1003 2015-03-05 11:23:31 +0000 A ConcurrentModificationException may occur while the IMR is serializing the server table to disk if a new POA is registered at the same time 2015-03-28 19:04:03 +0000 1 1 1 Unclassified JacORB Implementation Repository 3.5 PC Linux RESOLVED FIXED P5 normal --- 1 weiqigao jacorb-bugs jacorb oldest_to_newest 3275 0 weiqigao 2015-03-05 11:23:31 +0000 One of our customers has reported a CuncurrentModicationException during system start up: 2015-02-03 12:45:10.049 SEVERE Exception while saving server table java.util.ArrayList.writeObject(ArrayList.java:766) sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ... org.jacorb.imr.ImplementationRepositoryImpl.save_server_table(ImplementationRepositoryImpl.java:825) This is a manifestation of a race condition that exists between the WriteThread, which serializes the server_table to disk, and the thread calling register_poa() with a new POA. While adquate locking is provided for the fields in the ServerTable class through its table_lock, the call to _server.addPOA(_poa); while registering a new POA does not fall into the scope of that lock. This bug was reported against an older version of JacORB, JacORB 2.3.1. However, by reviewing the code in the latest head of the upstream, I see that it is also present there. I will attach a patch that introduce a new lock to prevent the ConcurrentModificationException. -- Weiqi Gao Principal Software Engineer Object Computing, Inc. 3276 1 457 weiqigao 2015-03-05 11:34:15 +0000 Created attachment 457 This patch introduces a ResourceLock to prevent a race condition described in the but report. 3277 2 jacorb 2015-03-05 11:53:02 +0000 Given ResourceLock is isolated to the IMR its fine to keep using it I think. Can you produce a junit regression test for this? (byteman?) Can you supply a pull request via github? 3286 3 jacorb 2015-03-28 19:04:03 +0000 Fixed by SHA 3753b586bac0b1e23fb578726cb4e927e535dc01 457 2015-03-05 11:34:15 +0000 2015-03-05 11:34:15 +0000 This patch introduces a ResourceLock to prevent a race condition described in the but report. 0001-Introduced-ResourceLock-to-prevent-a-race-condition-.patch text/plain 2288 weiqigao RnJvbSAyYWEwYTllNWY5MTk0MjhmYThhMTI5YTFjZDBlODUyZGEwNjY0ZDM4IE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBXZWlxaSBHYW8gPGdhb3dAb2Npd2ViLmNvbT4KRGF0ZTogVGh1 LCA1IE1hciAyMDE1IDEwOjMxOjI3IC0wNjAwClN1YmplY3Q6IFtQQVRDSF0gSW50cm9kdWNlZCBS ZXNvdXJjZUxvY2sgdG8gcHJldmVudCBhIHJhY2UgY29uZGl0aW9uIGJldHdlZW4KIHRoZSBJTVIg c2VyaWFsaXppbmcgdGhlIHNlcnZlciB0YWJsZSBhbmQgdGhlIHVzZXJyZWdpc3RlcmluZyBhIG5l dyBQT0EuIAogSmFjT1JCIEJ1Z3ppbGxhIEJ1ZyAxMDAzLgoKLS0tCiAuLi4vamF2YS9vcmcvamFj b3JiL2ltci9JbXBsZW1lbnRhdGlvblJlcG9zaXRvcnlJbXBsLmphdmEgICAgfCAxMiArKysrKysr KysrKysKIDEgZmlsZSBjaGFuZ2VkLCAxMiBpbnNlcnRpb25zKCspCgpkaWZmIC0tZ2l0IGEvY29y ZS9zcmMvbWFpbi9qYXZhL29yZy9qYWNvcmIvaW1yL0ltcGxlbWVudGF0aW9uUmVwb3NpdG9yeUlt cGwuamF2YSBiL2NvcmUvc3JjL21haW4vamF2YS9vcmcvamFjb3JiL2ltci9JbXBsZW1lbnRhdGlv blJlcG9zaXRvcnlJbXBsLmphdmEKaW5kZXggNjhiMmVkYS4uOWQ2MmQ2YyAxMDA2NDQKLS0tIGEv Y29yZS9zcmMvbWFpbi9qYXZhL29yZy9qYWNvcmIvaW1yL0ltcGxlbWVudGF0aW9uUmVwb3NpdG9y eUltcGwuamF2YQorKysgYi9jb3JlL3NyYy9tYWluL2phdmEvb3JnL2phY29yYi9pbXIvSW1wbGVt ZW50YXRpb25SZXBvc2l0b3J5SW1wbC5qYXZhCkBAIC0xMTcsNiArMTE3LDcgQEAgcHVibGljIGNs YXNzIEltcGxlbWVudGF0aW9uUmVwb3NpdG9yeUltcGwKIAogICAgIHByaXZhdGUgV3JpdGVUaHJl YWQgd3Q7CiAgICAgcHJpdmF0ZSBib29sZWFuIHVwZGF0ZVBlbmRpbmc7CisgICAgcHJpdmF0ZSBS ZXNvdXJjZUxvY2sgc2VydmVyX3RhYmxlX3Nlcl9sb2NrOwogICAgIHByaXZhdGUgU2h1dGRvd24g c2h1dGRvd25UaHJlYWQ7CiAKIApAQCAtMTI4LDYgKzEyOSw4IEBAIHB1YmxpYyBjbGFzcyBJbXBs ZW1lbnRhdGlvblJlcG9zaXRvcnlJbXBsCiAgICAgewogICAgICAgICB0aGlzLm9yYiA9IG9yYjsK IAorICAgICAgICB0aGlzLnNlcnZlcl90YWJsZV9zZXJfbG9jayA9IG5ldyBSZXNvdXJjZUxvY2so KTsKKwogICAgICAgICBzaHV0ZG93blRocmVhZCA9IG5ldyBTaHV0ZG93biAoKTsKICAgICB9CiAK QEAgLTQwMyw3ICs0MDYsMTEgQEAgcHVibGljIGNsYXNzIEltcGxlbWVudGF0aW9uUmVwb3NpdG9y eUltcGwKICAgICAgICAgICAgIC8vTmV3IFBPQUluZm8gaXMgdG8gYmUgY3JlYXRlZAogICAgICAg ICAgICAgX3BvYSA9IG5ldyBJbVJQT0FJbmZvKG5hbWUsIGhvc3QsIHBvcnQsIF9zZXJ2ZXIsCiAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgcG9hQWN0aXZhdGlvblRpbWVvdXQpOwor CisgICAgICAgICAgICBzZXJ2ZXJfdGFibGVfc2VyX2xvY2suZ2FpbkV4Y2x1c2l2ZUxvY2soKTsK ICAgICAgICAgICAgIF9zZXJ2ZXIuYWRkUE9BKF9wb2EpOworICAgICAgICAgICAgc2VydmVyX3Rh YmxlX3Nlcl9sb2NrLnJlbGVhc2VFeGNsdXNpdmVMb2NrKCk7CisKICAgICAgICAgICAgIHNlcnZl cl90YWJsZS5wdXRQT0EobmFtZSwgX3BvYSk7CiAKICAgICAgICAgICAgIHRoaXMubG9nZ2VyLmRl YnVnKCJJbVI6IG5ldyBwb2EgcmVnaXN0ZXJlZCIpOwpAQCAtMTYyNCwxMiArMTYzMSwxNyBAQCBw dWJsaWMgY2xhc3MgSW1wbGVtZW50YXRpb25SZXBvc2l0b3J5SW1wbAogICAgICAgICAgICAgewog ICAgICAgICAgICAgICAgIHRyeQogICAgICAgICAgICAgICAgIHsKKyAgICAgICAgICAgICAgICAg ICAgc2VydmVyX3RhYmxlX3Nlcl9sb2NrLmdhaW5FeGNsdXNpdmVMb2NrKCk7CiAgICAgICAgICAg ICAgICAgICAgIHNhdmVfc2VydmVyX3RhYmxlICh0YWJsZV9maWxlKTsKICAgICAgICAgICAgICAg ICB9CiAgICAgICAgICAgICAgICAgY2F0Y2ggKEZpbGVPcEZhaWxlZCBleCkKICAgICAgICAgICAg ICAgICB7CiAgICAgICAgICAgICAgICAgICAgIGxvZ2dlci5lcnJvcigiRXhjZXB0aW9uIHdoaWxl IHNhdmluZyBzZXJ2ZXIgdGFibGUiLCBleCk7CiAgICAgICAgICAgICAgICAgfQorICAgICAgICAg ICAgICAgIGZpbmFsbHkKKyAgICAgICAgICAgICAgICB7CisgICAgICAgICAgICAgICAgICAgIHNl cnZlcl90YWJsZV9zZXJfbG9jay5yZWxlYXNlRXhjbHVzaXZlTG9jaygpOworICAgICAgICAgICAg ICAgIH0KIAogICAgICAgICAgICAgICAgIGlmIChkb25lKQogICAgICAgICAgICAgICAgIHsKLS0g CjIuMS4wCgo=