Add an implementation for SubprocessFactory based on the new JNI interface to Windows process management.

With this change, Bazel can build itself using native Windows process management and Ctrl-C works in server mode as expected. Yay!

Flipping the flag will come in a separate change that's easy to roll back if need be.

--
MOS_MIGRATED_REVID=126408264

3 files changed, 23 insertions, 13 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/shell/Command.java b/src/main/java/com/google/devtools/build/lib/shell/Command.java
index e5a958c185..35d3b8720e 100644
--- a/src/main/java/com/google/devtools/build/lib/shell/Command.java
+++ b/src/main/java/com/google/devtools/build/lib/shell/Command.java
@@ -705,14 +705,7 @@ public final class Command {
 
       @Override
       public boolean isDone() {
-        try {
-          // exitValue seems to be the only non-blocking call for
-          // checking process liveness.
-          process.exitValue();
-          return true;
-        } catch (IllegalThreadStateException e) {
-          return false;
-        }
+        return process.finished();
       }
     };
   }
@@ -880,7 +873,8 @@ public final class Command {
     try {
       while (true) {
         try {
-          return new TerminationStatus(process.waitFor());
+          process.waitFor();
+          return new TerminationStatus(process.exitValue());
         } catch (InterruptedException ie) {
           wasInterrupted = true;
           if (killSubprocessOnInterrupt) {
diff --git a/src/main/java/com/google/devtools/build/lib/shell/JavaSubprocessFactory.java b/src/main/java/com/google/devtools/build/lib/shell/JavaSubprocessFactory.java
index c09a24a704..ab3acd4e44 100644
--- a/src/main/java/com/google/devtools/build/lib/shell/JavaSubprocessFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/shell/JavaSubprocessFactory.java
@@ -49,8 +49,19 @@ public class JavaSubprocessFactory implements Subprocess.Factory {
     }
 
     @Override
-    public int waitFor() throws InterruptedException {
-      return process.waitFor();
+    public boolean finished() {
+      try {
+        // this seems to be the only non-blocking call for checking liveness
+        process.exitValue();
+        return true;
+      } catch (IllegalThreadStateException e) {
+        return false;
+      }
+    }
+
+    @Override
+    public void waitFor() throws InterruptedException {
+      process.waitFor();
     }
 
     @Override
diff --git a/src/main/java/com/google/devtools/build/lib/shell/Subprocess.java b/src/main/java/com/google/devtools/build/lib/shell/Subprocess.java
index 99e55776ff..f8a8a553e7 100644
--- a/src/main/java/com/google/devtools/build/lib/shell/Subprocess.java
+++ b/src/main/java/com/google/devtools/build/lib/shell/Subprocess.java
@@ -42,14 +42,19 @@ public interface Subprocess {
   /**
    * Returns the exit value of the process.
    *
-   * <p>Throws {@code IllegalThreadStateException} if the process has not terminated yet.
+   * <p>Throws {@code IOException} if the process has not terminated yet.
    */
   int exitValue();
 
   /**
+   * Returns the if the process has finished.
+   */
+  boolean finished();
+
+  /**
    * Waits for the process to finish.
    */
-  int waitFor() throws InterruptedException;
+  void waitFor() throws InterruptedException;
 
   /**
    * Returns a stream into which data can be written that the process will get on its stdin.