commit 10dfb1dd3d1d26122cf18f29468ec17eb7222c3f
author Michael Anthony Knyszek <mknyszek@google.com> Wed Sep 16 17:08:55 2020 +0000
committer Michael Knyszek <mknyszek@google.com> Wed Sep 16 17:36:58 2020 +0000
tree 4807314ba1e6321c2e97574fb62e4a106c99fb75
parent 37f261010f837f945eaa2d33d90cd822b4e93459

runtime: actually fix locking in BenchmarkMSpanCountAlloc

I just submitted CL 255297 which mostly fixed this problem, but totally
forgot to actually acquire/release the heap lock. Oops.

Updates #41391.

Change-Id: I45b42f20a9fc765c4de52476db3654d4bfe9feb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/255298
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>

src/runtime/export_test.go

diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index e3d6441..f2fa11d 100644
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -991,7 +991,9 @@
 func AllocMSpan() *MSpan {
 	var s *mspan
 	systemstack(func() {
+		lock(&mheap_.lock)
 		s = (*mspan)(mheap_.spanalloc.alloc())
+		unlock(&mheap_.lock)
 	})
 	return (*MSpan)(s)
 }
@@ -999,7 +1001,9 @@
 // Free an allocated mspan.
 func FreeMSpan(s *MSpan) {
 	systemstack(func() {
+		lock(&mheap_.lock)
 		mheap_.spanalloc.free(unsafe.Pointer(s))
+		unlock(&mheap_.lock)
 	})
 }