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 /**
26 * @test
27 * @bug 8026775
28 * @summary Uncommon trap blob did not bang all the stack shadow pages
29 *
30 * @run main/othervm UncommonTrapStackBang
31 *
32 * Note: This test does not reproduce the problem with absolute
33 * certainty. Empirically the bug reproduces on Windows some 80+% of
34 * the time. Setting everything up to fail in 100% of the cases turns
35 * out to be tricky at best.
36 *
37 *
38 * The goal of this test is to set up the following stack:
39 *
40 * doIt()
41 * eatStack()
42 * ...
43 * eatStack()
44 * run()
45 *
46 *
47 * When doIt() gets executed it will hit an uncommon trap and expand
48 * into a huge interpreter frame. The doIt method then calls the
49 * compiled version of StringBuilder.<init>() which does a single
50 * stack bang StackShadowPages down.
51 *
52 * The uncommon trap blob is supposed to prepare for the interpreter
53 * by pre-touching stack pages. The bug was that it didn't correctly
54 * pre-touch all the stack shadow pages, leaving a "hole" on the stack
55 * which raises an exception on Windows when the stack bang in
56 * StringBuilder is performed.
57 */
58 public class UncommonTrapStackBang extends Thread {
59 class Foo { }
60
61 public static void main(String[] args) throws Exception {
62 doWarmup();
63
64 // Fork off a new thread to increase odds of the stack being unmapped
65 UncommonTrapStackBang htsb = new UncommonTrapStackBang();
66 htsb.run();
67 htsb.join();
68 }
69
70 // Make sure:
71 //
72 // a) StringBuilder.<init>()V is compiled
73 // b) doIt() is compiled with an uncommon trap in the unlikely path
74 public static void doWarmup() {
75 for (int i = 0; i < 100_000; i++) {
76 new StringBuilder();
77
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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 /**
26 * @test
27 * @bug 8026775
28 * @summary Uncommon trap blob did not bang all the stack shadow pages
29 *
30 * @run main/othervm compiler.uncommontrap.UncommonTrapStackBang
31 */
32
33 /*
34 * Note: This test does not reproduce the problem with absolute
35 * certainty. Empirically the bug reproduces on Windows some 80+% of
36 * the time. Setting everything up to fail in 100% of the cases turns
37 * out to be tricky at best.
38 *
39 *
40 * The goal of this test is to set up the following stack:
41 *
42 * doIt()
43 * eatStack()
44 * ...
45 * eatStack()
46 * run()
47 *
48 *
49 * When doIt() gets executed it will hit an uncommon trap and expand
50 * into a huge interpreter frame. The doIt method then calls the
51 * compiled version of StringBuilder.<init>() which does a single
52 * stack bang StackShadowPages down.
53 *
54 * The uncommon trap blob is supposed to prepare for the interpreter
55 * by pre-touching stack pages. The bug was that it didn't correctly
56 * pre-touch all the stack shadow pages, leaving a "hole" on the stack
57 * which raises an exception on Windows when the stack bang in
58 * StringBuilder is performed.
59 */
60
61 package compiler.uncommontrap;
62
63 public class UncommonTrapStackBang extends Thread {
64 class Foo { }
65
66 public static void main(String[] args) throws Exception {
67 doWarmup();
68
69 // Fork off a new thread to increase odds of the stack being unmapped
70 UncommonTrapStackBang htsb = new UncommonTrapStackBang();
71 htsb.run();
72 htsb.join();
73 }
74
75 // Make sure:
76 //
77 // a) StringBuilder.<init>()V is compiled
78 // b) doIt() is compiled with an uncommon trap in the unlikely path
79 public static void doWarmup() {
80 for (int i = 0; i < 100_000; i++) {
81 new StringBuilder();
82
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