8003488: (process) Provide Process.getPid()

Add Process.getPid

Reviewed-by: alanb, martin, igerasim

jdk/src/share/classes/java/lang/Process.java

@@ -262,4 +262,18 @@ public abstract class Process {
             return true;
         }
     }
+
+    /**
+     * Returns the native process id of the subprocess.
+     * The native process id is an identification number that the operating
+     * system assigns to the process.
+     *
+     * @return the native process id of the subprocess
+     * @throws UnsupportedOperationException if the Process implementation
+     *     does not support this operation
+     * @since 1.9
+     */
+    public long getPid() {
+        throw new UnsupportedOperationException();
+    }
 }

jdk/src/solaris/classes/java/lang/UNIXProcess.java

@@ -482,6 +482,11 @@ final class UNIXProcess extends Process {
         return this;
     }
 
+    @Override
+    public long getPid() {
+        return pid;
+    }
+
     @Override
     public synchronized boolean isAlive() {
         return !hasExited;

jdk/src/windows/classes/java/lang/ProcessImpl.java

@@ -25,15 +25,15 @@
 
 package java.lang;
 
-import java.io.IOException;
-import java.io.File;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.FileDescriptor;
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
+import java.io.File;
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.lang.ProcessBuilder.Redirect;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -482,6 +482,14 @@ final class ProcessImpl extends Process {
 
     private static native void terminateProcess(long handle);
 
+    @Override
+    public long getPid() {
+        int pid = getProcessId0(handle);
+        return pid;
+    }
+
+    private static native int getProcessId0(long handle);
+
     @Override
     public boolean isAlive() {
         return isProcessAlive(handle);

jdk/src/windows/native/java/lang/ProcessImpl_md.c

@@ -248,6 +248,17 @@ static void restoreIOEHandleState(
         }
 }
 
+/*
+ * Class:     java_lang_ProcessImpl
+ * Method:    getProcessId0
+ * Signature: (J)I
+ */
+JNIEXPORT jint JNICALL Java_java_lang_ProcessImpl_getProcessId0
+  (JNIEnv *env, jclass clazz, jlong handle) {
+    DWORD pid = GetProcessId((HANDLE) jlong_to_ptr(handle));
+    return (jint)pid;
+}
+
 /* Please, read about the MS inheritance problem
    http://support.microsoft.com/kb/315939
    and critical section/synchronized block solution. */

jdk/test/java/lang/ProcessBuilder/Basic.java

@@ -26,7 +26,7 @@
  * @bug 4199068 4738465 4937983 4930681 4926230 4931433 4932663 4986689
  *      5026830 5023243 5070673 4052517 4811767 6192449 6397034 6413313
  *      6464154 6523983 6206031 4960438 6631352 6631966 6850957 6850958
- *      4947220 7018606 7034570 4244896 5049299
+ *      4947220 7018606 7034570 4244896 5049299 8003488
  * @summary Basic tests for Process and Environment Variable code
  * @run main/othervm/timeout=300 Basic
  * @run main/othervm/timeout=300 -Djdk.lang.Process.launchMechanism=fork Basic
@@ -1136,6 +1136,53 @@ public class Basic {
         }
     }
 
+    static void checkProcessPid() {
+        long actualPid = 0;
+        long expectedPid = -1;
+        if (Windows.is()) {
+            String[] argsTasklist = {"tasklist.exe",  "/NH", "/FI",  "\"IMAGENAME eq tasklist.exe\""};
+            ProcessBuilder pb = new ProcessBuilder(argsTasklist);
+            try {
+                Process proc = pb.start();
+                expectedPid = proc.getPid();
+
+                String output = commandOutput(proc);
+                String[] splits = output.split("\\s+");
+                actualPid = Integer.valueOf(splits[2]);
+            } catch (Throwable t) {
+                unexpected(t);
+            }
+        } else if (Unix.is() || MacOSX.is()) {
+            String[]  shArgs = {"sh", "-c", "echo $$"};
+            ProcessBuilder pb = new ProcessBuilder(shArgs);
+            try {
+                Process proc = pb.start();
+                expectedPid = proc.getPid();
+
+                String output = commandOutput(proc);
+                String[] splits = output.split("\\s+");
+                actualPid = Integer.valueOf(splits[0]);
+            } catch (Throwable t) {
+                unexpected(t);
+            }
+        } else {
+            fail("No test for checkProcessPid on platform: " + System.getProperty("os.name"));
+            return;
+        }
+
+        equal(actualPid, expectedPid);
+
+        // Test the default implementation of Process.getPid
+        try {
+            DelegatingProcess p = new DelegatingProcess(null);
+            p.getPid();
+            fail("non-overridden Process.getPid method should throw UOE");
+        } catch (UnsupportedOperationException uoe) {
+            // correct
+        }
+
+    }
+
     private static void realMain(String[] args) throws Throwable {
         if (Windows.is())
             System.out.println("This appears to be a Windows system.");
@@ -1147,6 +1194,11 @@ public class Basic {
         try { testIORedirection(); }
         catch (Throwable t) { unexpected(t); }
 
+        //----------------------------------------------------------------
+        // Basic tests for getPid()
+        //----------------------------------------------------------------
+        checkProcessPid();
+
         //----------------------------------------------------------------
         // Basic tests for setting, replacing and deleting envvars
         //----------------------------------------------------------------