hotspot/src/os_cpu/bsd_x86/vm/thread_bsd_x86.cpp
author ccheung
Thu, 07 Apr 2016 22:03:04 -0700
changeset 37439 e8970711113b
parent 33160 c59f1676d27e
child 40644 39e631ed7145
permissions -rw-r--r--
8145221: Use trampolines for i2i and i2c entries in Methods that are stored in CDS archive Summary: This optimization reduces the size of the RW region of the CDS archive. It also reduces the amount of pages in the RW region that are actually written into during runtime. Reviewed-by: dlong, iklam, jiangli Contributed-by: ioi.lam@oracle.com, calvin.cheung@oracle.com, goetz.lindenmaier@sap.com

/*
 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "memory/metaspaceShared.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/thread.inline.hpp"

// For Forte Analyzer AsyncGetCallTrace profiling support - thread is
// currently interrupted by SIGPROF
bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  void* ucontext, bool isInJava) {
  assert(Thread::current() == this, "caller must be current thread");
  return pd_get_top_frame(fr_addr, ucontext, isInJava);
}

bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
  return pd_get_top_frame(fr_addr, ucontext, isInJava);
}

bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
  assert(this->is_Java_thread(), "must be JavaThread");
  JavaThread* jt = (JavaThread *)this;

  // If we have a last_Java_frame, then we should use it even if
  // isInJava == true.  It should be more reliable than ucontext info.
  if (jt->has_last_Java_frame()) {
    *fr_addr = jt->pd_last_frame();
    return true;
  }

  // At this point, we don't have a last_Java_frame, so
  // we try to glean some information out of the ucontext
  // if we were running Java code when SIGPROF came in.
  if (isInJava) {
    ucontext_t* uc = (ucontext_t*) ucontext;

    intptr_t* ret_fp;
    intptr_t* ret_sp;
    ExtendedPC addr = os::Bsd::fetch_frame_from_ucontext(this, uc,
      &ret_sp, &ret_fp);
    if (addr.pc() == NULL || ret_sp == NULL ) {
      // ucontext wasn't useful
      return false;
    }

#if INCLUDE_CDS
    if (UseSharedSpaces && MetaspaceShared::is_in_shared_region(addr.pc(), MetaspaceShared::md)) {
      // In the middle of a trampoline call. Bail out for safety.
      // This happens rarely so shouldn't affect profiling.
      return false;
    }
#endif

    frame ret_frame(ret_sp, ret_fp, addr.pc());
    if (!ret_frame.safe_for_sender(jt)) {
#if defined(COMPILER2) || INCLUDE_JVMCI
      // C2 and JVMCI use ebp as a general register see if NULL fp helps
      frame ret_frame2(ret_sp, NULL, addr.pc());
      if (!ret_frame2.safe_for_sender(jt)) {
        // nothing else to try if the frame isn't good
        return false;
      }
      ret_frame = ret_frame2;
#else
      // nothing else to try if the frame isn't good
      return false;
#endif /* COMPILER2 || INCLUDE_JVMCI */
    }
    *fr_addr = ret_frame;
    return true;
  }

  // nothing else to try
  return false;
}

void JavaThread::cache_global_variables() { }