1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5  * This code is free software; you can redistribute it and/or modify it
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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
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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
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23  */
24 
25 #include "precompiled.hpp"
26 #include "memory/metaspaceShared.hpp"
27 #include "runtime/frame.inline.hpp"
28 #include "runtime/thread.inline.hpp"
29 
pd_last_frame()30 frame JavaThread::pd_last_frame() {
31   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
32   vmassert(_anchor.last_Java_pc() != NULL, "not walkable");
33   return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
34 }
35 
36 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
37 // currently interrupted by SIGPROF
pd_get_top_frame_for_signal_handler(frame * fr_addr,void * ucontext,bool isInJava)38 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
39   void* ucontext, bool isInJava) {
40   assert(Thread::current() == this, "caller must be current thread");
41   return pd_get_top_frame(fr_addr, ucontext, isInJava);
42 }
43 
pd_get_top_frame_for_profiling(frame * fr_addr,void * ucontext,bool isInJava)44 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
45   return pd_get_top_frame(fr_addr, ucontext, isInJava);
46 }
47 
pd_get_top_frame(frame * fr_addr,void * ucontext,bool isInJava)48 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
49   assert(this->is_Java_thread(), "must be JavaThread");
50   JavaThread* jt = (JavaThread *)this;
51 
52   // If we have a last_Java_frame, then we should use it even if
53   // isInJava == true.  It should be more reliable than ucontext info.
54   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
55     *fr_addr = jt->pd_last_frame();
56     return true;
57   }
58 
59   // At this point, we don't have a last_Java_frame, so
60   // we try to glean some information out of the ucontext
61   // if we were running Java code when SIGPROF came in.
62   if (isInJava) {
63     ucontext_t* uc = (ucontext_t*) ucontext;
64 
65     intptr_t* ret_fp;
66     intptr_t* ret_sp;
67     ExtendedPC addr = os::Bsd::fetch_frame_from_ucontext(this, uc,
68       &ret_sp, &ret_fp);
69     if (addr.pc() == NULL || ret_sp == NULL ) {
70       // ucontext wasn't useful
71       return false;
72     }
73 
74     if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
75       // In the middle of a trampoline call. Bail out for safety.
76       // This happens rarely so shouldn't affect profiling.
77       return false;
78     }
79 
80     frame ret_frame(ret_sp, ret_fp, addr.pc());
81     if (!ret_frame.safe_for_sender(jt)) {
82 #if COMPILER2_OR_JVMCI
83       // C2 and JVMCI use ebp as a general register see if NULL fp helps
84       frame ret_frame2(ret_sp, NULL, addr.pc());
85       if (!ret_frame2.safe_for_sender(jt)) {
86         // nothing else to try if the frame isn't good
87         return false;
88       }
89       ret_frame = ret_frame2;
90 #else
91       // nothing else to try if the frame isn't good
92       return false;
93 #endif // COMPILER2_OR_JVMCI
94     }
95     *fr_addr = ret_frame;
96     return true;
97   }
98 
99   // nothing else to try
100   return false;
101 }
102 
cache_global_variables()103 void JavaThread::cache_global_variables() { }
104