Avoid initMainThread() except on vxworks

Move isOkToBlock tracking to osdThread.
Targets except vxworks can store this flag in epicsThreadOSD.
Continue to use TLS w/ vxWorks.

Note that setting of isOkToBlock for "main" thread becomes lazy.

modules/libcom/src/osi/epicsThread.cpp

@@ -339,32 +339,6 @@ void epicsThread :: show ( unsigned level ) const throw ()
 }
 
 extern "C" {
-    static epicsThreadOnceId okToBlockOnce = EPICS_THREAD_ONCE_INIT;
-    epicsThreadPrivateId okToBlockPrivate;
-    static const int okToBlockNo = 0;
-    static const int okToBlockYes = 1;
-
-    static void epicsThreadOnceIdInit(void *)
-    {
-        okToBlockPrivate = epicsThreadPrivateCreate();
-    }
-
-    int epicsStdCall epicsThreadIsOkToBlock(void)
-    {
-        const int *pokToBlock;
-        epicsThreadOnce(&okToBlockOnce, epicsThreadOnceIdInit, NULL);
-        pokToBlock = (int *) epicsThreadPrivateGet(okToBlockPrivate);
-        return (pokToBlock ? *pokToBlock : 0);
-    }
-
-    void epicsStdCall epicsThreadSetOkToBlock(int isOkToBlock)
-    {
-        const int *pokToBlock;
-        epicsThreadOnce(&okToBlockOnce, epicsThreadOnceIdInit, NULL);
-        pokToBlock = (isOkToBlock) ? &okToBlockYes : &okToBlockNo;
-        epicsThreadPrivateSet(okToBlockPrivate, (void *)pokToBlock);
-    }
-
     epicsThreadId epicsStdCall epicsThreadMustCreate (
         const char *name, unsigned int priority, unsigned int stackSize,
         EPICSTHREADFUNC funptr,void *parm)
@@ -375,12 +349,3 @@ extern "C" {
         return id;
     }
 } // extern "C"
-
-static epicsThreadId initMainThread(void) {
-    epicsThreadId main = epicsThreadGetIdSelf();
-    epicsThreadSetOkToBlock(1);
-    return main;
-}
-
-// Ensure the main thread gets a unique ID and allows blocking I/O
-epicsThreadId epicsThreadMainId = initMainThread();

modules/libcom/src/osi/os/Linux/osdThread.h

@@ -37,6 +37,7 @@ typedef struct epicsThreadOSD {
     int                isRealTimeScheduled;
     int                isOnThreadList;
     int                isRunning;
+    int                isOkToBlock;
     unsigned int       osiPriority;
     int                joinable;
     char               name[1];     /* actually larger */

modules/libcom/src/osi/os/RTEMS-score/osdThread.c

@@ -54,6 +54,7 @@ struct taskVar {
     int                refcnt;
     int                joinable;
     int                isRunning;
+    int                isOkToBlock;
     EPICSTHREADFUNC              funptr;
     void                *parm;
     unsigned int        threadVariableCapacity;
@@ -226,7 +227,7 @@ void epicsThreadExitMain (void)
 
 static rtems_status_code
 setThreadInfo(rtems_id tid, const char *name, EPICSTHREADFUNC funptr,
-    void *parm, int joinable)
+    void *parm, int joinable, int isOkToBlock)
 {
     struct taskVar *v;
     uint32_t note;
@@ -242,6 +243,7 @@ setThreadInfo(rtems_id tid, const char *name, EPICSTHREADFUNC funptr,
     v->threadVariableCapacity = 0;
     v->threadVariables = NULL;
     v->isRunning = 1;
+    v->isOkToBlock = isOkToBlock;
     if (joinable) {
         char c[3];
         strncpy(c, v->name, 3);
@@ -293,7 +295,7 @@ epicsThreadInit (void)
         if (!onceMutex || !taskVarMutex)
             cantProceed("epicsThreadInit() can't create global mutexes\n");
         rtems_task_ident (RTEMS_SELF, 0, &tid);
-        if(setThreadInfo (tid, "_main_", NULL, NULL, 0) != RTEMS_SUCCESSFUL)
+        if(setThreadInfo (tid, "_main_", NULL, NULL, 0, 1) != RTEMS_SUCCESSFUL)
             cantProceed("epicsThreadInit() unable to setup _main_");
         osdThreadHooksRunMain((epicsThreadId)tid);
         initialized = 1;
@@ -347,7 +349,7 @@ epicsThreadCreateOpt (
             name, rtems_status_text(sc));
         return 0;
     }
-    sc = setThreadInfo (tid, name, funptr, parm, opts->joinable);
+    sc = setThreadInfo (tid, name, funptr, parm, opts->joinable, 0);
     if (sc != RTEMS_SUCCESSFUL) {
         errlogPrintf ("epicsThreadCreate create failure during setup for %s: %s\n",
             name, rtems_status_text(sc));
@@ -879,3 +881,27 @@ LIBCOM_API int epicsThreadGetCPUs(void)
     return 1;
 #endif
 }
+
+
+int epicsStdCall epicsThreadIsOkToBlock(void)
+{
+    uint32_t note = 0;
+    struct taskVar *v;
+
+    rtems_task_get_note (RTEMS_SELF, RTEMS_NOTEPAD_TASKVAR, &note);
+    v = (void *)note;
+
+    return v && v->isOkToBlock;
+}
+
+void epicsStdCall epicsThreadSetOkToBlock(int isOkToBlock)
+{
+    uint32_t note = 0;
+    struct taskVar *v;
+
+    rtems_task_get_note (RTEMS_SELF, RTEMS_NOTEPAD_TASKVAR, &note);
+    v = (void *)note;
+
+    if(v)
+        v->isOkToBlock = !!isOkToBlock;
+}

modules/libcom/src/osi/os/WIN32/osdThread.c

@@ -103,6 +103,7 @@ typedef struct epicsThreadOSD {
     char isSuspended;
     int joinable;
     int isRunning;
+    int isOkToBlock;
     HANDLE timer; /* waitable timer */
 } win32ThreadParam;
 
@@ -586,6 +587,7 @@ static win32ThreadParam * epicsThreadImplicitCreate ( void )
 
         pParm->handle = handle;
         pParm->id = id;
+        pParm->isOkToBlock = 1;
         win32ThreadPriority = GetThreadPriority ( pParm->handle );
         assert ( win32ThreadPriority != THREAD_PRIORITY_ERROR_RETURN );
         pParm->epicsPriority = epicsThreadGetOsiPriorityValue ( win32ThreadPriority );
@@ -1224,3 +1226,17 @@ void testPriorityMapping ()
     return 0;
 }
 #endif
+
+int epicsStdCall epicsThreadIsOkToBlock(void)
+{
+    struct epicsThreadOSD *pthreadInfo = epicsThreadGetIdSelf();
+
+    return(pthreadInfo->isOkToBlock);
+}
+
+void epicsStdCall epicsThreadSetOkToBlock(int isOkToBlock)
+{
+    struct epicsThreadOSD *pthreadInfo = epicsThreadGetIdSelf();
+
+    pthreadInfo->isOkToBlock = !!isOkToBlock;
+}

modules/libcom/src/osi/os/posix/osdThread.c

@@ -658,6 +658,7 @@ static epicsThreadOSD *createImplicit(void)
     assert(pthreadInfo);
     pthreadInfo->tid = tid;
     pthreadInfo->osiPriority = 0;
+    pthreadInfo->isOkToBlock = 1;
 
 #if defined(_POSIX_THREAD_PRIORITY_SCHEDULING) && _POSIX_THREAD_PRIORITY_SCHEDULING > 0
     if(pthread_getschedparam(tid,&pthreadInfo->schedPolicy,&pthreadInfo->schedParam) == 0) {
@@ -1058,3 +1059,17 @@ LIBCOM_API int epicsThreadGetCPUs(void)
 #endif
     return 1;
 }
+
+int epicsStdCall epicsThreadIsOkToBlock(void)
+{
+    epicsThreadOSD *pthreadInfo = epicsThreadGetIdSelf();
+
+    return(pthreadInfo->isOkToBlock);
+}
+
+void epicsStdCall epicsThreadSetOkToBlock(int isOkToBlock)
+{
+    epicsThreadOSD *pthreadInfo = epicsThreadGetIdSelf();
+
+    pthreadInfo->isOkToBlock = !!isOkToBlock;
+}

modules/libcom/src/osi/os/posix/osdThread.h

@@ -35,6 +35,7 @@ typedef struct epicsThreadOSD {
     int                isRealTimeScheduled;
     int                isOnThreadList;
     int                isRunning;
+    int                isOkToBlock;
     unsigned int       osiPriority;
     int                joinable;
     char               name[1];     /* actually larger */

modules/libcom/src/osi/os/vxWorks/osdThread.c

@@ -127,7 +127,8 @@ static void epicsThreadInit(void)
         taskIdListSize = ID_LIST_CHUNK;
         atRebootRegister();
         ALLOT_JOIN(0);
-        done = 1;
+        done = 1; /* avoids recursive call */
+        epicsThreadSetOkToBlock(1);
     }
     lock = 0;
 }
@@ -577,3 +578,30 @@ LIBCOM_API int epicsThreadGetCPUs(void)
 {
     return 1;
 }
+
+
+static epicsThreadOnceId okToBlockOnce = EPICS_THREAD_ONCE_INIT;
+static epicsThreadPrivateId okToBlockPrivate;
+static const int okToBlockNo = 0;
+static const int okToBlockYes = 1;
+
+static void epicsThreadOnceIdInit(void *not_used)
+{
+    okToBlockPrivate = epicsThreadPrivateCreate();
+}
+
+int epicsStdCall epicsThreadIsOkToBlock(void)
+{
+    const int *pokToBlock;
+    epicsThreadOnce(&okToBlockOnce, epicsThreadOnceIdInit, NULL);
+    pokToBlock = (int *) epicsThreadPrivateGet(okToBlockPrivate);
+    return (pokToBlock ? *pokToBlock : 0);
+}
+
+void epicsStdCall epicsThreadSetOkToBlock(int isOkToBlock)
+{
+    const int *pokToBlock;
+    epicsThreadOnce(&okToBlockOnce, epicsThreadOnceIdInit, NULL);
+    pokToBlock = (isOkToBlock) ? &okToBlockYes : &okToBlockNo;
+    epicsThreadPrivateSet(okToBlockPrivate, (void *)pokToBlock);
+}