**		 ptr = c_salloc (nbytes)
+**
+** A contiguous segment of dynamic storage may be allocated with C_SALLOC,
+** much as is done with the UNIX emulation procedure MALLOC.  All buffer
+** space allocated on the stack since a call to C_SMARK to mark the position
+** of the stack pointer may be freed in a single call to C_SFREE.
+**
+** The stack is implemented as a linked list of a few large buffers allocated
+** on the heap with MALLOC, each of which normally contains many small buffers
+** allocated with individual C_SALLOC calls.  Stack allocation is very
+** efficient for buffers small enough to fit into a stack segment.  If it is
+** necessary to add a new segment to accomodate a large buffer, the expense is
+** about the same as for a buffer allocation with MALLOC.
+*/
+
+
+/* C_SALLOC -- Allocate a contiguous segment of memory on the stack.  The
+** contents of the buffer will be uninitialized.  The buffer is guaranteed to
+** have at least XDOUBLE alignment with the Mem common.  One extra XCHAR
+** of storage is automatically allocated for the EOS delimiter in the event
+** that the buffer is used to hold a character string (thus it is not necessary
+** to be forever adding +1 in calls to the memory allocator).
+**
+** N.B.: it is a fatal error if storage cannot be allocated on the stack,
+** hence error checking is not necessary.
+*/
+char *
+c_salloc (
+  unsigned nbytes		/* nbytes of storage to be allocated	*/
+)
+{
+	XINT	buf;
+	XINT	x_nchars = nbytes, x_dtype = TY_CHAR;
+
+
+	x_nchars = (nbytes + sizeof(XCHAR)-1) / sizeof(XCHAR);
+	SALLOC (&buf, &x_nchars, &x_dtype);
+	return ((char *)&Memc[buf]);
+}
+
+
+/* C_SMARK -- Mark the position of the stack pointer.
+*/
+void
+c_smark (
+  int	*sp			/* stack pointer is saved here		*/
+)
+{
+	XINT  x_sp = *sp;
+
+	SMARK (&x_sp);
+	*sp = x_sp;
+}
+
+
+/* C_SFREE -- Free all stack storage allocated since the stack pointer passed as
+** the sole argument was marked by C_SMARK.
+*/
+void
+c_sfree (
+  int	sp			/* saved stack pointer			*/
+)
+{
+	XINT  x_sp = sp;
+
+	SFREE (&x_sp);
+}