[JVMTI] RFA: Implement GetAllThreads

[Kyle Galloway <kgallowa at redhat dot com>]

Hi,

The attached patch implements the JVMTI GetAllThreads function.  I have
included a test case using the jvmti testsuite as well.  Nothing too
complicated, gets the root ThreadGroup, then grabs all the threads.  Are
the variable names a problem? I've seen a few different conventions, and
I'll refactor them if need be.

Questions/comments/concerns?

Kyle

2006-09-27  Kyle Galloway  <kgallowa@redhat.com>

    * jvmti.cc (_Jv_JVMTI_GetAllThreads): New method.
    * testsuite/getallthreads.java: New test.
    * testsuite/natgetallthreads.cc: Ditto.
    * testsuite/getallthreads.out: Output file for test.

Index: /home/kgallowa/workspace/gcc/libjava/jvmti.cc
===================================================================
--- /home/kgallowa/workspace/gcc/libjava/jvmti.cc	(revision 117251)
+++ /home/kgallowa/workspace/gcc/libjava/jvmti.cc	(working copy)
@@ -25,6 +25,7 @@
 #include <java/lang/ClassLoader.h>
 #include <java/lang/Object.h>
 #include <java/lang/Thread.h>
+#include <java/lang/ThreadGroup.h>
 #include <java/lang/Throwable.h>
 #include <java/lang/VMClassLoader.h>
 #include <java/lang/reflect/Field.h>
@@ -103,6 +104,50 @@
 	return JVMTI_ERROR_ILLEGAL_ARGUMENT;	\
     }						\
   while (0)
+  
+static jvmtiError JNICALL
+_Jv_JVMTI_GetAllThreads(MAYBE_UNUSED jvmtiEnv *env, jint *threadCount,
+                        jthread **threads)
+{
+  REQUIRE_PHASE (env, JVMTI_PHASE_LIVE);
+  NULL_CHECK (threadCount);
+  NULL_CHECK (threads);
+  
+  using namespace java::lang;
+  Thread *thr = Thread::currentThread ();
+  
+  ThreadGroup *thrGrp = thr->getThreadGroup ();
+  ThreadGroup *parent = thrGrp->getParent ();
+  
+  //get the root thread group
+  while (parent != NULL)
+    {
+      thrGrp = parent;
+      parent = thrGrp->getParent ();
+    }
+  
+  jint estimate = thrGrp->activeCount ();
+  
+  //allocate some extra space since threads can be created between calls
+  JArray<Thread *> *thrArray 
+   = (JArray<Thread *> *) JvNewObjectArray ((estimate * 2), &Thread::class$, 
+                                            NULL);
+   
+  (*threadCount) = thrGrp->enumerate (thrArray);
+  
+  env->Allocate ((jlong) ((*threadCount) * sizeof (jthread)), 
+                 reinterpret_cast<unsigned char **> (threads));
+  
+  //now transfer the threads to the result array
+  jthread *tArrPtr = (*threads);
+  
+  for (int i = 0; i < (*threadCount); i++) 
+    {
+	  tArrPtr[i] = reinterpret_cast<jthread> (elements(thrArray)[i]);
+    }
+  
+  return JVMTI_ERROR_NONE;
+}
 
 static jvmtiError JNICALL
 _Jv_JVMTI_SuspendThread (MAYBE_UNUSED jvmtiEnv *env, jthread thread)
@@ -1187,7 +1232,7 @@
   RESERVED,			// reserved1
   _Jv_JVMTI_SetEventNotificationMode, // SetEventNotificationMode
   RESERVED,			// reserved3
-  UNIMPLEMENTED,		// GetAllThreads
+  _Jv_JVMTI_GetAllThreads,		// GetAllThreads
   _Jv_JVMTI_SuspendThread,	// SuspendThread
   _Jv_JVMTI_ResumeThread,	// ResumeThread
   UNIMPLEMENTED,		// StopThread
Index: /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.java
===================================================================
--- /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.java	(revision 0)
+++ /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.java	(revision 0)
@@ -0,0 +1,33 @@
+// Test JVMTI GetAllThreads method
+
+public class getallthreads extends Thread
+{
+  private boolean loop;
+  
+  public getallthreads ()
+  {
+    super ();
+    loop = true;
+  }
+  
+  public void run ()
+  {
+    while (loop);
+  }
+  
+  public void done ()
+  {
+	loop = false;
+  }
+
+  public static native void do_getallthreads_tests ();
+
+  public static void main (String[] args)
+  {
+    System.out.println ("JVMTI GetAllThreads test");
+    getallthreads t = new getallthreads ();
+    t.start ();
+    do_getallthreads_tests ();
+    t.done ();
+  }
+}
\ No newline at end of file
Index: /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.out
===================================================================
--- /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.out	(revision 0)
+++ /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/getallthreads.out	(revision 0)
@@ -0,0 +1,8 @@
+JVMTI GetAllThreads test
+Threads:
+
+Found thread 0
+Found thread 1
+Found thread 2
+
+Thread count: 3
Index: /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/natgetallthreads.cc
===================================================================
--- /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/natgetallthreads.cc	(revision 0)
+++ /home/kgallowa/workspace/gcc/libjava/testsuite/libjava.jvmti/natgetallthreads.cc	(revision 0)
@@ -0,0 +1,36 @@
+#include <gcj/cni.h>
+
+#include <jvm.h>
+#include <jvmti.h>
+#include <stdio.h>
+
+#include "jvmti-int.h"
+#include "getallthreads.h"
+
+static void
+print_threads (jthread *threads, jint threadCount)
+{
+  printf("Threads:\n\n");
+  
+  java::lang::Thread *t = NULL;
+  
+  for (int i = 0; i < threadCount; i++)
+    {
+      printf("Found thread %d\n", i);
+    }
+    
+      printf("\nThread count: %d\n", (int) threadCount);
+}
+
+void
+getallthreads::do_getallthreads_tests ()
+{
+  jvmtiEnv *env;
+  JavaVM *vm = _Jv_GetJavaVM ();
+  vm->GetEnv (reinterpret_cast<void **> (&env), JVMTI_VERSION_1_0);
+  jthread *threads;
+  jint threadCount;
+  env->GetAllThreads (&threadCount, &threads);
+  print_threads (threads, threadCount);
+  env->Deallocate (reinterpret_cast<unsigned char *> (threads));
+}