sdk/fidl/fuchsia.kernel/kernel-counter.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.kernel;

using fuchsia.mem;
using zx;

/// Protocol for retrieving kcounter information.
@discoverable(server="platform")
closed protocol Counter {
    /// Retrives a VMO containining summarized kcounter data. The vmo returned
    /// in `buffer` is in "inspect-vmo" format, documented elsewhere.
    strict GetInspectVmo() -> (resource struct {
        status zx.Status;
        buffer fuchsia.mem.Buffer;
    });

    /// Request that the previously-returned VMO buffer's data be updated. The
    /// data may not be updated if it was already recently updated (updates are
    /// limited to an unspecified rate, but approximately every few seconds).
    strict UpdateInspectVmo() -> (struct {
        status zx.Status;
    });
};