[dev.cc] runtime: convert memory allocator and garbage collector to Go

The conversion was done with an automated tool and then
modified only as necessary to make it compile and run.

[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]

LGTM=r
R=r
CC=austin, dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/167540043

1 files changed, 59 insertions, 0 deletions

diff --git a/src/runtime/mfixalloc.go b/src/runtime/mfixalloc.go
new file mode 100644
index 0000000000..b66a17e41c
--- /dev/null
+++ b/src/runtime/mfixalloc.go
@@ -0,0 +1,59 @@
+// 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.
+
+package runtime
+
+import "unsafe"
+
+// Initialize f to allocate objects of the given size,
+// using the allocator to obtain chunks of memory.
+func fixAlloc_Init(f *fixalloc, size uintptr, first func(unsafe.Pointer, unsafe.Pointer), arg unsafe.Pointer, stat *uint64) {
+	f.size = size
+	f.first = *(*unsafe.Pointer)(unsafe.Pointer(&first))
+	f.arg = arg
+	f.list = nil
+	f.chunk = nil
+	f.nchunk = 0
+	f.inuse = 0
+	f.stat = stat
+}
+
+func fixAlloc_Alloc(f *fixalloc) unsafe.Pointer {
+	if f.size == 0 {
+		print("runtime: use of FixAlloc_Alloc before FixAlloc_Init\n")
+		gothrow("runtime: internal error")
+	}
+
+	if f.list != nil {
+		v := unsafe.Pointer(f.list)
+		f.list = f.list.next
+		f.inuse += f.size
+		return v
+	}
+	if uintptr(f.nchunk) < f.size {
+		f.chunk = (*uint8)(persistentalloc(_FixAllocChunk, 0, f.stat))
+		f.nchunk = _FixAllocChunk
+	}
+
+	v := (unsafe.Pointer)(f.chunk)
+	if f.first != nil {
+		fn := *(*func(unsafe.Pointer, unsafe.Pointer))(unsafe.Pointer(&f.first))
+		fn(f.arg, v)
+	}
+	f.chunk = (*byte)(add(unsafe.Pointer(f.chunk), f.size))
+	f.nchunk -= uint32(f.size)
+	f.inuse += f.size
+	return v
+}
+
+func fixAlloc_Free(f *fixalloc, p unsafe.Pointer) {
+	f.inuse -= f.size
+	v := (*mlink)(p)
+	v.next = f.list
+	f.list = v
+}