114893 2013-04-19 17:46:36 -0700 fast/workers/dedicated-worker-lifecycle.html needs a re-write 2013-04-21 13:28:55 -0700 1 1 1 Unclassified WebKit Tools / Tests 528+ (Nightly build) Unspecified Unspecified RESOLVED FIXED P2 Normal --- 1 mark.lam mark.lam fpizlo ggaren jberlin mhahnenberg msaboff oliver oldest_to_newest 878687 0 mark.lam 2013-04-19 17:46:36 -0700 Currently, fast/workers/dedicated-worker-lifecycle.html is relying on the GC collecting an orphaned Worker object in a timely manner. Since it is not realistic to assume when GC will collect a single object, this is an unreasonable expectation. As a result, the test can time out waiting for the GC to act. Instead, what is reasonable is to expect that the GC will collect Worker objects on a timely basis such that it keeps memory usage at an acceptable level. In this case, that means the test should create a lot more than 1 Worker (we'll go with 100) and expect the GC to leave no more than a small amount around (we'll go with 20 here) in the duration of the test. This shows that the GC is making adequate progress towards reclaiming dead Workers on a timely basis. 878829 1 198956 mark.lam 2013-04-20 23:22:44 -0700 Created attachment 198956 the patch. For the max remaining orphaned workers after GC’ing, I opted to go with 10 instead of 20 workers (which was previously proposed in the bug description). The choice is a bit arbitrary but is based on the following "back of a napkin" estimate: 1. 10 workers means 10 threads. 2. Assume each thread will take up ~128k of stack memory. 3. Assume memory used in JS heap for Worker objects, and WorkerGlobalScopes are insignificant (adequately covered by the the 128k per worker estimate above). Hence, total memory used by 10 workers = ~1.25M. On a typical desktop system with 4G of RAM these days of which 2G is available, this represents ~.06% of available memory. On an embedded device with just 256M of RAM of which 128M is available, the 1.25M represents .9% of available memory. This seems to be still tolerable. If we tolerate 20 workers instead, then the estimate wastage on the embedded device case will go up to 1.8% which I feel less comfortable with. So, I’m opting to go with only tolerating a max of 10 unreclaimed orphaned workers out of 100 in the amount of time the test gets to run. 878890 2 198956 ggaren 2013-04-21 12:26:26 -0700 Comment on attachment 198956 the patch. r=me 878901 3 mark.lam 2013-04-21 13:28:55 -0700 Thanks for the review. Landed in r148846: <http://trac.webkit.org/changeset/148846>. 198956 2013-04-20 23:22:44 -0700 2013-04-21 12:26:26 -0700 the patch. bug-114893.patch text/plain 7495 mark.lam SW5kZXg6IExheW91dFRlc3RzL0NoYW5nZUxvZwo9PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBMYXlvdXRUZXN0cy9D aGFuZ2VMb2cJKHJldmlzaW9uIDE0ODgwMikKKysrIExheW91dFRlc3RzL0NoYW5nZUxvZwkod29y a2luZyBjb3B5KQpAQCAtMSwzICsxLDIyIEBACisyMDEzLTA0LTIwICBNYXJrIExhbSAgPG1hcmsu bGFtQGFwcGxlLmNvbT4KKworICAgICAgICBSZXdyaXRlIGZhc3Qvd29ya2Vycy9kZWRpY2F0ZWQt d29ya2VyLWxpZmVjeWNsZS5odG1sIHRvIHZlcmlmeSB0aGF0CisgICAgICAgIHRoZSBHQyBpcyBh YmxlIHRvIHJlY2xhaW0gb3JwaGFuZWQgV29ya2VycyBvbiBhIHRpbWVseSBiYXNpcy4KKyAgICAg ICAgaHR0cHM6Ly9idWdzLndlYmtpdC5vcmcvc2hvd19idWcuY2dpP2lkPTExNDg5My4KKworICAg ICAgICBSZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICAqIGZhc3Qvd29ya2Vy cy9yZXNvdXJjZXMvZGVkaWNhdGVkLXdvcmtlci1saWZlY3ljbGUuanM6CisgICAgICAgIChvcnBo YW5BbGxXb3JrZXJzKToKKyAgICAgICAgKHJ1blRlc3RzLndvcmtlci5vbm1lc3NhZ2UpOgorICAg ICAgICAocnVuVGVzdHMpOgorICAgICAgICAob3JwaGFuZWRXb3JrZXJFeGl0ZWQud29ya2VyLm9u bWVzc2FnZSk6CisgICAgICAgIChvcnBoYW5lZFdvcmtlckV4aXRlZCk6CisgICAgICAgICogZmFz dC93b3JrZXJzL3Jlc291cmNlcy93b3JrZXItdXRpbC5qczoKKyAgICAgICAgKHdhaXRVbnRpbFRo cmVhZENvdW50TWF0Y2hlc0NvbmRpdGlvbik6CisgICAgICAgICh3YWl0VW50aWxUaHJlYWRDb3Vu dE1hdGNoZXMpOgorICAgICAgICAod2FpdFVudGlsVGhyZWFkQ291bnREb2VzTm90RXhjZWVkKToK KwogMjAxMy0wNC0yMCAgRGlyayBTY2h1bHplICA8a3JpdEB3ZWJraXQub3JnPgogCiAgICAgICAg IFtQYXJ0IDVdIFBhcnNlIGNvbG9yIHZhbHVlIGZvciBjdXN0b20oKSBmdW5jdGlvbiBwYXJhbWV0 ZXJzCkluZGV4OiBMYXlvdXRUZXN0cy9mYXN0L3dvcmtlcnMvcmVzb3VyY2VzL2RlZGljYXRlZC13 b3JrZXItbGlmZWN5Y2xlLmpzCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIExheW91dFRlc3RzL2Zhc3Qvd29ya2Vy cy9yZXNvdXJjZXMvZGVkaWNhdGVkLXdvcmtlci1saWZlY3ljbGUuanMJKHJldmlzaW9uIDE0ODgw MikKKysrIExheW91dFRlc3RzL2Zhc3Qvd29ya2Vycy9yZXNvdXJjZXMvZGVkaWNhdGVkLXdvcmtl ci1saWZlY3ljbGUuanMJKHdvcmtpbmcgY29weSkKQEAgLTEsNSArMSwyMiBAQAogZGVzY3JpcHRp b24oIlRoaXMgdGVzdCBjaGVja3Mgd2hldGhlciBvcnBoYW5lZCB3b3JrZXJzIGV4aXQgdW5kZXIg dmFyaW91cyBjb25kaXRpb25zIik7CiAKKy8vIFdlIGNyZWF0ZSBhIGxhcmdlIG51bWJlciBvZiBX b3JrZXJzIGFuZCBleHBlY3QgdGhlIEdDIHRvIGtlZXAgdXAgYW5kCisvLyByZWNsYWltIGEgcmVh c29uYWJsZSBudW1iZXIgb2YgdGhlbSBpbiBhIHRpbWVseSBtYW5uZXIgc28gdGhhdCB0aGUgdXNl cgorLy8gZXhwZXJpZW5jZSBpcyBub3QgaW1wYWN0ZWQuCisvLworLy8gRm9yIHRoaXMgdGVzdCwg ImEgdGltZWx5IG1hbm5lciIgbWVhbnMgdGhhdCB3ZSBoYXZlIGFuIGV4cGVjdGF0aW9uIHRoYXQK Ky8vIGJlZm9yZSB0aGUgdGVzdCB0aW1lcyBvdXQsIHdlIGV4cGVjdCB0aGF0IG5vIG1vcmUgdGhh bgorLy8gbWF4UmVtYWluaW5nT3JwaGFuZWRXb3JrZXJzIG9mIHRoZSBudW1iZXJPZldvcmtlcnMg d2UgY3JlYXRlZCB3aWxsIHN1cnZpdmUKKy8vIHRoZSBHQy4KKy8vCisvLyBXZSB1c2UgbWF4UmVt YWluaW5nT3JwaGFuZWRXb3JrZXJzIGFzIGFuIGFwcHJveGltYXRpb24gb2YgdGhlIHRvbGVyYWJs ZQorLy8gYW1vdW50IG9mIGdhcmJhZ2UgaW4gdGhlIHN5c3RlbSB0aGF0IHdvbid0IGltcGFjdCB0 aGUgdXNlciBleHBlcmllbmNlLgorCit2YXIgbnVtYmVyT2ZXb3JrZXJzID0gMTAwOwordmFyIG1h eFJlbWFpbmluZ09ycGhhbmVkV29ya2VycyA9IDEwOwordmFyIHdvcmtlcnMgPSBbIF07Cit2YXIg bnVtYmVyT2ZDcmVhdGVkV29ya2VycyA9IDA7CisKIGlmICh3aW5kb3cudGVzdFJ1bm5lcikgewog ICAgIHRlc3RSdW5uZXIuZHVtcEFzVGV4dCgpOwogICAgIHRlc3RSdW5uZXIud2FpdFVudGlsRG9u ZSgpOwpAQCAtOSw1MyArMjYsNTUgQEAgaWYgKHdpbmRvdy50ZXN0UnVubmVyKSB7CiAgICAgcnVu VGVzdHMoKTsKIH0KIAorZnVuY3Rpb24gb3JwaGFuQWxsV29ya2VycyhjYWxsYmFjaykKK3sKKyAg ICB2YXIgaTsKKyAgICBmb3IgKGkgPSAwOyBpIDwgbnVtYmVyT2ZXb3JrZXJzOyBpKyspIHsKKyAg ICAgICAgd29ya2Vyc1tpXS5vbm1lc3NhZ2UgPSAwOworICAgICAgICB3b3JrZXJzW2ldID0gMDsK KyAgICB9CisgICAgd29ya2VycyA9IFsgXTsKKyAgICB3YWl0VW50aWxUaHJlYWRDb3VudERvZXNO b3RFeGNlZWQoY2FsbGJhY2ssIG1heFJlbWFpbmluZ09ycGhhbmVkV29ya2Vycyk7Cit9CisKIC8v IENvbnRhaW5zIHRlc3RzIGZvciBkZWRpY2F0ZWQtd29ya2VyLXNwZWNpZmljIGxpZmVjeWNsZSBm dW5jdGlvbmFsaXR5LgogZnVuY3Rpb24gcnVuVGVzdHMoKQogewotICAgIC8vIFN0YXJ0IGEgd29y a2VyLCBkcm9wL0dDIG91ciByZWZlcmVuY2UgdG8gaXQsIG1ha2Ugc3VyZSBpdCBleGl0cy4KLSAg ICB2YXIgd29ya2VyID0gY3JlYXRlV29ya2VyKCk7Ci0gICAgd29ya2VyLnBvc3RNZXNzYWdlKCJw aW5nIik7Ci0gICAgd29ya2VyLm9ubWVzc2FnZSA9IGZ1bmN0aW9uKGV2ZW50KSB7Ci0gICAgICAg IGlmICh3aW5kb3cudGVzdFJ1bm5lcikgewotICAgICAgICAgICAgaWYgKGludGVybmFscy53b3Jr ZXJUaHJlYWRDb3VudCA9PSAxKQorICAgIHZhciBpOworICAgIGZvciAoaSA9IDA7IGkgPCBudW1i ZXJPZldvcmtlcnM7IGkrKykgeworICAgICAgICB2YXIgd29ya2VyID0gY3JlYXRlV29ya2VyKCk7 CisgICAgICAgIHdvcmtlcnNbaV0gPSB3b3JrZXI7CisKKyAgICAgICAgd29ya2VyLnBvc3RNZXNz YWdlKCJwaW5nIik7CisgICAgICAgIHdvcmtlci5vbm1lc3NhZ2UgPSBmdW5jdGlvbihldmVudCkg eworICAgICAgICAgICAgaWYgKGludGVybmFscy53b3JrZXJUaHJlYWRDb3VudCA9PSBudW1iZXJP ZldvcmtlcnMpIHsKICAgICAgICAgICAgICAgICB0ZXN0UGFzc2VkKCJPcnBoYW5lZCB3b3JrZXIg dGhyZWFkIGNyZWF0ZWQuIik7Ci0gICAgICAgICAgICBlbHNlCi0gICAgICAgICAgICAgICAgdGVz dEZhaWxlZCgiQWZ0ZXIgdGhyZWFkIGNyZWF0aW9uOiBpbnRlcm5hbHMud29ya2VyVGhyZWFkQ291 bnQgPSAiICsgaW50ZXJuYWxzLndvcmtlclRocmVhZENvdW50KTsKKyAgICAgICAgICAgICAgICBv cnBoYW5BbGxXb3JrZXJzKG9ycGhhbmVkV29ya2VyRXhpdGVkKTsKKyAgICAgICAgICAgIH0KICAg ICAgICAgfQotCi0gICAgICAgIC8vIE9ycGhhbiBvdXIgd29ya2VyIChubyBtb3JlIHJlZmVyZW5j ZXMgdG8gaXQpIGFuZCB3YWl0IGZvciBpdCB0byBleGl0LgotICAgICAgICB3b3JrZXIub25tZXNz YWdlID0gMDsKLSAgICAgICAgd29ya2VyID0gMDsKLSAgICAgICAgLy8gQWxsb2NhdGluZyBhIERh dGUgb2JqZWN0IHNlZW1zIHRvIHNjcmFtYmxlIHRoZSBzdGFjayBhbmQgZm9yY2UgdGhlIHdvcmtl ciBvYmplY3QgdG8gZ2V0IEdDJ2QuCi0gICAgICAgIG5ldyBEYXRlKCk7Ci0gICAgICAgIHdhaXRV bnRpbFdvcmtlclRocmVhZHNFeGl0KG9ycGhhbmVkV29ya2VyRXhpdGVkKTsKICAgICB9CiB9CiAK IGZ1bmN0aW9uIG9ycGhhbmVkV29ya2VyRXhpdGVkKCkKIHsKICAgICB0ZXN0UGFzc2VkKCJPcnBo YW5lZCB3b3JrZXIgdGhyZWFkIGV4aXRlZC4iKTsKLSAgICAvLyBTdGFydCBhIHdvcmtlciwgZHJv cC9HQyBvdXIgcmVmZXJlbmNlIHRvIGl0LCBtYWtlIHN1cmUgaXQgZXhpdHMuCi0gICAgdmFyIHdv cmtlciA9IGNyZWF0ZVdvcmtlcigpOwotICAgIHdvcmtlci5wb3N0TWVzc2FnZSgicGluZyIpOwot ICAgIHdvcmtlci5vbm1lc3NhZ2UgPSBmdW5jdGlvbihldmVudCkgewotICAgICAgICBpZiAod2lu ZG93LnRlc3RSdW5uZXIpIHsKLSAgICAgICAgICAgIGlmIChpbnRlcm5hbHMud29ya2VyVGhyZWFk Q291bnQgPT0gMSkKKworICAgIHZhciBpOworICAgIGZvciAoaSA9IDA7IGkgPCBudW1iZXJPZldv cmtlcnM7IGkrKykgeworICAgICAgICB2YXIgd29ya2VyID0gY3JlYXRlV29ya2VyKCk7CisgICAg ICAgIHdvcmtlcnNbaV0gPSB3b3JrZXI7CisKKyAgICAgICAgd29ya2VyLnBvc3RNZXNzYWdlKCJw aW5nIik7CisgICAgICAgIHdvcmtlci5vbm1lc3NhZ2UgPSBmdW5jdGlvbihldmVudCkgeworICAg ICAgICAgICAgLy8gU2VuZCBhIG1lc3NhZ2UgdGhhdCBzdGFydHMgdXAgYW4gYXN5bmMgb3BlcmF0 aW9uLCB0byBtYWtlIHN1cmUgdGhlIHRocmVhZCBleGl0cyB3aGVuIGl0IGNvbXBsZXRlcy4KKyAg ICAgICAgICAgIC8vIEZJWE1FOiBEaXNhYmxlZCBmb3Igbm93IC0gcmUtZW5hYmxlIHdoZW4gYnVn IDI4NzAyIGlzIGZpeGVkLgorICAgICAgICAgICAgLy8gd29ya2VyLnBvc3RNZXNzYWdlKCJldmFs IHNldFRpbWVvdXQoJycsIDEwKSIpOworCisgICAgICAgICAgICBpZiAoaW50ZXJuYWxzLndvcmtl clRocmVhZENvdW50ID49IG51bWJlck9mV29ya2VycykgewogICAgICAgICAgICAgICAgIHRlc3RQ YXNzZWQoIk9ycGhhbmVkIHRpbWVvdXQgd29ya2VyIHRocmVhZCBjcmVhdGVkLiIpOwotICAgICAg ICAgICAgZWxzZQotICAgICAgICAgICAgICAgIHRlc3RGYWlsZWQoIkFmdGVyIHRocmVhZCBjcmVh dGlvbjogaW50ZXJuYWxzLndvcmtlclRocmVhZENvdW50ID0gIiArIGludGVybmFscy53b3JrZXJU aHJlYWRDb3VudCk7CisgICAgICAgICAgICAgICAgb3JwaGFuQWxsV29ya2VycyhvcnBoYW5lZFRp bWVvdXRXb3JrZXJFeGl0ZWQpOworICAgICAgICAgICAgfQogICAgICAgICB9Ci0gICAgICAgIC8v IFNlbmQgYSBtZXNzYWdlIHRoYXQgc3RhcnRzIHVwIGFuIGFzeW5jIG9wZXJhdGlvbiwgdG8gbWFr ZSBzdXJlIHRoZSB0aHJlYWQgZXhpdHMgd2hlbiBpdCBjb21wbGV0ZXMuCi0gICAgICAgIC8vIEZJ WE1FOiBEaXNhYmxlZCBmb3Igbm93IC0gcmUtZW5hYmxlIHdoZW4gYnVnIDI4NzAyIGlzIGZpeGVk LgotICAgICAgICAvL3dvcmtlci5wb3N0TWVzc2FnZSgiZXZhbCBzZXRUaW1lb3V0KCcnLCAxMCki KTsKLQotICAgICAgICAvLyBPcnBoYW4gb3VyIHdvcmtlciAobm8gbW9yZSByZWZlcmVuY2VzIHRv IGl0KSBhbmQgd2FpdCBmb3IgaXQgdG8gZXhpdC4KLSAgICAgICAgd29ya2VyLm9ubWVzc2FnZSA9 IDA7Ci0gICAgICAgIHdvcmtlciA9IDA7Ci0gICAgICAgIC8vIEZvciBzb21lIHJlYXNvbiwgdGhl IHdvcmtlciBvYmplY3QgZG9lcyBub3QgZ2V0IEdDJ2QgdW5sZXNzIHdlIGFsbG9jYXRlIGEgbmV3 IG9iamVjdCBoZXJlLgotICAgICAgICAvLyBUaGUgY29uamVjdHVyZSBpcyB0aGF0IHRoZXJlJ3Mg YSB2YWx1ZSBvbiB0aGUgc3RhY2sgdGhhdCBhcHBlYXJzIHRvIHBvaW50IHRvIHRoZSB3b3JrZXIg d2hpY2ggdGhpcyBjbG9iYmVycy4KLSAgICAgICAgbmV3IERhdGUoKTsKLSAgICAgICAgd2FpdFVu dGlsV29ya2VyVGhyZWFkc0V4aXQob3JwaGFuZWRUaW1lb3V0V29ya2VyRXhpdGVkKTsKICAgICB9 CiB9CiAKSW5kZXg6IExheW91dFRlc3RzL2Zhc3Qvd29ya2Vycy9yZXNvdXJjZXMvd29ya2VyLXV0 aWwuanMKPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PQotLS0gTGF5b3V0VGVzdHMvZmFzdC93b3JrZXJzL3Jlc291cmNlcy93 b3JrZXItdXRpbC5qcwkocmV2aXNpb24gMTQ4ODAyKQorKysgTGF5b3V0VGVzdHMvZmFzdC93b3Jr ZXJzL3Jlc291cmNlcy93b3JrZXItdXRpbC5qcwkod29ya2luZyBjb3B5KQpAQCAtMjgsNyArMjgs NyBAQCBmdW5jdGlvbiB3YWl0VW50aWxXb3JrZXJUaHJlYWRzRXhpdChjYWxsCiAgICAgd2FpdFVu dGlsVGhyZWFkQ291bnRNYXRjaGVzKGNhbGxiYWNrLCAwKTsKIH0KIAotZnVuY3Rpb24gd2FpdFVu dGlsVGhyZWFkQ291bnRNYXRjaGVzKGNhbGxiYWNrLCBjb3VudCkKK2Z1bmN0aW9uIHdhaXRVbnRp bFRocmVhZENvdW50TWF0Y2hlc0NvbmRpdGlvbihjYWxsYmFjaywgY29uZGl0aW9uKQogewogICAg IC8vIFdoZW4gcnVubmluZyBpbiBhIGJyb3dzZXIsIGp1c3Qgd2FpdCBmb3Igb25lIHNlY29uZCB0 aGVuIGNhbGwgdGhlIGNhbGxiYWNrLgogICAgIGlmICghd2luZG93LnRlc3RSdW5uZXIpIHsKQEAg LTM2LDE3ICszNiwyNyBAQCBmdW5jdGlvbiB3YWl0VW50aWxUaHJlYWRDb3VudE1hdGNoZXMoY2Fs CiAgICAgICAgIHJldHVybjsKICAgICB9CiAKLSAgICBpZiAoaW50ZXJuYWxzLndvcmtlclRocmVh ZENvdW50ID09IGNvdW50KSB7CisgICAgaWYgKGNvbmRpdGlvbigpKSB7CiAgICAgICAgIC8vIFdv cmtlciB0aHJlYWRzIGhhdmUgZXhpdGVkLgogICAgICAgICBjYWxsYmFjaygpOwogICAgIH0gZWxz ZSB7CiAgICAgICAgIC8vIFBvbGwgdW50aWwgd29ya2VyIHRocmVhZHMgaGF2ZSBiZWVuIEdDJ2Qv ZXhpdGVkLgogICAgICAgICAvLyBGb3JjZSBhIEdDIHdpdGggYSBidW5jaCBvZiBhbGxvY2F0aW9u cyB0byB0cnkgdG8gc2NyYW1ibGUgdGhlIHN0YWNrIGFuZCBmb3JjZSB3b3JrZXIgb2JqZWN0cyB0 byBiZSBjb2xsZWN0ZWQuCiAgICAgICAgIGdjKHRydWUpOwotICAgICAgICBzZXRUaW1lb3V0KGZ1 bmN0aW9uKCkgeyB3YWl0VW50aWxUaHJlYWRDb3VudE1hdGNoZXMoY2FsbGJhY2ssIGNvdW50KTsg fSwgMTApOworICAgICAgICBzZXRUaW1lb3V0KGZ1bmN0aW9uKCkgeyB3YWl0VW50aWxUaHJlYWRD b3VudE1hdGNoZXNDb25kaXRpb24oY2FsbGJhY2ssIGNvbmRpdGlvbik7IH0sIDEwKTsKICAgICB9 CiB9CiAKK2Z1bmN0aW9uIHdhaXRVbnRpbFRocmVhZENvdW50TWF0Y2hlcyhjYWxsYmFjaywgY291 bnQpCit7CisgICAgd2FpdFVudGlsVGhyZWFkQ291bnRNYXRjaGVzQ29uZGl0aW9uKGNhbGxiYWNr LCBmdW5jdGlvbigpIHsgcmV0dXJuIGludGVybmFscy53b3JrZXJUaHJlYWRDb3VudCA9PSBjb3Vu dDsgfSk7Cit9CisKK2Z1bmN0aW9uIHdhaXRVbnRpbFRocmVhZENvdW50RG9lc05vdEV4Y2VlZChj YWxsYmFjaywgY291bnQpCit7CisgICAgd2FpdFVudGlsVGhyZWFkQ291bnRNYXRjaGVzQ29uZGl0 aW9uKGNhbGxiYWNrLCBmdW5jdGlvbigpIHsgcmV0dXJuIGludGVybmFscy53b3JrZXJUaHJlYWRD b3VudCA8PSBjb3VudDsgfSk7Cit9CisKIGZ1bmN0aW9uIGVuc3VyZVRocmVhZENvdW50TWF0Y2hl cyhjYWxsYmFjaywgY291bnQpCiB7CiAgICAgLy8gSnVzdCB3YWl0IHVudGlsIHRoZSB0aHJlYWQg Y291bnQgbWF0Y2hlcywgdGhlbiB3YWl0IGFub3RoZXIgMTAwbXMgdG8gc2VlIGlmIGl0IGNoYW5n ZXMsIHRoZW4gZmlyZSB0aGUgY2FsbGJhY2suCg==