8255696: JDWP debug agent's canSuspendResumeThreadLists() should be removed

Reviewed-by: amenkov, sspitsyn

Author: plummercj

src/jdk.jdwp.agent/share/native/libjdwp/threadControl.c

@@ -1516,22 +1516,9 @@ threadControl_suspendAll(void)
             error = AGENT_ERROR_OUT_OF_MEMORY;
             goto err;
         }
-        if (canSuspendResumeThreadLists()) {
-            error = commonSuspendList(env, count, threads);
-            if (error != JVMTI_ERROR_NONE) {
-                goto err;
-            }
-        } else {
-
-            int i;
-
-            for (i = 0; i < count; i++) {
-                error = commonSuspend(env, threads[i], JNI_FALSE);
-
-                if (error != JVMTI_ERROR_NONE) {
-                    goto err;
-                }
-            }
+        error = commonSuspendList(env, count, threads);
+        if (error != JVMTI_ERROR_NONE) {
+            goto err;
         }
 
         /*
@@ -1590,12 +1577,7 @@ threadControl_resumeAll(void)
      * no need to get the whole thread list from JVMTI (unlike
      * suspendAll).
      */
-    if (canSuspendResumeThreadLists()) {
-        error = commonResumeList(env);
-    } else {
-        error = enumerateOverThreadList(env, &runningThreads,
-                                        resumeHelper, NULL);
-    }
+    error = commonResumeList(env);
     if ((error == JVMTI_ERROR_NONE) && (otherThreads.first != NULL)) {
         error = enumerateOverThreadList(env, &otherThreads,
                                         resumeHelper, NULL);

src/jdk.jdwp.agent/share/native/libjdwp/util.c

@@ -962,16 +962,6 @@ jvmtiMicroVersion(void)
                     >> JVMTI_VERSION_SHIFT_MICRO;
 }
 
-jboolean
-canSuspendResumeThreadLists(void)
-{
-    jvmtiError error;
-    jvmtiCapabilities cap;
-
-    error = jvmtiGetCapabilities(&cap);
-    return (error == JVMTI_ERROR_NONE && cap.can_suspend);
-}
-
 jvmtiError
 getSourceDebugExtension(jclass clazz, char **extensionPtr)
 {

src/jdk.jdwp.agent/share/native/libjdwp/util.h

@@ -337,7 +337,6 @@ jint jvmtiMajorVersion(void);
 jint jvmtiMinorVersion(void);
 jint jvmtiMicroVersion(void);
 jvmtiError getSourceDebugExtension(jclass clazz, char **extensionPtr);
-jboolean canSuspendResumeThreadLists(void);
 
 jrawMonitorID debugMonitorCreate(char *name);
 void debugMonitorEnter(jrawMonitorID theLock);