workers: Restart worker processes when their binary has changed since they were launched.

--
MOS_MIGRATED_REVID=107050157

1 files changed, 18 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/worker/WorkerKey.java b/src/main/java/com/google/devtools/build/lib/worker/WorkerKey.java
index 076b1d4638..86494ea586 100644
--- a/src/main/java/com/google/devtools/build/lib/worker/WorkerKey.java
+++ b/src/main/java/com/google/devtools/build/lib/worker/WorkerKey.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.worker;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.hash.HashCode;
 import com.google.devtools.build.lib.actions.BaseSpawn;
 import com.google.devtools.build.lib.vfs.Path;
 
@@ -32,11 +33,23 @@ final class WorkerKey {
   private final Path workDir;
   private final String mnemonic;
 
-  WorkerKey(List<String> args, Map<String, String> env, Path workDir, String mnemonic) {
+  /**
+   * This is used during validation whether a worker is still usable. It is not used to uniquely
+   * identify a kind of worker, thus it is not to be used by the .equals() / .hashCode() methods.
+   */
+  private final HashCode workerFilesHash;
+
+  WorkerKey(
+      List<String> args,
+      Map<String, String> env,
+      Path workDir,
+      String mnemonic,
+      HashCode workerFilesHash) {
     this.args = ImmutableList.copyOf(Preconditions.checkNotNull(args));
     this.env = ImmutableMap.copyOf(Preconditions.checkNotNull(env));
     this.workDir = Preconditions.checkNotNull(workDir);
     this.mnemonic = Preconditions.checkNotNull(mnemonic);
+    this.workerFilesHash = Preconditions.checkNotNull(workerFilesHash);
   }
 
   public ImmutableList<String> getArgs() {
@@ -55,6 +68,10 @@ final class WorkerKey {
     return mnemonic;
   }
 
+  public HashCode getWorkerFilesHash() {
+    return workerFilesHash;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {