From 3ae0edc963f85a0e03fb2a51a9848fc8583cfdc3 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Sat, 1 Mar 2025 18:26:22 +0000
Subject: [PATCH] ext/sockets: adding SO_BUSY_POLL socket option for Linux.

To possibly reduce the latency when polling packets by activating it
from the network interface for N microseconds.
The kernel by doing so, increase the CPU(s) activity bound to
the socket significantly.
Note that not only the kernel needs to have support enabled for it
(which the average distribution usually does) but the network
interface itself needs to support it too. If not, it is just a no-op.
---
 NEWS                          | 1 +
 UPGRADING                     | 1 +
 ext/sockets/sockets.stub.php  | 7 +++++++
 ext/sockets/sockets_arginfo.h | 5 ++++-
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 675ac03745659..40a886fc338f8 100644
--- a/NEWS
+++ b/NEWS
@@ -145,6 +145,7 @@ PHP                                                                        NEWS
   . socket_getsockname/socket_create/socket_bind handled AF_PACKET family socket.
     (David Carlier)
   . Added IP_BINDANY for a socket to bind to any address. (David Carlier)
+  . Added SO_BUSY_POOL to reduce packets poll latency. (David Carlier)
 
 - Sodium:
   . Fix overall theorical overflows on zend_string buffer allocations.
diff --git a/UPGRADING b/UPGRADING
index 6b4f6c335843a..fcb09a339ec0f 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -301,6 +301,7 @@ PHP 8.5 UPGRADE NOTES
   . TCP_BBR_ALGORITHM (FreeBSD only).
   . AF_PACKET (Linux only).
   . IP_BINDANY (FreeBSD/NetBSD/OpenBSD only).
+  . SO_BUSY_POLL (Linux only).
 
 ========================================
 11. Changes to INI File Handling
diff --git a/ext/sockets/sockets.stub.php b/ext/sockets/sockets.stub.php
index 4d6200fcd1ffe..d647f46b80dca 100644
--- a/ext/sockets/sockets.stub.php
+++ b/ext/sockets/sockets.stub.php
@@ -454,6 +454,13 @@
  */
 const SO_EXCLBIND = UNKNOWN;
 #endif
+#ifdef SO_BUSY_POLL
+/**
+ * @var int
+ * @cvalue SO_BUSY_POLL
+ */
+const SO_BUSY_POLL = UNKNOWN;
+#endif
 #ifdef SKF_AD_OFF
 /**
  * @var int
diff --git a/ext/sockets/sockets_arginfo.h b/ext/sockets/sockets_arginfo.h
index 4a90b4d789feb..45714fb285174 100644
--- a/ext/sockets/sockets_arginfo.h
+++ b/ext/sockets/sockets_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: aac197335037777d31d83d4a4040bbfcd0c55813 */
+ * Stub hash: 42d486d2666d23569e70860e2b1ef203161792b3 */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_socket_select, 0, 4, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(1, read, IS_ARRAY, 1)
@@ -476,6 +476,9 @@ static void register_sockets_symbols(int module_number)
 #if defined(SO_EXCLBIND)
 	REGISTER_LONG_CONSTANT("SO_EXCLBIND", SO_EXCLBIND, CONST_PERSISTENT);
 #endif
+#if defined(SO_BUSY_POLL)
+	REGISTER_LONG_CONSTANT("SO_BUSY_POLL", SO_BUSY_POLL, CONST_PERSISTENT);
+#endif
 #if defined(SKF_AD_OFF)
 	REGISTER_LONG_CONSTANT("SKF_AD_OFF", SKF_AD_OFF, CONST_PERSISTENT);
 #endif