1 /*
   2  * Copyright (c) 2006, 2018, 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 "code/codeCache.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "runtime/deoptimization.hpp"
  29 #include "runtime/flags/jvmFlag.hpp"
  30 #include "runtime/vmThread.hpp"
  31 #include "runtime/vmOperations.hpp"
  32 #include "services/dtraceAttacher.hpp"
  33 
  34 #ifdef SOLARIS
  35 
  36 static void set_bool_flag(const char* flag, bool value) {
  37   JVMFlag::boolAtPut((char*)flag, strlen(flag), &value,
  38                               JVMFlag::ATTACH_ON_DEMAND);
  39 }
  40 
  41 // Enable only the "fine grained" flags. Do *not* touch
  42 // the overall "ExtendedDTraceProbes" flag.
  43 void DTrace::enable_dprobes(int probes) {
  44   bool changed = false;
  45   if (!DTraceAllocProbes && (probes & DTRACE_ALLOC_PROBES)) {
  46     set_bool_flag("DTraceAllocProbes", true);
  47     changed = true;
  48   }
  49   if (!DTraceMethodProbes && (probes & DTRACE_METHOD_PROBES)) {
  50     set_bool_flag("DTraceMethodProbes", true);
  51     changed = true;
  52   }
  53   if (!DTraceMonitorProbes && (probes & DTRACE_MONITOR_PROBES)) {
  54     set_bool_flag("DTraceMonitorProbes", true);
  55     changed = true;
  56   }
  57 
  58   if (changed) {
  59     // one or more flags changed, need to deoptimize
  60     CodeCache::mark_all_nmethods_for_deoptimization();
  61     Deoptimization::deoptimize_all_marked();
  62   }
  63 }
  64 
  65 // Disable only the "fine grained" flags. Do *not* touch
  66 // the overall "ExtendedDTraceProbes" flag.
  67 void DTrace::disable_dprobes(int probes) {
  68   bool changed = false;
  69   if (DTraceAllocProbes && (probes & DTRACE_ALLOC_PROBES)) {
  70     set_bool_flag("DTraceAllocProbes", false);
  71     changed = true;
  72   }
  73   if (DTraceMethodProbes && (probes & DTRACE_METHOD_PROBES)) {
  74     set_bool_flag("DTraceMethodProbes", false);
  75     changed = true;
  76   }
  77   if (DTraceMonitorProbes && (probes & DTRACE_MONITOR_PROBES)) {
  78     set_bool_flag("DTraceMonitorProbes", false);
  79     changed = true;
  80   }
  81   if (changed) {
  82     // one or more flags changed, need to deoptimize
  83     CodeCache::mark_all_nmethods_for_deoptimization();
  84     Deoptimization::deoptimize_all_marked();
  85   }
  86 }
  87 
  88 // Do clean-up on "all door clients detached" event.
  89 void DTrace::detach_all_clients() {
  90   /*
  91    * We restore the state of the fine grained flags
  92    * to be consistent with overall ExtendedDTraceProbes.
  93    * This way, we will honour command line setting or the
  94    * last explicit modification of ExtendedDTraceProbes by
  95    * a call to set_extended_dprobes.
  96    */
  97   if (ExtendedDTraceProbes) {
  98     enable_dprobes(DTRACE_ALL_PROBES);
  99   } else {
 100     disable_dprobes(DTRACE_ALL_PROBES);
 101   }
 102 }
 103 
 104 void DTrace::set_extended_dprobes(bool flag) {
 105   // explicit setting of ExtendedDTraceProbes flag
 106   set_bool_flag("ExtendedDTraceProbes", flag);
 107 
 108   // make sure that the fine grained flags reflect the change.
 109   if (flag) {
 110     enable_dprobes(DTRACE_ALL_PROBES);
 111   } else {
 112     /*
 113      * FIXME: Revisit this: currently all-client-detach detection
 114      * does not work and hence disabled. The following scheme does
 115      * not work. So, we have to disable fine-grained flags here.
 116      *
 117      * disable_dprobes call has to be delayed till next "detach all "event.
 118      * This is to be  done so that concurrent DTrace clients that may
 119      * have enabled one or more fine grained dprobes and may be running
 120      * still. On "detach all" clients event, we would sync ExtendedDTraceProbes
 121      * with  fine grained flags which would take care of disabling fine grained flags.
 122      */
 123     disable_dprobes(DTRACE_ALL_PROBES);
 124   }
 125 }
 126 
 127 void DTrace::set_monitor_dprobes(bool flag) {
 128   // explicit setting of DTraceMonitorProbes flag
 129   set_bool_flag("DTraceMonitorProbes", flag);
 130 }
 131 
 132 #endif /* SOLARIS */