Ensure performance measurement collection is not taken too frequently (…

…#3221)

* performance measurement collection now waits at least 10ms between collections
* compiled regex in AndroidCpuCollector to parse the cpu file, to improve speed

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ### Fixes
 
+- Ensure performance measurement collection is not taken too frequently ([#3221](https://github.com/getsentry/sentry-java/pull/3221))
 - Fix old profiles deletion on SDK init ([#3216](https://github.com/getsentry/sentry-java/pull/3216))
 
 ## 7.4.0

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

@@ -14,6 +14,7 @@
 import io.sentry.util.Objects;
 import java.io.File;
 import java.io.IOException;
+import java.util.regex.Pattern;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
@@ -42,6 +43,7 @@ public final class AndroidCpuCollector implements IPerformanceSnapshotCollector
   private final @NotNull ILogger logger;
   private final @NotNull BuildInfoProvider buildInfoProvider;
   private boolean isEnabled = false;
+  private final @NotNull Pattern newLinePattern = Pattern.compile("[\n\t\r ]");
 
   public AndroidCpuCollector(
       final @NotNull ILogger logger, final @NotNull BuildInfoProvider buildInfoProvider) {
@@ -102,7 +104,7 @@ private long readTotalCpuNanos() {
     }
     if (stat != null) {
       stat = stat.trim();
-      String[] stats = stat.split("[\n\t\r ]");
+      String[] stats = newLinePattern.split(stat);
       try {
         // Amount of clock ticks this process has been scheduled in user mode
         long uTime = Long.parseLong(stats[13]);

sentry/src/main/java/io/sentry/DefaultTransactionPerformanceCollector.java

@@ -28,6 +28,7 @@ public final class DefaultTransactionPerformanceCollector
 
   private final @NotNull SentryOptions options;
   private final @NotNull AtomicBoolean isStarted = new AtomicBoolean(false);
+  private long lastCollectionTimestamp = 0;
 
   public DefaultTransactionPerformanceCollector(final @NotNull SentryOptions options) {
     this.options = Objects.requireNonNull(options, "The options object is required.");
@@ -104,6 +105,14 @@ public void run() {
             new TimerTask() {
               @Override
               public void run() {
+                long now = System.currentTimeMillis();
+                // The timer is scheduled to run every 100ms on average. In case it takes longer,
+                // subsequent tasks are executed more quickly. If two tasks are scheduled to run in
+                // less than 10ms, the measurement that we collect is not meaningful, so we skip it
+                if (now - lastCollectionTimestamp < 10) {
+                  return;
+                }
+                lastCollectionTimestamp = now;
                 final @NotNull PerformanceCollectionData tempData = new PerformanceCollectionData();
 
                 for (IPerformanceSnapshotCollector collector : snapshotCollectors) {