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authorRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
committerRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
commitc007ce824d9a4fccb148f9204e04c23ed2984b71 (patch)
tree7dcac257114ef5c446be5b7b68c27dea230b7c09 /src/runtime/runtime.go
parent220a6de47eced55956eb8af8d643d4f5b67fd634 (diff)
downloadgo-c007ce824d9a4fccb148f9204e04c23ed2984b71.tar.gz
go-c007ce824d9a4fccb148f9204e04c23ed2984b71.zip
build: move package sources from src/pkg to src
Preparation was in CL 134570043. This CL contains only the effect of 'hg mv src/pkg/* src'. For more about the move, see golang.org/s/go14nopkg.
Diffstat (limited to 'src/runtime/runtime.go')
-rw-r--r--src/runtime/runtime.go37
1 files changed, 37 insertions, 0 deletions
diff --git a/src/runtime/runtime.go b/src/runtime/runtime.go
new file mode 100644
index 0000000000..d5b31559a2
--- /dev/null
+++ b/src/runtime/runtime.go
@@ -0,0 +1,37 @@
+// 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.
+
+package runtime
+
+var ticks struct {
+ lock mutex
+ val uint64
+}
+
+// Note: Called by runtime/pprof in addition to runtime code.
+func tickspersecond() int64 {
+ r := int64(atomicload64(&ticks.val))
+ if r != 0 {
+ return r
+ }
+ lock(&ticks.lock)
+ r = int64(ticks.val)
+ if r == 0 {
+ t0 := nanotime()
+ c0 := cputicks()
+ usleep(100 * 1000)
+ t1 := nanotime()
+ c1 := cputicks()
+ if t1 == t0 {
+ t1++
+ }
+ r = (c1 - c0) * 1000 * 1000 * 1000 / (t1 - t0)
+ if r == 0 {
+ r++
+ }
+ atomicstore64(&ticks.val, uint64(r))
+ }
+ unlock(&ticks.lock)
+ return r
+}