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8223313: Use handshakes for CountStackFrames

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Reviewed-by: dholmes, rrich, dcubed
This commit is contained in:
Robbin Ehn 2019-05-21 10:46:08 +02:00
parent 8cab46d6ca
commit 0171fba9b8
1 changed files with 28 additions and 11 deletions
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39
src/hotspot/share/prims/jvm.cpp
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@ -64,6 +64,7 @@
#include "runtime/init.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/deoptimization.hpp"
#include "runtime/handshake.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/jfieldIDWorkaround.hpp"
@ -3006,31 +3007,47 @@ JVM_ENTRY(jobject, JVM_CurrentThread(JNIEnv* env, jclass threadClass))
return JNIHandles::make_local(env, jthread);
JVM_END
class CountStackFramesTC : public ThreadClosure {
int _count;
bool _suspended;
public:
CountStackFramesTC() : _count(0), _suspended(false) {}
virtual void do_thread(Thread* thread) {
JavaThread* jt = (JavaThread*)thread;
if (!jt->is_external_suspend()) {
// To keep same behavior we fail this operation,
// even if it would work perfectly.
return;
}
_suspended = true;
// Count all java activation, i.e., number of vframes.
for (vframeStream vfst(jt); !vfst.at_end(); vfst.next()) {
// Native frames are not counted.
if (!vfst.method()->is_native()) _count++;
}
}
int count() { return _count; }
int suspended() { return _suspended; }
};
JVM_ENTRY(jint, JVM_CountStackFrames(JNIEnv* env, jobject jthread))
JVMWrapper("JVM_CountStackFrames");
uint32_t debug_bits = 0;
ThreadsListHandle tlh(thread);
JavaThread* receiver = NULL;
bool is_alive = tlh.cv_internal_thread_to_JavaThread(jthread, &receiver, NULL);
int count = 0;
if (is_alive) {
// jthread refers to a live JavaThread.
if (receiver->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) {
// Count all java activation, i.e., number of vframes.
for (vframeStream vfst(receiver); !vfst.at_end(); vfst.next()) {
// Native frames are not counted.
if (!vfst.method()->is_native()) count++;
}
} else {
CountStackFramesTC csf;
Handshake::execute(&csf, receiver);
if (!csf.suspended()) {
THROW_MSG_0(vmSymbols::java_lang_IllegalThreadStateException(),
"this thread is not suspended");
}
return csf.count();
}
// Implied else: if JavaThread is not alive simply return a count of 0.
return count;
return 0;
JVM_END