From 69e92f69a7909465820f26afc331375dbeaa68b2 Mon Sep 17 00:00:00 2001
From: ayeteadoe <ayeteadoe@gmail.com>
Date: Sat, 23 Aug 2025 20:58:43 -0700
Subject: [PATCH] LibCore: Implement SIGTERM-based kill() on Windows

There is no direct Win32 API equivalent, but calling WM_CLOSE on
the top-level windows allows for a graceful shutdown where resources
are able to clean themselves up properly
---
 Libraries/LibCore/System.h          |  2 +-
 Libraries/LibCore/SystemWindows.cpp | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/Libraries/LibCore/System.h b/Libraries/LibCore/System.h
index 2de5b798c35..cc84c5eedb5 100644
--- a/Libraries/LibCore/System.h
+++ b/Libraries/LibCore/System.h
@@ -128,8 +128,8 @@ ErrorOr<void> access(StringView pathname, int mode, int flags = 0);
 ErrorOr<ByteString> readlink(StringView pathname);
 ErrorOr<int> poll(Span<struct pollfd>, int timeout);
 
-#if !defined(AK_OS_WINDOWS)
 ErrorOr<void> kill(pid_t, int signal);
+#if !defined(AK_OS_WINDOWS)
 ErrorOr<void> chown(StringView pathname, uid_t uid, gid_t gid);
 ErrorOr<pid_t> posix_spawn(StringView path, posix_spawn_file_actions_t const* file_actions, posix_spawnattr_t const* attr, char* const arguments[], char* const envp[]);
 ErrorOr<pid_t> posix_spawnp(StringView path, posix_spawn_file_actions_t* const file_actions, posix_spawnattr_t* const attr, char* const arguments[], char* const envp[]);
diff --git a/Libraries/LibCore/SystemWindows.cpp b/Libraries/LibCore/SystemWindows.cpp
index 98a202bb9b6..289551730c5 100644
--- a/Libraries/LibCore/SystemWindows.cpp
+++ b/Libraries/LibCore/SystemWindows.cpp
@@ -384,4 +384,23 @@ ErrorOr<void> connect(int socket, struct sockaddr const* address, socklen_t addr
     return {};
 }
 
+ErrorOr<void> kill(pid_t pid, int signal)
+{
+    if (signal == SIGTERM) {
+        if (!EnumWindows([](HWND hwnd, LPARAM l_param) -> BOOL {
+                DWORD window_pid = 0;
+                GetWindowThreadProcessId(hwnd, &window_pid);
+                if (window_pid == static_cast<DWORD>(l_param)) {
+                    PostMessage(hwnd, WM_CLOSE, 0, 0);
+                }
+                return TRUE;
+            },
+                pid))
+            return Error::from_windows_error();
+    } else {
+        return Error::from_string_literal("Unsupported signal value");
+    }
+    return {};
+}
+
 }