view src/share/vm/compiler/compilerOracle.cpp @ 452:00b023ae2d78

6722113: CMS: Incorrect overflow handling during precleaning of Reference lists Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery. Reviewed-by: apetrusenko, jcoomes
author ysr
date Thu, 20 Nov 2008 12:27:41 -0800
parents a61af66fc99e
children 4e6abf09f540
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/_compilerOracle.cpp.incl"

class MethodMatcher : public CHeapObj {
 public:
  enum Mode {
    Exact,
    Prefix = 1,
    Suffix = 2,
    Substring = Prefix | Suffix,
    Any,
    Unknown = -1
  };

 protected:
  jobject        _class_name;
  Mode           _class_mode;
  jobject        _method_name;
  Mode           _method_mode;
  jobject        _signature;
  MethodMatcher* _next;

  static bool match(symbolHandle candidate, symbolHandle match, Mode match_mode);

  symbolHandle class_name() const { return (symbolOop)JNIHandles::resolve_non_null(_class_name); }
  symbolHandle method_name() const { return (symbolOop)JNIHandles::resolve_non_null(_method_name); }
  symbolHandle signature() const { return (symbolOop)JNIHandles::resolve(_signature); }

 public:
  MethodMatcher(symbolHandle class_name, Mode class_mode,
                symbolHandle method_name, Mode method_mode,
                symbolHandle signature, MethodMatcher* next);
  MethodMatcher(symbolHandle class_name, symbolHandle method_name, MethodMatcher* next);

  // utility method
  MethodMatcher* find(methodHandle method) {
    symbolHandle class_name  = Klass::cast(method->method_holder())->name();
    symbolHandle method_name = method->name();
    for (MethodMatcher* current = this; current != NULL; current = current->_next) {
      if (match(class_name, current->class_name(), current->_class_mode) &&
          match(method_name, current->method_name(), current->_method_mode) &&
          (current->signature().is_null() || current->signature()() == method->signature())) {
        return current;
      }
    }
    return NULL;
  }

  bool match(methodHandle method) {
    return find(method) != NULL;
  }

  MethodMatcher* next() const { return _next; }

  static void print_symbol(symbolHandle h, Mode mode) {
    ResourceMark rm;

    if (mode == Suffix || mode == Substring || mode == Any) {
      tty->print("*");
    }
    if (mode != Any) {
      h()->print_symbol_on(tty);
    }
    if (mode == Prefix || mode == Substring) {
      tty->print("*");
    }
  }

  void print_base() {
    print_symbol(class_name(), _class_mode);
    tty->print(".");
    print_symbol(method_name(), _method_mode);
    if (!signature().is_null()) {
      tty->print(" ");
      signature()->print_symbol_on(tty);
    }
  }

  virtual void print() {
    print_base();
    tty->cr();
  }
};

MethodMatcher::MethodMatcher(symbolHandle class_name, symbolHandle method_name, MethodMatcher* next) {
  _class_name  = JNIHandles::make_global(class_name);
  _method_name = JNIHandles::make_global(method_name);
  _next        = next;
  _class_mode  = MethodMatcher::Exact;
  _method_mode = MethodMatcher::Exact;
  _signature   = NULL;
}


MethodMatcher::MethodMatcher(symbolHandle class_name, Mode class_mode,
                             symbolHandle method_name, Mode method_mode,
                             symbolHandle signature, MethodMatcher* next):
    _class_mode(class_mode)
  , _method_mode(method_mode)
  , _next(next)
  , _class_name(JNIHandles::make_global(class_name()))
  , _method_name(JNIHandles::make_global(method_name()))
  , _signature(JNIHandles::make_global(signature())) {
}

bool MethodMatcher::match(symbolHandle candidate, symbolHandle match, Mode match_mode) {
  if (match_mode == Any) {
    return true;
  }

  if (match_mode == Exact) {
    return candidate() == match();
  }

  ResourceMark rm;
  const char * candidate_string = candidate->as_C_string();
  const char * match_string = match->as_C_string();

  switch (match_mode) {
  case Prefix:
    return strstr(candidate_string, match_string) == candidate_string;

  case Suffix: {
    size_t clen = strlen(candidate_string);
    size_t mlen = strlen(match_string);
    return clen >= mlen && strcmp(candidate_string + clen - mlen, match_string) == 0;
  }

  case Substring:
    return strstr(candidate_string, match_string) != NULL;

  default:
    return false;
  }
}


class MethodOptionMatcher: public MethodMatcher {
  const char * option;
 public:
  MethodOptionMatcher(symbolHandle class_name, Mode class_mode,
                             symbolHandle method_name, Mode method_mode,
                             symbolHandle signature, const char * opt, MethodMatcher* next):
    MethodMatcher(class_name, class_mode, method_name, method_mode, signature, next) {
    option = opt;
  }

  bool match(methodHandle method, const char* opt) {
    MethodOptionMatcher* current = this;
    while (current != NULL) {
      current = (MethodOptionMatcher*)current->find(method);
      if (current == NULL) {
        return false;
      }
      if (strcmp(current->option, opt) == 0) {
        return true;
      }
      current = current->next();
    }
    return false;
  }

  MethodOptionMatcher* next() {
    return (MethodOptionMatcher*)_next;
  }

  virtual void print() {
    print_base();
    tty->print(" %s", option);
    tty->cr();
  }
};



// this must parallel the command_names below
enum OracleCommand {
  UnknownCommand = -1,
  OracleFirstCommand = 0,
  BreakCommand = OracleFirstCommand,
  PrintCommand,
  ExcludeCommand,
  InlineCommand,
  DontInlineCommand,
  CompileOnlyCommand,
  LogCommand,
  OptionCommand,
  QuietCommand,
  HelpCommand,
  OracleCommandCount
};

// this must parallel the enum OracleCommand
static const char * command_names[] = {
  "break",
  "print",
  "exclude",
  "inline",
  "dontinline",
  "compileonly",
  "log",
  "option",
  "quiet",
  "help"
};

static const char * command_name(OracleCommand command) {
  if (command < OracleFirstCommand || command >= OracleCommandCount) {
    return "unknown command";
  }
  return command_names[command];
}

class MethodMatcher;
static MethodMatcher* lists[OracleCommandCount] = { 0, };


static bool check_predicate(OracleCommand command, methodHandle method) {
  return ((lists[command] != NULL) &&
          !method.is_null() &&
          lists[command]->match(method));
}


static MethodMatcher* add_predicate(OracleCommand command,
                                    symbolHandle class_name, MethodMatcher::Mode c_mode,
                                    symbolHandle method_name, MethodMatcher::Mode m_mode,
                                    symbolHandle signature) {
  assert(command != OptionCommand, "must use add_option_string");
  if (command == LogCommand && !LogCompilation && lists[LogCommand] == NULL)
    tty->print_cr("Warning:  +LogCompilation must be enabled in order for individual methods to be logged.");
  lists[command] = new MethodMatcher(class_name, c_mode, method_name, m_mode, signature, lists[command]);
  return lists[command];
}



static MethodMatcher* add_option_string(symbolHandle class_name, MethodMatcher::Mode c_mode,
                                        symbolHandle method_name, MethodMatcher::Mode m_mode,
                                        symbolHandle signature,
                                        const char* option) {
  lists[OptionCommand] = new MethodOptionMatcher(class_name, c_mode, method_name, m_mode,
                                                 signature, option, lists[OptionCommand]);
  return lists[OptionCommand];
}


bool CompilerOracle::has_option_string(methodHandle method, const char* option) {
  return lists[OptionCommand] != NULL &&
    ((MethodOptionMatcher*)lists[OptionCommand])->match(method, option);
}


bool CompilerOracle::should_exclude(methodHandle method, bool& quietly) {
  quietly = true;
  if (lists[ExcludeCommand] != NULL) {
    if (lists[ExcludeCommand]->match(method)) {
      quietly = _quiet;
      return true;
    }
  }

  if (lists[CompileOnlyCommand] != NULL) {
    return !lists[CompileOnlyCommand]->match(method);
  }
  return false;
}


bool CompilerOracle::should_inline(methodHandle method) {
  return (check_predicate(InlineCommand, method));
}


bool CompilerOracle::should_not_inline(methodHandle method) {
  return (check_predicate(DontInlineCommand, method));
}


bool CompilerOracle::should_print(methodHandle method) {
  return (check_predicate(PrintCommand, method));
}


bool CompilerOracle::should_log(methodHandle method) {
  if (!LogCompilation)            return false;
  if (lists[LogCommand] == NULL)  return true;  // by default, log all
  return (check_predicate(LogCommand, method));
}


bool CompilerOracle::should_break_at(methodHandle method) {
  return check_predicate(BreakCommand, method);
}


static OracleCommand parse_command_name(const char * line, int* bytes_read) {
  assert(ARRAY_SIZE(command_names) == OracleCommandCount,
         "command_names size mismatch");

  *bytes_read = 0;
  char command[32];
  int result = sscanf(line, "%32[a-z]%n", command, bytes_read);
  for (uint i = 0; i < ARRAY_SIZE(command_names); i++) {
    if (strcmp(command, command_names[i]) == 0) {
      return (OracleCommand)i;
    }
  }
  return UnknownCommand;
}


static void usage() {
  tty->print_cr("  CompileCommand and the CompilerOracle allows simple control over");
  tty->print_cr("  what's allowed to be compiled.  The standard supported directives");
  tty->print_cr("  are exclude and compileonly.  The exclude directive stops a method");
  tty->print_cr("  from being compiled and compileonly excludes all methods except for");
  tty->print_cr("  the ones mentioned by compileonly directives.  The basic form of");
  tty->print_cr("  all commands is a command name followed by the name of the method");
  tty->print_cr("  in one of two forms: the standard class file format as in");
  tty->print_cr("  class/name.methodName or the PrintCompilation format");
  tty->print_cr("  class.name::methodName.  The method name can optionally be followed");
  tty->print_cr("  by a space then the signature of the method in the class file");
  tty->print_cr("  format.  Otherwise the directive applies to all methods with the");
  tty->print_cr("  same name and class regardless of signature.  Leading and trailing");
  tty->print_cr("  *'s in the class and/or method name allows a small amount of");
  tty->print_cr("  wildcarding.  ");
  tty->cr();
  tty->print_cr("  Examples:");
  tty->cr();
  tty->print_cr("  exclude java/lang/StringBuffer.append");
  tty->print_cr("  compileonly java/lang/StringBuffer.toString ()Ljava/lang/String;");
  tty->print_cr("  exclude java/lang/String*.*");
  tty->print_cr("  exclude *.toString");
}


// The characters allowed in a class or method name.  All characters > 0x7f
// are allowed in order to handle obfuscated class files (e.g. Volano)
#define RANGEBASE "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789$_<>" \
        "\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f" \
        "\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f" \
        "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf" \
        "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf" \
        "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf" \
        "\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf" \
        "\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef" \
        "\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff"

#define RANGE0 "[*" RANGEBASE "]"
#define RANGEDOT "[*" RANGEBASE ".]"
#define RANGESLASH "[*" RANGEBASE "/]"


// Accept several syntaxes for these patterns
//  original syntax
//   cmd  java.lang.String foo
//  PrintCompilation syntax
//   cmd  java.lang.String::foo
//  VM syntax
//   cmd  java/lang/String[. ]foo
//

static const char* patterns[] = {
  "%*[ \t]%255" RANGEDOT    " "     "%255"  RANGE0 "%n",
  "%*[ \t]%255" RANGEDOT   "::"     "%255"  RANGE0 "%n",
  "%*[ \t]%255" RANGESLASH "%*[ .]" "%255"  RANGE0 "%n",
};

static MethodMatcher::Mode check_mode(char name[], const char*& error_msg) {
  if (strcmp(name, "*") == 0) return MethodMatcher::Any;

  int match = MethodMatcher::Exact;
  if (name[0] == '*') {
    match |= MethodMatcher::Suffix;
    strcpy(name, name + 1);
  }

  size_t len = strlen(name);
  if (len > 0 && name[len - 1] == '*') {
    match |= MethodMatcher::Prefix;
    name[len - 1] = '\0';
  }

  if (strstr(name, "*") != NULL) {
    error_msg = "  Embedded * not allowed";
    return MethodMatcher::Unknown;
  }
  return (MethodMatcher::Mode)match;
}

static bool scan_line(const char * line,
                      char class_name[],  MethodMatcher::Mode* c_mode,
                      char method_name[], MethodMatcher::Mode* m_mode,
                      int* bytes_read, const char*& error_msg) {
  *bytes_read = 0;
  error_msg = NULL;
  for (uint i = 0; i < ARRAY_SIZE(patterns); i++) {
    if (2 == sscanf(line, patterns[i], class_name, method_name, bytes_read)) {
      *c_mode = check_mode(class_name, error_msg);
      *m_mode = check_mode(method_name, error_msg);
      return *c_mode != MethodMatcher::Unknown && *m_mode != MethodMatcher::Unknown;
    }
  }
  return false;
}



void CompilerOracle::parse_from_line(char* line) {
  if (line[0] == '\0') return;
  if (line[0] == '#')  return;

  bool have_colon = (strstr(line, "::") != NULL);
  for (char* lp = line; *lp != '\0'; lp++) {
    // Allow '.' to separate the class name from the method name.
    // This is the preferred spelling of methods:
    //      exclude java/lang/String.indexOf(I)I
    // Allow ',' for spaces (eases command line quoting).
    //      exclude,java/lang/String.indexOf
    // For backward compatibility, allow space as separator also.
    //      exclude java/lang/String indexOf
    //      exclude,java/lang/String,indexOf
    // For easy cut-and-paste of method names, allow VM output format
    // as produced by methodOopDesc::print_short_name:
    //      exclude java.lang.String::indexOf
    // For simple implementation convenience here, convert them all to space.
    if (have_colon) {
      if (*lp == '.')  *lp = '/';   // dots build the package prefix
      if (*lp == ':')  *lp = ' ';
    }
    if (*lp == ',' || *lp == '.')  *lp = ' ';
  }

  char* original_line = line;
  int bytes_read;
  OracleCommand command = parse_command_name(line, &bytes_read);
  line += bytes_read;

  if (command == QuietCommand) {
    _quiet = true;
    return;
  }

  if (command == HelpCommand) {
    usage();
    return;
  }

  MethodMatcher::Mode c_match = MethodMatcher::Exact;
  MethodMatcher::Mode m_match = MethodMatcher::Exact;
  char class_name[256];
  char method_name[256];
  char sig[1024];
  char errorbuf[1024];
  const char* error_msg = NULL;
  MethodMatcher* match = NULL;

  if (scan_line(line, class_name, &c_match, method_name, &m_match, &bytes_read, error_msg)) {
    EXCEPTION_MARK;
    symbolHandle c_name = oopFactory::new_symbol_handle(class_name, CHECK);
    symbolHandle m_name = oopFactory::new_symbol_handle(method_name, CHECK);
    symbolHandle signature;

    line += bytes_read;
    // there might be a signature following the method.
    // signatures always begin with ( so match that by hand
    if (1 == sscanf(line, "%*[ \t](%254[);/" RANGEBASE "]%n", sig + 1, &bytes_read)) {
      sig[0] = '(';
      line += bytes_read;
      signature = oopFactory::new_symbol_handle(sig, CHECK);
    }

    if (command == OptionCommand) {
      // Look for trailing options to support
      // ciMethod::has_option("string") to control features in the
      // compiler.  Multiple options may follow the method name.
      char option[256];
      while (sscanf(line, "%*[ \t]%255[a-zA-Z0-9]%n", option, &bytes_read) == 1) {
        if (match != NULL && !_quiet) {
          // Print out the last match added
          tty->print("CompilerOracle: %s ", command_names[command]);
          match->print();
        }
        match = add_option_string(c_name, c_match, m_name, m_match, signature, strdup(option));
        line += bytes_read;
      }
    } else {
      bytes_read = 0;
      sscanf(line, "%*[ \t]%n", &bytes_read);
      if (line[bytes_read] != '\0') {
        jio_snprintf(errorbuf, sizeof(errorbuf), "  Unrecognized text after command: %s", line);
        error_msg = errorbuf;
      } else {
        match = add_predicate(command, c_name, c_match, m_name, m_match, signature);
      }
    }
  }

  if (match != NULL) {
    if (!_quiet) {
      tty->print("CompilerOracle: %s ", command_names[command]);
      match->print();
    }
  } else {
    tty->print_cr("CompilerOracle: unrecognized line");
    tty->print_cr("  \"%s\"", original_line);
    if (error_msg != NULL) {
      tty->print_cr(error_msg);
    }
  }
}

static const char* cc_file() {
  if (CompileCommandFile == NULL)
    return ".hotspot_compiler";
  return CompileCommandFile;
}
bool CompilerOracle::_quiet = false;

void CompilerOracle::parse_from_file() {
  FILE* stream = fopen(cc_file(), "rt");
  if (stream == NULL) return;

  char token[1024];
  int  pos = 0;
  int  c = getc(stream);
  while(c != EOF) {
    if (c == '\n') {
      token[pos++] = '\0';
      parse_from_line(token);
      pos = 0;
    } else {
      token[pos++] = c;
    }
    c = getc(stream);
  }
  token[pos++] = '\0';
  parse_from_line(token);

  fclose(stream);
}

void CompilerOracle::parse_from_string(const char* str, void (*parse_line)(char*)) {
  char token[1024];
  int  pos = 0;
  const char* sp = str;
  int  c = *sp++;
  while (c != '\0') {
    if (c == '\n') {
      token[pos++] = '\0';
      parse_line(token);
      pos = 0;
    } else {
      token[pos++] = c;
    }
    c = *sp++;
  }
  token[pos++] = '\0';
  parse_line(token);
}

void CompilerOracle::append_comment_to_file(const char* message) {
  fileStream stream(fopen(cc_file(), "at"));
  stream.print("# ");
  for (int index = 0; message[index] != '\0'; index++) {
    stream.put(message[index]);
    if (message[index] == '\n') stream.print("# ");
  }
  stream.cr();
}

void CompilerOracle::append_exclude_to_file(methodHandle method) {
  fileStream stream(fopen(cc_file(), "at"));
  stream.print("exclude ");
  Klass::cast(method->method_holder())->name()->print_symbol_on(&stream);
  stream.print(".");
  method->name()->print_symbol_on(&stream);
  method->signature()->print_symbol_on(&stream);
  stream.cr();
  stream.cr();
}


void compilerOracle_init() {
  CompilerOracle::parse_from_string(CompileCommand, CompilerOracle::parse_from_line);
  CompilerOracle::parse_from_string(CompileOnly, CompilerOracle::parse_compile_only);
  CompilerOracle::parse_from_file();
}


void CompilerOracle::parse_compile_only(char * line) {
  int i;
  char name[1024];
  const char* className = NULL;
  const char* methodName = NULL;

  bool have_colon = (strstr(line, "::") != NULL);
  char method_sep = have_colon ? ':' : '.';

  if (Verbose) {
    tty->print_cr(line);
  }

  ResourceMark rm;
  while (*line != '\0') {
    MethodMatcher::Mode c_match = MethodMatcher::Exact;
    MethodMatcher::Mode m_match = MethodMatcher::Exact;

    for (i = 0;
         i < 1024 && *line != '\0' && *line != method_sep && *line != ',' && !isspace(*line);
         line++, i++) {
      name[i] = *line;
      if (name[i] == '.')  name[i] = '/';  // package prefix uses '/'
    }

    if (i > 0) {
      char* newName = NEW_RESOURCE_ARRAY( char, i + 1);
      if (newName == NULL)
        return;
      strncpy(newName, name, i);
      newName[i] = '\0';

      if (className == NULL) {
        className = newName;
        c_match = MethodMatcher::Prefix;
      } else {
        methodName = newName;
      }
    }

    if (*line == method_sep) {
      if (className == NULL) {
        className = "";
        c_match = MethodMatcher::Any;
      } else {
        // foo/bar.blah is an exact match on foo/bar, bar.blah is a suffix match on bar
        if (strchr(className, '/') != NULL) {
          c_match = MethodMatcher::Exact;
        } else {
          c_match = MethodMatcher::Suffix;
        }
      }
    } else {
      // got foo or foo/bar
      if (className == NULL) {
        ShouldNotReachHere();
      } else {
        // got foo or foo/bar
        if (strchr(className, '/') != NULL) {
          c_match = MethodMatcher::Prefix;
        } else if (className[0] == '\0') {
          c_match = MethodMatcher::Any;
        } else {
          c_match = MethodMatcher::Substring;
        }
      }
    }

    // each directive is terminated by , or NUL or . followed by NUL
    if (*line == ',' || *line == '\0' || (line[0] == '.' && line[1] == '\0')) {
      if (methodName == NULL) {
        methodName = "";
        if (*line != method_sep) {
          m_match = MethodMatcher::Any;
        }
      }

      EXCEPTION_MARK;
      symbolHandle c_name = oopFactory::new_symbol_handle(className, CHECK);
      symbolHandle m_name = oopFactory::new_symbol_handle(methodName, CHECK);
      symbolHandle signature;

      add_predicate(CompileOnlyCommand, c_name, c_match, m_name, m_match, signature);
      if (PrintVMOptions) {
        tty->print("CompileOnly: compileonly ");
        lists[CompileOnlyCommand]->print();
      }

      className = NULL;
      methodName = NULL;
    }

    line = *line == '\0' ? line : line + 1;
  }
}