diff --git a/ChangeLog.txt b/ChangeLog.txt
index f9c05398e2..9aa27bb6b5 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -7,6 +7,64 @@
    Entries may not always be in chronological/commit order.
    See license at the end of file. */
 
+2017-12-19 21:42 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * config/darwin/clang.mk
+  * config/darwin/gcc.mk
+  * config/darwin/global.mk
+  * config/darwin/icc.mk
+  * config/darwin/libs.mk
+  * utils/hbmk2/hbmk2.prg
+    * synced with Viktor's modifications in 3.4 branch:
+    ; 2017-11-11 13:14 UTC Viktor Szakats:
+    * switch to call the C compiler to link dynamic libs on darwin,
+      which is the recommended way to do this, as suggested by Apple.
+      This also aligns the platform better with other *nix platforms.
+      'libtool' was used before, but that started having intermittent
+      issues around Sierra (mitigated by disabling parallel build),
+      which returned and got worse in High Sierra (with no remedy).
+      The symptom was 'ld: file not found: ' errors with the filename
+      not shown or appearing as garbage, then a 'libtool: internal link
+      edit command failed'. This was reported and will be fixed in a
+      future Xcode release.
+      Ref: Apple Radar 34944562
+
+  * config/global.mk
+  * config/rules.mk
+    + added new user build envvar HB_USER_DCFLAGS
+      It allows to set C compiler parameters to compile .c code for
+      dynamic libraries.
+
+  * src/rtl/hbsocket.c
+    ! fixed fcntl(F_SETFL) 3-rd parameter in hb_socketSetBlockingIO(),
+      By mistake I used long instead of int. it created problem on big
+      endian 64 bit machines.
+
+  * include/hbgtcore.h
+  * src/rtl/hbgtcore.c
+    + added new C functions for GT programmers:
+         void hb_gt_BaseUnlock( PHB_GT pGT );
+         void hb_gt_BaseLock( PHB_GT pGT );
+         void hb_gtSleep( PHB_GT pGT, double dSeconds );
+
+  * src/rtl/hbgtcore.c
+  * src/rtl/gtcrs/gtcrs.c
+  * src/rtl/gtdos/gtdos.c
+  * src/rtl/gtgui/gtgui.c
+  * src/rtl/gtos2/gtos2.c
+  * src/rtl/gtpca/gtpca.c
+  * src/rtl/gtsln/gtsln.c
+  * src/rtl/gtstd/gtstd.c
+  * src/rtl/gttrm/gttrm.c
+  * src/rtl/gtwin/gtwin.c
+  * src/rtl/gtwvt/gtwvt.c
+  * src/rtl/gtxwc/gtxwc.c
+    * use new functions to unblock GT when low level TONE() code is
+      executed. It allows other threads to access shared GT driver
+      when one of them executes TONE()
+
+  * contrib/hbexpat/hbexpat.hbx
+    * regenerated automatically
+
 2017-12-15 19:53 UTC+0100 Aleksander Czajczynski (hb fki.pl)
   * contrib/hbexpat/3rd/expat/expat.hbp
     ! add missing bits, previous commit failed to include expat_co[nfig].h
diff --git a/config/darwin/clang.mk b/config/darwin/clang.mk
index c6e0380b2d..327d98ceb4 100644
--- a/config/darwin/clang.mk
+++ b/config/darwin/clang.mk
@@ -14,6 +14,10 @@ OBJ_EXT := .o
 LIB_PREF := lib
 LIB_EXT := .a
 
+ifeq ($(filter $(HB_PLATFORM),darwin win),)
+   HB_DYN_COPT := -DHB_DYNLIB -fPIC
+endif
+
 CC := $(HB_CCACHE) $(HB_CCPREFIX)$(HB_CMP)$(HB_CCSUFFIX)
 ifneq ($(filter --analyze, $(HB_USER_CFLAGS)),)
    CC_IN :=
@@ -53,18 +57,12 @@ LD := $(CC)
 LD_OUT := -o$(subst x,x, )
 
 LIBPATHS := $(foreach dir,$(LIB_DIR) $(SYSLIBPATHS),-L$(dir))
-LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 
+LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 LDFLAGS += $(LIBPATHS)
 
-AR := libtool
-AR_RULE = ( $(AR) -static -no_warning_for_no_symbols $(ARFLAGS) $(HB_AFLAGS) $(HB_USER_AFLAGS) -o $(LIB_DIR)/$@ $(^F) $(ARSTRIP) ) || ( $(RM) $(LIB_DIR)/$@ && $(FALSE) )
-
-DY := $(AR)
-DFLAGS += -dynamic -flat_namespace -undefined warning -multiply_defined suppress -single_module $(LIBPATHS)
-DY_OUT := -o$(subst x,x, )
+DY := $(CC)
 DLIBS := $(foreach lib,$(HB_USER_LIBS) $(SYSLIBS),-l$(lib))
-
-DY_RULE = $(DY) $(DFLAGS) -install_name "$(DYN_NAME_NVR)" -compatibility_version $(HB_VER_MAJOR).$(HB_VER_MINOR) -current_version $(HB_VER_MAJOR).$(HB_VER_MINOR).$(HB_VER_RELEASE) $(HB_USER_DFLAGS) $(DY_OUT)$(DYN_DIR)/$@ $^ $(DLIBS) $(DYSTRIP) && $(LN) $(@F) $(DYN_FILE_NVR) && $(LN) $(@F) $(DYN_FILE_CPT)
+DFLAGS += $(LIBPATHS)
 
 include $(TOP)$(ROOT)config/rules.mk
diff --git a/config/darwin/gcc.mk b/config/darwin/gcc.mk
index dd71eaad6c..d4f5bd1495 100644
--- a/config/darwin/gcc.mk
+++ b/config/darwin/gcc.mk
@@ -49,18 +49,12 @@ LD := $(CC)
 LD_OUT := -o$(subst x,x, )
 
 LIBPATHS := $(foreach dir,$(LIB_DIR) $(SYSLIBPATHS),-L$(dir))
-LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 
+LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 LDFLAGS += $(LIBPATHS)
 
-AR := libtool
-AR_RULE = ( $(AR) -static -no_warning_for_no_symbols $(ARFLAGS) $(HB_AFLAGS) $(HB_USER_AFLAGS) -o $(LIB_DIR)/$@ $(^F) $(ARSTRIP) ) || ( $(RM) $(LIB_DIR)/$@ && $(FALSE) )
-
-DY := $(AR)
-DFLAGS += -dynamic -flat_namespace -undefined warning -multiply_defined suppress -single_module $(LIBPATHS)
-DY_OUT := -o$(subst x,x, )
+DY := $(CC)
 DLIBS := $(foreach lib,$(HB_USER_LIBS) $(SYSLIBS),-l$(lib))
-
-DY_RULE = $(DY) $(DFLAGS) -install_name "$(DYN_NAME_NVR)" -compatibility_version $(HB_VER_MAJOR).$(HB_VER_MINOR) -current_version $(HB_VER_MAJOR).$(HB_VER_MINOR).$(HB_VER_RELEASE) $(HB_USER_DFLAGS) $(DY_OUT)$(DYN_DIR)/$@ $^ $(DLIBS) $(DYSTRIP) && $(LN) $(@F) $(DYN_FILE_NVR) && $(LN) $(@F) $(DYN_FILE_CPT)
+DFLAGS += $(LIBPATHS)
 
 include $(TOP)$(ROOT)config/rules.mk
diff --git a/config/darwin/global.mk b/config/darwin/global.mk
index c2d0dafa34..f17b8b30c9 100644
--- a/config/darwin/global.mk
+++ b/config/darwin/global.mk
@@ -13,3 +13,19 @@ ifneq ($(filter $(HB_BUILD_STRIP),all bin),)
    LDSTRIP = && strip $(BIN_DIR)/$@
    DYSTRIP = && strip -S $(DYN_DIR)/$@
 endif
+
+AR := libtool
+AR_RULE = ( $(AR) -static \
+   -no_warning_for_no_symbols $(ARFLAGS) $(HB_AFLAGS) $(HB_USER_AFLAGS) \
+   -o $(LIB_DIR)/$@ $(^F) $(ARSTRIP) ) \
+   || ( $(RM) $(LIB_DIR)/$@ && $(FALSE) )
+
+DY_OUT := -o$(subst x,x, )
+
+DY_RULE = $(DY) -dynamiclib -flat_namespace $(DFLAGS) \
+   -install_name "$(DYN_NAME_NVR)" \
+   -compatibility_version $(HB_VER_MAJOR).$(HB_VER_MINOR) \
+   -current_version $(HB_VER_MAJOR).$(HB_VER_MINOR).$(HB_VER_RELEASE) \
+   $(HB_USER_DFLAGS) $(DY_OUT)$(DYN_DIR)/$@ $^ $(DLIBS) $(DYSTRIP) \
+   && $(LN) $(@F) $(DYN_FILE_NVR) \
+   && $(LN) $(@F) $(DYN_FILE_CPT)
diff --git a/config/darwin/icc.mk b/config/darwin/icc.mk
index 04145f2e22..f6fd50949d 100644
--- a/config/darwin/icc.mk
+++ b/config/darwin/icc.mk
@@ -32,29 +32,12 @@ LD := $(CC)
 LD_OUT := -o
 
 LIBPATHS := $(foreach dir,$(LIB_DIR) $(SYSLIBPATHS),-L$(dir))
-LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 
+LDLIBS := $(foreach lib,$(HB_USER_LIBS) $(LIBS) $(SYSLIBS),-l$(lib))
 LDFLAGS += $(LIBPATHS)
 
-AR := libtool
-AR_RULE = ( $(AR) -static -no_warning_for_no_symbols $(ARFLAGS) $(HB_AFLAGS) $(HB_USER_AFLAGS) -o $(LIB_DIR)/$@ $(^F) $(ARSTRIP) ) || ( $(RM) $(LIB_DIR)/$@ && $(FALSE) )
-
-DY := $(AR)
-DFLAGS += -dynamic -flat_namespace -undefined warning -multiply_defined suppress -single_module $(LIBPATHS)
-DY_OUT := -o$(subst x,x, )
+DY := $(CC)
 DLIBS := $(foreach lib,$(HB_USER_LIBS) $(SYSLIBS),-l$(lib))
-
-# NOTE: The empty line directly before 'endef' HAS TO exist!
-define dynlib_object
-   @$(ECHO) $(ECHOQUOTE)$(subst \,/,$(file))$(ECHOQUOTE) >> __dyn__.tmp
-
-endef
-define create_dynlib
-   $(if $(wildcard __dyn__.tmp),@$(RM) __dyn__.tmp,)
-   $(foreach file,$^,$(dynlib_object))
-   $(DY) $(DFLAGS) -install_name "$(DYN_NAME_NVR)" -compatibility_version $(HB_VER_MAJOR).$(HB_VER_MINOR) -current_version $(HB_VER_MAJOR).$(HB_VER_MINOR).$(HB_VER_RELEASE) $(HB_USER_DFLAGS) $(DY_OUT)$(DYN_DIR)/$@ -filelist __dyn__.tmp $(DLIBS) $(DYSTRIP) && $(LN) $(@F) $(DYN_FILE_NVR) && $(LN) $(@F) $(DYN_FILE_CPT)
-endef
-
-DY_RULE = $(create_dynlib)
+DFLAGS += $(LIBPATHS)
 
 include $(TOP)$(ROOT)config/rules.mk
diff --git a/config/darwin/libs.mk b/config/darwin/libs.mk
index 2eb0e6a801..ddd7788244 100644
--- a/config/darwin/libs.mk
+++ b/config/darwin/libs.mk
@@ -6,6 +6,9 @@ ifneq ($(HB_LINKING_RTL),)
    endif
    ifneq ($(HB_HAS_CURSES),)
       SYSLIBS += $(HB_LIBNAME_CURSES)
+      ifneq ($(wildcard /usr/local/opt/ncurses/lib),)
+         SYSLIBPATHS += /usr/local/opt/ncurses/lib
+      endif
    endif
    ifneq ($(HB_HAS_SLANG),)
       SYSLIBS += slang
@@ -13,16 +16,24 @@ ifneq ($(HB_LINKING_RTL),)
       ifneq ($(HB_HAS_CURSES),)
          SYSLIBS += $(HB_LIBNAME_CURSES)
       endif
-      ifneq ($(wildcard /sw/lib),)
-         SYSLIBPATHS += /sw/lib
+      ifneq ($(wildcard /usr/local/lib),)
+         SYSLIBPATHS += /usr/local/lib
       endif
       ifneq ($(wildcard /opt/local/lib),)
          SYSLIBPATHS += /opt/local/lib
       endif
+      ifneq ($(wildcard /sw/lib),)
+         SYSLIBPATHS += /sw/lib
+      endif
    endif
    ifneq ($(HB_HAS_X11),)
       SYSLIBS += X11
-      SYSLIBPATHS += /usr/X11R6/lib
+      ifneq ($(wildcard /usr/X11R6/lib),)
+         SYSLIBPATHS += /usr/X11R6/lib
+      endif
+      ifneq ($(wildcard /opt/X11/lib),)
+         SYSLIBPATHS += /opt/X11/lib
+      endif
    endif
    ifneq ($(HB_HAS_PCRE),)
       ifeq ($(HB_HAS_PCRE_LOCAL),)
diff --git a/config/global.mk b/config/global.mk
index 9d23a88bfd..c4aa945921 100644
--- a/config/global.mk
+++ b/config/global.mk
@@ -208,6 +208,9 @@ ifeq ($(HB_INIT_DONE),)
    ifneq ($(HB_USER_DFLAGS),)
       $(info ! HB_USER_DFLAGS: $(HB_USER_DFLAGS))
    endif
+   ifneq ($(HB_USER_DCFLAGS),)
+      $(info ! HB_USER_DCFLAGS: $(HB_USER_DCFLAGS))
+   endif
    ifneq ($(HB_USER_LIBS),)
       $(info ! HB_USER_LIBS: $(HB_USER_LIBS))
    endif
diff --git a/config/rules.mk b/config/rules.mk
index 623ae04e95..a9b8dccc78 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -10,6 +10,10 @@ else
    endif
 endif
 
+ifneq ($(HB_USER_DCFLAGS),)
+   HB_DYN_COPT += $(HB_USER_DCFLAGS)
+endif
+
 ifeq ($(HB_DYN_COPT),)
    OBJ_DYN_SUFFIX :=
 else
diff --git a/contrib/hbexpat/hbexpat.hbx b/contrib/hbexpat/hbexpat.hbx
index d2807db5f0..387df59f53 100644
--- a/contrib/hbexpat/hbexpat.hbx
+++ b/contrib/hbexpat/hbexpat.hbx
@@ -39,6 +39,7 @@ DYNAMIC XML_GetSpecifiedAttributeCount
 DYNAMIC XML_GetUserData
 DYNAMIC XML_Parse
 DYNAMIC XML_ParserCreate
+DYNAMIC XML_ParserFree
 DYNAMIC XML_ParserReset
 DYNAMIC XML_ResumeParser
 DYNAMIC XML_SetAttlistDeclHandler
diff --git a/include/hbgtcore.h b/include/hbgtcore.h
index 6b6927ef2c..c92c41d6a0 100644
--- a/include/hbgtcore.h
+++ b/include/hbgtcore.h
@@ -347,6 +347,9 @@ typedef struct _HB_GT_BASE
 
 extern HB_EXPORT PHB_GT hb_gt_Base( void );
 extern HB_EXPORT void hb_gt_BaseFree( PHB_GT pGT );
+extern HB_EXPORT void hb_gt_BaseUnlock( PHB_GT pGT );
+extern HB_EXPORT void hb_gt_BaseLock( PHB_GT pGT );
+extern HB_EXPORT void hb_gtSleep( PHB_GT pGT, double dSeconds );
 extern HB_EXPORT PHB_GT hb_gt_ItemBase( PHB_ITEM pItemGT );
 extern HB_EXPORT void hb_gt_gcMark( void );
 
diff --git a/src/rtl/gtcrs/gtcrs.c b/src/rtl/gtcrs/gtcrs.c
index d1b4b59c73..2da64fe07c 100644
--- a/src/rtl/gtcrs/gtcrs.c
+++ b/src/rtl/gtcrs/gtcrs.c
@@ -2445,13 +2445,11 @@ static void hb_gt_crs_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 {
    HB_TRACE( HB_TR_DEBUG, ( "hb_gt_crs_Tone(%p,%lf,%lf)", ( void * ) pGT, dFrequency, dDuration ) );
 
-   HB_SYMBOL_UNUSED( pGT );
-
    gt_tone( s_ioBase, dFrequency, dDuration );
 
    if( s_ioBase->terminal_type == TERM_LINUX )
       /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-      hb_idleSleep( dDuration / 18.2 );
+      hb_gtSleep( pGT, dDuration / 18.2 );
 }
 
 /* *********************************************************************** */
diff --git a/src/rtl/gtdos/gtdos.c b/src/rtl/gtdos/gtdos.c
index 937dfb8304..68b52f4eae 100644
--- a/src/rtl/gtdos/gtdos.c
+++ b/src/rtl/gtdos/gtdos.c
@@ -984,7 +984,7 @@ static void hb_gt_dos_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 #endif
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pGT, dDuration / 18.2 );
 
 #if defined( __BORLANDC__ ) || defined( __WATCOMC__ )
    nosound();
diff --git a/src/rtl/gtgui/gtgui.c b/src/rtl/gtgui/gtgui.c
index e367b834d7..0dffd85dcc 100644
--- a/src/rtl/gtgui/gtgui.c
+++ b/src/rtl/gtgui/gtgui.c
@@ -258,8 +258,9 @@ static void hb_gt_gui_Tone( PHB_GT pGT, double dFrequency, double dDuration )
    HB_TRACE( HB_TR_DEBUG, ( "hb_gt_gui_Tone(%p,%lf,%lf)", ( void * ) pGT, dFrequency, dDuration ) );
 
 #if defined( HB_OS_WIN )
-   HB_SYMBOL_UNUSED( pGT );
+   hb_gt_BaseUnlock( pGT );
    hb_gt_winapi_tone( dFrequency, dDuration );
+   hb_gt_BaseLock( pGT );
 #else
    HB_GTSUPER_TONE( pGT, dFrequency, dDuration );
 #endif
diff --git a/src/rtl/gtos2/gtos2.c b/src/rtl/gtos2/gtos2.c
index 11478539a0..db7f3022a9 100644
--- a/src/rtl/gtos2/gtos2.c
+++ b/src/rtl/gtos2/gtos2.c
@@ -783,8 +783,6 @@ static void hb_gt_os2_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 
    HB_TRACE( HB_TR_DEBUG, ( "hb_gt_os2_Tone(%p,%lf,%lf)", ( void * ) pGT, dFrequency, dDuration ) );
 
-   HB_SYMBOL_UNUSED( pGT );
-
    /* The conversion from Clipper timer tick units to
       milliseconds is * 1000.0 / 18.2. */
 
@@ -794,12 +792,14 @@ static void hb_gt_os2_Tone( PHB_GT pGT, double dFrequency, double dDuration )
       dFrequency = 32767.0;
    ulDuration = ( ULONG ) ( dDuration * 1000.0 / 18.2 ); /* milliseconds */
 
+   hb_gt_BaseUnlock( pGT );
    while( ulDuration > 0 )
    {
       USHORT temp = ( USHORT ) HB_MIN( ulDuration, USHRT_MAX );
       ulDuration -= temp;
       DosBeep( ( USHORT ) dFrequency, temp );
    }
+   hb_gt_BaseLock( pGT );
 }
 
 static const char * hb_gt_os2_Version( PHB_GT pGT, int iType )
diff --git a/src/rtl/gtpca/gtpca.c b/src/rtl/gtpca/gtpca.c
index 671e8ecf2e..d2c5ac2a84 100644
--- a/src/rtl/gtpca/gtpca.c
+++ b/src/rtl/gtpca/gtpca.c
@@ -697,8 +697,6 @@ static void hb_gt_pca_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 
    HB_TRACE( HB_TR_DEBUG, ( "hb_gt_pca_Tone(%p, %lf, %lf)", ( void * ) pGT, dFrequency, dDuration ) );
 
-   HB_SYMBOL_UNUSED( pGT );
-
    /* Output an ASCII BEL character to cause a sound */
    /* but throttle to max once per second, in case of sound */
    /* effects prgs calling lots of short tone sequences in */
@@ -715,7 +713,7 @@ static void hb_gt_pca_Tone( PHB_GT pGT, double dFrequency, double dDuration )
    HB_SYMBOL_UNUSED( dFrequency );
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pGT, dDuration / 18.2 );
 }
 
 static void hb_gt_pca_Bell( PHB_GT pGT )
diff --git a/src/rtl/gtsln/gtsln.c b/src/rtl/gtsln/gtsln.c
index 3bd00ac3fe..16dc212725 100644
--- a/src/rtl/gtsln/gtsln.c
+++ b/src/rtl/gtsln/gtsln.c
@@ -777,8 +777,6 @@ static void hb_gt_sln_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 
    /* TODO: Implement this for other consoles than linux ? */
 
-   HB_SYMBOL_UNUSED( pGT );
-
    if( hb_sln_UnderLinuxConsole )
    {
       char escstr[ 64 ];
@@ -800,7 +798,7 @@ static void hb_gt_sln_Tone( PHB_GT pGT, double dFrequency, double dDuration )
       /* The conversion from Clipper (DOS) timer tick units to
          milliseconds is * 1000.0 / 18.2. */
       dDuration /= 18.2;
-      hb_idleSleep( dDuration );
+      hb_gtSleep( pGT, dDuration / 18.2 );
    }
 }
 
diff --git a/src/rtl/gtstd/gtstd.c b/src/rtl/gtstd/gtstd.c
index 8ada07bb5c..64e0f366cd 100644
--- a/src/rtl/gtstd/gtstd.c
+++ b/src/rtl/gtstd/gtstd.c
@@ -480,7 +480,7 @@ static void hb_gt_std_Tone( PHB_GT pGT, double dFrequency, double dDuration )
    HB_SYMBOL_UNUSED( dFrequency );
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pGT, dDuration / 18.2 );
 }
 
 static void hb_gt_std_Bell( PHB_GT pGT )
diff --git a/src/rtl/gttrm/gttrm.c b/src/rtl/gttrm/gttrm.c
index e058b45ec2..680807002f 100644
--- a/src/rtl/gttrm/gttrm.c
+++ b/src/rtl/gttrm/gttrm.c
@@ -1468,7 +1468,7 @@ static void hb_gt_trm_LinuxTone( PHB_GTTRM pTerm, double dFrequency, double dDur
    hb_gt_trm_termFlush( pTerm );
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pTerm->pGT, dDuration / 18.2 );
 }
 
 static void hb_gt_trm_LinuxSetCursorStyle( PHB_GTTRM pTerm, int iStyle )
@@ -1940,7 +1940,7 @@ static void hb_gt_trm_BsdTone( PHB_GTTRM pTerm, double dFrequency, double dDurat
    hb_gt_trm_termFlush( pTerm );
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pTerm->pGT, dDuration / 18.2 );
 }
 
 
@@ -2271,7 +2271,7 @@ static void hb_gt_trm_AnsiTone( PHB_GTTRM pTerm, double dFrequency, double dDura
    HB_SYMBOL_UNUSED( dFrequency );
 
    /* convert Clipper (DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pTerm->pGT, dDuration / 18.2 );
 }
 
 static void hb_gt_trm_AnsiInit( PHB_GTTRM pTerm )
diff --git a/src/rtl/gtwin/gtwin.c b/src/rtl/gtwin/gtwin.c
index c5edfa4f43..7c0815c771 100644
--- a/src/rtl/gtwin/gtwin.c
+++ b/src/rtl/gtwin/gtwin.c
@@ -1809,7 +1809,9 @@ static void hb_gt_win_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 
    HB_SYMBOL_UNUSED( pGT );
 
+   hb_gt_BaseUnlock( pGT );
    hb_gt_winapi_tone( dFrequency, dDuration );
+   hb_gt_BaseLock( pGT );
 }
 
 /* *********************************************************************** */
diff --git a/src/rtl/gtwvt/gtwvt.c b/src/rtl/gtwvt/gtwvt.c
index ad580ee1e6..2be1797c90 100644
--- a/src/rtl/gtwvt/gtwvt.c
+++ b/src/rtl/gtwvt/gtwvt.c
@@ -3504,7 +3504,9 @@ static void hb_gt_wvt_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 
    HB_SYMBOL_UNUSED( pGT );
 
+   hb_gt_BaseUnlock( pGT );
    hb_gt_winapi_tone( dFrequency, dDuration );
+   hb_gt_BaseLock( pGT );
 }
 
 /* ********************************************************************** */
diff --git a/src/rtl/gtxwc/gtxwc.c b/src/rtl/gtxwc/gtxwc.c
index 1304ec1c1b..719cb4ecb0 100644
--- a/src/rtl/gtxwc/gtxwc.c
+++ b/src/rtl/gtxwc/gtxwc.c
@@ -5138,7 +5138,7 @@ static void hb_gt_xwc_Tone( PHB_GT pGT, double dFrequency, double dDuration )
       XSync( wnd->dpy, False );
       HB_XWC_XLIB_UNLOCK( wnd->dpy );
    }
-   hb_idleSleep( dDuration );
+   hb_gtSleep( pGT, dDuration );
 }
 
 /* *********************************************************************** */
diff --git a/src/rtl/hbgtcore.c b/src/rtl/hbgtcore.c
index 6e71631b51..096bd259ba 100644
--- a/src/rtl/hbgtcore.c
+++ b/src/rtl/hbgtcore.c
@@ -82,6 +82,23 @@ void hb_gt_BaseFree( PHB_GT pGT )
       HB_GTSELF_UNLOCK( pGT );
 }
 
+void hb_gt_BaseUnlock( PHB_GT pGT )
+{
+   HB_GTSELF_UNLOCK( pGT );
+}
+
+void hb_gt_BaseLock( PHB_GT pGT )
+{
+   HB_GTSELF_LOCK( pGT );
+}
+
+void hb_gtSleep( PHB_GT pGT, double dSeconds )
+{
+   HB_GTSELF_UNLOCK( pGT );
+   hb_idleSleep( dSeconds );
+   HB_GTSELF_LOCK( pGT );
+}
+
 /* helper internal function */
 static void hb_gt_def_BaseInit( PHB_GT_BASE pGT )
 {
@@ -743,11 +760,10 @@ static void hb_gt_def_OutErr( PHB_GT pGT, const char * szStr, HB_SIZE nLen )
 
 static void hb_gt_def_Tone( PHB_GT pGT, double dFrequency, double dDuration )
 {
-   HB_SYMBOL_UNUSED( pGT );
    HB_SYMBOL_UNUSED( dFrequency );
 
    /* convert Clipper (MS-DOS) timer tick units to seconds ( x / 18.2 ) */
-   hb_idleSleep( dDuration / 18.2 );
+   hb_gtSleep( pGT, dDuration / 18.2 );
 }
 
 static void hb_gt_def_Bell( PHB_GT pGT )
diff --git a/src/rtl/hbsocket.c b/src/rtl/hbsocket.c
index 549d5fad89..9e4f734351 100644
--- a/src/rtl/hbsocket.c
+++ b/src/rtl/hbsocket.c
@@ -2786,7 +2786,7 @@ int hb_socketSetBlockingIO( HB_SOCKET sd, HB_BOOL fBlocking )
    if( ret != -1 )
    {
       HB_BOOL fBlocked;
-      long flags;
+      int flags;
       fBlocked = ( ret & O_NONBLOCK ) == 0;
       if( fBlocking ? ! fBlocked : fBlocked )
       {
diff --git a/utils/hbmk2/hbmk2.prg b/utils/hbmk2/hbmk2.prg
index 99b1abf806..bd59d81819 100644
--- a/utils/hbmk2/hbmk2.prg
+++ b/utils/hbmk2/hbmk2.prg
@@ -4111,11 +4111,10 @@ STATIC FUNCTION __hbmk( aArgs, nArgTarget, nLevel, /* @ */ lPause, /* @ */ lExit
          ENDIF
          AAddNotEmpty( hbmk[ _HBMK_aOPTCX ], gcc_opt_lngc_fill( hbmk ) )
          AAddNotEmpty( hbmk[ _HBMK_aOPTCPPX ], gcc_opt_lngcpp_fill( hbmk ) )
+         cBin_Dyn := cBin_CompC
          IF hbmk[ _HBMK_cPLAT ] == "darwin"
-            cBin_Dyn := cBin_Lib
-            cOpt_Dyn := "-dynamic -o {OD} -flat_namespace -undefined suppress -single_module {FD} {DL} {LO} {LS}" /* NOTE: -single_module is now the default in ld/libtool. */
+            cOpt_Dyn := "-dynamiclib -o {OD} -flat_namespace -undefined dynamic_lookup {FD} {DL} {LO} {LS}" /* NOTE: -single_module is now the default in ld/libtool. */
          ELSE
-            cBin_Dyn := cBin_CompC
             cOpt_Dyn := "-shared -o {OD} {LO} {FD} {DL} {LS}"
          ENDIF
          cBin_Link := cBin_CompC
@@ -4140,10 +4139,15 @@ STATIC FUNCTION __hbmk( aArgs, nArgTarget, nLevel, /* @ */ lPause, /* @ */ lExit
             AAdd( hbmk[ _HBMK_aOPTD ], "{LL} {LB} {LF}" )
             l_aLIBHBBASE_2 := iif( hbmk[ _HBMK_lMT ], aLIB_BASE_2_MT, aLIB_BASE_2 )
          ENDIF
+         IF hbmk[ _HBMK_cPLAT ] == "darwin"
+            /* Leave space for later modifying .dylib paths using `install_name_tool`.
+               '400' is a hexadecimal value. */
+            AAdd( hbmk[ _HBMK_aOPTL ], "-Wl,-headerpad,400" )
+            AAdd( hbmk[ _HBMK_aOPTD ], "-Wl,-headerpad,400" )
+         ENDIF
          IF hbmk[ _HBMK_lMAP ]
             IF hbmk[ _HBMK_cPLAT ] == "darwin"
                AAdd( hbmk[ _HBMK_aOPTL ], "-Wl,-map,{OM}" )
-               AAdd( hbmk[ _HBMK_aOPTD ], "-Wl,-map,{OM}" )
             ELSE
                AAdd( hbmk[ _HBMK_aOPTL ], "-Wl,-Map,{OM}" )
                AAdd( hbmk[ _HBMK_aOPTD ], "-Wl,-Map,{OM}" )