From db97e36e5858887cc069165106004565732f4585 Mon Sep 17 00:00:00 2001
From: Ulf Wohlers <finsterr@users.sourceforge.net>
Date: Mon, 11 Aug 2003 11:50:30 +0000
Subject: [PATCH] Added reference counting for dos_files

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1181
---
 include/dos_system.h    |  5 ++++-
 src/dos/dos_files.cpp   | 12 +++++++++---
 src/dos/drive_local.cpp |  8 ++++++--
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/include/dos_system.h b/include/dos_system.h
index 41624704..68380b59 100644
--- a/include/dos_system.h
+++ b/include/dos_system.h
@@ -51,7 +51,7 @@ class DOS_DTA;
 
 class DOS_File {
 public:
-	DOS_File():flags(0)		{ name=0; };
+	DOS_File():flags(0)		{ name=0; refCtr = 0; };
 	virtual	~DOS_File(){};
 	virtual bool	Read(Bit8u * data,Bit16u * size)=0;
 	virtual bool	Write(Bit8u * data,Bit16u * size)=0;
@@ -62,12 +62,15 @@ public:
 	virtual char*	GetName(void)				{ return name; };
 	virtual bool	IsOpen()					{ return open; };
 	virtual bool	IsName(const char* _name)	{ if (!name) return false; return strcmp(name,_name)==0; };
+	virtual void	AddRef()					{ refCtr++; };
+	virtual Bits	RemoveRef()					{ return --refCtr; };
 	Bit8u type;
 	Bit32u flags;
 	Bit16u time;
 	Bit16u date;
 	Bit16u attr;
 	Bit32u size;
+	Bits refCtr;
 	bool open;
 	char* name;
 /* Some Device Specific Stuff */
diff --git a/src/dos/dos_files.cpp b/src/dos/dos_files.cpp
index 8c725df9..086a1f88 100644
--- a/src/dos/dos_files.cpp
+++ b/src/dos/dos_files.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dos_files.cpp,v 1.42 2003-08-01 16:48:55 qbix79 Exp $ */
+/* $Id: dos_files.cpp,v 1.43 2003-08-11 11:49:58 finsterr Exp $ */
 
 #include <string.h>
 #include <stdlib.h>
@@ -315,8 +315,10 @@ bool DOS_CloseFile(Bit16u entry) {
 	{   //if close succesfull => delete file/update psp
 		DOS_PSP psp(dos.psp);
 		psp.SetFileHandle(entry,0xff);
-		delete Files[handle];
-		Files[handle]=0;
+		if (Files[handle]->RemoveRef()<=0) {
+			delete Files[handle];
+			Files[handle]=0;
+		}
 	}
 	return true;
 }
@@ -345,6 +347,7 @@ bool DOS_CreateFile(char * name,Bit16u attributes,Bit16u * entry) {
 	}
 	bool foundit=Drives[drive]->FileCreate(&Files[handle],fullname,attributes);
 	if (foundit) { 
+		Files[handle]->AddRef();
 		psp.SetFileHandle(*entry,handle);
 		return true;
 	} else {
@@ -387,6 +390,7 @@ bool DOS_OpenFile(char * name,Bit8u flags,Bit16u * entry) {
 	bool exists=false;
 	if (!device) exists=Drives[drive]->FileOpen(&Files[handle],fullname,flags);
 	if (exists || device ) { 
+		Files[handle]->AddRef();
 		psp.SetFileHandle(*entry,handle);
 		return true;
 	} else {
@@ -476,6 +480,7 @@ bool DOS_DuplicateEntry(Bit16u entry,Bit16u * newentry) {
 		DOS_SetError(DOSERR_TOO_MANY_OPEN_FILES);
 		return false;
 	}
+	Files[handle]->AddRef();	
 	psp.SetFileHandle(*newentry,handle);
 	return true;
 };
@@ -500,6 +505,7 @@ bool DOS_ForceDuplicateEntry(Bit16u entry,Bit16u newentry) {
 		return false;
 	};
 	DOS_PSP psp(dos.psp);
+	Files[orig]->AddRef();
 	psp.SetFileHandle(newentry,(Bit8u)entry);
 	return true;
 };
diff --git a/src/dos/drive_local.cpp b/src/dos/drive_local.cpp
index 991a9dbc..8c0c119e 100644
--- a/src/dos/drive_local.cpp
+++ b/src/dos/drive_local.cpp
@@ -372,8 +372,12 @@ bool localFile::Seek(Bit32u * pos,Bit32u type) {
 
 bool localFile::Close() {
 	
-	open=false;
-	fclose(fhandle);
+	// only close if one reference left
+	if (refCtr==1) {
+		fclose(fhandle);
+		fhandle = 0;
+		open = false;
+	};
 	return true;
 }