Currently we call StoreRegistration() in ServiceWorkerRegistrationInfo::TransitionInstallingToWaiting(). This is in anticipation of actually implementating bug 1426401. Until we implement that bug, though, calling StoreRegistration() is just a waste of resources. The entries it produces are not correct and won't result anything being usefully read.

Comment on attachment 8966213 [details] [diff] [review] Avoid empty entries in serviceworker.txt. r=asuth Andrew, I realized recently that we are stacking up a lot of service worker changes at once. Each one tries to trigger its own write to the serviceworker.txt file. This is probably exacerbating write failures on windows. This patch is a first step to trying to calm the situation down. Currently we try to write out some entries that can't be useful read in yet. In particular: 1. We are writing out when installing transitions to waiting. We haven't implemented bug 1426401, though, so we don't really handle this case yet and the entry in the file doesn't have a script URL. 2. When we resurrect a service worker we write out the file again to reflect that the registration is back. We don't check to see if we are resurrecting a registration with an active worker, though. In theory it could just have an installing/waiting worker. This patch tries to close these loop holes and add some debug-only assertions. I also added some read/write validation code as a safe guard to avoid actually writing this stuff to disk and to immediately ignore it if its read.

Stacking up a lot of writes is bad because of the overlapping runnables on STS. See bug 1452373.

Comment on attachment 8966213 [details] [diff] [review] Avoid empty entries in serviceworker.txt. r=asuth Review of attachment 8966213 [details] [diff] [review]: ----------------------------------------------------------------- Great cleanup, and great catch on the STS snafu in bug 1452373... I feel like anytime DOM code uses it without a TaskQueue we're usually mis-using...

Pushed by bkelly@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/c913924064a5 Avoid empty entries in serviceworker.txt. r=asuth