rev 4773 : 8005849: JEP 167: Event-Based JVM Tracing
Reviewed-by: acorn, coleenp, sla
Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>

   1 /*
   2  * Copyright (c) 2005, 2013, 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 "classfile/javaClasses.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "gc_implementation/shared/vmGCOperations.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "prims/jvmtiExport.hpp"
  31 #include "runtime/arguments.hpp"
  32 #include "runtime/globals.hpp"
  33 #include "runtime/java.hpp"
  34 #include "runtime/javaCalls.hpp"
  35 #include "runtime/os.hpp"
  36 #include "services/attachListener.hpp"
  37 #include "services/diagnosticCommand.hpp"
  38 #include "services/heapDumper.hpp"
  39 
  40 volatile bool AttachListener::_initialized;
  41 
  42 // Implementation of "properties" command.
  43 //
  44 // Invokes sun.misc.VMSupport.serializePropertiesToByteArray to serialize
  45 // the system properties into a byte array.
  46 
  47 static Klass* load_and_initialize_klass(Symbol* sh, TRAPS) {
  48   Klass* k = SystemDictionary::resolve_or_fail(sh, true, CHECK_NULL);
  49   instanceKlassHandle ik (THREAD, k);
  50   if (ik->should_be_initialized()) {
  51     ik->initialize(CHECK_NULL);
  52   }
  53   return ik();
  54 }
  55 
  56 static jint get_properties(AttachOperation* op, outputStream* out, Symbol* serializePropertiesMethod) {
  57   Thread* THREAD = Thread::current();
  58   HandleMark hm;
  59 
  60   // load sun.misc.VMSupport
  61   Symbol* klass = vmSymbols::sun_misc_VMSupport();
  62   Klass* k = load_and_initialize_klass(klass, THREAD);
  63   if (HAS_PENDING_EXCEPTION) {
  64     java_lang_Throwable::print(PENDING_EXCEPTION, out);
  65     CLEAR_PENDING_EXCEPTION;
  66     return JNI_ERR;
  67   }
  68   instanceKlassHandle ik(THREAD, k);
  69 
  70   // invoke the serializePropertiesToByteArray method
  71   JavaValue result(T_OBJECT);
  72   JavaCallArguments args;
  73 
  74 
  75   Symbol* signature = vmSymbols::serializePropertiesToByteArray_signature();
  76   JavaCalls::call_static(&result,
  77                            ik,
  78                            serializePropertiesMethod,
  79                            signature,
  80                            &args,
  81                            THREAD);
  82   if (HAS_PENDING_EXCEPTION) {
  83     java_lang_Throwable::print(PENDING_EXCEPTION, out);
  84     CLEAR_PENDING_EXCEPTION;
  85     return JNI_ERR;
  86   }
  87 
  88   // The result should be a [B
  89   oop res = (oop)result.get_jobject();
  90   assert(res->is_typeArray(), "just checking");
  91   assert(TypeArrayKlass::cast(res->klass())->element_type() == T_BYTE, "just checking");
  92 
  93   // copy the bytes to the output stream
  94   typeArrayOop ba = typeArrayOop(res);
  95   jbyte* addr = typeArrayOop(res)->byte_at_addr(0);
  96   out->print_raw((const char*)addr, ba->length());
  97 
  98   return JNI_OK;
  99 }
 100 
 101 // Implementation of "properties" command.
 102 // See also: PrintSystemPropertiesDCmd class
 103 static jint get_system_properties(AttachOperation* op, outputStream* out) {
 104   return get_properties(op, out, vmSymbols::serializePropertiesToByteArray_name());
 105 }
 106 
 107 // Implementation of "agent_properties" command.
 108 static jint get_agent_properties(AttachOperation* op, outputStream* out) {
 109   return get_properties(op, out, vmSymbols::serializeAgentPropertiesToByteArray_name());
 110 }
 111 
 112 // Implementation of "datadump" command.
 113 //
 114 // Raises a SIGBREAK signal so that VM dump threads, does deadlock detection,
 115 // etc. In theory this command should only post a DataDumpRequest to any
 116 // JVMTI environment that has enabled this event. However it's useful to
 117 // trigger the SIGBREAK handler.
 118 
 119 static jint data_dump(AttachOperation* op, outputStream* out) {
 120   if (!ReduceSignalUsage) {
 121     AttachListener::pd_data_dump();
 122   } else {
 123     if (JvmtiExport::should_post_data_dump()) {
 124       JvmtiExport::post_data_dump();
 125     }
 126   }
 127   return JNI_OK;
 128 }
 129 
 130 // Implementation of "threaddump" command - essentially a remote ctrl-break
 131 // See also: ThreadDumpDCmd class
 132 //
 133 static jint thread_dump(AttachOperation* op, outputStream* out) {
 134   bool print_concurrent_locks = false;
 135   if (op->arg(0) != NULL && strcmp(op->arg(0), "-l") == 0) {
 136     print_concurrent_locks = true;
 137   }
 138 
 139   // thread stacks
 140   VM_PrintThreads op1(out, print_concurrent_locks);
 141   VMThread::execute(&op1);
 142 
 143   // JNI global handles
 144   VM_PrintJNI op2(out);
 145   VMThread::execute(&op2);
 146 
 147   // Deadlock detection
 148   VM_FindDeadlocks op3(out);
 149   VMThread::execute(&op3);
 150 
 151   return JNI_OK;
 152 }
 153 
 154 // A jcmd attach operation request was received, which will now
 155 // dispatch to the diagnostic commands used for serviceability functions.
 156 static jint jcmd(AttachOperation* op, outputStream* out) {
 157   Thread* THREAD = Thread::current();
 158   // All the supplied jcmd arguments are stored as a single
 159   // string (op->arg(0)). This is parsed by the Dcmd framework.
 160   DCmd::parse_and_execute(DCmd_Source_AttachAPI, out, op->arg(0), ' ', THREAD);
 161   if (HAS_PENDING_EXCEPTION) {
 162     java_lang_Throwable::print(PENDING_EXCEPTION, out);
 163     out->cr();
 164     CLEAR_PENDING_EXCEPTION;
 165     // The exception has been printed on the output stream
 166     // If the JVM returns JNI_ERR, the attachAPI throws a generic I/O
 167     // exception and the content of the output stream is not processed.
 168     // By returning JNI_OK, the exception will be displayed on the client side
 169   }
 170   return JNI_OK;
 171 }
 172 
 173 // Implementation of "dumpheap" command.
 174 // See also: HeapDumpDCmd class
 175 //
 176 // Input arguments :-
 177 //   arg0: Name of the dump file
 178 //   arg1: "-live" or "-all"
 179 jint dump_heap(AttachOperation* op, outputStream* out) {
 180   const char* path = op->arg(0);
 181   if (path == NULL || path[0] == '\0') {
 182     out->print_cr("No dump file specified");
 183   } else {
 184     bool live_objects_only = true;   // default is true to retain the behavior before this change is made
 185     const char* arg1 = op->arg(1);
 186     if (arg1 != NULL && (strlen(arg1) > 0)) {
 187       if (strcmp(arg1, "-all") != 0 && strcmp(arg1, "-live") != 0) {
 188         out->print_cr("Invalid argument to dumpheap operation: %s", arg1);
 189         return JNI_ERR;
 190       }
 191       live_objects_only = strcmp(arg1, "-live") == 0;
 192     }
 193 
 194     // Request a full GC before heap dump if live_objects_only = true
 195     // This helps reduces the amount of unreachable objects in the dump
 196     // and makes it easier to browse.
 197     HeapDumper dumper(live_objects_only /* request GC */);
 198     int res = dumper.dump(op->arg(0));
 199     if (res == 0) {
 200       out->print_cr("Heap dump file created");
 201     } else {
 202       // heap dump failed
 203       ResourceMark rm;
 204       char* error = dumper.error_as_C_string();
 205       if (error == NULL) {
 206         out->print_cr("Dump failed - reason unknown");
 207       } else {
 208         out->print_cr("%s", error);
 209       }
 210     }
 211   }
 212   return JNI_OK;
 213 }
 214 
 215 // Implementation of "inspectheap" command
 216 // See also: ClassHistogramDCmd class
 217 //
 218 // Input arguments :-
 219 //   arg0: "-live" or "-all"
 220 static jint heap_inspection(AttachOperation* op, outputStream* out) {
 221   bool live_objects_only = true;   // default is true to retain the behavior before this change is made
 222   const char* arg0 = op->arg(0);
 223   if (arg0 != NULL && (strlen(arg0) > 0)) {
 224     if (strcmp(arg0, "-all") != 0 && strcmp(arg0, "-live") != 0) {
 225       out->print_cr("Invalid argument to inspectheap operation: %s", arg0);
 226       return JNI_ERR;
 227     }
 228     live_objects_only = strcmp(arg0, "-live") == 0;
 229   }
 230   VM_GC_HeapInspection heapop(out, live_objects_only /* request full gc */);
 231   VMThread::execute(&heapop);
 232   return JNI_OK;
 233 }
 234 
 235 // set a boolean global flag using value from AttachOperation
 236 static jint set_bool_flag(const char* name, AttachOperation* op, outputStream* out) {
 237   bool value = true;
 238   const char* arg1;
 239   if ((arg1 = op->arg(1)) != NULL) {
 240     int tmp;
 241     int n = sscanf(arg1, "%d", &tmp);
 242     if (n != 1) {
 243       out->print_cr("flag value must be a boolean (1 or 0)");
 244       return JNI_ERR;
 245     }
 246     value = (tmp != 0);
 247   }
 248   bool res = CommandLineFlags::boolAtPut((char*)name, &value, ATTACH_ON_DEMAND);
 249   if (! res) {
 250     out->print_cr("setting flag %s failed", name);
 251   }
 252   return res? JNI_OK : JNI_ERR;
 253 }
 254 
 255 // set a intx global flag using value from AttachOperation
 256 static jint set_intx_flag(const char* name, AttachOperation* op, outputStream* out) {
 257   intx value;
 258   const char* arg1;
 259   if ((arg1 = op->arg(1)) != NULL) {
 260     int n = sscanf(arg1, INTX_FORMAT, &value);
 261     if (n != 1) {
 262       out->print_cr("flag value must be an integer");
 263       return JNI_ERR;
 264     }
 265   }
 266   bool res = CommandLineFlags::intxAtPut((char*)name, &value, ATTACH_ON_DEMAND);
 267   if (! res) {
 268     out->print_cr("setting flag %s failed", name);
 269   }
 270 
 271   return res? JNI_OK : JNI_ERR;
 272 }
 273 
 274 // set a uintx global flag using value from AttachOperation
 275 static jint set_uintx_flag(const char* name, AttachOperation* op, outputStream* out) {
 276   uintx value;
 277   const char* arg1;
 278   if ((arg1 = op->arg(1)) != NULL) {
 279     int n = sscanf(arg1, UINTX_FORMAT, &value);
 280     if (n != 1) {
 281       out->print_cr("flag value must be an unsigned integer");
 282       return JNI_ERR;
 283     }
 284   }
 285   bool res = CommandLineFlags::uintxAtPut((char*)name, &value, ATTACH_ON_DEMAND);
 286   if (! res) {
 287     out->print_cr("setting flag %s failed", name);
 288   }
 289 
 290   return res? JNI_OK : JNI_ERR;
 291 }
 292 
 293 // set a uint64_t global flag using value from AttachOperation
 294 static jint set_uint64_t_flag(const char* name, AttachOperation* op, outputStream* out) {
 295   uint64_t value;
 296   const char* arg1;
 297   if ((arg1 = op->arg(1)) != NULL) {
 298     int n = sscanf(arg1, UINT64_FORMAT, &value);
 299     if (n != 1) {
 300       out->print_cr("flag value must be an unsigned 64-bit integer");
 301       return JNI_ERR;
 302     }
 303   }
 304   bool res = CommandLineFlags::uint64_tAtPut((char*)name, &value, ATTACH_ON_DEMAND);
 305   if (! res) {
 306     out->print_cr("setting flag %s failed", name);
 307   }
 308 
 309   return res? JNI_OK : JNI_ERR;
 310 }
 311 
 312 // set a string global flag using value from AttachOperation
 313 static jint set_ccstr_flag(const char* name, AttachOperation* op, outputStream* out) {
 314   const char* value;
 315   if ((value = op->arg(1)) == NULL) {
 316     out->print_cr("flag value must be a string");
 317     return JNI_ERR;
 318   }
 319   bool res = CommandLineFlags::ccstrAtPut((char*)name, &value, ATTACH_ON_DEMAND);
 320   if (res) {
 321     FREE_C_HEAP_ARRAY(char, value, mtInternal);
 322   } else {
 323     out->print_cr("setting flag %s failed", name);
 324   }
 325 
 326   return res? JNI_OK : JNI_ERR;
 327 }
 328 
 329 // Implementation of "setflag" command
 330 static jint set_flag(AttachOperation* op, outputStream* out) {
 331 
 332   const char* name = NULL;
 333   if ((name = op->arg(0)) == NULL) {
 334     out->print_cr("flag name is missing");
 335     return JNI_ERR;
 336   }
 337 
 338   Flag* f = Flag::find_flag((char*)name, strlen(name));
 339   if (f && f->is_external() && f->is_writeable()) {
 340     if (f->is_bool()) {
 341       return set_bool_flag(name, op, out);
 342     } else if (f->is_intx()) {
 343       return set_intx_flag(name, op, out);
 344     } else if (f->is_uintx()) {
 345       return set_uintx_flag(name, op, out);
 346     } else if (f->is_uint64_t()) {
 347       return set_uint64_t_flag(name, op, out);
 348     } else if (f->is_ccstr()) {
 349       return set_ccstr_flag(name, op, out);
 350     } else {
 351       ShouldNotReachHere();
 352       return JNI_ERR;
 353     }
 354   } else {
 355     return AttachListener::pd_set_flag(op, out);
 356   }
 357 }
 358 
 359 // Implementation of "printflag" command
 360 // See also: PrintVMFlagsDCmd class
 361 static jint print_flag(AttachOperation* op, outputStream* out) {
 362   const char* name = NULL;
 363   if ((name = op->arg(0)) == NULL) {
 364     out->print_cr("flag name is missing");
 365     return JNI_ERR;
 366   }
 367   Flag* f = Flag::find_flag((char*)name, strlen(name));
 368   if (f) {
 369     f->print_as_flag(out);
 370     out->print_cr("");
 371   } else {
 372     out->print_cr("no such flag '%s'", name);
 373   }
 374   return JNI_OK;
 375 }
 376 
 377 // Table to map operation names to functions.
 378 
 379 // names must be of length <= AttachOperation::name_length_max
 380 static AttachOperationFunctionInfo funcs[] = {
 381   { "agentProperties",  get_agent_properties },
 382   { "datadump",         data_dump },
 383   { "dumpheap",         dump_heap },
 384   { "load",             JvmtiExport::load_agent_library },
 385   { "properties",       get_system_properties },
 386   { "threaddump",       thread_dump },
 387   { "inspectheap",      heap_inspection },
 388   { "setflag",          set_flag },
 389   { "printflag",        print_flag },
 390   { "jcmd",             jcmd },
 391   { NULL,               NULL }
 392 };
 393 
 394 
 395 
 396 // The Attach Listener threads services a queue. It dequeues an operation
 397 // from the queue, examines the operation name (command), and dispatches
 398 // to the corresponding function to perform the operation.
 399 
 400 static void attach_listener_thread_entry(JavaThread* thread, TRAPS) {
 401   os::set_priority(thread, NearMaxPriority);
 402 
 403   thread->record_stack_base_and_size();
 404 
 405   if (AttachListener::pd_init() != 0) {
 406     return;
 407   }
 408   AttachListener::set_initialized();
 409 
 410   for (;;) {
 411     AttachOperation* op = AttachListener::dequeue();
 412     if (op == NULL) {
 413       return;   // dequeue failed or shutdown
 414     }
 415 
 416     ResourceMark rm;
 417     bufferedStream st;
 418     jint res = JNI_OK;
 419 
 420     // handle special detachall operation
 421     if (strcmp(op->name(), AttachOperation::detachall_operation_name()) == 0) {
 422       AttachListener::detachall();
 423     } else {
 424       // find the function to dispatch too
 425       AttachOperationFunctionInfo* info = NULL;
 426       for (int i=0; funcs[i].name != NULL; i++) {
 427         const char* name = funcs[i].name;
 428         assert(strlen(name) <= AttachOperation::name_length_max, "operation <= name_length_max");
 429         if (strcmp(op->name(), name) == 0) {
 430           info = &(funcs[i]);
 431           break;
 432         }
 433       }
 434 
 435       // check for platform dependent attach operation
 436       if (info == NULL) {
 437         info = AttachListener::pd_find_operation(op->name());
 438       }
 439 
 440       if (info != NULL) {
 441         // dispatch to the function that implements this operation
 442         res = (info->func)(op, &st);
 443       } else {
 444         st.print("Operation %s not recognized!", op->name());
 445         res = JNI_ERR;
 446       }
 447     }
 448 
 449     // operation complete - send result and output to client
 450     op->complete(res, &st);
 451   }
 452 }
 453 
 454 // Starts the Attach Listener thread
 455 void AttachListener::init() {
 456   EXCEPTION_MARK;
 457   Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
 458   instanceKlassHandle klass (THREAD, k);
 459   instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
 460 
 461   const char thread_name[] = "Attach Listener";
 462   Handle string = java_lang_String::create_from_str(thread_name, CHECK);
 463 
 464   // Initialize thread_oop to put it into the system threadGroup
 465   Handle thread_group (THREAD, Universe::system_thread_group());
 466   JavaValue result(T_VOID);
 467   JavaCalls::call_special(&result, thread_oop,
 468                        klass,
 469                        vmSymbols::object_initializer_name(),
 470                        vmSymbols::threadgroup_string_void_signature(),
 471                        thread_group,
 472                        string,
 473                        CHECK);
 474 
 475   KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
 476   JavaCalls::call_special(&result,
 477                         thread_group,
 478                         group,
 479                         vmSymbols::add_method_name(),
 480                         vmSymbols::thread_void_signature(),
 481                         thread_oop,             // ARG 1
 482                         CHECK);
 483 
 484   { MutexLocker mu(Threads_lock);
 485     JavaThread* listener_thread = new JavaThread(&attach_listener_thread_entry);
 486 
 487     // Check that thread and osthread were created
 488     if (listener_thread == NULL || listener_thread->osthread() == NULL) {
 489       vm_exit_during_initialization("java.lang.OutOfMemoryError",
 490                                     "unable to create new native thread");
 491     }
 492 
 493     java_lang_Thread::set_thread(thread_oop(), listener_thread);
 494     java_lang_Thread::set_daemon(thread_oop());
 495 
 496     listener_thread->set_threadObj(thread_oop());
 497     Threads::add(listener_thread);
 498     Thread::start(listener_thread);
 499   }
 500 }
 501 
 502 // Performs clean-up tasks on platforms where we can detect that the last
 503 // client has detached
 504 void AttachListener::detachall() {
 505   // call the platform dependent clean-up
 506   pd_detachall();
 507 }
--- EOF ---