src/hotspot/share/runtime/arguments.cpp

rev 47415 : Add Thread Local handshakes and thread local polling

*** 48,57 ****
--- 48,58 ----
  #include "runtime/commandLineFlagRangeList.hpp"
  #include "runtime/globals.hpp"
  #include "runtime/globals_extension.hpp"
  #include "runtime/java.hpp"
  #include "runtime/os.hpp"
+ #include "runtime/safepointMechanism.hpp"
  #include "runtime/vm_version.hpp"
  #include "services/management.hpp"
  #include "services/memTracker.hpp"
  #include "utilities/align.hpp"
  #include "utilities/defaultStream.hpp"
*** 4611,4620 ****
--- 4612,4634 ----
    if (!UseBiasedLocking || EmitSync != 0) {
      UseOptoBiasInlining = false;
    }
  #endif
  
+   bool aot_enabled = UseAOT && ((AOTLibrary != NULL) || !FLAG_IS_DEFAULT(UseAOT));
+   bool jvmci_enabled = NOT_JVMCI(false) JVMCI_ONLY(EnableJVMCI || UseJVMCICompiler);
+   bool handshakes_supported = SafepointMechanism::supports_thread_local_poll() && !aot_enabled && !jvmci_enabled;
+   if (handshakes_supported) {
+     if (FLAG_IS_DEFAULT(UseAOT)) {
+       FLAG_SET_DEFAULT(UseAOT, false); // Clear the AOT flag to make sure it doesn't try to initialize.
+     }
+     if (FLAG_IS_DEFAULT(ThreadLocalHandshakes) && !ThreadLocalHandshakes) {
+       FLAG_SET_ERGO(bool, ThreadLocalHandshakes, true);
+       log_info(ergo)("Enabling ThreadLocalHandshakes on supported platform");
+     }
+   }
+ 
    return JNI_OK;
  }
  
  jint Arguments::adjust_after_os() {
    if (UseNUMA) {