1 /*

     2  * Copyright (c) 2008, 2017, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #include "precompiled.hpp"

    26 #include "gc/shared/barrierSet.inline.hpp"

    27 #include "gc/shared/cardTableModRefBS.inline.hpp"

    28 #include "gc/shared/collectedHeap.hpp"

    29 #include "memory/metaspaceShared.hpp"

    30 #include "runtime/frame.inline.hpp"

    31 

    32 void JavaThread::cache_global_variables() {

    33   BarrierSet* bs = Universe::heap()->barrier_set();

    34 

    35   const bool allow_shared_alloc =

    36     Universe::heap()->supports_inline_contig_alloc();

    37 

    38   if (allow_shared_alloc) {

    39     _heap_top_addr = (address) Universe::heap()->top_addr();

    40   } else {

    41     _heap_top_addr = NULL;

    42   }

    43 

    44   if (bs->is_a(BarrierSet::CardTableModRef)) {

    45     _card_table_base = (address) (barrier_set_cast<CardTableModRefBS>(bs)->byte_map_base);

    46   } else {

    47     _card_table_base = NULL;

    48   }

    49 

    50 }

    51 

    52 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is

    53 // currently interrupted by SIGPROF

    54 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,

    55   void* ucontext, bool isInJava) {

    56   assert(Thread::current() == this, "caller must be current thread");

    57   return pd_get_top_frame(fr_addr, ucontext, isInJava);

    58 }

    59 

    60 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {

    61   return pd_get_top_frame(fr_addr, ucontext, isInJava);

    62 }

    63 

    64 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {

    65   assert(this->is_Java_thread(), "must be JavaThread");

    66 

    67   JavaThread* jt = (JavaThread *)this;

    68 

    69   // If we have a last_Java_frame, then we should use it even if

    70   // isInJava == true.  It should be more reliable than ucontext info.

    71   if (jt->has_last_Java_frame() AARCH64_ONLY(&& jt->last_Java_pc() != NULL)) {

    72     *fr_addr = jt->pd_last_frame();

    73     return true;

    74   }

    75 

    76   // Could be in a code section that plays with the stack, like

    77   // MacroAssembler::verify_heapbase()

    78   if (jt->in_top_frame_unsafe_section()) {

    79     return false;

    80   }

    81 

    82   // At this point, we don't have a last_Java_frame, so

    83   // we try to glean some information out of the ucontext

    84   // if we were running Java code when SIGPROF came in.

    85   if (isInJava) {

    86     ucontext_t* uc = (ucontext_t*) ucontext;

    87 

    88     intptr_t* ret_fp;

    89     intptr_t* ret_sp;

    90     ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,

    91       &ret_sp, &ret_fp);

    92     if (addr.pc() == NULL || ret_sp == NULL ) {

    93       // ucontext wasn't useful

    94       return false;

    95     }

    96 

    97     if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {

    98       // In the middle of a trampoline call. Bail out for safety.

    99       // This happens rarely so shouldn't affect profiling.

   100       return false;

   101     }

   102 

   103     frame ret_frame(ret_sp, ret_fp, addr.pc());

   104     if (!ret_frame.safe_for_sender(jt)) {

   105 #ifdef COMPILER2

   106       // C2 uses ebp as a general register see if NULL fp helps

   107       frame ret_frame2(ret_sp, NULL, addr.pc());

   108       if (!ret_frame2.safe_for_sender(jt)) {

   109         // nothing else to try if the frame isn't good

   110         return false;

   111       }

   112       ret_frame = ret_frame2;

   113 #else

   114       // nothing else to try if the frame isn't good

   115       return false;

   116 #endif /* COMPILER2 */

   117     }

   118     *fr_addr = ret_frame;

   119     return true;

   120   }

   121 

   122   // nothing else to try

   123   return false;

   124 }