RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 20:47:45 +00:00
Code Issues Activity Actions

Kernel: Only lock process file descriptor table once in sys$poll()

Browse source 
Grab the OpenFileDescriptions mutex once and hold on to it while
populating the SelectBlocker::FDVector.
This commit is contained in:
Andreas Kling 2022-01-29 02:09:18 +01:00
parent b56646e293
commit d748a3c173
1 changed files with 17 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

31
Kernel/Syscalls/poll.cpp
View file

@ -47,20 +47,23 @@ ErrorOr<FlatPtr> Process::sys$poll(Userspace<const Syscall::SC_poll_params*> use
Thread::SelectBlocker::FDVector fds_info; Thread::SelectBlocker::FDVector fds_info;
TRY(fds_info.try_ensure_capacity(params.nfds)); TRY(fds_info.try_ensure_capacity(params.nfds));
for (size_t i = 0; i < params.nfds; i++) { TRY(m_fds.with_shared([&](auto& fds) -> ErrorOr<void> {
auto& pfd = fds_copy[i]; for (size_t i = 0; i < params.nfds; i++) {
auto description = TRY(m_fds.with_shared([&](auto& fds) { return fds.open_file_description(pfd.fd); })); auto& pfd = fds_copy[i];
BlockFlags block_flags = BlockFlags::Exception; // always want POLLERR, POLLHUP, POLLNVAL auto description = TRY(fds.open_file_description(pfd.fd));
if (pfd.events & POLLIN) BlockFlags block_flags = BlockFlags::Exception; // always want POLLERR, POLLHUP, POLLNVAL
block_flags |= BlockFlags::Read; if (pfd.events & POLLIN)
if (pfd.events & POLLOUT) block_flags |= BlockFlags::Read;
block_flags |= BlockFlags::Write; if (pfd.events & POLLOUT)
if (pfd.events & POLLPRI) block_flags |= BlockFlags::Write;
block_flags |= BlockFlags::ReadPriority; if (pfd.events & POLLPRI)
if (pfd.events & POLLWRBAND) block_flags |= BlockFlags::ReadPriority;
block_flags |= BlockFlags::WritePriority; if (pfd.events & POLLWRBAND)
fds_info.unchecked_append({ move(description), block_flags }); block_flags |= BlockFlags::WritePriority;
} fds_info.unchecked_append({ move(description), block_flags });
}
return {};
}));
auto* current_thread = Thread::current(); auto* current_thread = Thread::current();