src/hotspot/share/runtime/safepointMechanism.cpp

rev 47414 : Move polling page allocation to SafepointMechanism initialization
rev 47415 : Add Thread Local handshakes and thread local polling

@@ -24,21 +24,50 @@
 
 #include "precompiled.hpp"
 #include "logging/log.hpp"
 #include "runtime/globals.hpp"
 #include "runtime/os.hpp"
-#include "runtime/safepointMechanism.hpp"
+#include "runtime/safepointMechanism.inline.hpp"
 #include "utilities/globalDefinitions.hpp"
 
+SafepointMechanism::PollingType SafepointMechanism::_polling_type = SafepointMechanism::_global_page_poll;
+void* SafepointMechanism::_poll_armed_value;
+void* SafepointMechanism::_poll_disarmed_value;
+
 void SafepointMechanism::default_initialize() {
+  if (ThreadLocalHandshakes) {
+    set_uses_thread_local_poll();
+    const size_t page_size = os::vm_page_size();
+    const size_t allocation_size = 2 * page_size;
+    char* polling_page = os::reserve_memory(allocation_size, NULL, page_size);
+    os::commit_memory_or_exit(polling_page, allocation_size, false, "Unable to commit Safepoint polling page");
+
+    char* bad_page  = polling_page;
+    char* good_page = polling_page + page_size;
+
+    os::protect_memory(bad_page, page_size, os::MEM_PROT_NONE);
+    os::protect_memory(good_page, page_size, os::MEM_PROT_READ);
+
+    log_info(os)("SafePoint Polling address, bad (protected) page:" INTPTR_FORMAT ", good (unprotected) page:" INTPTR_FORMAT, p2i(bad_page), p2i(good_page));
+    os::set_polling_page((address)(bad_page));
+
+    intptr_t poll_page_val = reinterpret_cast<intptr_t>(bad_page);
+    _poll_armed_value = reinterpret_cast<void*>(poll_page_val | poll_bit());
+    _poll_disarmed_value = good_page;
+  } else {
   const size_t page_size = os::vm_page_size();
   char* polling_page = os::reserve_memory(page_size, NULL, page_size);
   os::commit_memory_or_exit(polling_page, page_size, false, "Unable to commit Safepoint polling page");
-  bool res = os::protect_memory(polling_page, page_size, os::MEM_PROT_READ);
+    os::protect_memory(polling_page, page_size, os::MEM_PROT_READ);
 
   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
   os::set_polling_page((address)(polling_page));
+  }
+}
+
+void SafepointMechanism::initialize_header(JavaThread* thread) {
+  disarm_local_poll(thread);
 }
 
 void SafepointMechanism::initialize_serialize_page() {
   if (!UseMembar) {
     const size_t page_size = os::vm_page_size();