Re: [PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
On 2021-03-23 09:35, Jonathan Wakely wrote: On 23/03/21 09:26 -0700, Thiago Macieira via Libstdc++ wrote: On Tuesday, 23 March 2021 08:39:43 PDT Thomas Rodgers wrote: I will be submitting a new patch for the atomic.wait/barrier/latch/semaphore functionality a bit later today that subsumes the changes to atomic_wait and latch, and includes the changes to barrier. Thanks, Thomas Is that meant to be part of GCC 11's release? Yes. If not, what do we do about preventing the future BC break and potential heisenbugs? 1) do nothing, accept they will happen silently This is our current policy for experimental features and it isn't going to change for GCC 11. 2) cause non-silent BC breaks 3) disable the code for now (unless explicitly opted-in) -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel DPG Cloud Engineering FWIW, I would like to commit to an ABI for this with GCC12 and everything currently residing in the __detail namespace would be moved into the .so as part of that (likely with a third, and ideally final, rewrite).
Re: [PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
On 23/03/21 09:26 -0700, Thiago Macieira via Libstdc++ wrote: On Tuesday, 23 March 2021 08:39:43 PDT Thomas Rodgers wrote: I will be submitting a new patch for the atomic.wait/barrier/latch/semaphore functionality a bit later today that subsumes the changes to atomic_wait and latch, and includes the changes to barrier. Thanks, Thomas Is that meant to be part of GCC 11's release? Yes. If not, what do we do about preventing the future BC break and potential heisenbugs? 1) do nothing, accept they will happen silently This is our current policy for experimental features and it isn't going to change for GCC 11. 2) cause non-silent BC breaks 3) disable the code for now (unless explicitly opted-in) -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel DPG Cloud Engineering
Re: [PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
On Tuesday, 23 March 2021 08:39:43 PDT Thomas Rodgers wrote: > I will be submitting a new patch for the > atomic.wait/barrier/latch/semaphore functionality a bit later today that > subsumes the changes to atomic_wait and latch, and includes the changes > to barrier. Thanks, Thomas Is that meant to be part of GCC 11's release? If not, what do we do about preventing the future BC break and potential heisenbugs? 1) do nothing, accept they will happen silently 2) cause non-silent BC breaks 3) disable the code for now (unless explicitly opted-in) -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel DPG Cloud Engineering
Re: [PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
On 2021-03-22 08:29, Thiago Macieira via Libstdc++ wrote: Discussion at: https://gcc.gnu.org/pipermail/libstdc++/2021-February/052043.html This patch set includes the uncontroversial parts that improve performance but don't otherwise change ABI. Please note we still need to decide on how to deal with the future ABI break. Thiago Macieira (3): Atomic __platform_wait: accept any 32-bit type, not just int std::latch: reduce internal implementation from ptrdiff_t to int barrier: optimise by not having the hasher in a loop libstdc++-v3/include/bits/atomic_wait.h | 7 --- libstdc++-v3/include/std/barrier| 10 +- libstdc++-v3/include/std/latch | 4 ++-- 3 files changed, 11 insertions(+), 10 deletions(-) ping? I will be submitting a new patch for the atomic.wait/barrier/latch/semaphore functionality a bit later today that subsumes the changes to atomic_wait and latch, and includes the changes to barrier.
[PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
> Discussion at: > https://gcc.gnu.org/pipermail/libstdc++/2021-February/052043.html > > This patch set includes the uncontroversial parts that improve > performance but don't otherwise change ABI. > > Please note we still need to decide on how to deal with the future ABI > break. > > Thiago Macieira (3): > Atomic __platform_wait: accept any 32-bit type, not just int > std::latch: reduce internal implementation from ptrdiff_t to int > barrier: optimise by not having the hasher in a loop > > libstdc++-v3/include/bits/atomic_wait.h | 7 --- > libstdc++-v3/include/std/barrier| 10 +- > libstdc++-v3/include/std/latch | 4 ++-- > 3 files changed, 11 insertions(+), 10 deletions(-) ping? -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel DPG Cloud Engineering
[PATCH 0/3] Uncontroversial improvements to C++20 wait-related implementation
Discussion at: https://gcc.gnu.org/pipermail/libstdc++/2021-February/052043.html This patch set includes the uncontroversial parts that improve performance but don't otherwise change ABI. Please note we still need to decide on how to deal with the future ABI break. Thiago Macieira (3): Atomic __platform_wait: accept any 32-bit type, not just int std::latch: reduce internal implementation from ptrdiff_t to int barrier: optimise by not having the hasher in a loop libstdc++-v3/include/bits/atomic_wait.h | 7 --- libstdc++-v3/include/std/barrier| 10 +- libstdc++-v3/include/std/latch | 4 ++-- 3 files changed, 11 insertions(+), 10 deletions(-) -- 2.30.1
