zircon/kernel/vm/scanner.rs

// Copyright 2026 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

use scanner_bindings as bindings;

/// RAII guard to disable the VM scanner for a scope, restoring the scanner state on drop.
pub struct AutoVmScannerDisable(());

impl AutoVmScannerDisable {
    /// Creates a new `AutoVmScannerDisable` guard, disabling the VM scanner.
    pub fn new() -> Self {
        unsafe { bindings::cpp_scanner_push_disable_count() };
        Self(())
    }
}

impl Drop for AutoVmScannerDisable {
    fn drop(&mut self) {
        unsafe { bindings::cpp_scanner_pop_disable_count() };
    }
}

/// Returns true if no accessed scan has completed since `update_time`.
pub fn needs_accessed_scan(update_time: crate::platform_rs::timer::InstantMono) -> bool {
    unsafe { bindings::cpp_scanner_needs_accessed_scan(update_time.0) }
}

/// Blocks until the scanner has completed an access scan that occurred at `update_time` or later.
pub fn wait_for_accessed_scan(update_time: crate::platform_rs::timer::InstantMono) {
    unsafe { bindings::cpp_scanner_wait_for_accessed_scan(update_time.0) }
}