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

*** 24,44 ****
  
  #include "precompiled.hpp"
  #include "logging/log.hpp"
  #include "runtime/globals.hpp"
  #include "runtime/os.hpp"
! #include "runtime/safepointMechanism.hpp"
  #include "utilities/globalDefinitions.hpp"
  
  void SafepointMechanism::default_initialize() {
    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);
  
    log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
    os::set_polling_page((address)(polling_page));
  }
  
  void SafepointMechanism::initialize_serialize_page() {
    if (!UseMembar) {
      const size_t page_size = os::vm_page_size();
--- 24,73 ----
  
  #include "precompiled.hpp"
  #include "logging/log.hpp"
  #include "runtime/globals.hpp"
  #include "runtime/os.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");
!     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();