From 265764ff2fec038855193296588a887fc322d76a Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Thu, 2 Dec 2021 01:26:08 +0200
Subject: [PATCH] Kernel: Add support for the POLLWRBAND poll event

---
 Kernel/API/POSIX/poll.h    |  1 +
 Kernel/Syscalls/select.cpp |  6 ++++++
 Kernel/Thread.h            | 13 +++++++------
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Kernel/API/POSIX/poll.h b/Kernel/API/POSIX/poll.h
index b5bd1d7d8c..c481ab61c7 100644
--- a/Kernel/API/POSIX/poll.h
+++ b/Kernel/API/POSIX/poll.h
@@ -20,6 +20,7 @@ extern "C" {
 #define POLLERR (1u << 3)
 #define POLLHUP (1u << 4)
 #define POLLNVAL (1u << 5)
+#define POLLWRBAND (1u << 12)
 #define POLLRDHUP (1u << 13)
 
 struct pollfd {
diff --git a/Kernel/Syscalls/select.cpp b/Kernel/Syscalls/select.cpp
index 2800fa440b..af03a89b03 100644
--- a/Kernel/Syscalls/select.cpp
+++ b/Kernel/Syscalls/select.cpp
@@ -159,6 +159,8 @@ ErrorOr<FlatPtr> Process::sys$poll(Userspace<const Syscall::SC_poll_params*> use
             block_flags |= BlockFlags::Write;
         if (pfd.events & POLLPRI)
             block_flags |= BlockFlags::ReadPriority;
+        if (pfd.events & POLLWRBAND)
+            block_flags |= BlockFlags::WritePriority;
         TRY(fds_info.try_append({ move(description), block_flags }));
     }
 
@@ -208,6 +210,10 @@ ErrorOr<FlatPtr> Process::sys$poll(Userspace<const Syscall::SC_poll_params*> use
                 VERIFY(pfd.events & POLLOUT);
                 pfd.revents |= POLLOUT;
             }
+            if (has_flag(fds_entry.unblocked_flags, BlockFlags::WritePriority)) {
+                VERIFY(pfd.events & POLLWRBAND);
+                pfd.revents |= POLLWRBAND;
+            }
         }
         if (pfd.revents)
             fds_with_revents++;
diff --git a/Kernel/Thread.h b/Kernel/Thread.h
index 4e50c27c3d..50a5a57032 100644
--- a/Kernel/Thread.h
+++ b/Kernel/Thread.h
@@ -588,15 +588,16 @@ public:
             Read = 1 << 0,
             Write = 1 << 1,
             ReadPriority = 1 << 2,
+            WritePriority = 1 << 3,
 
-            Accept = 1 << 3,
-            Connect = 1 << 4,
+            Accept = 1 << 4,
+            Connect = 1 << 5,
             SocketFlags = Accept | Connect,
 
-            WriteNotOpen = 1 << 5,
-            WriteError = 1 << 6,
-            WriteHangUp = 1 << 7,
-            ReadHangUp = 1 << 8,
+            WriteNotOpen = 1 << 6,
+            WriteError = 1 << 7,
+            WriteHangUp = 1 << 8,
+            ReadHangUp = 1 << 9,
             Exception = WriteNotOpen | WriteError | WriteHangUp | ReadHangUp,
         };