From: Austin Clements <austin@google.com>
Date: Thu, 28 Apr 2016 15:19:53 +0000 (-0400)
Subject: [dev.garbage] runtime: document sysAlloc
X-Git-Tag: go1.7beta1~405^2~7
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=2e8b74b69574e969b5565e69cb54d39064b2dba1;p=gostls13.git

[dev.garbage] runtime: document sysAlloc

In particular, it always returns an aligned pointer.

Change-Id: I763789a539a4bfd8b0efb36a39a80be1a479d3e2
Reviewed-on: https://go-review.googlesource.com/22558
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index ec4939f1dd..2d8905b88d 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -387,6 +387,10 @@ func sysReserveHigh(n uintptr, reserved *bool) unsafe.Pointer {
 	return sysReserve(nil, n, reserved)
 }
 
+// sysAlloc allocates the next n bytes from the heap arena. The
+// returned pointer is always _PageSize aligned and between
+// h.arena_start and h.arena_end. sysAlloc returns nil on failure.
+// There is no corresponding free function.
 func (h *mheap) sysAlloc(n uintptr) unsafe.Pointer {
 	if n > h.arena_end-h.arena_used {
 		// We are in 32-bit mode, maybe we didn't use all possible address space yet.