8256304: should MonitorUsedDeflationThreshold be experimental or diagnostic

Daniel D. Daugherty · Daniel D. Daugherty · commit fe333431c8c0 · 2021-05-21T18:32:25.000Z
8256301: ObjectMonitor::is_busy() should return bool

Reviewed-by: coleenp, pchilanomate
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
@@ -712,7 +712,7 @@ const intx ObjectAlignmentInBytes = 8;
           "at one time (minimum is 1024).")                      \
           range(1024, max_jint)                                             \
                                                                             \
-  product(intx, MonitorUsedDeflationThreshold, 90, EXPERIMENTAL,            \
+  product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC,              \
           "Percentage of used monitors before triggering deflation (0 is "  \
           "off). The check is performed on GuaranteedSafepointInterval "    \
           "or AsyncDeflationInterval.")                                     \
diff --git a/src/hotspot/share/runtime/objectMonitor.cpp b/src/hotspot/share/runtime/objectMonitor.cpp
@@ -519,7 +519,7 @@ int ObjectMonitor::TryLock(JavaThread* current) {
 // Contending threads that see that condition know to retry their operation.
 //
 bool ObjectMonitor::deflate_monitor() {
-  if (is_busy() != 0) {
+  if (is_busy()) {
     // Easy checks are first - the ObjectMonitor is busy so no deflation.
     return false;
   }
diff --git a/src/hotspot/share/runtime/objectMonitor.hpp b/src/hotspot/share/runtime/objectMonitor.hpp
@@ -236,7 +236,7 @@ class ObjectMonitor : public CHeapObj<mtInternal> {
   volatile markWord* header_addr();
   void               set_header(markWord hdr);
 
-  intptr_t is_busy() const {
+  bool is_busy() const {
     // TODO-FIXME: assert _owner == null implies _recursions = 0
     intptr_t ret_code = _waiters | intptr_t(_cxq) | intptr_t(_EntryList);
     if (contentions() > 0) {
@@ -245,7 +245,7 @@ class ObjectMonitor : public CHeapObj<mtInternal> {
     if (!owner_is_DEFLATER_MARKER()) {
       ret_code |= intptr_t(owner_raw());
     }
-    return ret_code;
+    return ret_code != 0;
   }
   const char* is_busy_to_string(stringStream* ss);
 
diff --git a/src/hotspot/share/runtime/synchronizer.cpp b/src/hotspot/share/runtime/synchronizer.cpp
@@ -1771,9 +1771,9 @@ void ObjectSynchronizer::log_in_use_monitor_details(outputStream* out) {
       const markWord mark = mid->header();
       ResourceMark rm;
       out->print(INTPTR_FORMAT "  %d%d%d  " INTPTR_FORMAT "  %s", p2i(mid),
-                 mid->is_busy() != 0, mark.hash() != 0, mid->owner() != NULL,
+                 mid->is_busy(), mark.hash() != 0, mid->owner() != NULL,
                  p2i(obj), obj == NULL ? "" : obj->klass()->external_name());
-      if (mid->is_busy() != 0) {
+      if (mid->is_busy()) {
         out->print(" (%s)", mid->is_busy_to_string(&ss));
         ss.reset();
       }

Original file line number	Diff line number	Diff line change
`@@ -712,7 +712,7 @@ const intx ObjectAlignmentInBytes = 8;`
`712`	`712`	`"at one time (minimum is 1024).") \`
`713`	`713`	`range(1024, max_jint) \`
`714`	`714`	`\`
`715`		`- product(intx, MonitorUsedDeflationThreshold, 90, EXPERIMENTAL, \`
	`715`	`+ product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \`
`716`	`716`	`"Percentage of used monitors before triggering deflation (0 is " \`
`717`	`717`	`"off). The check is performed on GuaranteedSafepointInterval " \`
`718`	`718`	`"or AsyncDeflationInterval.") \`
Original file line number	Diff line number	Diff line change
`@@ -519,7 +519,7 @@ int ObjectMonitor::TryLock(JavaThread* current) {`
`519`	`519`	`// Contending threads that see that condition know to retry their operation.`
`520`	`520`	`//`
`521`	`521`	`bool ObjectMonitor::deflate_monitor() {`
`522`		`- if (is_busy() != 0) {`
	`522`	`+ if (is_busy()) {`
`523`	`523`	`// Easy checks are first - the ObjectMonitor is busy so no deflation.`
`524`	`524`	`return false;`
`525`	`525`	`}`