new venti library.
diff --git a/src/libventi/mem.c b/src/libventi/mem.c
new file mode 100644
index 0000000..cf86fe1
--- /dev/null
+++ b/src/libventi/mem.c
@@ -0,0 +1,87 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+enum {
+ IdealAlignment = 32,
+ ChunkSize = 128*1024,
+};
+
+
+void
+vtfree(void *p)
+{
+ if(p == 0)
+ return;
+ free(p);
+}
+
+void *
+vtmalloc(int size)
+{
+ void *p;
+
+ p = malloc(size);
+ if(p == 0)
+ sysfatal("vtmalloc: out of memory");
+ setmalloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtmallocz(int size)
+{
+ void *p = vtmalloc(size);
+ memset(p, 0, size);
+ setmalloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtrealloc(void *p, int size)
+{
+ if(p == nil)
+ return vtmalloc(size);
+ p = realloc(p, size);
+ if(p == 0)
+ sysfatal("vtMemRealloc: out of memory");
+ setrealloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtbrk(int n)
+{
+ static Lock lk;
+ static uchar *buf;
+ static int nbuf;
+ static int nchunk;
+ int align, pad;
+ void *p;
+
+ if(n >= IdealAlignment)
+ align = IdealAlignment;
+ else if(n > 8)
+ align = 8;
+ else
+ align = 4;
+
+ lock(&lk);
+ pad = (align - (ulong)buf) & (align-1);
+ if(n + pad > nbuf) {
+ buf = vtmallocz(ChunkSize);
+ nbuf = ChunkSize;
+ pad = (align - (ulong)buf) & (align-1);
+ nchunk++;
+ }
+
+ assert(n + pad <= nbuf);
+
+ p = buf + pad;
+ buf += pad + n;
+ nbuf -= pad + n;
+ unlock(&lk);
+
+ return p;
+}
+
