6953058: G1: A bigapp crashes with SIGSEGV in compiled code
Summary: In C2's G1 post write barrier, the loads of the buffer and index fields from the DirtyCardQueue structure may be moved across a safepoint. Use the current value of "control" in the C2 IR to limit how far these loads can move.
Reviewed-by: never, iveresov, kvn
/*
* Copyright 1997-2009 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/_symbolOop.cpp.incl"
// ------------------------------------------------------------------
// symbolOopDesc::equals
//
// Compares the symbol with a string of the given length.
bool symbolOopDesc::equals(const char* str, int len) const {
int l = utf8_length();
if (l != len) return false;
while (l-- > 0) {
if (str[l] != (char) byte_at(l))
return false;
}
assert(l == -1, "we should be at the beginning");
return true;
}
// ------------------------------------------------------------------
// symbolOopDesc::starts_with
//
// Tests if the symbol starts with the specified prefix of the given
// length.
bool symbolOopDesc::starts_with(const char* prefix, int len) const {
if (len > utf8_length()) return false;
while (len-- > 0) {
if (prefix[len] != (char) byte_at(len))
return false;
}
assert(len == -1, "we should be at the beginning");
return true;
}
// ------------------------------------------------------------------
// symbolOopDesc::index_of
//
// Finds if the given string is a substring of this symbol's utf8 bytes.
// Return -1 on failure. Otherwise return the first index where str occurs.
int symbolOopDesc::index_of_at(int i, const char* str, int len) const {
assert(i >= 0 && i <= utf8_length(), "oob");
if (len <= 0) return 0;
char first_char = str[0];
address bytes = (address) ((symbolOopDesc*)this)->base();
address limit = bytes + utf8_length() - len; // inclusive limit
address scan = bytes + i;
if (scan > limit)
return -1;
for (;;) {
scan = (address) memchr(scan, first_char, (limit + 1 - scan));
if (scan == NULL)
return -1; // not found
assert(scan >= bytes+i && scan <= limit, "scan oob");
if (memcmp(scan, str, len) == 0)
return (int)(scan - bytes);
}
}
char* symbolOopDesc::as_C_string(char* buf, int size) const {
if (size > 0) {
int len = MIN2(size - 1, utf8_length());
for (int i = 0; i < len; i++) {
buf[i] = byte_at(i);
}
buf[len] = '\0';
}
return buf;
}
char* symbolOopDesc::as_C_string() const {
int len = utf8_length();
char* str = NEW_RESOURCE_ARRAY(char, len + 1);
return as_C_string(str, len + 1);
}
char* symbolOopDesc::as_C_string_flexible_buffer(Thread* t,
char* buf, int size) const {
char* str;
int len = utf8_length();
int buf_len = len + 1;
if (size < buf_len) {
str = NEW_RESOURCE_ARRAY(char, buf_len);
} else {
str = buf;
}
return as_C_string(str, buf_len);
}
void symbolOopDesc::print_symbol_on(outputStream* st) {
st = st ? st : tty;
int length = UTF8::unicode_length((const char*)bytes(), utf8_length());
const char *ptr = (const char *)bytes();
jchar value;
for (int index = 0; index < length; index++) {
ptr = UTF8::next(ptr, &value);
if (value >= 32 && value < 127 || value == '\'' || value == '\\') {
st->put(value);
} else {
st->print("\\u%04x", value);
}
}
}
jchar* symbolOopDesc::as_unicode(int& length) const {
symbolOopDesc* this_ptr = (symbolOopDesc*)this;
length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length());
jchar* result = NEW_RESOURCE_ARRAY(jchar, length);
if (length > 0) {
UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length);
}
return result;
}
const char* symbolOopDesc::as_klass_external_name(char* buf, int size) const {
if (size > 0) {
char* str = as_C_string(buf, size);
int length = (int)strlen(str);
// Turn all '/'s into '.'s (also for array klasses)
for (int index = 0; index < length; index++) {
if (str[index] == '/') {
str[index] = '.';
}
}
return str;
} else {
return buf;
}
}
const char* symbolOopDesc::as_klass_external_name() const {
char* str = as_C_string();
int length = (int)strlen(str);
// Turn all '/'s into '.'s (also for array klasses)
for (int index = 0; index < length; index++) {
if (str[index] == '/') {
str[index] = '.';
}
}
return str;
}