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 "runtime/basicLock.hpp"
27 #include "runtime/synchronizer.hpp"
28
29 void BasicLock::print_on(outputStream* st) const {
30 st->print("monitor");
31 markWord moop = displaced_header();
32 if (moop.value() != 0)
33 moop.print_on(st);
34 }
35
36 void BasicLock::move_to(oop obj, BasicLock* dest) {
37 // Check to see if we need to inflate the lock. This is only needed
38 // if an object is locked using "this" lightweight monitor. In that
39 // case, the displaced_header() is unlocked, because the
40 // displaced_header() contains the header for the originally unlocked
41 // object. However the object could have already been inflated. But it
42 // does not matter, the inflation will just a no-op. For other cases,
43 // the displaced header will be either 0x0 or 0x3, which are location
44 // independent, therefore the BasicLock is free to move.
45 //
46 // During OSR we may need to relocate a BasicLock (which contains a
47 // displaced word) from a location in an interpreter frame to a
48 // new location in a compiled frame. "this" refers to the source
49 // basiclock in the interpreter frame. "dest" refers to the destination
50 // basiclock in the new compiled frame. We *always* inflate in move_to().
51 // The always-Inflate policy works properly, but in 1.5.0 it can sometimes
52 // cause performance problems in code that makes heavy use of a small # of
53 // uncontended locks. (We'd inflate during OSR, and then sync performance
|
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 "runtime/basicLock.hpp"
27 #include "runtime/synchronizer.hpp"
28
29 void BasicLock::print_on(outputStream* st) const {
30 st->print("monitor");
31 markWord mark_word = displaced_header();
32 if (mark_word.value() != 0)
33 mark_word.print_on(st);
34 }
35
36 void BasicLock::move_to(oop obj, BasicLock* dest) {
37 // Check to see if we need to inflate the lock. This is only needed
38 // if an object is locked using "this" lightweight monitor. In that
39 // case, the displaced_header() is unlocked, because the
40 // displaced_header() contains the header for the originally unlocked
41 // object. However the object could have already been inflated. But it
42 // does not matter, the inflation will just a no-op. For other cases,
43 // the displaced header will be either 0x0 or 0x3, which are location
44 // independent, therefore the BasicLock is free to move.
45 //
46 // During OSR we may need to relocate a BasicLock (which contains a
47 // displaced word) from a location in an interpreter frame to a
48 // new location in a compiled frame. "this" refers to the source
49 // basiclock in the interpreter frame. "dest" refers to the destination
50 // basiclock in the new compiled frame. We *always* inflate in move_to().
51 // The always-Inflate policy works properly, but in 1.5.0 it can sometimes
52 // cause performance problems in code that makes heavy use of a small # of
53 // uncontended locks. (We'd inflate during OSR, and then sync performance
|