jdk8-mips64-public/hotspot: src/share/vm/prims/forte.cpp@93b6525e3b82 (annotated)

src/share/vm/prims/forte.cpp@93b6525e3b82 (annotated)

src/share/vm/prims/forte.cpp

Tue, 08 Apr 2008 12:23:15 -0400

author: sgoldman
date: Tue, 08 Apr 2008 12:23:15 -0400
changeset 542: 93b6525e3b82
parent 435: a61af66fc99e
child 631: d1605aabd0a1
permissions: -rw-r--r--

6603919: Stackwalking crash on x86 -server with Sun Studio's collect -j on
Summary: Rewrite frame::safe_for_sender and friends to be safe for collector/analyzer
Reviewed-by: dcubed, kvn

 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 # include "incls/_precompiled.incl"
 # include "incls/_forte.cpp.incl"
 // These name match the names reported by the forte quality kit
 enum {
   ticks_no_Java_frame         =  0,
   ticks_no_class_load         = -1,
   ticks_GC_active             = -2,
   ticks_unknown_not_Java      = -3,
   ticks_not_walkable_not_Java = -4,
   ticks_unknown_Java          = -5,
   ticks_not_walkable_Java     = -6,
   ticks_unknown_state         = -7,
   ticks_thread_exit           = -8,
   ticks_deopt                 = -9,
   ticks_safepoint             = -10
 };
 //-------------------------------------------------------
 // Native interfaces for use by Forte tools.
 #ifndef IA64
 class vframeStreamForte : public vframeStreamCommon {
  public:
   // constructor that starts with sender of frame fr (top_frame)
   vframeStreamForte(JavaThread *jt, frame fr, bool stop_at_java_call_stub);
   void forte_next();
 };
 static void is_decipherable_compiled_frame(frame* fr, RegisterMap* map,
   bool* is_compiled_p, bool* is_walkable_p);
 static bool is_decipherable_interpreted_frame(JavaThread* thread,
                                                 frame* fr,
                                                 methodOop* method_p,
                                                 int* bci_p);
 vframeStreamForte::vframeStreamForte(JavaThread *jt,
                                      frame fr,
                                      bool stop_at_java_call_stub) : vframeStreamCommon(jt) {
   _stop_at_java_call_stub = stop_at_java_call_stub;
   _frame = fr;
   // We must always have a valid frame to start filling
   bool filled_in = fill_from_frame();
   assert(filled_in, "invariant");
 }
 // Solaris SPARC Compiler1 needs an additional check on the grandparent
 // of the top_frame when the parent of the top_frame is interpreted and
 // the grandparent is compiled. However, in this method we do not know
 // the relationship of the current _frame relative to the top_frame so
 // we implement a more broad sanity check. When the previous callee is
 // interpreted and the current sender is compiled, we verify that the
 // current sender is also walkable. If it is not walkable, then we mark
 // the current vframeStream as at the end.
 void vframeStreamForte::forte_next() {
   // handle frames with inlining
   if (_mode == compiled_mode &&
       vframeStreamCommon::fill_in_compiled_inlined_sender()) {
     return;
   }
   // handle general case
   int loop_count = 0;
   int loop_max = MaxJavaStackTraceDepth * 2;
   do {
     loop_count++;
     // By the time we get here we should never see unsafe but better
     // safe then segv'd
     if (loop_count > loop_max || !_frame.safe_for_sender(_thread)) {
       _mode = at_end_mode;
       return;
     }
     _frame = _frame.sender(&_reg_map);
   } while (!fill_from_frame());
 }
 // Determine if 'fr' is a decipherable compiled frame. We are already
 // assured that fr is for a java nmethod.
 static bool is_decipherable_compiled_frame(frame* fr) {
   assert(fr->cb() != NULL && fr->cb()->is_nmethod(), "invariant");
   nmethod* nm = (nmethod*) fr->cb();
   assert(nm->is_java_method(), "invariant");
   // First try and find an exact PcDesc
   PcDesc* pc_desc = nm->pc_desc_at(fr->pc());
   // Did we find a useful PcDesc?
   if (pc_desc != NULL &&
       pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) {
     address probe_pc = fr->pc() + 1;
     pc_desc = nm->pc_desc_near(probe_pc);
     // Now do we have a useful PcDesc?
     if (pc_desc != NULL &&
         pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) {
       // No debug information available for this pc
       // vframeStream would explode if we try and walk the frames.
       return false;
     }
     // This PcDesc is useful however we must adjust the frame's pc
     // so that the vframeStream lookups will use this same pc
     fr->set_pc(pc_desc->real_pc(nm));
   }
   return true;
 }
 // Determine if 'fr' is a walkable interpreted frame. Returns false
 // if it is not. *method_p, and *bci_p are not set when false is
 // returned. *method_p is non-NULL if frame was executing a Java
 // method. *bci_p is != -1 if a valid BCI in the Java method could
 // be found.
 // Note: this method returns true when a valid Java method is found
 // even if a valid BCI cannot be found.
 static bool is_decipherable_interpreted_frame(JavaThread* thread,
                                                 frame* fr,
                                                 methodOop* method_p,
                                                 int* bci_p) {
   assert(fr->is_interpreted_frame(), "just checking");
   // top frame is an interpreted frame
   // check if it is walkable (i.e. valid methodOop and valid bci)
   // Because we may be racing a gc thread the method and/or bci
   // of a valid interpreter frame may look bad causing us to
   // fail the is_interpreted_frame_valid test. If the thread
   // is in any of the following states we are assured that the
   // frame is in fact valid and we must have hit the race.
   JavaThreadState state = thread->thread_state();
   bool known_valid = (state == _thread_in_native ||
                       state == _thread_in_vm ||
                       state == _thread_blocked );
   if (known_valid || fr->is_interpreted_frame_valid(thread)) {
     // The frame code should completely validate the frame so that
     // references to methodOop and bci are completely safe to access
     // If they aren't the frame code should be fixed not this
     // code. However since gc isn't locked out the values could be
     // stale. This is a race we can never completely win since we can't
     // lock out gc so do one last check after retrieving their values
     // from the frame for additional safety
     methodOop method = fr->interpreter_frame_method();
     // We've at least found a method.
     // NOTE: there is something to be said for the approach that
     // if we don't find a valid bci then the method is not likely
     // a valid method. Then again we may have caught an interpreter
     // frame in the middle of construction and the bci field is
     // not yet valid.
     *method_p = method;
     // See if gc may have invalidated method since we validated frame
     if (!Universe::heap()->is_valid_method(method)) return false;
     intptr_t bcx = fr->interpreter_frame_bcx();
     int      bci = method->validate_bci_from_bcx(bcx);
     // note: bci is set to -1 if not a valid bci
     *bci_p = bci;
     return true;
   }
   return false;
 }
 // Determine if 'fr' can be used to find an initial Java frame.
 // Return false if it can not find a fully decipherable Java frame
 // (in other words a frame that isn't safe to use in a vframe stream).
 // Obviously if it can't even find a Java frame false will also be returned.
 //
 // If we find a Java frame decipherable or not then by definition we have
 // identified a method and that will be returned to the caller via method_p.
 // If we can determine a bci that is returned also. (Hmm is it possible
 // to return a method and bci and still return false? )
 //
 // The initial Java frame we find (if any) is return via initial_frame_p.
 //
 static bool find_initial_Java_frame(JavaThread* thread,
                                     frame* fr,
                                     frame* initial_frame_p,
                                     methodOop* method_p,
                                     int* bci_p) {
   // It is possible that for a frame containing an nmethod
   // we can capture the method but no bci. If we get no
   // bci the frame isn't walkable but the method is usable.
   // Therefore we init the returned methodOop to NULL so the
   // caller can make the distinction.
   *method_p = NULL;
   // On the initial call to this method the frame we get may not be
   // recognizable to us. This should only happen if we are in a JRT_LEAF
   // or something called by a JRT_LEAF method.
   frame candidate = *fr;
   // If the starting frame we were given has no codeBlob associated with
   // it see if we can find such a frame because only frames with codeBlobs
   // are possible Java frames.
   if (fr->cb() == NULL) {
     // See if we can find a useful frame
     int loop_count;
     int loop_max = MaxJavaStackTraceDepth * 2;
     RegisterMap map(thread, false);
     for (loop_count = 0; loop_count < loop_max; loop_count++) {
       if (!candidate.safe_for_sender(thread)) return false;
       candidate = candidate.sender(&map);
       if (candidate.cb() != NULL) break;
     }
     if (candidate.cb() == NULL) return false;
   }
   // We have a frame known to be in the codeCache
   // We will hopefully be able to figure out something to do with it.
   int loop_count;
   int loop_max = MaxJavaStackTraceDepth * 2;
   RegisterMap map(thread, false);
   for (loop_count = 0; loop_count < loop_max; loop_count++) {
     if (candidate.is_first_frame()) {
       // If initial frame is frame from StubGenerator and there is no
       // previous anchor, there are no java frames associated with a method
       return false;
     }
     if (candidate.is_interpreted_frame()) {
       if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
         *initial_frame_p = candidate;
         return true;
       }
       // Hopefully we got some data
       return false;
     }
     if (candidate.cb()->is_nmethod()) {
       nmethod* nm = (nmethod*) candidate.cb();
       *method_p = nm->method();
       // If the frame isn't fully decipherable then the default
       // value for the bci is a signal that we don't have a bci.
       // If we have a decipherable frame this bci value will
       // not be used.
       *bci_p = -1;
       *initial_frame_p = candidate;
       // Native wrapper code is trivial to decode by vframeStream
       if (nm->is_native_method()) return true;
       // If it isn't decipherable then we have found a pc that doesn't
       // have a PCDesc that can get us a bci however we did find
       // a method
       if (!is_decipherable_compiled_frame(&candidate)) {
         return false;
       }
       // is_decipherable_compiled_frame may modify candidate's pc
       *initial_frame_p = candidate;
       return true;
     }
     // Must be some stub frame that we don't care about
     if (!candidate.safe_for_sender(thread)) return false;
     candidate = candidate.sender(&map);
     // If it isn't in the code cache something is wrong
     // since once we find a frame in the code cache they
     // all should be there.
     if (candidate.cb() == NULL) return false;
   }
   return false;
 }
 // call frame copied from old .h file and renamed
 typedef struct {
     jint lineno;                      // line number in the source file
     jmethodID method_id;              // method executed in this frame
 } ASGCT_CallFrame;
 // call trace copied from old .h file and renamed
 typedef struct {
     JNIEnv *env_id;                   // Env where trace was recorded
     jint num_frames;                  // number of frames in this trace
     ASGCT_CallFrame *frames;          // frames
 } ASGCT_CallTrace;
 static void forte_fill_call_trace_given_top(JavaThread* thd,
                                             ASGCT_CallTrace* trace,
                                             int depth,
                                             frame top_frame) {
   NoHandleMark nhm;
   frame initial_Java_frame;
   methodOop method;
   int bci;
   int count;
   count = 0;
   assert(trace->frames != NULL, "trace->frames must be non-NULL");
   bool fully_decipherable = find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
   // The frame might not be walkable but still recovered a method
   // (e.g. an nmethod with no scope info for the pc
   if (method == NULL) return;
   CollectedHeap* ch = Universe::heap();
   // The method is not stored GC safe so see if GC became active
   // after we entered AsyncGetCallTrace() and before we try to
   // use the methodOop.
   // Yes, there is still a window after this check and before
   // we use methodOop below, but we can't lock out GC so that
   // has to be an acceptable risk.
   if (!ch->is_valid_method(method)) {
     trace->num_frames = ticks_GC_active; // -2
     return;
   }
   // We got a Java frame however it isn't fully decipherable
   // so it won't necessarily be safe to use it for the
   // initial frame in the vframe stream.
   if (!fully_decipherable) {
     // Take whatever method the top-frame decoder managed to scrape up.
     // We look further at the top frame only if non-safepoint
     // debugging information is available.
     count++;
     trace->num_frames = count;
     trace->frames[0].method_id = method->find_jmethod_id_or_null();
     if (!method->is_native()) {
       trace->frames[0].lineno = bci;
     } else {
       trace->frames[0].lineno = -3;
     }
     if (!initial_Java_frame.safe_for_sender(thd)) return;
     RegisterMap map(thd, false);
     initial_Java_frame = initial_Java_frame.sender(&map);
   }
   vframeStreamForte st(thd, initial_Java_frame, false);
   for (; !st.at_end() && count < depth; st.forte_next(), count++) {
     bci = st.bci();
     method = st.method();
     // The method is not stored GC safe so see if GC became active
     // after we entered AsyncGetCallTrace() and before we try to
     // use the methodOop.
     // Yes, there is still a window after this check and before
     // we use methodOop below, but we can't lock out GC so that
     // has to be an acceptable risk.
     if (!ch->is_valid_method(method)) {
       // we throw away everything we've gathered in this sample since
       // none of it is safe
       trace->num_frames = ticks_GC_active; // -2
       return;
     }
     trace->frames[count].method_id = method->find_jmethod_id_or_null();
     if (!method->is_native()) {
       trace->frames[count].lineno = bci;
     } else {
       trace->frames[count].lineno = -3;
     }
   }
   trace->num_frames = count;
   return;
 }
 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
 // on Linux X86, Solaris SPARC and Solaris X86.
 //
 // Async-safe version of GetCallTrace being called from a signal handler
 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
 // with different content (see below).
 //
 // This function must only be called when JVM/TI
 // CLASS_LOAD events have been enabled since agent startup. The enabled
 // event will cause the jmethodIDs to be allocated at class load time.
 // The jmethodIDs cannot be allocated in a signal handler because locks
 // cannot be grabbed in a signal handler safely.
 //
 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
 //
 // Called by the profiler to obtain the current method call stack trace for
 // a given thread. The thread is identified by the env_id field in the
 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
 // structure with enough memory for the requested stack depth. The VM fills in
 // the frames buffer and the num_frames field.
 //
 // Arguments:
 //
 //   trace    - trace data structure to be filled by the VM.
 //   depth    - depth of the call stack trace.
 //   ucontext - ucontext_t of the LWP
 //
 // ASGCT_CallTrace:
 //   typedef struct {
 //       JNIEnv *env_id;
 //       jint num_frames;
 //       ASGCT_CallFrame *frames;
 //   } ASGCT_CallTrace;
 //
 // Fields:
 //   env_id     - ID of thread which executed this trace.
 //   num_frames - number of frames in the trace.
 //                (< 0 indicates the frame is not walkable).
 //   frames     - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
 //
 //  ASGCT_CallFrame:
 //    typedef struct {
 //        jint lineno;
 //        jmethodID method_id;
 //    } ASGCT_CallFrame;
 //
 //  Fields:
 //    1) For Java frame (interpreted and compiled),
 //       lineno    - bci of the method being executed or -1 if bci is not available
 //       method_id - jmethodID of the method being executed
 //    2) For native method
 //       lineno    - (-3)
 //       method_id - jmethodID of the method being executed
 extern "C" {
 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
 // This is if'd out because we no longer use thread suspension.
 // However if someone wanted to backport this to a 5.0 jvm then this
 // code would be important.
 #if 0
   if (SafepointSynchronize::is_synchronizing()) {
     // The safepoint mechanism is trying to synchronize all the threads.
     // Since this can involve thread suspension, it is not safe for us
     // to be here. We can reduce the deadlock risk window by quickly
     // returning to the SIGPROF handler. However, it is still possible
     // for VMThread to catch us here or in the SIGPROF handler. If we
     // are suspended while holding a resource and another thread blocks
     // on that resource in the SIGPROF handler, then we will have a
     // three-thread deadlock (VMThread, this thread, the other thread).
     trace->num_frames = ticks_safepoint; // -10
     return;
   }
 #endif
   JavaThread* thread;
   if (trace->env_id == NULL ||
     (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
     thread->is_exiting()) {
     // bad env_id, thread has exited or thread is exiting
     trace->num_frames = ticks_thread_exit; // -8
     return;
   }
   if (thread->in_deopt_handler()) {
     // thread is in the deoptimization handler so return no frames
     trace->num_frames = ticks_deopt; // -9
     return;
   }
   assert(JavaThread::current() == thread,
          "AsyncGetCallTrace must be called by the current interrupted thread");
   if (!JvmtiExport::should_post_class_load()) {
     trace->num_frames = ticks_no_class_load; // -1
     return;
   }
   if (Universe::heap()->is_gc_active()) {
     trace->num_frames = ticks_GC_active; // -2
     return;
   }
   switch (thread->thread_state()) {
   case _thread_new:
   case _thread_uninitialized:
   case _thread_new_trans:
     // We found the thread on the threads list above, but it is too
     // young to be useful so return that there are no Java frames.
     trace->num_frames = 0;
     break;
   case _thread_in_native:
   case _thread_in_native_trans:
   case _thread_blocked:
   case _thread_blocked_trans:
   case _thread_in_vm:
   case _thread_in_vm_trans:
     {
       frame fr;
       // param isInJava == false - indicate we aren't in Java code
       if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
         trace->num_frames = ticks_unknown_not_Java;  // -3 unknown frame
       } else {
         if (!thread->has_last_Java_frame()) {
           trace->num_frames = 0; // No Java frames
         } else {
           trace->num_frames = ticks_not_walkable_not_Java;    // -4 non walkable frame by default
           forte_fill_call_trace_given_top(thread, trace, depth, fr);
           // This assert would seem to be valid but it is not.
           // It would be valid if we weren't possibly racing a gc
           // thread. A gc thread can make a valid interpreted frame
           // look invalid. It's a small window but it does happen.
           // The assert is left here commented out as a reminder.
           // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
         }
       }
     }
     break;
   case _thread_in_Java:
   case _thread_in_Java_trans:
     {
       frame fr;
       // param isInJava == true - indicate we are in Java code
       if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
         trace->num_frames = ticks_unknown_Java;  // -5 unknown frame
       } else {
         trace->num_frames = ticks_not_walkable_Java;  // -6, non walkable frame by default
         forte_fill_call_trace_given_top(thread, trace, depth, fr);
       }
     }
     break;
   default:
     // Unknown thread state
     trace->num_frames = ticks_unknown_state; // -7
     break;
   }
 }
 #ifndef _WINDOWS
 // Support for the Forte(TM) Peformance Tools collector.
 //
 // The method prototype is derived from libcollector.h. For more
 // information, please see the libcollect man page.
 // Method to let libcollector know about a dynamically loaded function.
 // Because it is weakly bound, the calls become NOP's when the library
 // isn't present.
 void    collector_func_load(char* name,
                             void* null_argument_1,
                             void* null_argument_2,
                             void *vaddr,
                             int size,
                             int zero_argument,
                             void* null_argument_3);
 #pragma weak collector_func_load
 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
         ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),0 : 0 )
 #endif // !_WINDOWS
 } // end extern "C"
 #endif // !IA64
 void Forte::register_stub(const char* name, address start, address end) {
 #if !defined(_WINDOWS) && !defined(IA64)
   assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
     "Code size exceeds maximum range")
   collector_func_load((char*)name, NULL, NULL, start,
     pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
 #endif // !_WINDOWS && !IA64
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/prims/forte.cpp@93b6525e3b82 (annotated)

src/share/vm/prims/forte.cpp