From 4076377820c328e299cebc72b7353621d60110a4 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Mon, 5 Feb 2024 02:46:57 +1100
Subject: [PATCH] [host] win: add comRef helpers for leak identification and
 tracking

---
 host/platform/Windows/include/com_ref.h | 13 ++++++++-----
 host/platform/Windows/src/com_ref.c     | 21 ++++++++++++++-------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/host/platform/Windows/include/com_ref.h b/host/platform/Windows/include/com_ref.h
index f9da1f6e..4ea44cc8 100644
--- a/host/platform/Windows/include/com_ref.h
+++ b/host/platform/Windows/include/com_ref.h
@@ -25,6 +25,7 @@
 #include <windows.h>
 #include <malloc.h>
 
+#include "common/util.h"
 #include "common/locking.h"
 
 /**
@@ -42,10 +43,10 @@ struct ComScope
   unsigned      used;
   struct
   {
-    IUnknown *** ptr;
     IUnknown   * ref;
+    const char * where;
   }
-  * refs;
+  *refs;
 
   void (*free)(void * ptr);
 };
@@ -55,7 +56,7 @@ void comRef_initScope(unsigned size, ComScope ** instance,
 
 void comRef_freeScope(ComScope ** instance);
 
-IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst);
+IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst, const char * where);
 
 #define comRef_initGlobalScope(size, scope) \
   comRef_initScope((size), &(scope), malloc, free, true)
@@ -73,11 +74,13 @@ IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst);
 
 #define comRef_defineLocal(type, name) \
   type ** name = NULL; \
-  comRef_new(_comRef_localScope, (IUnknown ***)&(name));
+  comRef_new(_comRef_localScope, (IUnknown ***)&(name), \
+    STR(name));
 
 #define _comRef_toGlobal(globalScope, dst, src) \
 { \
-  IUnknown ** global = comRef_new((globalScope), (IUnknown ***)&(dst)); \
+  IUnknown ** global = comRef_new((globalScope), (IUnknown ***)&(dst), \
+    STR(dst)); \
   *global = (IUnknown *)*(src); \
   *(src)  = NULL; \
 }
diff --git a/host/platform/Windows/src/com_ref.c b/host/platform/Windows/src/com_ref.c
index 74cd5d2c..a4c20b8d 100644
--- a/host/platform/Windows/src/com_ref.c
+++ b/host/platform/Windows/src/com_ref.c
@@ -55,12 +55,17 @@ void comRef_freeScope(ComScope ** instance)
     typeof(scope->refs) ref = &scope->refs[i];
     if (ref->ref)
     {
-      IUnknown_Release(ref->ref);
+      ULONG count = IUnknown_Release(ref->ref);
+
+#ifdef DEBUG_COMREF
+      if (count > 0 && scope->free)
+        DEBUG_INFO("comRef %s release is %lu", ref->where, count);
+#else
+      (void)count;
+#endif
+
       ref->ref = NULL;
     }
-
-    *ref->ptr = NULL;
-    ref->ptr = NULL;
   }
 
   if (scope->threadSafe)
@@ -72,7 +77,7 @@ void comRef_freeScope(ComScope ** instance)
   *instance = NULL;
 }
 
-IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst)
+IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst, const char * where)
 {
   /* check if the value it points to is already in our memory range and if it
    * does, then reuse it */
@@ -97,8 +102,10 @@ IUnknown ** comRef_new(ComScope * scope, IUnknown *** dst)
   if (scope->threadSafe)
     LG_LOCK(scope->lock);
 
-  scope->refs[scope->used].ptr = dst;
-  *dst = &scope->refs[scope->used].ref;
+  typeof(scope->refs[0]) * ref = &scope->refs[scope->used];
+  ref->where = where;
+  *dst = &ref->ref;
+
   ++scope->used;
 
   if (scope->threadSafe)