Add CPU/GPU_LOAD_SPIKE hints for one-off expensive workloads

Currently there is ambiguity between single-frame expensive ops
(eg: shader compilation) and longer-duration expensive ops (eg:
SF client compositon). This load hint aims to resolve this by
explicitly annotating one-time expensive workloads so they can
be given unique boost and hysteresis expectations.

For example, a load_spike aware tracker might want to ignore
the timing that comes from a LOAD_SPIKE-marked frame, as it is
known to not be representative of the overall workload.

Flag: EXEMPT NDK
Test: atest PerformanceHintNativeTestCases
Test: atest PerformanceHintManagerTest
Bug: 367803904
Change-Id: I22458f0d8f0819499f3463aa36e8bb7eb7af15be

Author: AndroidMatt1

include/android/performance_hint.h

@@ -358,6 +358,31 @@ int APerformanceHint_notifyWorkloadReset(
         APerformanceHintSession* _Nonnull session,
         bool cpu, bool gpu, const char* _Nonnull debugName) __INTRODUCED_IN(36);
 
+/**
+ * Informs the framework of an upcoming one-off expensive frame for a graphics pipeline
+ * bound to this session. This frame will be treated as not representative of the workload as a
+ * whole, and it will be discarded the purposes of load tracking. The user can specify
+ * whether the workload spike is expected to be on the CPU, GPU, or both.
+ *
+ * Sending hints for both CPU and GPU counts as two separate hints for the purposes of the
+ * rate limiter.
+ *
+ * @param cpu Indicates if the workload spike is expected to affect the CPU.
+ * @param gpu Indicates if the workload spike is expected to affect the GPU.
+ * @param debugName A required string used to identify this specific hint during
+ *        tracing. This debug string will only be held for the duration of the
+ *        method, and can be safely discarded after.
+ *
+ * @return 0 on success.
+ *         EINVAL if no hints were requested.
+ *         EBUSY if the hint was rate limited.
+ *         EPIPE if communication with the system service has failed.
+ *         ENOTSUP if the hint is not supported.
+ */
+int APerformanceHint_notifyWorkloadSpike(
+        APerformanceHintSession* _Nonnull session,
+        bool cpu, bool gpu, const char* _Nonnull debugName) __INTRODUCED_IN(36);
+
 /**
  * Associates a session with any {@link ASurfaceControl} or {@link ANativeWindow}
  * instances managed by this session.

include/private/performance_hint_private.h

@@ -74,6 +74,20 @@ enum SessionHint: int32_t {
      * baseline to prepare for an arbitrary load, and must wake up if inactive.
      */
     GPU_LOAD_RESET = 7,
+
+    /**
+     * This hint indicates an upcoming CPU workload that is abnormally large and
+     * not representative of the workload. This should be used for rare, one-time
+     * operations and should be ignored by any load tracking or session hysteresis.
+     */
+    CPU_LOAD_SPIKE = 8,
+
+    /**
+     * This hint indicates an upcoming GPU workload that is abnormally large and
+     * not representative of the workload. This should be used for rare, one-time
+     * operations and should be ignored by any load tracking or session hysteresis.
+     */
+    GPU_LOAD_SPIKE = 9,
 };
 
 // Allows access to PowerHAL's SessionTags without needing to import its AIDL