runtime: move heapLive and heapScan updates into a method

This change moves heapLive and heapScan updates on gcController into a
method for better testability. It's also less error-prone because code
that updates these fields needs to remember to emit traces and/or call
gcController.revise; this method now handles those cases.

For #44167.

Change-Id: I3d6f2e7abb22def27c93feacff50162b0b074da2
Reviewed-on: https://go-review.googlesource.com/c/go/+/309275
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/runtime/mgcpacer.go b/src/runtime/mgcpacer.go
index 503b8110b3..094dcc701a 100644
--- a/src/runtime/mgcpacer.go
+++ b/src/runtime/mgcpacer.go
@@ -669,6 +669,23 @@ func (c *gcControllerState) logWorkTime(mode gcMarkWorkerMode, duration int64) {
 	}
 }
 
+func (c *gcControllerState) update(dHeapLive, dHeapScan int64) {
+	if dHeapLive != 0 {
+		atomic.Xadd64(&gcController.heapLive, dHeapLive)
+		if trace.enabled {
+			// gcController.heapLive changed.
+			traceHeapAlloc()
+		}
+	}
+	if dHeapScan != 0 {
+		atomic.Xadd64(&gcController.heapScan, dHeapScan)
+	}
+	if gcBlackenEnabled != 0 {
+		// gcController.heapLive and heapScan changed.
+		c.revise()
+	}
+}
+
 // commit sets the trigger ratio and updates everything
 // derived from it: the absolute trigger, the heap goal, mark pacing,
 // and sweep pacing.