[#205] Ensure TP worker thread does not invoke YottaDB engine (even t…

…o issue an error); Nix NOTSUPSTAPI message

The simplethreadapi/tp subtest failed once with the following signature in the
tp5_TPTIMEOUT.c section of the test.

%YDB-F-ASSERT, Assert failed in sr_unix/gt_timers.c line 725 for expression
	(gtm_is_main_thread() || gtm_jvm_process || exit_handler_active && (DUMMY_SIG_NUM == why))

with the following C-stack

(gdb) where
 #0  __pthread_kill (threadid=<optimized out>, signo=3) at ../sysdeps/unix/sysv/linux/pthread_kill.c:62
 #1  gtm_dump_core () at sr_unix/gtm_dump_core.c:72
 #2  gtm_fork_n_core () at sr_unix/gtm_fork_n_core.c:148
 #3  ch_cond_core () at sr_unix/ch_cond_core.c:64
 #4  rts_error_va (csa=0x0, argcnt=7, var=0x7fe3a13888b0) at sr_unix/rts_error.c:194
 #5  rts_error_csa (csa=0x0, argcnt=7) at sr_unix/rts_error.c:101
 #6  timer_handler (why=0) at sr_unix/gt_timers.c:725
 #7  check_for_deferred_timers () at sr_unix/gt_timers.c:1179
 #8  deferred_signal_handler () at sr_port/deferred_signal_handler.c:49
 #9  rts_error_va (csa=0x0, argcnt=4, var=0x7fe3a1388c70) at sr_unix/rts_error.c:194
 #10 rts_error_csa (csa=0x0, argcnt=4) at sr_unix/rts_error.c:101
 #11 ydb_hiber_start (sleep_nsec=1000000) at sr_unix/ydb_hiber_start.c:46
 #12 gvnset (tptoken=1) at tp5_TPTIMEOUT.c:77
 #13 ydb_stm_tpthreadq_process (curTPWorkQHead=0x13dac40) at sr_unix/ydb_stm_tpthread.c:197
 #14 ydb_stm_tpthread (parm=0x0) at sr_unix/ydb_stm_tpthread.c:78
 #15 start_thread (arg=0x7fe3a1389700) at pthread_create.c:333
 #16 clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

This was a process that had already made SimpleThreadAPI calls but is now making a SimpleAPI call
(ydb_hiber_start()) and so a NOTSUPSTAPI error is about to be issued. But since this call is happening
in the user-defined callback function inside a TP transaction, it is the TP worker thread (not the
MAIN worker thread) that is executing the "ydb_hiber_start". This means the rts_error_csa invocation
is running in the TP worker thread while the YottaDB engine is concurrently being modified by the
MAIN worker thread. A no-no since the YottaDB engine is not multi-threaded.

To fix this issue, the VERIFY_NON_THREADED_API macro is now fixed to do a "return YDB_ERR_INVAPIMODE".
This means ydb_hiber_start() would return a lot sooner thereby not requiring an "rts_error" invocation.

But while doing this change, noticed a few issues. The VERIFY_NON_THREADED_API is used from a few
functions that do not return any value (sr_unix/ydb_free.c and sr_unix/ydb_timer_cancel.c) so a new
macro VERIFY_NON_THREADED_API_NORETVAL is created which is very similar except it does a plain "return".
sr_unix/ydb_malloc.c needed special handling since it was returning a "void *" and so a new
VERIFY_NON_THREADED_API_RETNULL macro is created for that purpose.

While at this, noticed that the VERIFY_NON_THREADED_API macro was not resetting
TREF(libyottadb_active_rtn) in case of an INVAPIMODE return (since this macro is usually invoked
after a LIBYOTTADB_INIT) so fixed it to do so.

Note that the VERIFY_THREADED_API macro stayed the same in that it did not do this reset since it is
usually invoked before the LIBYOTTADB_INIT macro. But two exceptions to this rule were found,
sr_unix/ydb_cip_helper.c and sr_unix/ydb_tp_s_common.c. They are now fixed so the VERIFY_THREADED_API
macro invocation happens before the LIBYOTTADB_INIT macro.

Another issue that was noticed is that "ydb_ci" and "ydb_cip" were not doing a VERIFY_NON_THREADED_API
check like other SimpleAPI calls do so a new sr_unix/ydb_ci.c and sr_unix/ydb_cip.c were created to
do this before invoking ydb_ci_exec(). And the existing ydb_ci() and ydb_cip() function definitions
in sr_unix/gtmci.c were removed. A new VERIFY_NON_THREADED_API_DO_NOT_SHUTOFF_ACTIVE_RTN macro was
introduced for this purpose since we do not want to do a LIBYOTTADB_INIT in these functions (to avoid
unnecessary SIMPLEAPINEST errors).

With all these changes, the NOTSUPSTAPI error (currently issued in sr_unix/ydb_hiber_start_wait_any.c
and sr_unix/ydb_hiber_start.c) was no longer necessary since an INVAPIMODE error would have been issued
before this error codepath  is reached in all callers. So this error message is now removed.

sr_port/libydberrors2.h

@@ -42,5 +42,4 @@
 #define YDB_ERR_INVLNPAIRLIST -151027930
 #define YDB_ERR_INVTPTRANS -151027938
 #define YDB_ERR_INVAPIMODE -151027946
-#define YDB_ERR_NOTSUPSTAPI -151027954
-#define YDB_ERR_STAPIFORKEXEC -151027962
+#define YDB_ERR_STAPIFORKEXEC -151027954

sr_port/ydberrors.h

@@ -42,5 +42,4 @@
 #define ERR_INVLNPAIRLIST 151027930
 #define ERR_INVTPTRANS 151027938
 #define ERR_INVAPIMODE 151027946
-#define ERR_NOTSUPSTAPI 151027954
-#define ERR_STAPIFORKEXEC 151027962
+#define ERR_STAPIFORKEXEC 151027954

sr_port/ydberrors.msg

@@ -58,7 +58,6 @@ NODEEND		<End of list of nodes/subscripts>/error/fao=0
 INVLNPAIRLIST	<Invalid lockname/subscript pair list (uneven number of lockname/subscript parameters)>/error/fao=0
 INVTPTRANS	<Invalid TP transaction - either invalid TP token or transaction not in progress>/error/fao=0
 INVAPIMODE	<Process not allowed to first use !AD then switch to using !AD>/error/fao=4
-NOTSUPSTAPI	<Calls to !AD are not supported if threaded Simple API functions are in use>/error/fao=2
 STAPIFORKEXEC	<Calls to YottaDB are not supported after a fork() if threaded Simple API functions were in use in parent. Call exec() first>/error/fao=0
 !
 ! If there are UNUSEDMSG* lines unused for more than one year and at least two non-patch releases, use them before adding new lines.

sr_port/ydberrors_ctl.c

@@ -46,7 +46,6 @@ LITDEF	err_msg ydberrors[] = {
 	{ "INVLNPAIRLIST", "Invalid lockname/subscript pair list (uneven number of lockname/subscript parameters)", 0 },
 	{ "INVTPTRANS", "Invalid TP transaction - either invalid TP token or transaction not in progress", 0 },
 	{ "INVAPIMODE", "Process not allowed to first use !AD then switch to using !AD", 4 },
-	{ "NOTSUPSTAPI", "Calls to !AD are not supported if threaded Simple API functions are in use", 2 },
 	{ "STAPIFORKEXEC", "Calls to YottaDB are not supported after a fork() if threaded Simple API functions were in use in parent. Call exec() first", 0 },
 };
 
@@ -60,7 +59,7 @@ GBLDEF	err_ctl ydberrors_ctl = {
 	256,
 	"YDB",
 	&ydberrors[0],
-	31,
+	30,
 	&ydberrors_undocarr[0],
 	0
 };

sr_unix/gtmci.c

@@ -1095,28 +1095,6 @@ int ydb_ci_exec(const char *c_rtn_name, void *callin_handle, int populate_handle
 	return 0;
 }
 
-/* Initial call-in driver version - does name lookup on each call */
-int ydb_ci(const char *c_rtn_name, ...)
-{
-	va_list var;
-
-	VAR_START(var, c_rtn_name);
-	/* Note: "va_end(var)" done inside "ydb_ci_exec" */
-	return ydb_ci_exec(c_rtn_name, NULL, FALSE, var, FALSE);
-}
-
-/* Fast path call-in driver version - Adds a struct parm that contains name resolution info after first call
- * to speed up dispatching.
- */
-int ydb_cip(ci_name_descriptor* ci_info, ...)
-{
-	va_list var;
-
-	VAR_START(var, ci_info);
-	/* Note: "va_end(var)" done inside "ydb_ci_exec" */
-	return ydb_ci_exec(ci_info->rtn_name.address, ci_info->handle, TRUE, var, FALSE);
-}
-
 int gtm_ci_filter(const char *c_rtn_name, ...)
 {
 	va_list var;

sr_unix/libyottadb_int.h

@@ -654,9 +654,93 @@ MBSTART {												\
 	{													\
 		if (!IS_STAPI_WORKER_THREAD)									\
 		{												\
+			SETUP_GENERIC_ERROR_4PARMS(ERR_INVAPIMODE, THREADED_STR_LEN, THREADED_STR,		\
+						   UNTHREADED_STR_LEN, UNTHREADED_STR);				\
+			DBGAPITP_ONLY(gtm_fork_n_core());							\
+			/* Reset active routine indicator before returning an error.				\
+			 * Caller would have done LIBYOTTADB_INIT before invoking this macro. Assert that.	\
+			 */											\
+			assert(LYDB_RTN_NONE != TREF(libyottadb_active_rtn));					\
+			TREF(libyottadb_active_rtn) = LYDB_RTN_NONE;						\
+			return YDB_ERR_INVAPIMODE;								\
+		}												\
+		/* We are in threaded mode but running an unthreaded command in the main work thread which	\
+		 * is allowed. In that case just fall out (verified).						\
+		 */												\
+	} else													\
+		noThreadAPI_active = TRUE;									\
+} MBEND
+
+/* Variant of VERIFY_NON_THREADED_API macro that does a "return" but without any value */
+#define VERIFY_NON_THREADED_API_NORETVAL									\
+MBSTART {	/* If threaded API but in worker thread, that is OK */						\
+	GBLREF boolean_t noThreadAPI_active;									\
+	GBLREF boolean_t simpleThreadAPI_active;								\
+	GBLREF stm_workq *stmWorkQueue[];									\
+	if (simpleThreadAPI_active)										\
+	{													\
+		if (!IS_STAPI_WORKER_THREAD)									\
+		{												\
+			SETUP_GENERIC_ERROR_4PARMS(ERR_INVAPIMODE, THREADED_STR_LEN, THREADED_STR,		\
+						   UNTHREADED_STR_LEN, UNTHREADED_STR);				\
+			DBGAPITP_ONLY(gtm_fork_n_core());							\
+			/* Reset active routine indicator before returning an error.				\
+			 * Caller would have done LIBYOTTADB_INIT before invoking this macro. Assert that.	\
+			 */											\
+			assert(LYDB_RTN_NONE != TREF(libyottadb_active_rtn));					\
+			TREF(libyottadb_active_rtn) = LYDB_RTN_NONE;						\
+			return;											\
+		}												\
+		/* We are in threaded mode but running an unthreaded command in the main work thread which	\
+		 * is allowed. In that case just fall out (verified).						\
+		 */												\
+	} else													\
+		noThreadAPI_active = TRUE;									\
+} MBEND
+
+/* Variant of VERIFY_NON_THREADED_API macro that does a "return" but with a NULL pointer value */
+#define VERIFY_NON_THREADED_API_RETNULL										\
+	MBSTART {	/* If threaded API but in worker thread, that is OK */					\
+	GBLREF boolean_t noThreadAPI_active;									\
+	GBLREF boolean_t simpleThreadAPI_active;								\
+	GBLREF stm_workq *stmWorkQueue[];									\
+	if (simpleThreadAPI_active)										\
+	{													\
+		if (!IS_STAPI_WORKER_THREAD)									\
+		{												\
+			SETUP_GENERIC_ERROR_4PARMS(ERR_INVAPIMODE, THREADED_STR_LEN, THREADED_STR,		\
+						   UNTHREADED_STR_LEN, UNTHREADED_STR);				\
 			DBGAPITP_ONLY(gtm_fork_n_core());							\
+			/* Reset active routine indicator before returning an error.				\
+			 * Caller would have done LIBYOTTADB_INIT before invoking this macro. Assert that.	\
+			 */											\
+			assert(LYDB_RTN_NONE != TREF(libyottadb_active_rtn));					\
+			TREF(libyottadb_active_rtn) = LYDB_RTN_NONE;						\
+			return NULL;										\
+		}												\
+		/* We are in threaded mode but running an unthreaded command in the main work thread which	\
+		 * is allowed. In that case just fall out (verified).						\
+		 */												\
+	} else													\
+		noThreadAPI_active = TRUE;									\
+} MBEND
+
+/* Variant of VERIFY_NON_THREADED_API macro that does a "return" but without resetting TREF(libyottadb_active_rtn).
+ * Called by functions that do not do LIBYOTTADB_INIT but do call VERIFY_NON_THREADED_API* macro.
+ */
+#define VERIFY_NON_THREADED_API_DO_NOT_SHUTOFF_ACTIVE_RTN							\
+	MBSTART {	/* If threaded API but in worker thread, that is OK */					\
+	GBLREF boolean_t noThreadAPI_active;									\
+	GBLREF boolean_t simpleThreadAPI_active;								\
+	GBLREF stm_workq *stmWorkQueue[];									\
+	if (simpleThreadAPI_active)										\
+	{													\
+		if (!IS_STAPI_WORKER_THREAD)									\
+		{												\
 			SETUP_GENERIC_ERROR_4PARMS(ERR_INVAPIMODE, THREADED_STR_LEN, THREADED_STR,		\
 						   UNTHREADED_STR_LEN, UNTHREADED_STR);				\
+			DBGAPITP_ONLY(gtm_fork_n_core());							\
+			return YDB_ERR_INVAPIMODE;								\
 		}												\
 		/* We are in threaded mode but running an unthreaded command in the main work thread which	\
 		 * is allowed. In that case just fall out (verified).						\

sr_unix/ydb_ci.c

@@ -0,0 +1,40 @@
+/****************************************************************
+ *								*
+ * Copyright (c) 2018 YottaDB LLC. and/or its subsidiaries.	*
+ * All rights reserved.						*
+ *								*
+ *	This source code contains the intellectual property	*
+ *	of its copyright holder(s), and is made available	*
+ *	under a license.  If you do not know the terms of	*
+ *	the license, please stop and do not read further.	*
+ *								*
+ ****************************************************************/
+
+#include "mdef.h"
+
+#include <stdarg.h>
+
+#include "libyottadb_int.h"
+#include "gtmci.h"
+
+/* Simple YottaDB wrapper to do a call-in. Does name lookup on each call whereas "ydb_cip" does not. */
+int ydb_ci(const char *c_rtn_name, ...)
+{
+	va_list		var;
+	int		retval;
+	DCL_THREADGBL_ACCESS;
+
+	SETUP_THREADGBL_ACCESS;
+	/* Do not use LIBYOTTADB_INIT to avoid unnecessary SIMPLEAPINEST errors. Instead call LIBYOTTADB_RUNTIME_CHECK macro. */
+	LIBYOTTADB_RUNTIME_CHECK((int));		/* Note: macro could return from this function in case of errors */
+	VERIFY_NON_THREADED_API_DO_NOT_SHUTOFF_ACTIVE_RTN;	/* Need to call this version of VERIFY_NON_THREADED_API macro
+								 * since LIBYOTTADB_INIT was not called.
+								 */
+	/* "ydb_ci_exec" already sets up a condition handler "gtmci_ch" so we do not do an
+	 * ESTABLISH_RET of ydb_simpleapi_ch here like is done for other SimpleAPI function calls.
+	 */
+	VAR_START(var, c_rtn_name);
+	/* Note: "va_end(var)" done inside "ydb_ci_exec" */
+	retval = ydb_ci_exec(c_rtn_name, NULL, FALSE, var, FALSE);
+	return retval;
+}

sr_unix/ydb_cip.c

@@ -0,0 +1,42 @@
+/****************************************************************
+ *								*
+ * Copyright (c) 2018 YottaDB LLC. and/or its subsidiaries.	*
+ * All rights reserved.						*
+ *								*
+ *	This source code contains the intellectual property	*
+ *	of its copyright holder(s), and is made available	*
+ *	under a license.  If you do not know the terms of	*
+ *	the license, please stop and do not read further.	*
+ *								*
+ ****************************************************************/
+
+#include "mdef.h"
+
+#include <stdarg.h>
+
+#include "libyottadb_int.h"
+#include "gtmci.h"
+
+/* Fast path YottaDB wrapper to do a call-in.
+ * Adds a struct parm that contains name resolution info after first call to speed up dispatching.
+ */
+int ydb_cip(ci_name_descriptor* ci_info, ...)
+{
+	va_list		var;
+	int		retval;
+	DCL_THREADGBL_ACCESS;
+
+	SETUP_THREADGBL_ACCESS;
+	/* Do not use LIBYOTTADB_INIT to avoid unnecessary SIMPLEAPINEST errors. Instead call LIBYOTTADB_RUNTIME_CHECK macro. */
+	LIBYOTTADB_RUNTIME_CHECK((int));		/* Note: macro could return from this function in case of errors */
+	VERIFY_NON_THREADED_API_DO_NOT_SHUTOFF_ACTIVE_RTN;	/* Need to call this version of VERIFY_NON_THREADED_API macro
+								 * since LIBYOTTADB_INIT was not called.
+								 */
+	/* "ydb_ci_exec" already sets up a condition handler "gtmci_ch" so we do not do an
+	 * ESTABLISH_RET of ydb_simpleapi_ch here like is done for other SimpleAPI function calls.
+	 */
+	VAR_START(var, ci_info);
+	/* Note: "va_end(var)" done inside "ydb_ci_exec" */
+	retval = ydb_ci_exec(ci_info->rtn_name.address, ci_info->handle, TRUE, var, FALSE);
+	return retval;
+}

sr_unix/ydb_cip_helper.c

@@ -30,11 +30,14 @@ int ydb_cip_helper(int calltyp, ci_name_descriptor *ci_info, va_list *var)
 	SETUP_THREADGBL_ACCESS;
 	/* Verify entry conditions, make sure YDB CI environment is up etc. */
 	assert((LYDB_RTN_YDB_CI == calltyp) || (LYDB_RTN_YDB_CIP == calltyp));
+	/* Need to call VERIFY_THREADED_API before LIBYOTTADB_INIT.
+	 * Moving this to after LIBYOTTADB_INIT implies LIBYOTTADB_DONE would not be done in case of INVAPIMODE error.
+	 */
+	VERIFY_THREADED_API((int));
 	LIBYOTTADB_INIT(calltyp, (int));	/* Note: macro could "return" from this function in case of errors */
 	assert(0 == TREF(sapi_mstrs_for_gc_indx));	/* previously unused entries should have been cleared by that
 							 * corresponding ydb_*_s() call.
 							 */
-	VERIFY_THREADED_API((int));
 	ESTABLISH_NORET(ydb_simpleapi_ch, error_encountered);
 	if (error_encountered)
 	{

sr_unix/ydb_free.c

@@ -29,7 +29,7 @@ void ydb_free(void *ptr)
 	assert(0 == TREF(sapi_mstrs_for_gc_indx));	/* Previously unused entries should have been cleared by that
 							 * corresponding ydb_*_s() call.
 							 */
-	VERIFY_NON_THREADED_API;
+	VERIFY_NON_THREADED_API_NORETVAL;
 	ESTABLISH_NORET(ydb_simpleapi_ch, error_encountered);
 	if (error_encountered)
 	{	/* Some error occurred - just return to the caller ($ZSTATUS is set) */

sr_unix/ydb_hiber_start.c

@@ -19,7 +19,9 @@
 #include "libyottadb_int.h"
 #include "libydberrors.h"
 
+#ifdef DEBUG
 GBLREF	boolean_t	simpleThreadAPI_active;
+#endif
 
 /* Simple YottaDB wrapper for gtm_hiber_start() */
 int	ydb_hiber_start(unsigned long long sleep_nsec)
@@ -42,8 +44,7 @@ int	ydb_hiber_start(unsigned long long sleep_nsec)
 		return -(TREF(ydb_error_code));
 	}
 	ISSUE_TIME2LONG_ERROR_IF_NEEDED(sleep_nsec);
-	if (simpleThreadAPI_active)
-		rts_error_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_NOTSUPSTAPI, 2, RTS_ERROR_LITERAL("ydb_hiber_start()"));
+	assert(!simpleThreadAPI_active);	/* or else an INVAPIMODE error would have been issued in VERIFY_NON_THREADED_API */
 	assert(MAXPOSINT4 >= (sleep_nsec / NANOSECS_IN_MSEC));	/* Or else a TIME2LONG error would have been issued above */
 	sleep_msec = (sleep_nsec / NANOSECS_IN_MSEC);
 	sleepms = (int)sleep_msec;

sr_unix/ydb_hiber_start_wait_any.c

@@ -18,7 +18,9 @@
 #include "libyottadb_int.h"
 #include "libydberrors.h"
 
+#ifdef DEBUG
 GBLREF	boolean_t	simpleThreadAPI_active;
+#endif
 
 /* Simple YottaDB wrapper for gtm_hiber_start_wait_any() */
 int	ydb_hiber_start_wait_any(unsigned long long sleep_nsec)
@@ -41,8 +43,7 @@ int	ydb_hiber_start_wait_any(unsigned long long sleep_nsec)
 		return -(TREF(ydb_error_code));
 	}
 	ISSUE_TIME2LONG_ERROR_IF_NEEDED(sleep_nsec);
-	if (simpleThreadAPI_active)
-		rts_error_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_NOTSUPSTAPI, 2, RTS_ERROR_LITERAL("ydb_hiber_startwaut_any()"));
+	assert(!simpleThreadAPI_active);	/* or else an INVAPIMODE error would have been issued in VERIFY_NON_THREADED_API */
 	assert(MAXPOSINT4 >= (sleep_nsec / NANOSECS_IN_MSEC));	/* Or else a TIME2LONG error would have been issued above */
 	sleep_msec = (sleep_nsec / NANOSECS_IN_MSEC);
 	sleepms = (int)sleep_msec;

sr_unix/ydb_malloc.c

@@ -30,7 +30,7 @@ void *ydb_malloc(size_t size)
 	assert(0 == TREF(sapi_mstrs_for_gc_indx));		/* Previously unused entries should have been cleared by that
 								 * corresponding ydb_*_s() call.
 								 */
-	VERIFY_NON_THREADED_API;
+	VERIFY_NON_THREADED_API_RETNULL;
 	ESTABLISH_NORET(ydb_simpleapi_ch, error_encountered);
 	if (error_encountered)
 	{	/* Some error occurred - return NULL to the caller ($ZSTATUS is set) */

sr_unix/ydb_timer_cancel.c

@@ -29,7 +29,7 @@ void ydb_timer_cancel(int timer_id)
 	assert(0 == TREF(sapi_mstrs_for_gc_indx));		/* Previously unused entries should have been cleared by that
 								 * corresponding ydb_*_s() call.
 								 */
-	VERIFY_NON_THREADED_API;
+	VERIFY_NON_THREADED_API_NORETVAL;
 	ESTABLISH_NORET(ydb_simpleapi_ch, error_encountered);
 	if (error_encountered)
 	{	/* Some error occurred - just return to the caller ($ZSTATUS is set) */

sr_unix/ydb_tp_s_common.c

@@ -88,16 +88,19 @@ int ydb_tp_s_common(libyottadb_routines lydbrtn,
 	assert((LYDB_RTN_TP == lydbrtn)
 		|| (LYDB_RTN_TP_START == lydbrtn) || (LYDB_RTN_TP_COMMIT == lydbrtn)
 		|| (LYDB_RTN_TP_RESTART == lydbrtn) || (LYDB_RTN_TP_ROLLBACK == lydbrtn));
+	/* Need to call VERIFY_THREADED_API before LIBYOTTADB_INIT.
+	 * Moving this to after LIBYOTTADB_INIT implies LIBYOTTADB_DONE would not be done in case of INVAPIMODE error.
+	 */
+	if (LYDB_RTN_TP != lydbrtn)
+	{	/* We have been called via the threaded interface so verify we are in a threaded environment */
+		VERIFY_THREADED_API((int));
+	}
 	/* Verify entry conditions, make sure YDB CI environment is up etc. */
 	LIBYOTTADB_INIT(lydbrtn, (int));		/* Note: macro could "return" from this function in case of errors */
 	assert(0 == TREF(sapi_mstrs_for_gc_indx));	/* previously unused entries should have been cleared by that
 							 * corresponding ydb_*_s() call.
 							 */
-
-	if (LYDB_RTN_TP != lydbrtn)
-	{	/* We have been called via the threaded interface so verify we are in a threaded environment */
-		VERIFY_THREADED_API((int));
-	} else
+	if (LYDB_RTN_TP == lydbrtn)
 	{	/* We have been called as non-threaded so verify we are not threaded */
 		VERIFY_NON_THREADED_API;
 	}