1 files changed, 108 insertions, 0 deletions
diff --git a/lib/libmalloc/getmem.c b/lib/libmalloc/getmem.c
new file mode 100644
index 000000000000..4140c6da4cc3
--- /dev/null
+++ b/lib/libmalloc/getmem.c
@@ -0,0 +1,108 @@
+/*  Author: Mark Moraes <moraes@csri.toronto.edu> */
+
+/*LINTLIBRARY*/
+
+#include "defs.h"
+#include "globals.h"
+
+RCSID("$Id: getmem.c,v 1.1 1994/03/06 22:59:42 nate Exp $")
+
+/* gets memory from the system via the sbrk() system call.  Most Un*xes */
+univptr_t
+_mal_sbrk(nbytes)
+size_t nbytes;
+{
+	return sbrk((int) nbytes);
+}
+
+/*
+ * gets memory from the system via mmaping a file.  This was written for SunOS
+ * versions greater than 4.0.  The filename is specified by the environment
+ * variable CSRIMALLOC_MMAPFILE or by the call to mal_mmapset().  Using this
+ * instead of sbrk() has the advantage of bypassing the swap system, allowing
+ * processes to run with huge heaps even on systems configured with small swap
+ * space.
+ */
+static char *mmap_filename;
+
+#ifdef HAVE_MMAP
+/* Sun gets size_t wrong, and these follow, thanks to my #defines! */
+#undef caddr_t
+#undef size_t
+#undef u_char
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+
+univptr_t
+_mal_mmap(nbytes)
+size_t nbytes;
+{
+	static struct {
+		int i_fd;
+		caddr_t i_data;
+		caddr_t i_end;
+		size_t i_size;
+		size_t i_alloced;
+	} mmf;
+	struct stat stbuf;
+
+	if (mmf.i_data != NULL) {
+		/* Already initialized & mmaped the file */
+		univptr_t p = mmf.i_data + mmf.i_alloced;
+		
+		if ((char *) p + nbytes > mmf.i_end) {
+			errno = ENOMEM;
+			return (univptr_t) -1;
+		}
+		mmf.i_alloced += nbytes;
+		return p;
+	}
+
+	/*
+	 * This code is run the first time the function is called, it opens
+	 * the file and mmaps the
+	 */
+	if (mmap_filename == NULL) {
+		mmap_filename = getenv("CSRIMALLOC_MMAPFILE");
+		if (mmap_filename == NULL) {
+			errno = ENOMEM;
+			return (univptr_t) -1;
+		}
+	}
+
+	mmf.i_fd = open(mmap_filename, O_RDWR, 0666);
+	if (mmf.i_fd < 0 || fstat(mmf.i_fd, &stbuf) < 0)
+		return (univptr_t) -1;
+	if (stbuf.st_size < nbytes) {
+		errno = ENOMEM;
+		return (univptr_t) -1;
+	}
+	mmf.i_size = stbuf.st_size;
+	mmf.i_data = mmap((caddr_t) 0, mmf.i_size, PROT_READ|PROT_WRITE,
+			  MAP_SHARED, mmf.i_fd, (off_t) 0);
+	if (mmf.i_data == (caddr_t) -1)
+		return (univptr_t) -1;
+	mmf.i_end = mmf.i_data + mmf.i_size;
+	mmf.i_alloced = nbytes;
+	/* Advise vm system of random access pattern */
+	(void) madvise(mmf.i_data, mmf.i_size, MADV_RANDOM);
+	return mmf.i_data;
+}
+#else /* !HAVE_MMAP */
+univptr_t
+_mal_mmap(nbytes)
+size_t nbytes;
+{
+	return (univptr_t) -1;
+}
+#endif /* HAVE_MMAP */
+
+void
+mal_mmap(fname)
+char *fname;
+{
+	_malloc_memfunc = _mal_mmap;
+	mmap_filename = fname;
+}