Fix deadlock potential in IngestJob/DataSourceIngestJob interactions

Core/src/org/sleuthkit/autopsy/ingest/IngestJob.java

@@ -22,9 +22,10 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import org.sleuthkit.datamodel.Content;
 
@@ -39,7 +40,8 @@ public final class IngestJob {
     private static final AtomicLong nextId = new AtomicLong(0L);
     private final long id;
     private final Map<Long, DataSourceIngestJob> dataSourceJobs;
-    private boolean cancelled;
+    private final AtomicInteger incompleteJobsCount;
+    private volatile boolean cancelled;
 
     /**
      * Constructs an ingest job that runs a collection of data sources through a
@@ -52,11 +54,12 @@ public final class IngestJob {
      */
     IngestJob(Collection<Content> dataSources, IngestJobSettings settings, boolean runInteractively) {
         this.id = IngestJob.nextId.getAndIncrement();
-        this.dataSourceJobs = new HashMap<>();
+        this.dataSourceJobs = new ConcurrentHashMap<>();
         for (Content dataSource : dataSources) {
             DataSourceIngestJob dataSourceIngestJob = new DataSourceIngestJob(this, dataSource, settings, runInteractively);
             this.dataSourceJobs.put(dataSourceIngestJob.getId(), dataSourceIngestJob);
         }
+        incompleteJobsCount = new AtomicInteger(dataSourceJobs.size());
     }
 
     /**
@@ -74,7 +77,7 @@ public final class IngestJob {
      *
      * @return True or false.
      */
-    synchronized boolean hasIngestPipeline() {
+    boolean hasIngestPipeline() {
         for (DataSourceIngestJob dataSourceJob : this.dataSourceJobs.values()) {
             if (dataSourceJob.hasIngestPipeline()) {
                 return true;
@@ -89,16 +92,29 @@ public final class IngestJob {
      *
      * @return A collection of ingest module start up errors, empty on success.
      */
-    synchronized List<IngestModuleError> start() {
+    List<IngestModuleError> start() {
         List<IngestModuleError> errors = new ArrayList<>();
         for (DataSourceIngestJob dataSourceJob : this.dataSourceJobs.values()) {
             errors.addAll(dataSourceJob.start());
             if (!errors.isEmpty()) {
-                // RJCTODO: Need to let sucessfully started data source ingest 
-                // jobs know they should shut down.
                 break;
             }
         }
+
+        /**
+         * TODO: Need to let successfully started data source ingest jobs know
+         * they should shut down. This means that the start up of the ingest
+         * module pipelines and the submission of ingest tasks should be
+         * separated. This cancellation is just a stop gap; fortunately, if
+         * startup is going to fail, it will likely fail for the first child
+         * data source ingest job.
+         */
+        if (!errors.isEmpty()) {
+            for (DataSourceIngestJob dataSourceJob : this.dataSourceJobs.values()) {
+                dataSourceJob.cancel();
+            }
+        }
+
         return errors;
     }
 
@@ -107,7 +123,7 @@ public final class IngestJob {
      *
      * @return The snapshot.
      */
-    synchronized public ProgressSnapshot getSnapshot() {
+    public ProgressSnapshot getSnapshot() {
         return new ProgressSnapshot();
     }
 
@@ -117,7 +133,7 @@ public final class IngestJob {
      *
      * @return A list of data source ingest job progress snapshots.
      */
-    synchronized List<DataSourceIngestJob.Snapshot> getDataSourceIngestJobSnapshots() {
+    List<DataSourceIngestJob.Snapshot> getDataSourceIngestJobSnapshots() {
         List<DataSourceIngestJob.Snapshot> snapshots = new ArrayList<>();
         for (DataSourceIngestJob dataSourceJob : this.dataSourceJobs.values()) {
             snapshots.add(dataSourceJob.getSnapshot());
@@ -131,7 +147,7 @@ public final class IngestJob {
      * but there may be a delay before all of the ingest modules in the
      * pipelines respond by stopping processing.
      */
-    synchronized public void cancel() {
+    public void cancel() {
         for (DataSourceIngestJob job : this.dataSourceJobs.values()) {
             job.cancel();
         }
@@ -144,7 +160,7 @@ public final class IngestJob {
      *
      * @return True or false.
      */
-    synchronized public boolean isCancelled() {
+    public boolean isCancelled() {
         return this.cancelled;
     }
 
@@ -154,9 +170,8 @@ public final class IngestJob {
      *
      * @param dataSourceIngestJob A completed data source ingest job.
      */
-    synchronized void dataSourceJobFinished(DataSourceIngestJob dataSourceIngestJob) {
-        this.dataSourceJobs.remove(dataSourceIngestJob.getId());
-        if (this.dataSourceJobs.isEmpty()) {
+    void dataSourceJobFinished(DataSourceIngestJob dataSourceIngestJob) {
+        if (incompleteJobsCount.decrementAndGet() == 0) {
             IngestManager.getInstance().finishIngestJob(this);
         }
     }