view src/share/vm/utilities/exceptions.cpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents a61af66fc99e
children fcb148c6b605
line wrap: on
line source

/*
 * Copyright 1998-2007 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/_exceptions.cpp.incl"


// Implementation of ThreadShadow
void check_ThreadShadow() {
  const ByteSize offset1 = byte_offset_of(ThreadShadow, _pending_exception);
  const ByteSize offset2 = Thread::pending_exception_offset();
  if (offset1 != offset2) fatal("ThreadShadow::_pending_exception is not positioned correctly");
}


void ThreadShadow::set_pending_exception(oop exception, const char* file, int line) {
  assert(exception != NULL && exception->is_oop(), "invalid exception oop");
  _pending_exception = exception;
  _exception_file    = file;
  _exception_line    = line;
}

void ThreadShadow::clear_pending_exception() {
  if (TraceClearedExceptions) {
    if (_pending_exception != NULL) {
      tty->print_cr("Thread::clear_pending_exception: cleared exception:");
      _pending_exception->print();
    }
  }
  _pending_exception = NULL;
  _exception_file    = NULL;
  _exception_line    = 0;
}
// Implementation of Exceptions

bool Exceptions::special_exception(Thread* thread, const char* file, int line, Handle h_exception) {
  // bootstrapping check
  if (!Universe::is_fully_initialized()) {
   vm_exit_during_initialization(h_exception);
   ShouldNotReachHere();
  }

  if (thread->is_VM_thread()
      || thread->is_Compiler_thread() ) {
    // We do not care what kind of exception we get for the vm-thread or a thread which
    // is compiling.  We just install a dummy exception object
    thread->set_pending_exception(Universe::vm_exception(), file, line);
    return true;
  }

  return false;
}

bool Exceptions::special_exception(Thread* thread, const char* file, int line, symbolHandle h_name, const char* message) {
  // bootstrapping check
  if (!Universe::is_fully_initialized()) {
    if (h_name.is_null()) {
      // atleast an informative message.
      vm_exit_during_initialization("Exception", message);
    } else {
      vm_exit_during_initialization(h_name, message);
    }
    ShouldNotReachHere();
  }

  if (thread->is_VM_thread()
      || thread->is_Compiler_thread() ) {
    // We do not care what kind of exception we get for the vm-thread or a thread which
    // is compiling.  We just install a dummy exception object
    thread->set_pending_exception(Universe::vm_exception(), file, line);
    return true;
  }

  return false;
}

// This method should only be called from generated code,
// therefore the exception oop should be in the oopmap.
void Exceptions::_throw_oop(Thread* thread, const char* file, int line, oop exception) {
  assert(exception != NULL, "exception should not be NULL");
  Handle h_exception = Handle(thread, exception);
  _throw(thread, file, line, h_exception);
}

void Exceptions::_throw(Thread* thread, const char* file, int line, Handle h_exception) {
  assert(h_exception() != NULL, "exception should not be NULL");

  // tracing (do this up front - so it works during boot strapping)
  if (TraceExceptions) {
    ttyLocker ttyl;
    ResourceMark rm;
    tty->print_cr("Exception <%s> (" INTPTR_FORMAT " ) \nthrown [%s, line %d]\nfor thread " INTPTR_FORMAT,
                      h_exception->print_value_string(), (address)h_exception(), file, line, thread);
  }
  // for AbortVMOnException flag
  NOT_PRODUCT(Exceptions::debug_check_abort(h_exception));

  // Check for special boot-strapping/vm-thread handling
  if (special_exception(thread, file, line, h_exception)) return;

  assert(h_exception->is_a(SystemDictionary::throwable_klass()), "exception is not a subclass of java/lang/Throwable");

  // set the pending exception
  thread->set_pending_exception(h_exception(), file, line);

  // vm log
  Events::log("throw_exception " INTPTR_FORMAT, (address)h_exception());
}


void Exceptions::_throw_msg(Thread* thread, const char* file, int line, symbolHandle h_name, const char* message, Handle h_loader, Handle h_protection_domain) {
  // Check for special boot-strapping/vm-thread handling
  if (special_exception(thread, file, line, h_name, message)) return;
  // Create and throw exception
  Handle h_cause(thread, NULL);
  Handle h_exception = new_exception(thread, h_name, message, h_cause, h_loader, h_protection_domain);
  _throw(thread, file, line, h_exception);
}

// Throw an exception with a message and a cause
void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line, symbolHandle h_name, const char* message, Handle h_cause, Handle h_loader, Handle h_protection_domain) {
  // Check for special boot-strapping/vm-thread handling
  if (special_exception(thread, file, line, h_name, message)) return;
  // Create and throw exception and init cause
  Handle h_exception = new_exception(thread, h_name, message, h_cause, h_loader, h_protection_domain);
  _throw(thread, file, line, h_exception);
}

// This version creates handles and calls the other version
void Exceptions::_throw_msg(Thread* thread, const char* file, int line,
                            symbolOop name, const char* message) {
  symbolHandle h_name(thread, name);
  Handle       h_loader(thread, NULL);
  Handle       h_protection_domain(thread, NULL);
  Exceptions::_throw_msg(thread, file, line, h_name, message, h_loader, h_protection_domain);
}

// This version already has a handle for name
void Exceptions::_throw_msg(Thread* thread, const char* file, int line,
                            symbolHandle name, const char* message) {
  Handle       h_loader(thread, NULL);
  Handle       h_protection_domain(thread, NULL);
  Exceptions::_throw_msg(thread, file, line, name, message, h_loader, h_protection_domain);
}

// This version already has a handle for name
void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line,
                            symbolHandle name, const char* message, Handle cause) {
  Handle       h_loader(thread, NULL);
  Handle       h_protection_domain(thread, NULL);
  Exceptions::_throw_msg_cause(thread, file, line, name, message, cause, h_loader, h_protection_domain);
}

void Exceptions::_throw_args(Thread* thread, const char* file, int line, symbolHandle h_name, symbolHandle h_signature, JavaCallArguments *args) {
  // Check for special boot-strapping/vm-thread handling
  if (special_exception(thread, file, line, h_name, NULL)) return;
  // Create and throw exception
  Handle h_loader(thread, NULL);
  Handle h_prot(thread, NULL);
  Handle h_cause(thread, NULL);
  Handle exception = new_exception(thread, h_name, h_signature, args, h_cause, h_loader, h_prot);
  _throw(thread, file, line, exception);
}


void Exceptions::throw_stack_overflow_exception(Thread* THREAD, const char* file, int line) {
  Handle exception;
  if (!THREAD->has_pending_exception()) {
    klassOop k = SystemDictionary::StackOverflowError_klass();
    oop e = instanceKlass::cast(k)->allocate_instance(CHECK);
    exception = Handle(THREAD, e);  // fill_in_stack trace does gc
    if (StackTraceInThrowable) {
      java_lang_Throwable::fill_in_stack_trace(exception);
    }
  } else {
    // if prior exception, throw that one instead
    exception = Handle(THREAD, THREAD->pending_exception());
  }
  _throw_oop(THREAD, file, line, exception());
}

void Exceptions::fthrow(Thread* thread, const char* file, int line, symbolHandle h_name, const char* format, ...) {
  const int max_msg_size = 1024;
  va_list ap;
  va_start(ap, format);
  char msg[max_msg_size];
  vsnprintf(msg, max_msg_size, format, ap);
  msg[max_msg_size-1] = '\0';
  va_end(ap);
  _throw_msg(thread, file, line, h_name, msg);
}

// Creates an exception oop, calls the <init> method with the given signature.
// and returns a Handle
// Initializes the cause if cause non-null
Handle Exceptions::new_exception(Thread *thread, symbolHandle h_name,
                                 symbolHandle signature,
                                 JavaCallArguments *args,
                                 Handle h_cause, Handle h_loader,
                                 Handle h_protection_domain) {
  assert(Universe::is_fully_initialized(),
    "cannot be called during initialization");
  assert(thread->is_Java_thread(), "can only be called by a Java thread");
  assert(!thread->has_pending_exception(), "already has exception");

  Handle h_exception;

  // Resolve exception klass
  klassOop ik = SystemDictionary::resolve_or_fail(h_name, h_loader, h_protection_domain, true, thread);
  instanceKlassHandle klass (thread, ik);

  if (!thread->has_pending_exception()) {
    assert(klass.not_null(), "klass must exist");
    // We are about to create an instance - so make sure that klass is initialized
    klass->initialize(thread);
    if (!thread->has_pending_exception()) {
      // Allocate new exception
      h_exception = klass->allocate_instance_handle(thread);
      if (!thread->has_pending_exception()) {
        JavaValue result(T_VOID);
        args->set_receiver(h_exception);
        // Call constructor
        JavaCalls::call_special(&result, klass,
                                         vmSymbolHandles::object_initializer_name(),
                                         signature,
                                         args,
                                         thread);

      }
    }

    // Future: object initializer should take a cause argument
    if (h_cause() != NULL) {
      assert(h_cause->is_a(SystemDictionary::throwable_klass()),
          "exception cause is not a subclass of java/lang/Throwable");
      JavaValue result1(T_OBJECT);
      JavaCallArguments args1;
      args1.set_receiver(h_exception);
      args1.push_oop(h_cause);
      JavaCalls::call_virtual(&result1, klass,
                                     vmSymbolHandles::initCause_name(),
                                     vmSymbolHandles::throwable_throwable_signature(),
                                     &args1,
                                     thread);
    }
  }

  // Check if another exception was thrown in the process, if so rethrow that one
  if (thread->has_pending_exception()) {
    h_exception = Handle(thread, thread->pending_exception());
    thread->clear_pending_exception();
  }
  return h_exception;
}

// Convenience method. Calls either the <init>() or <init>(String) method when
// creating a new exception
Handle Exceptions::new_exception(Thread* thread, symbolHandle h_name,
                                 const char* message, Handle h_cause,
                                 Handle h_loader,
                                 Handle h_protection_domain,
                                 ExceptionMsgToUtf8Mode to_utf8_safe) {
  JavaCallArguments args;
  symbolHandle signature;
  if (message == NULL) {
    signature = vmSymbolHandles::void_method_signature();
  } else {
    // We want to allocate storage, but we can't do that if there's
    // a pending exception, so we preserve any pending exception
    // around the allocation.
    // If we get an exception from the allocation, prefer that to
    // the exception we are trying to build, or the pending exception.
    // This is sort of like what PRESERVE_EXCEPTION_MARK does, except
    // for the preferencing and the early returns.
    Handle incoming_exception (thread, NULL);
    if (thread->has_pending_exception()) {
      incoming_exception = Handle(thread, thread->pending_exception());
      thread->clear_pending_exception();
    }
    Handle msg;
    if (to_utf8_safe == safe_to_utf8) {
      // Make a java UTF8 string.
      msg = java_lang_String::create_from_str(message, thread);
    } else {
      // Make a java string keeping the encoding scheme of the original string.
      msg = java_lang_String::create_from_platform_dependent_str(message, thread);
    }
    if (thread->has_pending_exception()) {
      Handle exception(thread, thread->pending_exception());
      thread->clear_pending_exception();
      return exception;
    }
    if (incoming_exception.not_null()) {
      return incoming_exception;
    }
    args.push_oop(msg);
    signature = vmSymbolHandles::string_void_signature();
  }
  return new_exception(thread, h_name, signature, &args, h_cause, h_loader, h_protection_domain);
}

// Another convenience method that creates handles for null class loaders and
// protection domains and null causes.
// If the last parameter 'to_utf8_mode' is safe_to_utf8,
// it means we can safely ignore the encoding scheme of the message string and
// convert it directly to a java UTF8 string. Otherwise, we need to take the
// encoding scheme of the string into account. One thing we should do at some
// point is to push this flag down to class java_lang_String since other
// classes may need similar functionalities.
Handle Exceptions::new_exception(Thread* thread,
                                 symbolOop name,
                                 const char* message,
                                 ExceptionMsgToUtf8Mode to_utf8_safe) {

  symbolHandle h_name(thread, name);
  Handle       h_loader(thread, NULL);
  Handle       h_prot(thread, NULL);
  Handle       h_cause(thread, NULL);
  return Exceptions::new_exception(thread, h_name, message, h_cause, h_loader,
                                   h_prot, to_utf8_safe);
}

// Implementation of ExceptionMark

ExceptionMark::ExceptionMark(Thread*& thread) {
  thread     = Thread::current();
  _thread    = thread;
  if (_thread->has_pending_exception()) {
    oop exception = _thread->pending_exception();
    _thread->clear_pending_exception(); // Needed to avoid infinite recursion
    exception->print();
    fatal("ExceptionMark constructor expects no pending exceptions");
  }
}


ExceptionMark::~ExceptionMark() {
  if (_thread->has_pending_exception()) {
    Handle exception(_thread, _thread->pending_exception());
    _thread->clear_pending_exception(); // Needed to avoid infinite recursion
    if (is_init_completed()) {
      exception->print();
      fatal("ExceptionMark destructor expects no pending exceptions");
    } else {
      vm_exit_during_initialization(exception);
    }
  }
}

// ----------------------------------------------------------------------------------------

#ifndef PRODUCT
// caller frees value_string if necessary
void Exceptions::debug_check_abort(const char *value_string) {
  if (AbortVMOnException != NULL && value_string != NULL &&
      strstr(value_string, AbortVMOnException)) {
    fatal1("Saw %s, aborting", value_string);
  }
}

void Exceptions::debug_check_abort(Handle exception) {
  if (AbortVMOnException != NULL) {
    ResourceMark rm;
    debug_check_abort(instanceKlass::cast(exception()->klass())->external_name());
  }
}
#endif