Allow dynamic update of agent parameters

Made the agent profilers re-entrant allowing
to attach and update profiling parameters at runtime

This is useful when the VM is not started with the agent
but can be later attached and controlled, e.g:
- update profiling interval
- enabling/disabling profilers

For time being only profilers parameters can be updated.
Transformers, reporter not

Author: amuraru

src/main/java/com/uber/profiling/AgentImpl.java

@@ -23,7 +23,6 @@
 import com.uber.profiling.util.DummyConfigProvider;
 import com.uber.profiling.util.JsonUtils;
 import com.uber.profiling.util.ReflectionUtils;
-
 import java.lang.reflect.Constructor;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -59,6 +58,7 @@ public class Arguments {
     private boolean noop = false;
 
     private Constructor<Reporter> reporterConstructor;
+    private Reporter reporter;
     private Constructor<ConfigProvider> configProviderConstructor;
     private String configFile;
 
@@ -260,11 +260,14 @@ public Map<String, List<String>> getRawArgValues() {
     }
 
     public Reporter getReporter() {
+        if (reporter != null) {
+            return reporter;
+        }
         if (reporterConstructor == null) {
             return new ConsoleOutputReporter();
         } else {
             try {
-                Reporter reporter = reporterConstructor.newInstance();
+                reporter = reporterConstructor.newInstance();
                 reporter.updateArguments(getRawArgValues());
                 return reporter;
             } catch (Throwable e) {

src/main/java/com/uber/profiling/Arguments.java

@@ -16,10 +16,20 @@
 
 package com.uber.profiling;
 
-public interface Profiler {
-    long getIntervalMillis();
+public abstract class Profiler {
+  private ProfilerRunner runner;
 
-    void setReporter(Reporter reporter);
+  public abstract long getIntervalMillis();
+  public abstract void setIntervalMillis(long millis);
 
-    void profile();
+  public abstract void setReporter(Reporter reporter);
+
+  public abstract void profile();
+
+  void setRunner(ProfilerRunner runner){
+    this.runner = runner;
+  }
+  ProfilerRunner getRunner(){
+    return this.runner;
+  }
 }

src/main/java/com/uber/profiling/Profiler.java

@@ -18,6 +18,7 @@
 
 import com.uber.profiling.util.AgentLogger;
 
+import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.atomic.AtomicLong;
 
 public class ProfilerRunner implements Runnable {
@@ -27,6 +28,7 @@ public class ProfilerRunner implements Runnable {
 
     private final Profiler profiler;
     private final AtomicLong errorCounter = new AtomicLong(0);
+    private ScheduledFuture<?> handler;
 
     public ProfilerRunner(Profiler profiler) {
         this.profiler = profiler;
@@ -45,4 +47,12 @@ public void run() {
             }
         }
     }
+
+    public void setHandler(ScheduledFuture<?> handler) {
+        this.handler = handler;
+    }
+
+    public ScheduledFuture<?> getHandler() {
+        return handler;
+    }
 }

src/main/java/com/uber/profiling/ProfilerGroup.java

@@ -42,6 +42,10 @@ public void run() {
 
         for (Profiler profiler : profilers) {
             try {
+                if (profiler.getIntervalMillis() <=0 ){
+                    //one time profiler, skip
+                    continue;
+                }
                 logShutdownMessage("Running periodic profiler (last run): " + profiler);
                 profiler.profile();
                 logShutdownMessage("Ran periodic profiler (last run): " + profiler);

src/main/java/com/uber/profiling/ProfilerRunner.java

@@ -16,7 +16,6 @@
 
 package com.uber.profiling.profilers;
 
-import com.uber.profiling.Profiler;
 import com.uber.profiling.Reporter;
 import com.uber.profiling.util.AgentLogger;
 import com.uber.profiling.util.ProcFileUtils;
@@ -36,7 +35,7 @@
 import java.util.List;
 import java.util.Map;
 
-public class CpuAndMemoryProfiler extends ProcessInfoBase implements Profiler {
+public class CpuAndMemoryProfiler extends ProcessInfoBase {
     public final static String PROFILER_NAME = "CpuAndMemory";
 
     private static final AgentLogger logger = AgentLogger.getLogger(CpuAndMemoryProfiler.class.getName());
@@ -70,6 +69,7 @@ public long getIntervalMillis() {
         return intervalMillis;
     }
 
+    @Override
     public void setIntervalMillis(long intervalMillis) {
         this.intervalMillis = intervalMillis;
     }

src/main/java/com/uber/profiling/ShutdownHookRunner.java

@@ -16,15 +16,14 @@
 
 package com.uber.profiling.profilers;
 
-import com.uber.profiling.Profiler;
 import com.uber.profiling.Reporter;
 import com.uber.profiling.util.ProcFileUtils;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-public class IOProfiler extends ProcessInfoBase implements Profiler {
+public class IOProfiler extends ProcessInfoBase {
     public final static String PROFILER_NAME = "IO";
 
     private long intervalMillis = Constants.DEFAULT_METRIC_INTERVAL;

src/main/java/com/uber/profiling/profilers/CpuAndMemoryProfiler.java

@@ -19,6 +19,7 @@
 import com.uber.profiling.util.ClassMethodArgumentMetricBuffer;
 
 public class MethodArgumentCollector {
+    public static final String PROFILER_NAME = "MethodArgumentCollector";
     private ClassMethodArgumentMetricBuffer buffer;
 
     public MethodArgumentCollector(ClassMethodArgumentMetricBuffer buffer) {

src/main/java/com/uber/profiling/profilers/IOProfiler.java

@@ -16,7 +16,6 @@
 
 package com.uber.profiling.profilers;
 
-import com.uber.profiling.Profiler;
 import com.uber.profiling.Reporter;
 import com.uber.profiling.reporters.ConsoleOutputReporter;
 import com.uber.profiling.util.ClassAndMethodMetricKey;
@@ -26,7 +25,7 @@
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 
-public class MethodArgumentProfiler extends ProcessInfoBase implements Profiler {
+public class MethodArgumentProfiler extends ProcessInfoBase {
     public static final String PROFILER_NAME = "MethodArgument";
 
     private ClassMethodArgumentMetricBuffer buffer;