profcollectd: Add a log file in the report

This is to detect possible errors while collecting ETM data.

1. Create a trace.log file in the output directory. It will
   be put in the report zip file.
2. Register a custom log function writing to the log file via
   SetLogger. So both rust and c++ code can log to the file.
3. Add log messages when calling simpleperf functions.
4. The log file is cleared after config change (e.g. after a device
   update).

Bug: 272547391
Test: run profcollectd manually
Change-Id: I1f0d5e5209eab46f1b9893406ba365da43dd77c2

6 files changed, 29 insertions, 2 deletions

diff --git a/profcollectd/libprofcollectd/config.rs b/profcollectd/libprofcollectd/config.rs
index d68f02e7..2888aab7 100644
--- a/profcollectd/libprofcollectd/config.rs
+++ b/profcollectd/libprofcollectd/config.rs
@@ -40,6 +40,7 @@ lazy_static! {
     pub static ref REPORT_OUTPUT_DIR: &'static Path = Path::new("/data/misc/profcollectd/report/");
     pub static ref CONFIG_FILE: &'static Path =
         Path::new("/data/misc/profcollectd/output/config.json");
+    pub static ref LOG_FILE: &'static Path = Path::new("/data/misc/profcollectd/output/trace.log");
 }
 
 /// Dynamic configs, stored in config.json.
@@ -151,7 +152,7 @@ pub fn clear_data() -> Result<()> {
         read_dir(path)?
             .filter_map(|e| e.ok())
             .map(|e| e.path())
-            .filter(|e| e.is_file())
+            .filter(|e| e.is_file() && e != *LOG_FILE)
             .try_for_each(remove_file)?;
         Ok(())
     }
diff --git a/profcollectd/libprofcollectd/logging_trace_provider.rs b/profcollectd/libprofcollectd/logging_trace_provider.rs
index fda4c66a..0b9e36fc 100644
--- a/profcollectd/libprofcollectd/logging_trace_provider.rs
+++ b/profcollectd/libprofcollectd/logging_trace_provider.rs
@@ -51,6 +51,9 @@ impl TraceProvider for LoggingTraceProvider {
         log::info!("Process event triggered");
         Ok(())
     }
+
+    fn set_log_file(&self, filename: &Path) {}
+    fn reset_log_file(&self) {}
 }
 
 impl LoggingTraceProvider {
diff --git a/profcollectd/libprofcollectd/scheduler.rs b/profcollectd/libprofcollectd/scheduler.rs
index 9af4d5d3..c4d68805 100644
--- a/profcollectd/libprofcollectd/scheduler.rs
+++ b/profcollectd/libprofcollectd/scheduler.rs
@@ -25,7 +25,7 @@ use std::sync::Mutex;
 use std::thread;
 use std::time::{Duration, Instant};
 
-use crate::config::{Config, PROFILE_OUTPUT_DIR, TRACE_OUTPUT_DIR};
+use crate::config::{Config, LOG_FILE, PROFILE_OUTPUT_DIR, TRACE_OUTPUT_DIR};
 use crate::trace_provider::{self, TraceProvider};
 use anyhow::{anyhow, ensure, Context, Result};
 
@@ -41,6 +41,7 @@ pub struct Scheduler {
 impl Scheduler {
     pub fn new() -> Result<Self> {
         let p = trace_provider::get_trace_provider()?;
+        p.lock().map_err(|e| anyhow!(e.to_string()))?.set_log_file(&LOG_FILE);
         Ok(Scheduler {
             termination_ch: None,
             trace_provider: p,
@@ -158,6 +159,17 @@ impl Scheduler {
             }
         });
     }
+
+    pub fn clear_trace_log(&self) -> Result<()> {
+        let provider = self.trace_provider.lock().map_err(|e| anyhow!(e.to_string()))?;
+        provider.reset_log_file();
+        let mut result = Ok(());
+        if LOG_FILE.exists() {
+            result = fs::remove_file(*LOG_FILE).map_err(|e| anyhow!(e));
+        }
+        provider.set_log_file(&LOG_FILE);
+        result
+    }
 }
 
 /// Run if space usage is under limit.
diff --git a/profcollectd/libprofcollectd/service.rs b/profcollectd/libprofcollectd/service.rs
index 8ae51527..87c3b3cf 100644
--- a/profcollectd/libprofcollectd/service.rs
+++ b/profcollectd/libprofcollectd/service.rs
@@ -132,6 +132,7 @@ impl ProfcollectdBinderService {
             clear_data()?;
 
             write(*CONFIG_FILE, new_config.to_string())?;
+            new_scheduler.clear_trace_log()?;
         }
 
         // Clear profile reports out of rentention period.
diff --git a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
index 14911ffb..6b326b4a 100644
--- a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
+++ b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
@@ -76,6 +76,14 @@ impl TraceProvider for SimpleperfEtmTraceProvider {
             .filter(is_etm_extension)
             .try_for_each(process_trace_file)
     }
+
+    fn set_log_file(&self, filename: &Path) {
+        simpleperf_profcollect::set_log_file(filename);
+    }
+
+    fn reset_log_file(&self) {
+        simpleperf_profcollect::reset_log_file();
+    }
 }
 
 impl SimpleperfEtmTraceProvider {
diff --git a/profcollectd/libprofcollectd/trace_provider.rs b/profcollectd/libprofcollectd/trace_provider.rs
index 13059199..704eb9cb 100644
--- a/profcollectd/libprofcollectd/trace_provider.rs
+++ b/profcollectd/libprofcollectd/trace_provider.rs
@@ -32,6 +32,8 @@ pub trait TraceProvider {
     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<()>;
+    fn set_log_file(&self, filename: &Path);
+    fn reset_log_file(&self);
 }
 
 pub fn get_trace_provider() -> Result<Arc<Mutex<dyn TraceProvider + Send>>> {