Add uuid generation to test programs.

.gitattributes

@@ -341,6 +341,8 @@ tests/cksum_read.c -text
 tests/cksum_verify.c -text
 tests/cksum_write.c -text
 tests/cksum_write_chunk.c -text
+tests/create_uuid.c -text
+tests/create_uuid.h -text
 tests/deco2d_model.c -text
 tests/ensure_array_size.c -text
 tests/ensure_array_size.h -text

Makefile.in

@@ -338,6 +338,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

app/Makefile.in

@@ -311,6 +311,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

configure

@@ -699,6 +699,7 @@ ax_pthread_config
 SYSTEM_TYPE
 HOST_NAME
 USER_NAME
+UUID_C_LIB
 AS
 CXXCPP
 am__fastdepCXX_FALSE
@@ -24323,24 +24324,13 @@ fi
 #  ----------------------------------------------------------------------
 # Checks for header files
-for ac_header in malloc.h
+for ac_header in malloc.h execinfo.h uuid.h uuid/uuid.h
 do :
-  ac_fn_c_check_header_mongrel "$LINENO" "malloc.h" "ac_cv_header_malloc_h" "$ac_includes_default"
-if test "x$ac_cv_header_malloc_h" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_MALLOC_H 1
-_ACEOF
-
-fi
-
-done
-
-for ac_header in execinfo.h
-do :
-  ac_fn_c_check_header_mongrel "$LINENO" "execinfo.h" "ac_cv_header_execinfo_h" "$ac_includes_default"
-if test "x$ac_cv_header_execinfo_h" = xyes; then :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_EXECINFO_H 1
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
 _ACEOF
 fi
@@ -24371,6 +24361,89 @@ _ACEOF
 fi
 done
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate in -luuid" >&5
+$as_echo_n "checking for uuid_generate in -luuid... " >&6; }
+if ${ac_cv_lib_uuid_uuid_generate+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-luuid  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char uuid_generate ();
+int
+main ()
+{
+return uuid_generate ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_uuid_uuid_generate=yes
+else
+  ac_cv_lib_uuid_uuid_generate=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_uuid_uuid_generate" >&5
+$as_echo "$ac_cv_lib_uuid_uuid_generate" >&6; }
+if test "x$ac_cv_lib_uuid_uuid_generate" = xyes; then :
+  ac_fn_c_check_decl "$LINENO" "uuid_generate" "ac_cv_have_decl_uuid_generate" "$ac_includes_default
+#include <uuid/uuid.h>
+"
+if test "x$ac_cv_have_decl_uuid_generate" = xyes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_UUID_GENERATE $ac_have_decl
+_ACEOF
+if test $ac_have_decl = 1; then :
+  UUID_C_LIB=-luuid
+fi
+
+else
+  for ac_func in uuid_create
+do :
+  ac_fn_c_check_func "$LINENO" "uuid_create" "ac_cv_func_uuid_create"
+if test "x$ac_cv_func_uuid_create" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_UUID_CREATE 1
+_ACEOF
+ ac_fn_c_check_decl "$LINENO" "uuid_create" "ac_cv_have_decl_uuid_create" "$ac_includes_default
+#include <uuid.h>
+"
+if test "x$ac_cv_have_decl_uuid_create" = xyes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_UUID_CREATE $ac_have_decl
+_ACEOF
+if test $ac_have_decl = 1; then :
+  UUID_C_LIB=""
+fi
+
+fi
+done
+
+fi
+
+
 #  ----------------------------------------------------------------------
 # Checks for the availability of ANSI-C99 functions
 ac_fn_c_check_decl "$LINENO" "isnan" "ac_cv_have_decl_isnan" "$ac_includes_default

configure.ac

@@ -64,12 +64,20 @@ AC_CHECK_LIB(malloc, malloc)
 AC_CHECK_MEMBERS([struct stat.st_blksize])
 #  ----------------------------------------------------------------------
 # Checks for header files
-AC_CHECK_HEADERS(malloc.h)
-AC_CHECK_HEADERS(execinfo.h)
+AC_CHECK_HEADERS([malloc.h execinfo.h uuid.h uuid/uuid.h])
 #  ----------------------------------------------------------------------
 # Checks for the availability of functions
 AC_CHECK_FUNCS([mallinfo])
 AC_CHECK_FUNCS([getline])
+AC_CHECK_LIB([uuid],[uuid_generate],
+  [AC_CHECK_DECLS([uuid_generate],
+  [UUID_C_LIB=-luuid],,[AC_INCLUDES_DEFAULT
+@%:@include <uuid/uuid.h>])],
+  [AC_CHECK_FUNCS([uuid_create],
+     [AC_CHECK_DECLS([uuid_create],
+        [UUID_C_LIB=""],,[AC_INCLUDES_DEFAULT
+@%:@include <uuid.h>])])])
+AC_SUBST([UUID_C_LIB])
 #  ----------------------------------------------------------------------
 # Checks for the availability of ANSI-C99 functions
 AC_CHECK_DECLS([isnan],,,[AC_INCLUDES_DEFAULT

examples/Makefile.in

@@ -359,6 +359,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

examples/pio/Makefile.in

@@ -353,6 +353,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

interfaces/Makefile.in

@@ -337,6 +337,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

src/Makefile.in

@@ -364,6 +364,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@

src/config.h.in

@@ -16,6 +16,14 @@
    */
 #undef HAVE_DECL_ISNAN
 
+/* Define to 1 if you have the declaration of `uuid_create', and to 0 if you
+   don't. */
+#undef HAVE_DECL_UUID_CREATE
+
+/* Define to 1 if you have the declaration of `uuid_generate', and to 0 if you
+   don't. */
+#undef HAVE_DECL_UUID_GENERATE
+
 /* Define to 1 if you have the declaration of `__builtin_ctz', and to 0 if you
    don't. */
 #undef HAVE_DECL___BUILTIN_CTZ
@@ -167,6 +175,15 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
+/* Define to 1 if you have the `uuid_create' function. */
+#undef HAVE_UUID_CREATE
+
+/* Define to 1 if you have the <uuid.h> header file. */
+#undef HAVE_UUID_H
+
+/* Define to 1 if you have the <uuid/uuid.h> header file. */
+#undef HAVE_UUID_UUID_H
+
 /* yaxt library is available */
 #undef HAVE_YAXT
 

tests/Makefile.am

@@ -22,24 +22,26 @@ cksum_read_SOURCES = cksum_read.c \
 	stream_cksum.c stream_cksum.h \
 	ensure_array_size.h ensure_array_size.c
 pio_write_SOURCES = pio_write.c pio_write.h simple_model.c \
-	simple_model_helper.h simple_model_helper.c
+	simple_model_helper.h simple_model_helper.c \
+	create_uuid.h create_uuid.c
 pio_write_deco2d_SOURCES = pio_write.c pio_write.h deco2d_model.c \
-	simple_model_helper.h simple_model_helper.c
+	simple_model_helper.h simple_model_helper.c \
+	create_uuid.h create_uuid.c
 test_resource_copy_SOURCES = test_resource_copy.c \
 	$(top_srcdir)/src/resource_unpack.c
 test_resource_copy_mpi_SOURCES = test_resource_copy.c
 #
 AM_CFLAGS = $(PPM_CORE_CFLAGS) $(YAXT_CFLAGS)
 if USE_MPI
-pio_write_LDADD = ../src/libcdipio.la
-pio_write_deco2d_LDADD = ../src/libcdipio.la
+pio_write_LDADD = ../src/libcdipio.la $(UUID_C_LIB)
+pio_write_deco2d_LDADD = ../src/libcdipio.la $(UUID_C_LIB)
 TESTS +=  test_resource_copy_mpi_run
 check_PROGRAMS += test_resource_copy_mpi
 test_resource_copy_mpi_LDADD = ../src/libcdipio.la
 test_resource_copy_mpi_CFLAGS = $(AM_CFLAGS) $(CFLAGS) -DMPI_MARSHALLING
 else
-pio_write_LDADD = $(LDADD)
-pio_write_deco2d_LDADD = $(LDADD)
+pio_write_LDADD = $(LDADD) $(UUID_C_LIB)
+pio_write_deco2d_LDADD = $(LDADD) $(UUID_C_LIB)
 endif
 
 LDADD = ../src/libcdi.la -lm

tests/Makefile.in

@@ -153,16 +153,22 @@ cksum_write_chunk_OBJECTS = $(am_cksum_write_chunk_OBJECTS)
 cksum_write_chunk_LDADD = $(LDADD)
 cksum_write_chunk_DEPENDENCIES = ../src/libcdi.la
 am_pio_write_OBJECTS = pio_write.$(OBJEXT) simple_model.$(OBJEXT) \
-	simple_model_helper.$(OBJEXT)
+	simple_model_helper.$(OBJEXT) create_uuid.$(OBJEXT)
 pio_write_OBJECTS = $(am_pio_write_OBJECTS)
 am__DEPENDENCIES_1 = ../src/libcdi.la
-@USE_MPI_FALSE@pio_write_DEPENDENCIES = $(am__DEPENDENCIES_1)
-@USE_MPI_TRUE@pio_write_DEPENDENCIES = ../src/libcdipio.la
+am__DEPENDENCIES_2 =
+@USE_MPI_FALSE@pio_write_DEPENDENCIES = $(am__DEPENDENCIES_1) \
+@USE_MPI_FALSE@	$(am__DEPENDENCIES_2)
+@USE_MPI_TRUE@pio_write_DEPENDENCIES = ../src/libcdipio.la \
+@USE_MPI_TRUE@	$(am__DEPENDENCIES_2)
 am_pio_write_deco2d_OBJECTS = pio_write.$(OBJEXT) \
-	deco2d_model.$(OBJEXT) simple_model_helper.$(OBJEXT)
+	deco2d_model.$(OBJEXT) simple_model_helper.$(OBJEXT) \
+	create_uuid.$(OBJEXT)
 pio_write_deco2d_OBJECTS = $(am_pio_write_deco2d_OBJECTS)
-@USE_MPI_FALSE@pio_write_deco2d_DEPENDENCIES = $(am__DEPENDENCIES_1)
-@USE_MPI_TRUE@pio_write_deco2d_DEPENDENCIES = ../src/libcdipio.la
+@USE_MPI_FALSE@pio_write_deco2d_DEPENDENCIES = $(am__DEPENDENCIES_1) \
+@USE_MPI_FALSE@	$(am__DEPENDENCIES_2)
+@USE_MPI_TRUE@pio_write_deco2d_DEPENDENCIES = ../src/libcdipio.la \
+@USE_MPI_TRUE@	$(am__DEPENDENCIES_2)
 am_test_grib_OBJECTS = test_grib.$(OBJEXT)
 test_grib_OBJECTS = $(am_test_grib_OBJECTS)
 test_grib_LDADD = $(LDADD)
@@ -396,6 +402,7 @@ THREADS_INCLUDE = @THREADS_INCLUDE@
 THREADS_LIBS = @THREADS_LIBS@
 USER_NAME = @USER_NAME@
 USE_MPI = @USE_MPI@
+UUID_C_LIB = @UUID_C_LIB@
 VERSION = @VERSION@
 YAXT_CFLAGS = @YAXT_CFLAGS@
 YAXT_LIBS = @YAXT_LIBS@
@@ -470,10 +477,12 @@ cksum_read_SOURCES = cksum_read.c \
 	ensure_array_size.h ensure_array_size.c
 
 pio_write_SOURCES = pio_write.c pio_write.h simple_model.c \
-	simple_model_helper.h simple_model_helper.c
+	simple_model_helper.h simple_model_helper.c \
+	create_uuid.h create_uuid.c
 
 pio_write_deco2d_SOURCES = pio_write.c pio_write.h deco2d_model.c \
-	simple_model_helper.h simple_model_helper.c
+	simple_model_helper.h simple_model_helper.c \
+	create_uuid.h create_uuid.c
 
 test_resource_copy_SOURCES = test_resource_copy.c \
 	$(top_srcdir)/src/resource_unpack.c
@@ -481,10 +490,10 @@ test_resource_copy_SOURCES = test_resource_copy.c \
 test_resource_copy_mpi_SOURCES = test_resource_copy.c
 #
 AM_CFLAGS = $(PPM_CORE_CFLAGS) $(YAXT_CFLAGS)
-@USE_MPI_FALSE@pio_write_LDADD = $(LDADD)
-@USE_MPI_TRUE@pio_write_LDADD = ../src/libcdipio.la
-@USE_MPI_FALSE@pio_write_deco2d_LDADD = $(LDADD)
-@USE_MPI_TRUE@pio_write_deco2d_LDADD = ../src/libcdipio.la
+@USE_MPI_FALSE@pio_write_LDADD = $(LDADD) $(UUID_C_LIB)
+@USE_MPI_TRUE@pio_write_LDADD = ../src/libcdipio.la $(UUID_C_LIB)
+@USE_MPI_FALSE@pio_write_deco2d_LDADD = $(LDADD) $(UUID_C_LIB)
+@USE_MPI_TRUE@pio_write_deco2d_LDADD = ../src/libcdipio.la $(UUID_C_LIB)
 @USE_MPI_TRUE@test_resource_copy_mpi_LDADD = ../src/libcdipio.la
 @USE_MPI_TRUE@test_resource_copy_mpi_CFLAGS = $(AM_CFLAGS) $(CFLAGS) -DMPI_MARSHALLING
 LDADD = ../src/libcdi.la -lm
@@ -619,6 +628,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/cksum_verify.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/cksum_write.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/cksum_write_chunk.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/create_uuid.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/deco2d_model.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ensure_array_size.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pio_write.Po@am__quote@

tests/cksum_write.c

@@ -216,6 +216,28 @@ main(int argc, char *argv[])
   zaxisID[1] = zaxisCreate(ZAXIS_PRESSURE, nlev);
   zaxisDefLevels(zaxisID[1], levs);
 
+  /* add uuids to zaxis and grid */
+  {
+    unsigned char uuid[16];
+    int str2uuid(const char *uuidstr, unsigned char *uuid);
+
+    static char gridUUIDTxt[] = "107d7a5b-348c-4d1a-90a9-d745914f2fb6";
+
+    str2uuid(gridUUIDTxt, uuid);
+    gridDefUUID(gridID, uuid);
+
+    static char zaxisUUIDTxt[2][37] = {
+      { "d157f399-5496-4097-a3d8-437a6dda6311" },
+      { "6f784a65-bce8-48c9-afa4-4c40130709c7" }
+    };
+
+    for (int i = 0; i < 2; ++i)
+      {
+        str2uuid(zaxisUUIDTxt[i], uuid);
+        zaxisDefUUID(zaxisID[i], uuid);
+      }
+  }
+
   // Create a Time axis
   taxisID = taxisCreate(TAXIS_ABSOLUTE);
 
@@ -241,7 +263,7 @@ main(int argc, char *argv[])
   // Assign the Time axis to the variable list
   vlistDefTaxis(vlistID, taxisID);
 
-  // Create a dataset in netCDF fromat
+  // Create a dataset
   {
     char *fname = fname_create(prefix, suffix);
     if ((streamID = streamOpenWrite(fname, filetype)) < 0)

tests/create_uuid.c

+#if defined (HAVE_CONFIG_H)
+#  include "config.h"
+#endif
+
+#define _XOPEN_SOURCE 600
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "create_uuid.h"
+
+
+
+#ifdef HAVE_DECL_UUID_GENERATE
+#include <sys/time.h>
+#include <uuid/uuid.h>
+void
+create_uuid(unsigned char *uuid)
+{
+  static int uuid_seeded = 0;
+  static char uuid_rand_state[31 * sizeof (long)];
+  char *caller_rand_state;
+  if (uuid_seeded)
+    caller_rand_state = setstate(uuid_rand_state);
+  else
+    {
+      struct timeval tv;
+      int status = gettimeofday(&tv, NULL);
+      if (status != 0)
+        {
+          perror("uuid random seed generation failed!");
+          exit(1);
+        }
+      unsigned seed = (unsigned)(tv.tv_sec ^ tv.tv_usec);
+      caller_rand_state = initstate(seed, uuid_rand_state,
+                                    sizeof (uuid_rand_state));
+      uuid_seeded = 1;
+    }
+  uuid_generate(uuid);
+  setstate(caller_rand_state);
+}
+#elif defined (HAVE_DECL_UUID_CREATE)
+typedef uint8_t u_int8_t;
+typedef uint16_t u_int16_t;
+typedef uint32_t u_int32_t;
+#include <uuid.h>
+void
+create_uuid(unsigned char *uuid)
+{
+  unsigned32 status;
+  uuid_create((uuid_t *)uuid, &status);
+  if (status == -1)
+    {
+      perror("uuid generation failed!");
+      exit(1);
+    }
+}
+#else
+#include <sys/time.h>
+void
+create_uuid(unsigned char *uuid)
+{
+  static int uuid_seeded = 0;
+  static char uuid_rand_state[31 * sizeof (long)];
+  char *caller_rand_state;
+  if (uuid_seeded)
+    caller_rand_state = setstate(uuid_rand_state);
+  else
+    {
+      struct timeval tv;
+      int status = gettimeofday(&tv, NULL);
+      if (status != 0)
+        {
+          perror("failed seed generation!");
+          exit(1);
+        }
+      unsigned seed = tv.tv_sec ^ tv.tv_usec;
+      caller_rand_state = initstate(seed, uuid_rand_state,
+                                    sizeof (uuid_rand_state));
+      uuid_seeded = 1;
+    }
+  for (size_t i = 0; i < CDI_UUID_SIZE; ++i)
+    uuid[i] = (unsigned char)random();
+  /* encode variant into msb of octet 8 */
+  uuid[8] = (unsigned char)((uuid[8] & 0x3f) | (1 << 7));
+  /* encode version 4 ((pseudo-)random uuid) into msb of octet 7 */
+  uuid[7] = (unsigned char)((uuid[7] & 0x0f) | (4 << 4));
+  setstate(caller_rand_state);
+}
+#endif

tests/create_uuid.h

+#ifndef CREATE_UUID_H
+#define CREATE_UUID_H
+
+#if defined (HAVE_CONFIG_H)
+#  include "config.h"
+#endif
+
+#include "cdi.h"
+
+void
+create_uuid(unsigned char uuid[CDI_UUID_SIZE]);
+
+#endif

tests/simple_model.c

@@ -29,6 +29,7 @@ typedef int MPI_Comm;
 #include "pio_write.h"
 
 #include "simple_model_helper.h"
+#include "create_uuid.h"
 
 enum {
   ntfiles     = 2,
@@ -114,7 +115,15 @@ modelRun(struct model_config setup, MPI_Comm comm)
     lats[i] = ((double)(i * 180))/nlat - 90.0;
   gridDefXvals ( gridID, lons );
   gridDefYvals ( gridID, lats );
-
+  {
+    unsigned char uuid[CDI_UUID_SIZE];
+    if (rank == 0)
+      create_uuid(uuid);
+#if USE_MPI
+    MPI_Bcast(uuid, CDI_UUID_SIZE, MPI_UNSIGNED_CHAR, 0, comm);
+#endif
+    gridDefUUID(gridID, uuid);
+  }
   levs = xmalloc((size_t)setup.max_nlev * sizeof (levs[0]));
   for (i = 0; i < setup.max_nlev; ++i)
     levs[i] = 101300.0
@@ -146,9 +155,23 @@ modelRun(struct model_config setup, MPI_Comm comm)
             varDesc[varIdx].zaxisID = varDesc[i].zaxisID;
             goto zaxisIDset;
           }
-      varDesc[varIdx].zaxisID
-        = zaxisCreate(ZAXIS_PRESSURE, varDesc[varIdx].nlev);
-      zaxisDefLevels(varDesc[varIdx].zaxisID, levs);
+      if (varLevs == 1)
+        varDesc[varIdx].zaxisID = zaxisCreate(ZAXIS_SURFACE, 1);
+      else
+        {
+          varDesc[varIdx].zaxisID
+            = zaxisCreate(ZAXIS_PRESSURE, varDesc[varIdx].nlev);
+          zaxisDefLevels(varDesc[varIdx].zaxisID, levs);
+        }
+      {
+        unsigned char uuid[16];
+        if (rank == 0)
+          create_uuid(uuid);
+#if USE_MPI
+        MPI_Bcast(uuid, CDI_UUID_SIZE, MPI_UNSIGNED_CHAR, 0, comm);
+#endif
+        zaxisDefUUID(varDesc[varIdx].zaxisID, uuid);
+      }
       zaxisIDset:
       varDesc[varIdx].id
         = vlistDefVar(vlistID, gridID, varDesc[varIdx].zaxisID, TIME_VARIABLE);