malloc in runtime (not used by default)

R=r
DELTA=1551  (1550 added, 0 deleted, 1 changed)
OCL=21404
CL=21538

1 files changed, 52 insertions, 0 deletions

diff --git a/src/runtime/mfixalloc.c b/src/runtime/mfixalloc.c
new file mode 100644
index 0000000000..904ca7e2af
--- /dev/null
+++ b/src/runtime/mfixalloc.c
@@ -0,0 +1,52 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Fixed-size object allocator.  Returned memory is not zeroed.
+//
+// See malloc.h for overview.
+
+#include "runtime.h"
+#include "malloc.h"
+
+// Initialize f to allocate objects of the given size,
+// using the allocator to obtain chunks of memory.
+void
+FixAlloc_Init(FixAlloc *f, uintptr size, void *(*alloc)(uintptr))
+{
+	f->size = size;
+	f->alloc = alloc;
+	f->list = nil;
+	f->chunk = nil;
+	f->nchunk = 0;
+}
+
+void*
+FixAlloc_Alloc(FixAlloc *f)
+{
+	void *v;
+
+	if(f->list) {
+		v = f->list;
+		f->list = *(void**)f->list;
+		return v;
+	}
+	if(f->nchunk < f->size) {
+		f->chunk = f->alloc(FixAllocChunk);
+		if(f->chunk == nil)
+			throw("out of memory (FixAlloc)");
+		f->nchunk = FixAllocChunk;
+	}
+	v = f->chunk;
+	f->chunk += f->size;
+	f->nchunk -= f->size;
+	return v;
+}
+
+void
+FixAlloc_Free(FixAlloc *f, void *p)
+{
+	*(void**)p = f->list;
+	f->list = p;
+}
+