erlsrv: gracefully stop emulator on Windows shutdown

Windows will send the SERVICE_CONTROL_SHUTDOWN event to the service control
handler when shutting down the system. Instead of ignoring the event, erlsrv
will now invoke the stop action.  Likewise, the Erlang emulator (and it's port
drivers) must not quit upon reception of the CTRL_SHUTDOWN_EVENT event in the
console control handler.

1 files changed, 8 insertions, 5 deletions

diff --git a/erts/doc/src/erlsrv.xml b/erts/doc/src/erlsrv.xml
index c1ecbc7b77..b2f34ed247 100644
--- a/erts/doc/src/erlsrv.xml
+++ b/erts/doc/src/erlsrv.xml
@@ -357,11 +357,12 @@ The environment of an Erlang machine started
       the console subsystem and programs running as window
       applications. An application which runs in the console subsystem
       (normal for port programs) uses the win32 function
-      <c><![CDATA[SetConsoleCtrlHandler]]></c> to a control handler that returns
-      TRUE in answer to the <c><![CDATA[CTRL_LOGOFF_EVENT]]></c>. Other
-      applications just forward <c><![CDATA[WM_ENDSESSION]]></c> and
-      <c><![CDATA[WM_QUERYENDSESSION]]></c> to the default window procedure. Here
-      is a brief example in C of how to set the console control
+      <c><![CDATA[SetConsoleCtrlHandler]]></c> to register a control handler
+      that returns TRUE in answer to the <c><![CDATA[CTRL_LOGOFF_EVENT]]></c>
+      and <c><![CDATA[CTRL_SHUTDOWN_EVENT]]></c> events. Other applications
+      just forward <c><![CDATA[WM_ENDSESSION]]></c> and
+      <c><![CDATA[WM_QUERYENDSESSION]]></c> to the default window procedure.
+      Here is a brief example in C of how to set the console control
       handler:</p>
     <code type="none"><![CDATA[
 #include <windows.h>
@@ -372,6 +373,8 @@ The environment of an Erlang machine started
 BOOL WINAPI service_aware_handler(DWORD ctrl){
     if(ctrl == CTRL_LOGOFF_EVENT)
         return TRUE;
+    if(ctrl == CTRL_SHUTDOWN_EVENT)
+        return TRUE;
     return FALSE;
 }