On Sun, 3 Jul 2022 22:19:50 GMT, David Holmes <dhol...@openjdk.org> wrote:
>> Ryan Ernst has updated the pull request incrementally with one additional >> commit since the last revision: >> >> better clarify multiple threads behavior > > src/java.base/share/classes/java/lang/Runtime.java line 89: > >> 87: * of the first invocation will be used; the status codes from other >> invocations >> 88: * will be ignored. If this method is invoked from a shutdown hook >> the system >> 89: * will deadlock. > > Expressing this accurately is tricky - what is "first" here? I suggest the > following: > >> Invocations of this method are serialized such that only one invocation will >> actually proceed with the shutdown sequence and terminate the VM with the >> given status code. All other invocations will block indefinitely. If this >> method is invoked from a shutdown hook the system will deadlock. +1 - except for the "deadlock" part (see other comment). I think the old paragraph is at least confusing, and perhaps even just wrong. Let's say we've run `shutdown` so run all the hooks but not halted. Then someone calls `exit(0)`. That seems to suggest the call will block indefinitely, which is neither desirable nor what was actually implemented. ------------- PR: https://git.openjdk.org/jdk/pull/9351
