src/hotspot/os/aix/safepointMechanism_aix.cpp

rev 50788 : 8205609: [PPC64] Fix PPC64 part of 8010319 and TLH without UseSIGTRAP on AIX
Reviewed-by: dholmes

*** 36,46 ****
      return;
    }
  
    // Allocate one protected page
    char* map_address = (char*)MAP_FAILED;
!   const size_t page_size = os::vm_page_size();
    const int prot  = PROT_READ;
    const int flags = MAP_PRIVATE | MAP_ANONYMOUS;
  
    // Use optimized addresses for the polling page,
    // e.g. map it to a special 32-bit address.
--- 36,46 ----
      return;
    }
  
    // Allocate one protected page
    char* map_address = (char*)MAP_FAILED;
!   const size_t map_size = ThreadLocalHandshakes ? 2 * os::vm_page_size() : os::vm_page_size();
    const int prot  = PROT_READ;
    const int flags = MAP_PRIVATE | MAP_ANONYMOUS;
  
    // Use optimized addresses for the polling page,
    // e.g. map it to a special 32-bit address.
*** 66,76 ****
      for (int i = 0; i < address_wishes_length; i++) {
        // Try to map with current address wish.
        // AIX: AIX needs MAP_FIXED if we provide an address and mmap will
        // fail if the address is already mapped.
        map_address = (char*) ::mmap(address_wishes[i],
!                                    page_size, prot,
                                     flags | MAP_FIXED,
                                     -1, 0);
        log_debug(os)("SafePoint Polling Page address: %p (wish) => %p",
                      address_wishes[i], map_address);
  
--- 66,76 ----
      for (int i = 0; i < address_wishes_length; i++) {
        // Try to map with current address wish.
        // AIX: AIX needs MAP_FIXED if we provide an address and mmap will
        // fail if the address is already mapped.
        map_address = (char*) ::mmap(address_wishes[i],
!                                    map_size, prot,
                                     flags | MAP_FIXED,
                                     -1, 0);
        log_debug(os)("SafePoint Polling Page address: %p (wish) => %p",
                      address_wishes[i], map_address);
  
*** 79,104 ****
          break;
        }
  
        if (map_address != (char*)MAP_FAILED) {
          // Map succeeded, but polling_page is not at wished address, unmap and continue.
!         ::munmap(map_address, page_size);
          map_address = (char*)MAP_FAILED;
        }
        // Map failed, continue loop.
      }
    }
    if (map_address == (char*)MAP_FAILED) {
!     map_address = (char*) ::mmap(NULL, page_size, prot, flags, -1, 0);
    }
!   guarantee(map_address != (char*)MAP_FAILED, "SafepointMechanism::pd_initialize: failed to allocate polling page");
    log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(map_address));
    os::set_polling_page((address)(map_address));
  
    // Use same page for ThreadLocalHandshakes without SIGTRAP
    if (ThreadLocalHandshakes) {
      set_uses_thread_local_poll();
!     intptr_t bad_page_val = reinterpret_cast<intptr_t>(map_address);
!     _poll_armed_value    = reinterpret_cast<void*>(bad_page_val | poll_bit());
!     _poll_disarmed_value = NULL; // Readable on AIX
    }
  }
--- 79,107 ----
          break;
        }
  
        if (map_address != (char*)MAP_FAILED) {
          // Map succeeded, but polling_page is not at wished address, unmap and continue.
!         ::munmap(map_address, map_size);
          map_address = (char*)MAP_FAILED;
        }
        // Map failed, continue loop.
      }
    }
    if (map_address == (char*)MAP_FAILED) {
!     map_address = (char*) ::mmap(NULL, map_size, prot, flags, -1, 0);
    }
!   guarantee(map_address != (char*)MAP_FAILED && map_address != NULL,
!             "SafepointMechanism::pd_initialize: failed to allocate polling page");
    log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(map_address));
    os::set_polling_page((address)(map_address));
  
    // Use same page for ThreadLocalHandshakes without SIGTRAP
    if (ThreadLocalHandshakes) {
      set_uses_thread_local_poll();
!     os::make_polling_page_unreadable();
!     intptr_t bad_page_val  = reinterpret_cast<intptr_t>(map_address),
!              good_page_val = bad_page_val + os::vm_page_size();
!     _poll_armed_value    = reinterpret_cast<void*>(bad_page_val  + poll_bit());
!     _poll_disarmed_value = reinterpret_cast<void*>(good_page_val);
    }
  }