sentry: capture CPU usage metadata for save.

PiperOrigin-RevId: 195466647
Change-Id: Ib5ca815f7b64a4881441e58567adedf344b206f1

1 files changed, 33 insertions, 0 deletions

diff --git a/pkg/sentry/state/state_unsafe.go b/pkg/sentry/state/state_unsafe.go
new file mode 100644
index 000000000..53814ef70
--- /dev/null
+++ b/pkg/sentry/state/state_unsafe.go
@@ -0,0 +1,33 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package state
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+)
+
+func cpuTime() (time.Duration, error) {
+	var ts syscall.Timespec
+	_, _, errno := syscall.RawSyscall(syscall.SYS_CLOCK_GETTIME, uintptr(linux.CLOCK_PROCESS_CPUTIME_ID), uintptr(unsafe.Pointer(&ts)), 0)
+	if errno != 0 {
+		return 0, fmt.Errorf("failed calling clock_gettime(CLOCK_PROCESS_CPUTIME_ID): errno=%d", errno)
+	}
+	return time.Duration(ts.Nano()), nil
+}