On Mon, Dec 31, 2007 at 02:28:44PM +0000, Ciaran McCreesh wrote: > On Sun, 30 Dec 2007 20:11:16 -0800 > "Alec Warner" <[EMAIL PROTECTED]> wrote: > > On 12/30/07, Ciaran McCreesh <[EMAIL PROTECTED]> wrote: > > > Is it legal for ebuilds to call has_version and friends in > > > parallel? Is it legal for ebuilds to call has_version and friends > > > after the ebuild process has terminated? Discuss. > > > > If the pm implements read/write locking on the underlying datastore > > (which it should probably have regardless of this request) then I > > don't see a problem in parallel has_version calls. > > Actually, it's the communication channel that's the issue... If, for > example, has_version is implemented in terms of a request on a pipe > rather than execing a new package manager, we get into messy bash > locking territory... > > > I don't get your second example..do you mean the ebuild is running > > has_version in the background and then terminating? > > Yeah. Again, consider the pipe example. If the package manager closes > off the pipe when it thinks the ebuild's done, calling has_version will > get the backgrounded process SIGPIPEd.
Depends on the implementation; for pkgcore, if that comm pipe is dead, the ebuild env *should* be dead, or dieing. Background'ing processes from that env isn't valid imo, either. If you're refering to an ebuild that parallelizes itself while executing, iow, parallelization w/in the ebuild env/phase execution, I'd look more at being able to batch commands instead of trying to run them in parallel. Reasoning follows- 1) if doing an exec approach to service the request, this means reparsing of involved files for each request- inefficient, potentially horribly so on crappy hardware/setups. 2) screws up the pipe approach, should folks take it for control/env introspection gains. Summarizing, executing has_version (and friends) concurrently has it's own issues performance wise, and implementation wise; growing batch functionality into portageq however avoids those issues, and would be faster- thus the route I'd advocate. ~harring
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