1 files changed, 195 insertions, 0 deletions
diff --git a/src/runtime/mem_plan9.go b/src/runtime/mem_plan9.go
new file mode 100644
index 0000000..0e8bf74
--- /dev/null
+++ b/src/runtime/mem_plan9.go
@@ -0,0 +1,195 @@
+// Copyright 2010 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.
+
+package runtime
+
+import "unsafe"
+
+const memDebug = false
+
+var bloc uintptr
+var blocMax uintptr
+var memlock mutex
+
+type memHdr struct {
+	next memHdrPtr
+	size uintptr
+}
+
+var memFreelist memHdrPtr // sorted in ascending order
+
+type memHdrPtr uintptr
+
+func (p memHdrPtr) ptr() *memHdr   { return (*memHdr)(unsafe.Pointer(p)) }
+func (p *memHdrPtr) set(x *memHdr) { *p = memHdrPtr(unsafe.Pointer(x)) }
+
+func memAlloc(n uintptr) unsafe.Pointer {
+	n = memRound(n)
+	var prevp *memHdr
+	for p := memFreelist.ptr(); p != nil; p = p.next.ptr() {
+		if p.size >= n {
+			if p.size == n {
+				if prevp != nil {
+					prevp.next = p.next
+				} else {
+					memFreelist = p.next
+				}
+			} else {
+				p.size -= n
+				p = (*memHdr)(add(unsafe.Pointer(p), p.size))
+			}
+			*p = memHdr{}
+			return unsafe.Pointer(p)
+		}
+		prevp = p
+	}
+	return sbrk(n)
+}
+
+func memFree(ap unsafe.Pointer, n uintptr) {
+	n = memRound(n)
+	memclrNoHeapPointers(ap, n)
+	bp := (*memHdr)(ap)
+	bp.size = n
+	bpn := uintptr(ap)
+	if memFreelist == 0 {
+		bp.next = 0
+		memFreelist.set(bp)
+		return
+	}
+	p := memFreelist.ptr()
+	if bpn < uintptr(unsafe.Pointer(p)) {
+		memFreelist.set(bp)
+		if bpn+bp.size == uintptr(unsafe.Pointer(p)) {
+			bp.size += p.size
+			bp.next = p.next
+			*p = memHdr{}
+		} else {
+			bp.next.set(p)
+		}
+		return
+	}
+	for ; p.next != 0; p = p.next.ptr() {
+		if bpn > uintptr(unsafe.Pointer(p)) && bpn < uintptr(unsafe.Pointer(p.next)) {
+			break
+		}
+	}
+	if bpn+bp.size == uintptr(unsafe.Pointer(p.next)) {
+		bp.size += p.next.ptr().size
+		bp.next = p.next.ptr().next
+		*p.next.ptr() = memHdr{}
+	} else {
+		bp.next = p.next
+	}
+	if uintptr(unsafe.Pointer(p))+p.size == bpn {
+		p.size += bp.size
+		p.next = bp.next
+		*bp = memHdr{}
+	} else {
+		p.next.set(bp)
+	}
+}
+
+func memCheck() {
+	if memDebug == false {
+		return
+	}
+	for p := memFreelist.ptr(); p != nil && p.next != 0; p = p.next.ptr() {
+		if uintptr(unsafe.Pointer(p)) == uintptr(unsafe.Pointer(p.next)) {
+			print("runtime: ", unsafe.Pointer(p), " == ", unsafe.Pointer(p.next), "\n")
+			throw("mem: infinite loop")
+		}
+		if uintptr(unsafe.Pointer(p)) > uintptr(unsafe.Pointer(p.next)) {
+			print("runtime: ", unsafe.Pointer(p), " > ", unsafe.Pointer(p.next), "\n")
+			throw("mem: unordered list")
+		}
+		if uintptr(unsafe.Pointer(p))+p.size > uintptr(unsafe.Pointer(p.next)) {
+			print("runtime: ", unsafe.Pointer(p), "+", p.size, " > ", unsafe.Pointer(p.next), "\n")
+			throw("mem: overlapping blocks")
+		}
+		for b := add(unsafe.Pointer(p), unsafe.Sizeof(memHdr{})); uintptr(b) < uintptr(unsafe.Pointer(p))+p.size; b = add(b, 1) {
+			if *(*byte)(b) != 0 {
+				print("runtime: value at addr ", b, " with offset ", uintptr(b)-uintptr(unsafe.Pointer(p)), " in block ", p, " of size ", p.size, " is not zero\n")
+				throw("mem: uninitialised memory")
+			}
+		}
+	}
+}
+
+func memRound(p uintptr) uintptr {
+	return (p + _PAGESIZE - 1) &^ (_PAGESIZE - 1)
+}
+
+func initBloc() {
+	bloc = memRound(firstmoduledata.end)
+	blocMax = bloc
+}
+
+func sbrk(n uintptr) unsafe.Pointer {
+	// Plan 9 sbrk from /sys/src/libc/9sys/sbrk.c
+	bl := bloc
+	n = memRound(n)
+	if bl+n > blocMax {
+		if brk_(unsafe.Pointer(bl+n)) < 0 {
+			return nil
+		}
+		blocMax = bl + n
+	}
+	bloc += n
+	return unsafe.Pointer(bl)
+}
+
+func sysAllocOS(n uintptr) unsafe.Pointer {
+	lock(&memlock)
+	p := memAlloc(n)
+	memCheck()
+	unlock(&memlock)
+	return p
+}
+
+func sysFreeOS(v unsafe.Pointer, n uintptr) {
+	lock(&memlock)
+	if uintptr(v)+n == bloc {
+		// Address range being freed is at the end of memory,
+		// so record a new lower value for end of memory.
+		// Can't actually shrink address space because segment is shared.
+		memclrNoHeapPointers(v, n)
+		bloc -= n
+	} else {
+		memFree(v, n)
+		memCheck()
+	}
+	unlock(&memlock)
+}
+
+func sysUnusedOS(v unsafe.Pointer, n uintptr) {
+}
+
+func sysUsedOS(v unsafe.Pointer, n uintptr) {
+}
+
+func sysHugePageOS(v unsafe.Pointer, n uintptr) {
+}
+
+func sysMapOS(v unsafe.Pointer, n uintptr) {
+}
+
+func sysFaultOS(v unsafe.Pointer, n uintptr) {
+}
+
+func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
+	lock(&memlock)
+	var p unsafe.Pointer
+	if uintptr(v) == bloc {
+		// Address hint is the current end of memory,
+		// so try to extend the address space.
+		p = sbrk(n)
+	}
+	if p == nil && v == nil {
+		p = memAlloc(n)
+		memCheck()
+	}
+	unlock(&memlock)
+	return p
+}