profcollectd: add interface to wait for ETM after boot.

ETM device may not be ready when profcollectd is started.
So this CL adds interface to wait for ETM after boot:

1. In simpleperf_profcollect, split has_support() into
   has_driver_support() and has_device_support().
2. In ProfcollectdBinderService and Scheduler, add interface
   to register ProviderStatusCallback, which is called when
   the trace provider is ready.
3. In profcollectd, register ProviderStatusCallback after boot.
   Then record boot profile and schedule periodic recording in
   the callback.

Bug: 213519191
Test: on oriole EVT and DVT devices, profcollectd can record boot
Test: profile and periodic profiles.
Test: run simpleperf_unit_test.
Change-Id: I87befcd372ad85a0131116a7925f303b4990ec47

9 files changed, 145 insertions, 7 deletions

diff --git a/profcollectd/Android.bp b/profcollectd/Android.bp
index f1723006..122e4f61 100644
--- a/profcollectd/Android.bp
+++ b/profcollectd/Android.bp
@@ -59,6 +59,7 @@ filegroup {
     name: "profcollectd_aidl",
     srcs: [
         "binder/com/android/server/profcollect/IProfCollectd.aidl",
+        "binder/com/android/server/profcollect/IProviderStatusCallback.aidl",
     ],
     path: "binder",
 }
diff --git a/profcollectd/binder/com/android/server/profcollect/IProfCollectd.aidl b/profcollectd/binder/com/android/server/profcollect/IProfCollectd.aidl
index c8f33a1e..bfc24446 100644
--- a/profcollectd/binder/com/android/server/profcollect/IProfCollectd.aidl
+++ b/profcollectd/binder/com/android/server/profcollect/IProfCollectd.aidl
@@ -16,6 +16,8 @@
 
 package com.android.server.profcollect;
 
+import com.android.server.profcollect.IProviderStatusCallback;
+
 /** {@hide} */
 interface IProfCollectd {
     void schedule();
@@ -24,4 +26,5 @@ interface IProfCollectd {
     void process();
     @utf8InCpp String report();
     @utf8InCpp String get_supported_provider();
+    void registerProviderStatusCallback(IProviderStatusCallback cb);
 }
diff --git a/profcollectd/binder/com/android/server/profcollect/IProviderStatusCallback.aidl b/profcollectd/binder/com/android/server/profcollect/IProviderStatusCallback.aidl
new file mode 100644
index 00000000..b311cf91
--- /dev/null
+++ b/profcollectd/binder/com/android/server/profcollect/IProviderStatusCallback.aidl
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.profcollect;
+
+/** {@hide} */
+oneway interface IProviderStatusCallback {
+    void onProviderReady();
+}
diff --git a/profcollectd/libprofcollectd/lib.rs b/profcollectd/libprofcollectd/lib.rs
index abc11272..f95132f4 100644
--- a/profcollectd/libprofcollectd/lib.rs
+++ b/profcollectd/libprofcollectd/lib.rs
@@ -30,11 +30,34 @@ use anyhow::{Context, Result};
 use profcollectd_aidl_interface::aidl::com::android::server::profcollect::IProfCollectd::{
     self, BnProfCollectd,
 };
+use profcollectd_aidl_interface::aidl::com::android::server::profcollect::IProviderStatusCallback::{IProviderStatusCallback, BnProviderStatusCallback};
 use profcollectd_aidl_interface::binder::{self, BinderFeatures};
-use service::ProfcollectdBinderService;
+use service::{err_to_binder_status, ProfcollectdBinderService};
+use std::time::{Duration, Instant};
 
 const PROFCOLLECTD_SERVICE_NAME: &str = "profcollectd";
 
+struct ProviderStatusCallback {
+    service_start_time: Instant,
+}
+
+impl binder::Interface for ProviderStatusCallback {}
+
+impl IProviderStatusCallback for ProviderStatusCallback {
+    fn onProviderReady(&self) -> binder::Result<()> {
+        // If we have waited too long for the provider to be ready, then we have passed
+        // boot phase, and no need to collect boot profile.
+        // TODO: should we check boottime instead?
+        const TIMEOUT_TO_COLLECT_BOOT_PROFILE: Duration = Duration::from_secs(3);
+        let elapsed = Instant::now().duration_since(self.service_start_time);
+        if elapsed < TIMEOUT_TO_COLLECT_BOOT_PROFILE {
+            trace_once("boot").map_err(err_to_binder_status)?;
+        }
+        schedule().map_err(err_to_binder_status)?;
+        Ok(())
+    }
+}
+
 /// Initialise profcollectd service.
 /// * `schedule_now` - Immediately schedule collection after service is initialised.
 pub fn init_service(schedule_now: bool) -> Result<()> {
@@ -49,8 +72,11 @@ pub fn init_service(schedule_now: bool) -> Result<()> {
     .context("Failed to register service.")?;
 
     if schedule_now {
-        trace_once("boot")?;
-        schedule()?;
+        let cb = BnProviderStatusCallback::new_binder(
+            ProviderStatusCallback { service_start_time: Instant::now() },
+            BinderFeatures::default(),
+        );
+        get_profcollectd_service()?.registerProviderStatusCallback(&cb)?;
     }
 
     binder::ProcessState::join_thread_pool();
diff --git a/profcollectd/libprofcollectd/logging_trace_provider.rs b/profcollectd/libprofcollectd/logging_trace_provider.rs
index 1325855d..fda4c66a 100644
--- a/profcollectd/libprofcollectd/logging_trace_provider.rs
+++ b/profcollectd/libprofcollectd/logging_trace_provider.rs
@@ -32,6 +32,10 @@ impl TraceProvider for LoggingTraceProvider {
         "logging"
     }
 
+    fn is_ready(&self) -> bool {
+        true
+    }
+
     fn trace(&self, trace_dir: &Path, tag: &str, sampling_period: &Duration) {
         let trace_file = trace_provider::get_path(trace_dir, tag, LOGGING_TRACEFILE_EXTENSION);
 
diff --git a/profcollectd/libprofcollectd/scheduler.rs b/profcollectd/libprofcollectd/scheduler.rs
index 31a495a5..f58c4995 100644
--- a/profcollectd/libprofcollectd/scheduler.rs
+++ b/profcollectd/libprofcollectd/scheduler.rs
@@ -17,11 +17,13 @@
 //! ProfCollect tracing scheduler.
 
 use std::fs;
+use std::mem;
 use std::path::Path;
 use std::sync::mpsc::{sync_channel, SyncSender};
 use std::sync::Arc;
 use std::sync::Mutex;
 use std::thread;
+use std::time::{Duration, Instant};
 
 use crate::config::{Config, PROFILE_OUTPUT_DIR, TRACE_OUTPUT_DIR};
 use crate::trace_provider::{self, TraceProvider};
@@ -33,12 +35,17 @@ pub struct Scheduler {
     termination_ch: Option<SyncSender<()>>,
     /// The preferred trace provider for the system.
     trace_provider: Arc<Mutex<dyn TraceProvider + Send>>,
+    provider_ready_callbacks: Arc<Mutex<Vec<Box<dyn FnOnce() + Send>>>>,
 }
 
 impl Scheduler {
     pub fn new() -> Result<Self> {
         let p = trace_provider::get_trace_provider()?;
-        Ok(Scheduler { termination_ch: None, trace_provider: p })
+        Ok(Scheduler {
+            termination_ch: None,
+            trace_provider: p,
+            provider_ready_callbacks: Arc::new(Mutex::new(Vec::new())),
+        })
     }
 
     fn is_scheduled(&self) -> bool {
@@ -106,6 +113,51 @@ impl Scheduler {
     pub fn get_trace_provider_name(&self) -> &'static str {
         self.trace_provider.lock().unwrap().get_name()
     }
+
+    pub fn is_provider_ready(&self) -> bool {
+        self.trace_provider.lock().unwrap().is_ready()
+    }
+
+    pub fn register_provider_ready_callback(&self, cb: Box<dyn FnOnce() + Send>) {
+        let mut locked_callbacks = self.provider_ready_callbacks.lock().unwrap();
+        locked_callbacks.push(cb);
+        if locked_callbacks.len() == 1 {
+            self.start_thread_waiting_for_provider_ready();
+        }
+    }
+
+    fn start_thread_waiting_for_provider_ready(&self) {
+        let provider = self.trace_provider.clone();
+        let callbacks = self.provider_ready_callbacks.clone();
+
+        thread::spawn(move || {
+            let start_time = Instant::now();
+            loop {
+                let elapsed = Instant::now().duration_since(start_time);
+                if provider.lock().unwrap().is_ready() {
+                    break;
+                }
+                // Decide check period based on how long we have waited:
+                // For the first 10s waiting, check every 100ms (likely to work on EVT devices).
+                // For the first 10m waiting, check every 10s (likely to work on DVT devices).
+                // For others, check every 10m.
+                let sleep_duration = if elapsed < Duration::from_secs(10) {
+                    Duration::from_millis(100)
+                } else if elapsed < Duration::from_secs(60 * 10) {
+                    Duration::from_secs(10)
+                } else {
+                    Duration::from_secs(60 * 10)
+                };
+                thread::sleep(sleep_duration);
+            }
+
+            let mut locked_callbacks = callbacks.lock().unwrap();
+            let v = mem::take(&mut *locked_callbacks);
+            for cb in v {
+                cb();
+            }
+        });
+    }
 }
 
 /// Run if space usage is under limit.
diff --git a/profcollectd/libprofcollectd/service.rs b/profcollectd/libprofcollectd/service.rs
index 0199c105..3f338024 100644
--- a/profcollectd/libprofcollectd/service.rs
+++ b/profcollectd/libprofcollectd/service.rs
@@ -18,8 +18,9 @@
 
 use anyhow::{anyhow, Context, Error, Result};
 use binder::Result as BinderResult;
-use binder::Status;
+use binder::{SpIBinder, Status};
 use profcollectd_aidl_interface::aidl::com::android::server::profcollect::IProfCollectd::IProfCollectd;
+use profcollectd_aidl_interface::aidl::com::android::server::profcollect::IProviderStatusCallback::IProviderStatusCallback;
 use std::ffi::CString;
 use std::fs::{read_dir, read_to_string, remove_file, write};
 use std::str::FromStr;
@@ -32,7 +33,7 @@ use crate::config::{
 use crate::report::{get_report_ts, pack_report};
 use crate::scheduler::Scheduler;
 
-fn err_to_binder_status(msg: Error) -> Status {
+pub fn err_to_binder_status(msg: Error) -> Status {
     let msg = format!("{:#?}", msg);
     let msg = CString::new(msg).expect("Failed to convert to CString");
     Status::new_service_specific_error(1, Some(&msg))
@@ -89,6 +90,30 @@ impl IProfCollectd for ProfcollectdBinderService {
     fn get_supported_provider(&self) -> BinderResult<String> {
         Ok(self.lock().scheduler.get_trace_provider_name().to_string())
     }
+
+    fn registerProviderStatusCallback(
+        &self,
+        cb: &binder::Strong<(dyn IProviderStatusCallback)>,
+    ) -> BinderResult<()> {
+        if self.lock().scheduler.is_provider_ready() {
+            if let Err(e) = cb.onProviderReady() {
+                log::error!("Failed to call ProviderStatusCallback {:?}", e);
+            }
+            return Ok(());
+        }
+
+        let cb_binder: SpIBinder = cb.as_binder();
+        self.lock().scheduler.register_provider_ready_callback(Box::new(move || {
+            if let Ok(cb) = cb_binder.into_interface::<dyn IProviderStatusCallback>() {
+                if let Err(e) = cb.onProviderReady() {
+                    log::error!("Failed to call ProviderStatusCallback {:?}", e)
+                }
+            } else {
+                log::error!("SpIBinder is not a IProviderStatusCallback.");
+            }
+        }));
+        Ok(())
+    }
 }
 
 impl ProfcollectdBinderService {
diff --git a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
index 14fb7509..f25f5ffc 100644
--- a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
+++ b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
@@ -34,6 +34,10 @@ impl TraceProvider for SimpleperfEtmTraceProvider {
         "simpleperf_etm"
     }
 
+    fn is_ready(&self) -> bool {
+        simpleperf_profcollect::has_device_support()
+    }
+
     fn trace(&self, trace_dir: &Path, tag: &str, sampling_period: &Duration) {
         let trace_file = trace_provider::get_path(trace_dir, tag, ETM_TRACEFILE_EXTENSION);
 
@@ -76,6 +80,6 @@ impl TraceProvider for SimpleperfEtmTraceProvider {
 
 impl SimpleperfEtmTraceProvider {
     pub fn supported() -> bool {
-        simpleperf_profcollect::has_support()
+        simpleperf_profcollect::has_driver_support()
     }
 }
diff --git a/profcollectd/libprofcollectd/trace_provider.rs b/profcollectd/libprofcollectd/trace_provider.rs
index 98cd5ec4..13059199 100644
--- a/profcollectd/libprofcollectd/trace_provider.rs
+++ b/profcollectd/libprofcollectd/trace_provider.rs
@@ -29,6 +29,7 @@ use crate::logging_trace_provider::LoggingTraceProvider;
 
 pub trait TraceProvider {
     fn get_name(&self) -> &'static str;
+    fn is_ready(&self) -> bool;
     fn trace(&self, trace_dir: &Path, tag: &str, sampling_period: &Duration);
     fn process(&self, trace_dir: &Path, profile_dir: &Path, binary_filter: &str) -> Result<()>;
 }