On 18 January 2012 19:43, James Greensky <gsk...@gmail.com> wrote: > On Tue, Jan 17, 2012 at 7:03 PM, 陳韋任 <che...@iis.sinica.edu.tw> wrote: >> I think those numbers (0, 1, and 2) means tb_add_jump 2nd parameter here, so >> it's intentionally to check jmp_first when n is 2. Since tb->jmp_first is >> never >> to be zero, then condition is always false (do nothing) when n is 2.
> Chenwj, you are correct, the check bypasses the whole function, I was > not paying enough attention to that check, it should never be null, in > which case the code doesn't get executed and the chaining remains > unchanged. The question that occurs to me is, is this working like this by design, or is it a bug that just happens to have no ill effects? The fact that the condition in tb_add_jump() is commented as "only needed for thread safety" suggests the latter to me... -- PMM
