[reactos] 02/02: [SHSVCS] Don't call UnregisterWait from within the wait callback.

[Thomas Faber]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=5a5ba1ad107d1af37241d…

commit 5a5ba1ad107d1af37241d444c567abc6f7cb6eb3
Author:     Thomas Faber <thomas.faber(a)reactos.org>
AuthorDate: Wed Apr 15 12:09:49 2020 +0200
Commit:     Thomas Faber <thomas.faber(a)reactos.org>
CommitDate: Wed Apr 22 12:37:26 2020 +0200

    [SHSVCS] Don't call UnregisterWait from within the wait callback.
    
    Doing this causes deadlocks, the process runs out of worker threads and
    the system runs out of memory by allocating too many I/O completion ports
    when using ntdll.dll from Windows.
---
 base/services/shsvcs/thmserver.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/base/services/shsvcs/thmserver.c b/base/services/shsvcs/thmserver.c
index c4169446f44..a374079f9f8 100644
--- a/base/services/shsvcs/thmserver.c
+++ b/base/services/shsvcs/thmserver.c
@@ -76,7 +76,6 @@ CALLBACK
 ThemeStopCallback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
 {
     CloseHandle(hServiceProcess);
-    UnregisterWait(hThemeStopWaitObject);
     UnregisterWait(hThemeServiceWaitObject);
 
     ThemeWatchForStart();
@@ -92,7 +91,10 @@ ThemeServiceDiedCallback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
     ResetEvent(hStartEvent);
     ResetEvent(hStopEvent);
 
-    ThemeStopCallback(lpParameter, TimerOrWaitFired);
+    CloseHandle(hServiceProcess);
+    UnregisterWait(hThemeStopWaitObject);
+    ThemeWatchForStart();
+    ThemeHooksRemove();
 }
 
 static
@@ -100,12 +102,10 @@ VOID
 CALLBACK
 ThemeStartCallback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
 {
-    UnregisterWait(hThemeStartWaitObject);
-
     hServiceProcess = GetThemeServiceProcessHandle();
 
-    RegisterWaitForSingleObject(&hThemeStopWaitObject, hStopEvent, ThemeStopCallback,
NULL, INFINITE, WT_EXECUTEDEFAULT);
-    RegisterWaitForSingleObject(&hThemeServiceWaitObject, hServiceProcess,
ThemeServiceDiedCallback, NULL, INFINITE, WT_EXECUTEDEFAULT);
+    RegisterWaitForSingleObject(&hThemeStopWaitObject, hStopEvent, ThemeStopCallback,
NULL, INFINITE, WT_EXECUTEONLYONCE);
+    RegisterWaitForSingleObject(&hThemeServiceWaitObject, hServiceProcess,
ThemeServiceDiedCallback, NULL, INFINITE, WT_EXECUTEONLYONCE);
 
     ThemeHooksInstall();
 }
@@ -117,7 +117,7 @@ ThemeWatchForStart(VOID)
     hStartEvent = CreateEventW(NULL, TRUE, FALSE, L"Global\\ThemeStartEvent");
     hStopEvent = CreateEventW(NULL, TRUE, FALSE, L"Global\\ThemeStopEvent");
 
-    RegisterWaitForSingleObject(&hThemeStartWaitObject, hStartEvent,
ThemeStartCallback, NULL, INFINITE, WT_EXECUTEDEFAULT);
+    RegisterWaitForSingleObject(&hThemeStartWaitObject, hStartEvent,
ThemeStartCallback, NULL, INFINITE, WT_EXECUTEONLYONCE);
 
     return TRUE;
 }