WIP

ndk/Cargo.toml

@@ -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"]
 

ndk/src/lib.rs

@@ -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;

ndk/src/performance_hint.rs

@@ -0,0 +1,325 @@
+//! Bindings for the [Performance Hint Manager]
+//!
+//! `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].
+//!
+//! [Performance Hint Manager]: https://developer.android.com/ndk/reference/group/a-performance-hint
+//! [Java PerformanceHintManager SDK API]: https://developer.android.com/reference/android/os/PerformanceHintManager
+#![cfg(feature = "api-level-33")]
+
+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.
+// TODO: * It must be released after use.
+///
+/// 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(Debug)]
+#[doc(alias = "APerformanceHintManager")]
+pub struct PerformanceHintManager {
+    ptr: NonNull<ffi::APerformanceHintManager>,
+}
+
+impl PerformanceHintManager {
+    /// Acquire an instance of 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 })
+    }
+
+    /// 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.
+///
+// TODO links:
+/// All timings should be from `std::chrono::steady_clock` or `clock_gettime(CLOCK_MONOTONIC, ...)`.
+#[derive(Debug)]
+#[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)]
+#[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 `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"),
+            )
+        }
+    }
+}
+
+// TODO: Does this make sense?
+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()) }
+    }
+}