Il 26/09/2012 16:34, Peter Maydell ha scritto: >> It makes sense to use it for other implementations than ucontext, too. >> > Coroutine *qemu_coroutine_create(CoroutineEntry *entry) >> > { >> > - Coroutine *co = qemu_coroutine_new(); >> > + Coroutine *co; >> > + >> > + co = QSLIST_FIRST(&pool); >> > + if (co) { >> > + QSLIST_REMOVE_HEAD(&pool, pool_next); >> > + pool_size--; >> > + } else { >> > + co = qemu_coroutine_new(); >> > + } >> > co->entry = entry; >> > return co; >> > } > Since this is obviously going to blow up badly if it's called > from multiple threads, is there some kind of assert we can add > so that we fail obviously if somebody makes that coding error? > [the difficulty is probably when your backend is the gthread > one, at least I assume creating a coroutine inside a coroutine > is allowed.]
Yes, it is; however, creating a coroutine outside the big QEMU lock is not allowed. Since one coroutine only runs at a time the code is safe, just like the other global variables that are used in qemu-coroutine-lock.c for example. Paolo