VFD plugins (#602)

* Implement support for loading of Virtual File Drivers as plugins

Fix plugin caching for VOL connector and VFD plugins

Fix plugin iteration to skip paths that can't be opened

* Enable dynamic loading of VFDs with HDF5_DRIVER environment variable

* Temporarily disable error reporting during H5F_open double file open

* Default to using HDstat in h5_get_file_size for unknown VFDs

* Use macros for some environment variables that HDF5 interprets

* Update "null" and "ctl testing" VFDs

1 files changed, 15 insertions, 3 deletions

diff --git a/test/vfd.c b/test/vfd.c
index 4e9b9ee..ea526b1 100644
--- a/test/vfd.c
+++ b/test/vfd.c
@@ -51,7 +51,7 @@
 const char *FILENAME[] = {"sec2_file",            /*0*/
                           "core_file",            /*1*/
                           "family_file",          /*2*/
-                          "new_family_v16_",      /*3*/
+                          "new_family_v16",       /*3*/
                           "multi_file",           /*4*/
                           "direct_file",          /*5*/
                           "log_file",             /*6*/
@@ -68,7 +68,7 @@ const char *FILENAME[] = {"sec2_file",            /*0*/
 
 #define LOG_FILENAME "log_vfd_out.log"
 
-#define COMPAT_BASENAME       "family_v16_"
+#define COMPAT_BASENAME       "family_v16"
 #define MULTI_COMPAT_BASENAME "multi_file_v16"
 #define SPLITTER_DATASET_NAME "dataset"
 
@@ -3488,6 +3488,7 @@ H5FD__ctl_test_vfd_ctl(H5FD_t H5_ATTR_UNUSED *_file, uint64_t op_code, uint64_t
 
 /* Minimal VFD for ctl feature tests */
 static const H5FD_class_t H5FD_ctl_test_vfd_g = {
+    (H5FD_class_value_t)201,    /* value                 */
     "ctl_test_vfd",             /* name                  */
     HADDR_MAX,                  /* maxaddr               */
     H5F_CLOSE_SEMI,             /* fc_degree             */
@@ -3925,7 +3926,18 @@ error:
 int
 main(void)
 {
-    int nerrors = 0;
+    char *env_h5_drvr = NULL;
+    int   nerrors     = 0;
+
+    /* Don't run VFD tests when HDF5_DRIVER is set. These tests expect a
+     * specific VFD to be set and HDF5_DRIVER being set can interfere
+     * with that.
+     */
+    env_h5_drvr = HDgetenv(HDF5_DRIVER);
+    if (env_h5_drvr) {
+        HDprintf(" -- SKIPPED VFD tests because %s is set -- \n", HDF5_DRIVER);
+        HDexit(EXIT_SUCCESS);
+    }
 
     h5_reset();