Bug 1573679: Add IsCurrentThread(Explicit|Implicit)MTA utility functions to mscom; r=Jamie

This patch provides us with utility functions that give us more specific
information about the current thread's MTA if so desired.

Differential Revision: https://phabricator.services.mozilla.com/D41852

--HG--
extra : moz-landing-system : lando

Author: dblohm7

ipc/mscom/Utils.cpp

@@ -50,6 +50,30 @@ bool IsCurrentThreadMTA() {
   return aptType == APTTYPE_MTA;
 }
 
+bool IsCurrentThreadExplicitMTA() {
+  APTTYPE aptType;
+  APTTYPEQUALIFIER aptTypeQualifier;
+  HRESULT hr = CoGetApartmentType(&aptType, &aptTypeQualifier);
+  if (FAILED(hr)) {
+    return false;
+  }
+
+  return aptType == APTTYPE_MTA &&
+         aptTypeQualifier != APTTYPEQUALIFIER_IMPLICIT_MTA;
+}
+
+bool IsCurrentThreadImplicitMTA() {
+  APTTYPE aptType;
+  APTTYPEQUALIFIER aptTypeQualifier;
+  HRESULT hr = CoGetApartmentType(&aptType, &aptTypeQualifier);
+  if (FAILED(hr)) {
+    return false;
+  }
+
+  return aptType == APTTYPE_MTA &&
+         aptTypeQualifier == APTTYPEQUALIFIER_IMPLICIT_MTA;
+}
+
 bool IsProxy(IUnknown* aUnknown) {
   if (!aUnknown) {
     return false;

ipc/mscom/Utils.h

@@ -22,6 +22,8 @@ namespace mscom {
 
 bool IsCOMInitializedOnCurrentThread();
 bool IsCurrentThreadMTA();
+bool IsCurrentThreadExplicitMTA();
+bool IsCurrentThreadImplicitMTA();
 bool IsProxy(IUnknown* aUnknown);
 bool IsValidGUID(REFGUID aCheckGuid);
 uintptr_t GetContainingModuleHandle();