libCom/osi: Fix nesting for epicsThreadHooks, add WIN32 implementation, lock traversal

- call (generic) exit hook after calling the (specific) epicsExitCallAtThreadExits()
- for start hooks added as 1-2-3, run exit hooks in opposite order: 3-2-1
- add calls to hooks module to WIN32 osdThread.c
- add lock/unlock to hook list traversal

src/libCom/osi/os/RTEMS/osdThread.c

@@ -166,8 +166,8 @@ threadWrapper (rtems_task_argument arg)
 
     epicsThreadRunStartHooks(pthreadInfo);
     (*v->funptr)(v->parm);
-    epicsThreadRunExitHooks(pthreadInfo);
     epicsExitCallAtThreadExits ();
+    epicsThreadRunExitHooks(pthreadInfo);
     taskVarLock ();
     if (v->back)
         v->back->forw = v->forw;

src/libCom/osi/os/WIN32/osdThread.c

@@ -16,13 +16,6 @@
  *
  */
 
-/* FIXME:
- * The Windows implementation for thread hooks is still missing.
- * epicsThreadHooksInit();                    as part of the initialization
- * epicsThreadRunStartHooks(pthreadInfo);     from thread context before the user func runs
- * epicsThreadRunExitHooks(pthreadInfo);      from thread context after the user func exits
- */
-
 #include <string.h>
 #include <stdlib.h>
 #include <stddef.h>
@@ -233,6 +226,7 @@ static win32ThreadGlobal * fetchWin32ThreadGlobal ( void )
         pWin32ThreadGlobal = 0;
         return 0;
     }
+    epicsThreadHooksInit();
 
     InterlockedExchange ( & initCompleted, 1 );
 
@@ -503,6 +497,7 @@ static unsigned WINAPI epicsWin32ThreadEntry ( LPVOID lpParameter )
 
         success = TlsSetValue ( pGbl->tlsIndexThreadLibraryEPICS, pParm );
         if ( success ) {
+            epicsThreadRunStartHooks(pParm);
             /* printf ( "starting thread %d\n", pParm->id ); */
             ( *pParm->funptr ) ( pParm->parm );
             /* printf ( "terminating thread %d\n", pParm->id ); */
@@ -518,6 +513,8 @@ static unsigned WINAPI epicsWin32ThreadEntry ( LPVOID lpParameter )
 
     epicsExitCallAtThreadExits ();
 
+    epicsThreadRunExitHooks(pParm);
+
     /*
      * CAUTION: !!!! the thread id might continue to be used after this thread exits !!!!
      */

src/libCom/osi/os/default/osdThreadHooks.c

@@ -32,9 +32,11 @@ typedef struct epicsThreadHook {
 
 static ELLLIST startHooks = ELLLIST_INIT;
 static ELLLIST exitHooks = ELLLIST_INIT;
+
+/* Locking could probably be avoided, if elllist implementation was using atomic ops */
 static epicsMutexId hookLock;
 
-static void addHook (ELLLIST *list, EPICS_THREAD_HOOK_ROUTINE func)
+static void addHook (ELLLIST *list, EPICS_THREAD_HOOK_ROUTINE func, int atHead)
 {
     epicsThreadHook *pHook;
 
@@ -42,29 +44,33 @@ static void addHook (ELLLIST *list, EPICS_THREAD_HOOK_ROUTINE func)
     if (!pHook) checkStatusOnceReturn(errno,"calloc","epicsThreadAddStartHook");
     pHook->func = func;
     epicsMutexLock(hookLock);
-    ellInsert(list, NULL, &pHook->node);
+    if (atHead)
+        ellInsert(list, NULL, &pHook->node);
+    else
+        ellAdd(list, &pHook->node);
     epicsMutexUnlock(hookLock);
 }
 
 static void runHooks (ELLLIST *list, epicsThreadId id) {
     epicsThreadHook *pHook;
 
-    /* As we're only ever inserting hooks at the head of the list, forward traversing is safe */
+    epicsMutexLock(hookLock);
     pHook = (epicsThreadHook *) ellFirst(list);
     while (pHook) {
         pHook->func(id);
         pHook = (epicsThreadHook *) ellNext(&pHook->node);
     }
+    epicsMutexUnlock(hookLock);
 }
 
 epicsShareFunc void epicsShareAPI epicsThreadAddStartHook(EPICS_THREAD_HOOK_ROUTINE hook)
 {
-    addHook(&startHooks, hook);
+    addHook(&startHooks, hook, 0);
 }
 
 epicsShareFunc void epicsShareAPI epicsThreadAddExitHook(EPICS_THREAD_HOOK_ROUTINE hook)
 {
-    addHook(&exitHooks, hook);
+    addHook(&exitHooks, hook, 1);
 }
 
 epicsShareFunc void epicsShareAPI epicsThreadHooksInit(void)

src/libCom/osi/os/posix/osdThread.c

@@ -378,8 +378,8 @@ static void * start_routine(void *arg)
 
     (*pthreadInfo->createFunc)(pthreadInfo->createArg);
 
-    epicsThreadRunExitHooks(pthreadInfo);
     epicsExitCallAtThreadExits ();
+    epicsThreadRunExitHooks(pthreadInfo);
 
     free_threadInfo(pthreadInfo);
     return(0);

src/libCom/osi/os/vxWorks/osdThread.c

@@ -165,8 +165,8 @@ static void createFunction(EPICSTHREADFUNC func, void *parm)
     papTSD = 0;
     epicsThreadRunStartHooks(pthreadInfo);
     (*func)(parm);
-    epicsThreadRunExitHooks(pthreadInfo);
     epicsExitCallAtThreadExits ();
+    epicsThreadRunExitHooks(pthreadInfo);
     free(papTSD);
     taskVarDelete(tid,(int *)(char *)&papTSD);
 }