XPC services should release their os transaction when given a SIGTERM…

… signal

https://bugs.webkit.org/show_bug.cgi?id=227747
<rdar://72430454>

Patch by Alex Christensen <achristensen@webkit.org> on 2021-07-07
Reviewed by Geoff Garen.

Apparently when you shut down your computer, processes are given a SIGTERM signal and expected to release their os_transaction_t
to indicate that they can now be terminated "cleanly".

* Shared/EntryPointUtilities/Cocoa/XPCService/XPCServiceEntryPoint.h:
(WebKit::XPCServiceInitializer):

Canonical link: https://commits.webkit.org/239460@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@279647 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebKit/ChangeLog

@@ -1,3 +1,17 @@
+2021-07-07  Alex Christensen  <achristensen@webkit.org>
+
+        XPC services should release their os transaction when given a SIGTERM signal
+        https://bugs.webkit.org/show_bug.cgi?id=227747
+        <rdar://72430454>
+
+        Reviewed by Geoff Garen.
+
+        Apparently when you shut down your computer, processes are given a SIGTERM signal and expected to release their os_transaction_t
+        to indicate that they can now be terminated "cleanly".
+
+        * Shared/EntryPointUtilities/Cocoa/XPCService/XPCServiceEntryPoint.h:
+        (WebKit::XPCServiceInitializer):
+
 2021-07-07  Alex Christensen  <achristensen@webkit.org>
 
         Use more Span

Source/WebKit/Shared/EntryPointUtilities/Cocoa/XPCService/XPCServiceEntryPoint.h

@@ -101,6 +101,10 @@ void XPCServiceInitializer(OSObjectPtr<xpc_connection_t> connection, xpc_object_
     // the UIProcess takes process assertions on behalf of its child processes.
 #if PLATFORM(MAC)
     osTransaction() = adoptOSObject(os_transaction_create("WebKit XPC Service"));
+    signal(SIGTERM, [] (int signal) {
+        RELEASE_ASSERT(signal == SIGTERM);
+        osTransaction() = nullptr;
+    });
 #endif
 
     InitializeWebKit2();