amicommon: properly arbitrate access to the open file list in a multithreaded environment

git-svn-id: trunk@30899 -

rtl/amicommon/sysfile.inc

@@ -40,6 +40,7 @@ var
   tmpHandle : LongInt;
 begin
   if l=nil then exit;
+  ObtainSemaphore(ASYS_fileSemaphore);
 
   { First, close all tracked files }
   tmpNext:=l^.next;
@@ -58,6 +59,7 @@ begin
     l:=l^.next;
     dispose(tmpNext);
   end;
+  ReleaseSemaphore(ASYS_fileSemaphore);
 end;
 
 { Function to be called to add a file to the opened file list }
@@ -67,6 +69,8 @@ var
   inList: Boolean;
 begin
   inList:=False;
+  ObtainSemaphore(ASYS_fileSemaphore);
+
   if l<>nil then begin
     { if there is a valid filelist, search for the value }
     { in the list to avoid double additions }
@@ -93,6 +97,7 @@ begin
     RawDoFmt('FPC_FILE_DEBUG: Error! Trying add filehandle a filehandle twice: $%lx !'+#10,@h,pointer(1),nil);
 {$ENDIF}
   ;
+  ReleaseSemaphore(ASYS_fileSemaphore);
 end;
 
 { Function to be called to remove a file from the list }
@@ -108,6 +113,7 @@ begin
     exit;
   end;
 
+  ObtainSemaphore(ASYS_fileSemaphore);
   p:=l;
   while (p^.next<>nil) and (not inList) do
     if p^.next^.handle=h then inList:=True
@@ -123,6 +129,7 @@ begin
     RawDoFmt('FPC_FILE_DEBUG: Error! Trying to remove not existing filehandle: $%lx !'+#10,@h,pointer(1),nil);
 {$ENDIF}
   ;
+  ReleaseSemaphore(ASYS_fileSemaphore);
 
   RemoveFromList:=inList;
 end;
@@ -140,6 +147,7 @@ begin
     exit;
   end;
 
+  ObtainSemaphore(ASYS_fileSemaphore);
   p:=l;
   while (p^.next<>nil) and (inList=nil) do
     if p^.next^.handle=h then inList:=p^.next
@@ -150,6 +158,7 @@ begin
     RawDoFmt('FPC_FILE_DEBUG: Warning! Check for not existing filehandle: $%lx !'+#10,@h,pointer(1),nil);
 {$ENDIF}
 
+  ReleaseSemaphore(ASYS_fileSemaphore);
   CheckInList:=inList;
 end;
 

rtl/amiga/system.pp

@@ -80,6 +80,7 @@ var
 
   ASYS_heapPool : Pointer; { pointer for the OS pool for growing the heap }
   ASYS_heapSemaphore: Pointer; { 68k OS from 3.x has no MEMF_SEM_PROTECTED for pools, have to do it ourselves }
+  ASYS_fileSemaphore: Pointer; { mutex semaphore for filelist access arbitration }
   ASYS_origDir  : LongInt; { original directory on startup }
   AOS_wbMsg    : Pointer; public name '_WBenchMsg'; { the "public" part is amunits compatibility kludge }
   _WBenchMsg   : Pointer; external name '_WBenchMsg'; { amunits compatibility kludge }
@@ -355,8 +356,14 @@ begin
   ASYS_heapPool:=CreatePool(MEMF_FAST,growheapsize2,growheapsize1);
   if ASYS_heapPool=nil then Halt(1);
   ASYS_heapSemaphore:=AllocPooled(ASYS_heapPool,sizeof(TSignalSemaphore));
+  if ASYS_heapSemaphore = nil then Halt(1);
   InitSemaphore(ASYS_heapSemaphore);
 
+  { Initialize semaphore for filelist access arbitration }
+  ASYS_fileSemaphore:=AllocPooled(ASYS_heapPool,sizeof(TSignalSemaphore));
+  if ASYS_fileSemaphore = nil then Halt(1);
+  InitSemaphore(ASYS_fileSemaphore);
+
   if AOS_wbMsg=nil then begin
     StdInputHandle:=dosInput;
     StdOutputHandle:=dosOutput;

rtl/aros/system.pp

@@ -67,6 +67,7 @@ var
   AROS_ThreadLib : Pointer; public name 'AROS_THREADLIB';
 
   ASYS_heapPool : Pointer; { pointer for the OS pool for growing the heap }
+  ASYS_fileSemaphore: Pointer; { mutex semaphore for filelist access arbitration }
   ASYS_origDir  : LongInt; { original directory on startup }
   AOS_wbMsg    : Pointer;
   AOS_ConName  : PChar ='CON:10/30/620/100/FPC Console Output/AUTO/CLOSE/WAIT';
@@ -415,6 +416,12 @@ begin
   if ASYS_heapPool = nil then
     Halt(1);
 
+  { Initialize semaphore for filelist access arbitration }
+  ASYS_fileSemaphore:=AllocPooled(ASYS_heapPool,sizeof(TSignalSemaphore));
+  if ASYS_fileSemaphore = nil then
+    Halt(1);
+  InitSemaphore(ASYS_fileSemaphore);
+
   if AOS_wbMsg = nil then begin
     StdInputHandle := THandle(dosInput);
     StdOutputHandle := THandle(dosOutput);

rtl/morphos/system.pp

@@ -64,6 +64,7 @@ var
   MOS_UtilityBase: Pointer;
 
   ASYS_heapPool : Pointer; { pointer for the OS pool for growing the heap }
+  ASYS_fileSemaphore: Pointer; { mutex semaphore for filelist access arbitration }
   ASYS_origDir  : LongInt; { original directory on startup }
   MOS_ambMsg   : Pointer;
   MOS_ConName  : PChar ='CON:10/30/620/100/FPC Console Output/AUTO/CLOSE/WAIT';
@@ -367,6 +368,11 @@ begin
  { Creating the memory pool for growing heap }
  ASYS_heapPool:=CreatePool(MEMF_FAST or MEMF_SEM_PROTECTED,growheapsize2,growheapsize1);
  if ASYS_heapPool=nil then Halt(1);
+ 
+ { Initialize semaphore for filelist access arbitration }
+ ASYS_fileSemaphore:=AllocPooled(ASYS_heapPool,sizeof(TSignalSemaphore));
+ if ASYS_fileSemaphore = nil then Halt(1);
+ InitSemaphore(ASYS_fileSemaphore);
 
  if MOS_ambMsg=nil then begin
    MOS_ConHandle:=0;