Change continuous profiling to session sample rate (#4180)

* Set continuousProfilesSampleRate and startProfiler() and stopProfiler() as experimental
* Added chunk start timestamp to ProfileChunk
* Moved setContinuousProfilesSampleRate into ExperimentalOptions
* increased chunk duration to 1 minute
* replaced continuousProfilesSampleRate with profileSessionSampleRate (Default null)
* sample rate is now evaluated inside AndroidContinuousProfiler and every time a session finishes

Author: stefanosiano

CHANGELOG.md

@@ -6,7 +6,7 @@
 
 - Add Continuous Profiling Support ([#3710](https://github.com/getsentry/sentry-java/pull/3710))
 
-  To enable Continuous Profiling use the `Sentry.startProfiler` and `Sentry.stopProfiler` experimental APIs. Sampling rate can be set through `options.continuousProfilesSampleRate` (defaults to 1.0).   
+  To enable Continuous Profiling use the `Sentry.startProfiler` and `Sentry.stopProfiler` experimental APIs. Sampling rate can be set through `options.continuousProfilesSampleRate`, which defaults to null (disabled).   
   Note: Both `options.profilesSampler` and `options.profilesSampleRate` must **not** be set to enable Continuous Profiling.
 
   ```java
@@ -15,7 +15,7 @@
   SentryAndroid.init(context) { options ->
 
     // Currently under experimental options:
-    options.getExperimental().setContinuousProfilesSampleRate(1.0);
+    options.getExperimental().setProfileSessionSampleRate(1.0);
   }
   // Start profiling
   Sentry.startProfiler();
@@ -29,7 +29,7 @@
   SentryAndroid.init(context) { options ->
 
     // Currently under experimental options:
-    options.experimental.continuousProfilesSampleRate = 1.0
+    options.experimental.profileSessionSampleRate = 1.0
   }
   // Start profiling
   Sentry.startProfiler()

sentry-android-core/api/sentry-android-core.api

@@ -42,7 +42,8 @@ public class io/sentry/android/core/AndroidContinuousProfiler : io/sentry/IConti
 	public fun getProfilerId ()Lio/sentry/protocol/SentryId;
 	public fun isRunning ()Z
 	public fun onRateLimitChanged (Lio/sentry/transport/RateLimiter;)V
-	public fun start ()V
+	public fun reevaluateSampling ()V
+	public fun start (Lio/sentry/TracesSampler;)V
 	public fun stop ()V
 }
 

sentry-android-core/src/main/java/io/sentry/android/core/AndroidContinuousProfiler.java

@@ -20,6 +20,7 @@
 import io.sentry.SentryLevel;
 import io.sentry.SentryNanotimeDate;
 import io.sentry.SentryOptions;
+import io.sentry.TracesSampler;
 import io.sentry.android.core.internal.util.SentryFrameMetricsCollector;
 import io.sentry.protocol.SentryId;
 import io.sentry.transport.RateLimiter;
@@ -55,6 +56,8 @@ public class AndroidContinuousProfiler
   private @NotNull SentryId chunkId = SentryId.EMPTY_ID;
   private final @NotNull AtomicBoolean isClosed = new AtomicBoolean(false);
   private @NotNull SentryDate startProfileChunkTimestamp = new SentryNanotimeDate();
+  private boolean shouldSample = true;
+  private boolean isSampled = false;
 
   public AndroidContinuousProfiler(
       final @NotNull BuildInfoProvider buildInfoProvider,
@@ -100,7 +103,24 @@ private void init() {
             logger);
   }
 
-  public synchronized void start() {
+  public synchronized void start(final @NotNull TracesSampler tracesSampler) {
+    if (shouldSample) {
+      isSampled = tracesSampler.sampleSessionProfile();
+      shouldSample = false;
+    }
+    if (!isSampled) {
+      logger.log(SentryLevel.DEBUG, "Profiler was not started due to sampling decision.");
+      return;
+    }
+    if (isRunning()) {
+      logger.log(SentryLevel.DEBUG, "Profiler is already running.");
+      return;
+    }
+    logger.log(SentryLevel.DEBUG, "Started Profiler.");
+    startProfile();
+  }
+
+  private synchronized void startProfile() {
     if ((scopes == null || scopes == NoOpScopes.getInstance())
         && Sentry.getCurrentScopes() != NoOpScopes.getInstance()) {
       this.scopes = Sentry.getCurrentScopes();
@@ -236,14 +256,18 @@ private synchronized void stop(final boolean restartProfiler) {
 
     if (restartProfiler) {
       logger.log(SentryLevel.DEBUG, "Profile chunk finished. Starting a new one.");
-      start();
+      startProfile();
     } else {
       // When the profiler is stopped manually, we have to reset its id
       profilerId = SentryId.EMPTY_ID;
       logger.log(SentryLevel.DEBUG, "Profile chunk finished.");
     }
   }
 
+  public synchronized void reevaluateSampling() {
+    shouldSample = true;
+  }
+
   public synchronized void close() {
     stop();
     isClosed.set(true);

sentry-android-core/src/main/java/io/sentry/android/core/ManifestMetadataReader.java

@@ -64,8 +64,8 @@ final class ManifestMetadataReader {
 
   static final String PROFILES_SAMPLE_RATE = "io.sentry.traces.profiling.sample-rate";
 
-  static final String CONTINUOUS_PROFILES_SAMPLE_RATE =
-      "io.sentry.traces.profiling.continuous-sample-rate";
+  static final String PROFILE_SESSION_SAMPLE_RATE =
+      "io.sentry.traces.profiling.session-sample-rate";
 
   @ApiStatus.Experimental static final String TRACE_SAMPLING = "io.sentry.traces.trace-sampling";
   static final String TRACE_PROPAGATION_TARGETS = "io.sentry.traces.trace-propagation-targets";
@@ -318,11 +318,11 @@ static void applyMetadata(
           }
         }
 
-        if (options.getContinuousProfilesSampleRate() == 1.0) {
-          final double continuousProfilesSampleRate =
-              readDouble(metadata, logger, CONTINUOUS_PROFILES_SAMPLE_RATE);
-          if (continuousProfilesSampleRate != -1) {
-            options.getExperimental().setContinuousProfilesSampleRate(continuousProfilesSampleRate);
+        if (options.getProfileSessionSampleRate() == null) {
+          final double profileSessionSampleRate =
+              readDouble(metadata, logger, PROFILE_SESSION_SAMPLE_RATE);
+          if (profileSessionSampleRate != -1) {
+            options.getExperimental().setProfileSessionSampleRate(profileSessionSampleRate);
           }
         }
 

sentry-android-core/src/main/java/io/sentry/android/core/SentryPerformanceProvider.java

@@ -22,6 +22,7 @@
 import io.sentry.SentryExecutorService;
 import io.sentry.SentryLevel;
 import io.sentry.SentryOptions;
+import io.sentry.TracesSampler;
 import io.sentry.TracesSamplingDecision;
 import io.sentry.android.core.internal.util.FirstDrawDoneListener;
 import io.sentry.android.core.internal.util.SentryFrameMetricsCollector;
@@ -180,7 +181,12 @@ private void createAndStartContinuousProfiler(
     appStartMetrics.setAppStartProfiler(null);
     appStartMetrics.setAppStartContinuousProfiler(appStartContinuousProfiler);
     logger.log(SentryLevel.DEBUG, "App start continuous profiling started.");
-    appStartContinuousProfiler.start();
+    SentryOptions sentryOptions = SentryOptions.empty();
+    // Let's fake a sampler to accept the sampling decision that was calculated on last run
+    sentryOptions
+        .getExperimental()
+        .setProfileSessionSampleRate(profilingOptions.isContinuousProfileSampled() ? 1.0 : 0.0);
+    appStartContinuousProfiler.start(new TracesSampler(sentryOptions));
   }
 
   private void createAndStartTransactionProfiler(