[7/11] ntdll: Implement TpCallbackReleaseMutexOnCompletion.

[Sebastian Lackner]

Various internal details about the order and error handling of completion
actions are documented in "Concurrent Programming on Windows" by Joe Duffy.

---
 dlls/ntdll/ntdll.spec   |    1 +
 dlls/ntdll/threadpool.c |   19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index 5cfcfd7..4ccb3e7 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -975,6 +975,7 @@
 @ stdcall TpAllocWork(ptr ptr ptr ptr)
 @ stdcall TpCallbackLeaveCriticalSectionOnCompletion(ptr ptr)
 @ stdcall TpCallbackMayRunLong(ptr)
+@ stdcall TpCallbackReleaseMutexOnCompletion(ptr long)
 @ stdcall TpPostWork(ptr)
 @ stdcall TpReleaseCleanupGroup(ptr)
 @ stdcall TpReleaseCleanupGroupMembers(ptr long ptr)
diff --git a/dlls/ntdll/threadpool.c b/dlls/ntdll/threadpool.c
index 21e5b7d..28dd88b 100644
--- a/dlls/ntdll/threadpool.c
+++ b/dlls/ntdll/threadpool.c
@@ -206,6 +206,7 @@ struct threadpool_instance
     struct
     {
         CRITICAL_SECTION    *critical_section;
+        HANDLE              mutex;
     } cleanup;
 };
 
@@ -1635,6 +1636,7 @@ static void CALLBACK threadpool_worker_proc( void *param )
             instance.threadid                   = GetCurrentThreadId();
             instance.may_run_long               = object->may_run_long;
             instance.cleanup.critical_section   = NULL;
+            instance.cleanup.mutex              = NULL;
 
             switch (object->type)
             {
@@ -1675,6 +1677,10 @@ static void CALLBACK threadpool_worker_proc( void *param )
             {
                 RtlLeaveCriticalSection( instance.cleanup.critical_section );
             }
+            if (instance.cleanup.mutex)
+            {
+                NtReleaseMutant( instance.cleanup.mutex, NULL );
+            }
 
             RtlEnterCriticalSection( &pool->cs );
             pool->num_busy_workers--;
@@ -1827,6 +1833,19 @@ NTSTATUS WINAPI TpCallbackMayRunLong( TP_CALLBACK_INSTANCE *instance )
 }
 
 /***********************************************************************
+ *           TpCallbackReleaseMutexOnCompletion    (NTDLL.@)
+ */
+VOID WINAPI TpCallbackReleaseMutexOnCompletion( TP_CALLBACK_INSTANCE *instance, HANDLE mutex )
+{
+    struct threadpool_instance *this = impl_from_TP_CALLBACK_INSTANCE( instance );
+
+    TRACE( "%p %p\n", instance, mutex );
+
+    if (!this->cleanup.mutex)
+        this->cleanup.mutex = mutex;
+}
+
+/***********************************************************************
  *           TpPostWork    (NTDLL.@)
  */
 VOID WINAPI TpPostWork( TP_WORK *work )
-- 
2.4.4