Hey Ryan, I think what you've identified is a bug rather than an RFE: what you describe is how raise() was intended to work. It sounds like there are cases in which that's falling down and that should be addressed. If you haven't already, please file a bug on bugs.opensolaris.org.
Thanks. Adam On Oct 8, 2008, at 3:54 PM, Ryan wrote: >> Would it be possible to add an equivalent to >> lwp_kill() that specifically targets a thread? > > Hmm... after poking around in the code a bit, it's not clear that > this would be easy to implement (some details below). However, it > looks much easier to change raise() to accept a second, optional > argument. The updated wiki entry might read like this: > > ========================== > void raise(int sig, int directed) > void raise(int sig) > > The /raise/ action sends the specified signal to the currently > running process, or, if /directed/ is non-zero, to the currently > running thread. > ========================== > > Given that there's no real way for probes on different threads to > coordinate, a directed raise() probably covers most potential uses > for lwp_kill() anyway. > > Thoughts? > Ryan > > Details on why implementing lwp_kill() might be hard: > > With raise() dtrace just marks the thread and lets regular signal > handling pick it up "soon"; to target a specific other thread would > require finding that thread and marking it, which in turn would > require acquiring the process lock (which dtrace doesn't normally > touch) and performing several other actions that raise() defers to > the regular signal handling code. Whether this deferral is due to > some constraint or whether it was just easier to code up and > maintain that way, I wouldn't know. > > Alternatively, dtrace could just store the request for later, but > then it can't tell the user if the target lwp exists or not. Plus, a > thread could accumulate any number of pending lwp kills before they > get processed. > -- > This message posted from opensolaris.org > _______________________________________________ > dtrace-discuss mailing list > dtrace-discuss@opensolaris.org -- Adam Leventhal, Fishworks http://blogs.sun.com/ahl _______________________________________________ dtrace-discuss mailing list dtrace-discuss@opensolaris.org
