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Add bindings for Performance Hint Manager #480

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1 change: 1 addition & 0 deletions ndk/CHANGELOG.md
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
# Unreleased

- image_reader: Add `ImageReader::new_with_data_space()` constructor and `ImageReader::data_space()` getter from API level 34. (#474)
- Add bindings for Performance Hint manager (`APerformanceHintManager`, `APerformanceHintSession`, `AWorkDuration`). (#480)

# 0.9.0 (2024-04-26)

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1 change: 1 addition & 0 deletions ndk/Cargo.toml
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ api-level-31 = ["api-level-30"]
api-level-32 = ["api-level-31"]
api-level-33 = ["api-level-32"]
api-level-34 = ["api-level-33"]
api-level-35 = ["api-level-34"]

test = ["ffi/test", "jni", "all"]

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1 change: 1 addition & 0 deletions ndk/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@ pub mod media;
pub mod media_error;
pub mod native_activity;
pub mod native_window;
pub mod performance_hint;
pub mod shared_memory;
pub mod surface_texture;
pub mod sync;
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332 changes: 332 additions & 0 deletions ndk/src/performance_hint.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,332 @@
//! Bindings for [`APerformanceHintManager`] and [`APerformanceHintSession`]
//!
//! `APerformanceHint` allows apps to create performance hint sessions for groups of
//! threads, and provide hints to the system about the workload of those threads, to help the
//! system more accurately allocate power for them. It is the NDK counterpart to the [Java
//! PerformanceHintManager SDK API].
//!
//! [`APerformanceHintManager`]: https://developer.android.com/ndk/reference/group/a-performance-hint#aperformancehintmanager
//! [`APerformanceHintSession`]: https://developer.android.com/ndk/reference/group/a-performance-hint#aperformancehintsession
//! [Java PerformanceHintManager SDK API]: https://developer.android.com/reference/android/os/PerformanceHintManager
#![cfg(feature = "api-level-33")]

#[cfg(doc)]
use std::io::ErrorKind;
use std::{io::Result, ptr::NonNull, time::Duration};

use crate::utils::status_to_io_result;

/// An opaque type representing a handle to a performance hint manager.
///
/// To use:
/// - Obtain the performance hint manager instance by calling [`PerformanceHintManager::new()`].
/// - Create a [`PerformanceHintSession`] with [`PerformanceHintManager::new()`].
/// - Get the preferred update rate with [`PerformanceHintManager::preferred_update_rate()`].
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[doc(alias = "APerformanceHintManager")]
pub struct PerformanceHintManager {
ptr: NonNull<ffi::APerformanceHintManager>,
}

// SAFETY: The NDK stores a per-process global singleton that is accessible from any thread, and the
// only public methods perform thread-safe operations (i.e. the underlying AIBinder API to implement
// `IHintManager->createHintSession()` is thread-safe).
unsafe impl Send for PerformanceHintManager {}
unsafe impl Sync for PerformanceHintManager {}

impl PerformanceHintManager {
/// Retrieve a reference to the performance hint manager.
///
/// Returns [`None`] on failure.
#[doc(alias = "APerformanceHint_getManager")]
pub fn new() -> Option<Self> {
NonNull::new(unsafe { ffi::APerformanceHint_getManager() }).map(|ptr| Self { ptr })
}
Comment on lines +38 to +44
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As it turns out there was a hidden static keyword in this C function, this should always return the same singleton for the process:

https://issuetracker.google.com/issues/357214902#comment7

Meaning we can also derive Send/Sync and Copy/Clone since the user could anyway cheaply retrieve the same singleton from any thread.


/// Creates a session for the given set of threads and sets their initial target work duration.
///
/// # Parameters
/// - `thread_ids`: The list of threads to be associated with this session. They must be part of
/// this process' thread group.
/// - `initial_target_work_duration`: The target duration for the new session. This must be
/// positive if using the work duration API, or [`Duration::ZERO`] otherwise.
#[doc(alias = "APerformanceHint_createSession")]
pub fn create_session(
&self,
thread_ids: &[i32],
initial_target_work_duration: Duration,
) -> Option<PerformanceHintSession> {
NonNull::new(unsafe {
ffi::APerformanceHint_createSession(
self.ptr.as_ptr(),
thread_ids.as_ptr(),
thread_ids.len(),
initial_target_work_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
})
.map(|ptr| PerformanceHintSession { ptr })
}

/// Get preferred update rate information for this device.
///
/// Returns the preferred update rate supported by device software.
#[doc(alias = "APerformanceHint_getPreferredUpdateRateNanos")]
pub fn preferred_update_rate(&self) -> Duration {
Duration::from_nanos(unsafe {
ffi::APerformanceHint_getPreferredUpdateRateNanos(self.ptr.as_ptr())
.try_into()
.expect("getPreferredUpdateRateNanos should not return negative")
})
}
}

/// An opaque type representing a handle to a performance hint session. A session can only be
/// acquired from a [`PerformanceHintManager`] with [`PerformanceHintManager::create_session()`].
/// It will be freed automatically on [`drop()`] after use.
///
/// A Session represents a group of threads with an inter-related workload such that hints for their
/// performance should be considered as a unit. The threads in a given session should be long-lived
/// and not created or destroyed dynamically.
///
/// The work duration API can be used with periodic workloads to dynamically adjust
/// thread performance and keep the work on schedule while optimizing the available
/// power budget. When using the work duration API, the starting target duration
/// should be specified while creating the session, and can later be adjusted with
/// [`PerformanceHintSession::update_target_work_duration()`]. While using the work duration API,
/// the client is expected to call [`PerformanceHintSession::report_actual_work_duration()`] each
/// cycle to report the actual time taken to complete to the system.
///
/// All timings should be from [`ffi::CLOCK_MONOTONIC`].
#[derive(Debug, PartialEq, Eq, Hash)]
#[doc(alias = "APerformanceHintSession")]
pub struct PerformanceHintSession {
ptr: NonNull<ffi::APerformanceHintSession>,
}

impl PerformanceHintSession {
/// Updates this session's target duration for each cycle of work.
///
/// `target_duration` is the new desired duration.
///
/// # Returns
/// - [`ErrorKind::InvalidInput`] if `target_duration` is not positive.
/// - [`ErrorKind::BrokenPipe`] if communication with the system service has failed.
#[doc(alias = "APerformanceHint_updateTargetWorkDuration")]
pub fn update_target_work_duration(&self, target_duration: Duration) -> Result<()> {
status_to_io_result(unsafe {
ffi::APerformanceHint_updateTargetWorkDuration(
self.ptr.as_ptr(),
target_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
})
}

/// Reports the actual duration for the last cycle of work.
///
/// The system will attempt to adjust the scheduling and performance of the threads within the
/// thread group to bring the actual duration close to the target duration.
///
/// `actual_duration` is the duration of time the thread group took to complete its last
/// task.
///
/// # Returns
/// - [`ErrorKind::InvalidInput`] if `actual_duration` is not positive.
/// - [`ErrorKind::BrokenPipe`] if communication with the system service has failed.
#[doc(alias = "APerformanceHint_reportActualWorkDuration")]
pub fn report_actual_work_duration(&self, actual_duration: Duration) -> Result<()> {
status_to_io_result(unsafe {
ffi::APerformanceHint_reportActualWorkDuration(
self.ptr.as_ptr(),
actual_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
})
}

/// Set a list of threads to the performance hint session. This operation will replace the
/// current list of threads with the given list of threads.
///
/// `thread_ids` is the list of threads to be associated with this session. They must be part of
/// this app's thread group.
///
/// # Returns
/// - [`ErrorKind::InvalidInput`] if the list of thread ids is empty or if any of the thread ids
/// are not part of the thread group.
/// - [`ErrorKind::BrokenPipe`] if communication with the system service has failed.
/// - [`ErrorKind::PermissionDenied`] if any thread id doesn't belong to the application.
#[cfg(feature = "api-level-34")]
#[doc(alias = "APerformanceHint_setThreads")]
pub fn set_threads(&self, thread_ids: &[i32]) -> Result<()> {
status_to_io_result(unsafe {
ffi::APerformanceHint_setThreads(
self.ptr.as_ptr(),
thread_ids.as_ptr(),
thread_ids.len(),
)
})
}

/// This tells the session that these threads can be safely scheduled to prefer power efficiency
/// over performance.
///
/// `enabled` is the flag which sets whether this session will use power-efficient scheduling.
///
/// # Returns
/// - [`ErrorKind::BrokenPipe`] if communication with the system service has failed.
#[cfg(feature = "api-level-35")]
#[doc(alias = "APerformanceHint_setPreferPowerEfficiency")]
pub fn set_prefer_power_efficiency(&self, enabled: bool) -> Result<()> {
status_to_io_result(unsafe {
ffi::APerformanceHint_setPreferPowerEfficiency(self.ptr.as_ptr(), enabled)
})
}

/// Reports the durations for the last cycle of work.
///
/// The system will attempt to adjust the scheduling and performance of the threads within the
/// thread group to bring the actual duration close to the target duration.
///
/// # Parameters
/// - `work_duration` is the [`WorkDuration`] structure of times the thread group took to
/// complete its last task breaking down into different components.
///
/// The work period start timestamp and actual total duration must be greater than zero.
///
/// The actual CPU and GPU durations must be greater than or equal to [`Duration::ZERO`], and
/// at least one of them must be greater than [`Duration::ZERO`]. When one of them is equal to
/// [`Duration::ZERO`], it means that type of work was not measured for this workload.
///
/// # Returns
/// - [`ErrorKind::BrokenPipe`] if communication with the system service has failed.
#[cfg(feature = "api-level-35")]
#[doc(alias = "APerformanceHint_reportActualWorkDuration2")]
pub fn report_actual_work_duration2(&self, work_duration: &WorkDuration) -> Result<()> {
status_to_io_result(unsafe {
ffi::APerformanceHint_reportActualWorkDuration2(
self.ptr.as_ptr(),
work_duration.ptr.as_ptr(),
)
})
}
}

impl Drop for PerformanceHintSession {
/// Release the performance hint manager pointer acquired via
/// [`PerformanceHintManager::create_session()`].
#[doc(alias = "APerformanceHint_closeSession")]
fn drop(&mut self) {
unsafe { ffi::APerformanceHint_closeSession(self.ptr.as_ptr()) }
}
}

#[cfg(feature = "api-level-35")]
#[derive(Debug, PartialEq, Eq, Hash)]
#[doc(alias = "AWorkDuration")]
pub struct WorkDuration {
ptr: NonNull<ffi::AWorkDuration>,
}

#[cfg(feature = "api-level-35")]
impl WorkDuration {
/// Creates a new [`WorkDuration`]. When the client finishes using [`WorkDuration`], it will
/// automatically be released on [`drop()`].
#[doc(alias = "AWorkDuration_create")]
pub fn new() -> Self {
Self {
ptr: NonNull::new(unsafe { ffi::AWorkDuration_create() })
.expect("AWorkDuration_create should not return NULL"),
}
}

/// Sets the work period start timestamp in nanoseconds.
///
/// `work_period_start_timestamp` is the work period start timestamp based on
/// [`ffi::CLOCK_MONOTONIC`] about when the work starts. This timestamp must be greater than
/// [`Duration::ZERO`].
#[doc(alias = "AWorkDuration_setWorkPeriodStartTimestampNanos")]
pub fn set_work_period_start_timestamp(&self, work_period_start_timestamp: Duration) {
unsafe {
ffi::AWorkDuration_setWorkPeriodStartTimestampNanos(
self.ptr.as_ptr(),
work_period_start_timestamp
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
}
}

/// Sets the actual total work duration in nanoseconds.
///
/// `actual_total_duration` is the actual total work duration. This number must be greater
/// than [`Duration::ZERO`].
#[doc(alias = "AWorkDuration_setActualTotalDurationNanos")]
pub fn set_actual_total_duration(&self, actual_total_duration: Duration) {
unsafe {
ffi::AWorkDuration_setActualTotalDurationNanos(
self.ptr.as_ptr(),
actual_total_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
}
}

/// Sets the actual CPU work duration in nanoseconds.
///
/// `actual_cpu_duration` is the actual CPU work duration. If it is equal to
/// [`Duration::ZERO`], that means the CPU was not measured.
#[doc(alias = "AWorkDuration_setActualCpuDurationNanos")]
pub fn set_actual_cpu_duration(&self, actual_cpu_duration: Duration) {
unsafe {
ffi::AWorkDuration_setActualCpuDurationNanos(
self.ptr.as_ptr(),
actual_cpu_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
}
}

/// Sets the actual GPU work duration in nanoseconds.
///
/// `actual_gpu_duration` is the actual GPU work duration. If it is equal to
/// [`Duration::ZERO`], that means the GPU was not measured.
#[doc(alias = "AWorkDuration_setActualGpuDurationNanos")]
pub fn set_actual_gpu_duration(&self, actual_gpu_duration: Duration) {
unsafe {
ffi::AWorkDuration_setActualGpuDurationNanos(
self.ptr.as_ptr(),
actual_gpu_duration
.as_nanos()
.try_into()
.expect("Duration should be convertible to i64 nanoseconds"),
)
}
}
}

impl Default for WorkDuration {
#[doc(alias = "AWorkDuration_create")]
fn default() -> Self {
Self::new()
}
}

impl Drop for WorkDuration {
/// Destroys [`WorkDuration`] and free all resources associated to it.
#[doc(alias = "AWorkDuration_release")]
fn drop(&mut self) {
unsafe { ffi::AWorkDuration_release(self.ptr.as_ptr()) }
}
}
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