[svn-r26460] HDFFV-8520: Add api to control plugins

h5committest

11 files changed, 335 insertions, 183 deletions

diff --git a/MANIFEST b/MANIFEST
index cbd58c2..f1ce7ed 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -742,6 +742,7 @@
 ./src/H5Ptest.c
 ./src/H5PL.c
 ./src/H5PLprivate.h
+./src/H5PLpublic.h
 ./src/H5PLextern.h
 ./src/H5R.c
 ./src/H5Rdeprec.c
diff --git a/hl/src/H5LTparse.c b/hl/src/H5LTparse.c
index 36591d3..6ca95c54 100644
--- a/hl/src/H5LTparse.c
+++ b/hl/src/H5LTparse.c
@@ -1641,229 +1641,229 @@ yyreduce:
   switch (yyn)
     {
         case 2:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 101 "H5LTparse.y"
     { memset(arr_stack, 0, STACK_SIZE*sizeof(struct arr_info)); /*initialize here?*/ }
     break;
 
   case 3:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 102 "H5LTparse.y"
     { return (yyval.hid);}
     break;
 
   case 13:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 116 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I8BE); }
     break;
 
   case 14:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 117 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I8LE); }
     break;
 
   case 15:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 118 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I16BE); }
     break;
 
   case 16:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 119 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I16LE); }
     break;
 
   case 17:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 120 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I32BE); }
     break;
 
   case 18:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 121 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I32LE); }
     break;
 
   case 19:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 122 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I64BE); }
     break;
 
   case 20:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 123 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_I64LE); }
     break;
 
   case 21:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 124 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U8BE); }
     break;
 
   case 22:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 125 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U8LE); }
     break;
 
   case 23:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 126 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U16BE); }
     break;
 
   case 24:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 127 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U16LE); }
     break;
 
   case 25:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 128 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U32BE); }
     break;
 
   case 26:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 129 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U32LE); }
     break;
 
   case 27:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 130 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U64BE); }
     break;
 
   case 28:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 131 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_STD_U64LE); }
     break;
 
   case 29:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 132 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_CHAR); }
     break;
 
   case 30:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 133 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_SCHAR); }
     break;
 
   case 31:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 134 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_UCHAR); }
     break;
 
   case 32:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 135 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_SHORT); }
     break;
 
   case 33:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 136 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_USHORT); }
     break;
 
   case 34:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 137 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_INT); }
     break;
 
   case 35:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 138 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_UINT); }
     break;
 
   case 36:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 139 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_LONG); }
     break;
 
   case 37:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 140 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_ULONG); }
     break;
 
   case 38:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 141 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_LLONG); }
     break;
 
   case 39:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 142 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_ULLONG); }
     break;
 
   case 40:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 145 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_IEEE_F32BE); }
     break;
 
   case 41:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 146 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_IEEE_F32LE); }
     break;
 
   case 42:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 147 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_IEEE_F64BE); }
     break;
 
   case 43:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 148 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_IEEE_F64LE); }
     break;
 
   case 44:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 149 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_FLOAT); }
     break;
 
   case 45:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 150 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_DOUBLE); }
     break;
 
   case 46:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 151 "H5LTparse.y"
     { (yyval.hid) = H5Tcopy(H5T_NATIVE_LDOUBLE); }
     break;
 
   case 47:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 155 "H5LTparse.y"
     { csindex++; cmpd_stack[csindex].id = H5Tcreate(H5T_COMPOUND, 1); /*temporarily set size to 1*/ }
     break;
 
   case 48:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 157 "H5LTparse.y"
     { (yyval.hid) = cmpd_stack[csindex].id; 
                               cmpd_stack[csindex].id = 0;
@@ -1873,13 +1873,13 @@ yyreduce:
     break;
 
   case 51:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 166 "H5LTparse.y"
     { cmpd_stack[csindex].is_field = 1; /*notify lexer a compound member is parsed*/ }
     break;
 
   case 52:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 168 "H5LTparse.y"
     {   
                             size_t origin_size, new_size;
@@ -1915,7 +1915,7 @@ yyreduce:
     break;
 
   case 53:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 201 "H5LTparse.y"
     {
                             (yyval.sval) = yylval.sval;
@@ -1923,25 +1923,25 @@ yyreduce:
     break;
 
   case 54:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 206 "H5LTparse.y"
     { (yyval.ival) = 0; }
     break;
 
   case 55:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 208 "H5LTparse.y"
     { (yyval.ival) = yylval.ival; }
     break;
 
   case 57:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 212 "H5LTparse.y"
     { asindex++; /*pushd onto the stack*/ }
     break;
 
   case 58:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 214 "H5LTparse.y"
     { 
                           (yyval.hid) = H5Tarray_create2((yyvsp[(5) - (6)].hid), arr_stack[asindex].ndims, arr_stack[asindex].dims);
@@ -1952,13 +1952,13 @@ yyreduce:
     break;
 
   case 61:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 224 "H5LTparse.y"
     { arr_stack[asindex].is_dim = 1; /*notice lexer of dimension size*/ }
     break;
 
   case 62:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 225 "H5LTparse.y"
     { unsigned ndims = arr_stack[asindex].ndims;
                                   arr_stack[asindex].dims[ndims] = (hsize_t)yylval.ival; 
@@ -1968,19 +1968,19 @@ yyreduce:
     break;
 
   case 65:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 236 "H5LTparse.y"
     { (yyval.hid) = H5Tvlen_create((yyvsp[(3) - (4)].hid)); H5Tclose((yyvsp[(3) - (4)].hid)); }
     break;
 
   case 66:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 241 "H5LTparse.y"
     { is_opq_size = 1; }
     break;
 
   case 67:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 242 "H5LTparse.y"
     {   
                                 size_t size = (size_t)yylval.ival;
@@ -1990,13 +1990,13 @@ yyreduce:
     break;
 
   case 68:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 247 "H5LTparse.y"
     { is_opq_tag = 1; }
     break;
 
   case 69:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 248 "H5LTparse.y"
     {  
                                 H5Tset_tag((yyvsp[(7) - (13)].hid), yylval.sval);
@@ -2005,19 +2005,19 @@ yyreduce:
     break;
 
   case 70:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 252 "H5LTparse.y"
     { (yyval.hid) = (yyvsp[(7) - (15)].hid); }
     break;
 
   case 73:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 260 "H5LTparse.y"
     { is_str_size = 1; }
     break;
 
   case 74:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 261 "H5LTparse.y"
     {  
                                 if((yyvsp[(5) - (6)].ival) == H5T_VARIABLE_TOKEN)
@@ -2029,7 +2029,7 @@ yyreduce:
     break;
 
   case 75:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 269 "H5LTparse.y"
     {
                                 if((yyvsp[(9) - (10)].ival) == H5T_STR_NULLTERM_TOKEN)
@@ -2042,7 +2042,7 @@ yyreduce:
     break;
 
   case 76:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 278 "H5LTparse.y"
     {  
                                 if((yyvsp[(13) - (14)].ival) == H5T_CSET_ASCII_TOKEN)
@@ -2053,7 +2053,7 @@ yyreduce:
     break;
 
   case 77:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 285 "H5LTparse.y"
     {
                                 if((yyvsp[(17) - (18)].hid) == H5T_C_S1_TOKEN)
@@ -2064,7 +2064,7 @@ yyreduce:
     break;
 
   case 78:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 292 "H5LTparse.y"
     {   
                                 hid_t str_id = (yyvsp[(19) - (20)].hid);
@@ -2085,67 +2085,67 @@ yyreduce:
     break;
 
   case 79:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 309 "H5LTparse.y"
     {(yyval.ival) = H5T_VARIABLE_TOKEN;}
     break;
 
   case 81:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 312 "H5LTparse.y"
     {(yyval.ival) = H5T_STR_NULLTERM_TOKEN;}
     break;
 
   case 82:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 313 "H5LTparse.y"
     {(yyval.ival) = H5T_STR_NULLPAD_TOKEN;}
     break;
 
   case 83:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 314 "H5LTparse.y"
     {(yyval.ival) = H5T_STR_SPACEPAD_TOKEN;}
     break;
 
   case 84:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 316 "H5LTparse.y"
     {(yyval.ival) = H5T_CSET_ASCII_TOKEN;}
     break;
 
   case 85:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 317 "H5LTparse.y"
     {(yyval.ival) = H5T_CSET_UTF8_TOKEN;}
     break;
 
   case 86:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 319 "H5LTparse.y"
     {(yyval.hid) = H5T_C_S1_TOKEN;}
     break;
 
   case 87:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 320 "H5LTparse.y"
     {(yyval.hid) = H5T_FORTRAN_S1_TOKEN;}
     break;
 
   case 88:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 324 "H5LTparse.y"
     { is_enum = 1; enum_id = H5Tenum_create((yyvsp[(3) - (4)].hid)); H5Tclose((yyvsp[(3) - (4)].hid)); }
     break;
 
   case 89:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 326 "H5LTparse.y"
     { is_enum = 0; /*reset*/ (yyval.hid) = enum_id; }
     break;
 
   case 92:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 331 "H5LTparse.y"
     {
                                                 is_enum_memb = 1; /*indicate member of enum*/
@@ -2158,7 +2158,7 @@ yyreduce:
     break;
 
   case 93:
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 340 "H5LTparse.y"
     {
                                 char char_val=(char)yylval.ival;
@@ -2205,7 +2205,7 @@ yyreduce:
     break;
 
 
-/* Line 1792 of yacc.c  */
+/* Line 1807 of yacc.c  */
 #line 2191 "H5LTparse.c"
       default: break;
     }
diff --git a/hl/src/H5LTparse.h b/hl/src/H5LTparse.h
index 1461830..621dacd 100644
--- a/hl/src/H5LTparse.h
+++ b/hl/src/H5LTparse.h
@@ -109,7 +109,7 @@ extern int H5LTyydebug;
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 typedef union YYSTYPE
 {
-/* Line 2058 of yacc.c  */
+/* Line 2065 of yacc.c  */
 #line 68 "H5LTparse.y"
 
     int     ival;         /*for integer token*/
@@ -117,7 +117,7 @@ typedef union YYSTYPE
     hid_t   hid;          /*for hid_t token*/
 
 
-/* Line 2058 of yacc.c  */
+/* Line 2065 of yacc.c  */
 #line 122 "H5LTparse.h"
 } YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1
diff --git a/src/H5PL.c b/src/H5PL.c
index 96a4415..d691eb5 100644
--- a/src/H5PL.c
+++ b/src/H5PL.c
@@ -23,11 +23,12 @@
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"		/* Generic Functions			*/
-#include "H5Eprivate.h"		/* Error handling		  	*/
-#include "H5MMprivate.h"	/* Memory management			*/
-#include "H5PLprivate.h"	/* Plugin       			*/
-#include "H5Zprivate.h"		/* Filter pipeline			*/
+#include "H5private.h"      /* Generic Functions            */
+#include "H5Eprivate.h"     /* Error handling               */
+#include "H5MMprivate.h"    /* Memory management            */
+#include "H5PLprivate.h"    /* Plugin                       */
+#include "H5Zprivate.h"     /* Filter pipeline              */
+
 
 /****************/
 /* Local Macros */
@@ -96,6 +97,7 @@ typedef const void *(__cdecl *H5PL_get_plugin_info_t)(void);
 typedef const void *(*H5PL_get_plugin_info_t)(void);
 #endif /* H5_HAVE_WIN32_API */
 
+/* Whether to preload pathnames for plugin libraries */
 #define H5PL_DEFAULT_PATH       H5_DEFAULT_PLUGINDIR
 
 /* Special symbol to indicate no plugin loading */
@@ -107,9 +109,9 @@ typedef const void *(*H5PL_get_plugin_info_t)(void);
 
 /* Type for the list of info for opened plugin libraries */
 typedef struct H5PL_table_t {
-    H5PL_type_t pl_type;			/* plugin type	     */
-    int         pl_id;                          /* ID for the plugin */
-    H5PL_HANDLE handle;			/* plugin handle     */
+    H5PL_type_t pl_type;            /* plugin type          */
+    int         pl_id;              /* ID for the plugin    */
+    H5PL_HANDLE handle;             /* plugin handle        */
 } H5PL_table_t;
 
 
@@ -139,8 +141,8 @@ static herr_t H5PL__close(H5PL_HANDLE handle);
 /*******************/
 
 /* Table for opened plugin libraries */
-static size_t		H5PL_table_alloc_g = 0;
-static size_t		H5PL_table_used_g = 0;
+static size_t           H5PL_table_alloc_g = 0;
+static size_t           H5PL_table_used_g = 0;
 static H5PL_table_t     *H5PL_table_g = NULL;
 
 /* Table of location paths for plugin libraries */
@@ -148,8 +150,8 @@ static char             *H5PL_path_table_g[H5PL_MAX_PATH_NUM];
 static size_t           H5PL_num_paths_g = 0;
 static hbool_t          H5PL_path_found_g = FALSE;
 
-/* Whether to preload pathnames for plugin libraries */
-static hbool_t          H5PL_no_plugin_g = FALSE;
+/* Enable all plugin libraries */
+static unsigned int     H5PL_plugin_g = H5PL_ALL_PLUGIN;
 
 
 /*--------------------------------------------------------------------------
@@ -176,7 +178,7 @@ H5PL__init_interface(void)
     if(NULL != (preload_path = HDgetenv("HDF5_PLUGIN_PRELOAD"))) {
         /* Special symbal "::" means no plugin during data reading. */
         if(!HDstrcmp(preload_path, H5PL_NO_PLUGIN))
-            H5PL_no_plugin_g = TRUE;
+            H5PL_plugin_g = 0;
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
@@ -184,46 +186,83 @@ H5PL__init_interface(void)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL_no_plugin
+ * Function: H5PLset_loading_state
  *
- * Purpose:	Quick way for filter module to query whether to load plugin 
+ * Purpose: Control the loading of dynamic plugin types.
  *
- * Return:	TRUE:	No plugin loading during data reading
+ * This function will not allow plugin types if the pathname from the HDF5_PLUGIN_PRELOAD
+ * environment variable is set to the special "::" string.
  *
- * 		FALSE:	Load plugin during data reading
+ * plugin bit = 0, will prevent the use of that dynamic plugin type.
+ * plugin bit = 1, will allow the use of that dynamic plugin type.
  *
- * Programmer:	Raymond Lu
- *              20 February 2013
+ * H5PL_TYPE_FILTER changes just dynamic filters
+ * A H5PL_ALL_PLUGIN will enable all dynamic plugin types
+ * A zero value will disable all dynamic plugin types
+ *
+ * Return: Non-negative or success
  *
  *-------------------------------------------------------------------------
  */
-htri_t
-H5PL_no_plugin(void)
+herr_t
+H5PLset_loading_state(unsigned int plugin_type)
 {
-    htri_t ret_value;
+    char *preload_path;
+    herr_t ret_value = SUCCEED; /* Return value */
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("e", "Iu", plugin_type);
+    /* change the bit value of the requested plugin type(s) */
+    H5PL_plugin_g = plugin_type;
+    /* check if special ENV variable is set and disable all plugin types */
+    if(NULL != (preload_path = HDgetenv("HDF5_PLUGIN_PRELOAD"))) {
+        /* Special symbol "::" means no plugin during data reading. */
+        if(!HDstrcmp(preload_path, H5PL_NO_PLUGIN))
+            H5PL_plugin_g = 0;
+    }
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5PLset_loading_state() */
 
-    FUNC_ENTER_NOAPI(FAIL)
 
-    ret_value = (htri_t)H5PL_no_plugin_g;
+/*-------------------------------------------------------------------------
+ * Function: H5PLget_loading_state
+ *
+ * Purpose: Query state of the loading of dynamic plugin types.
+ *
+ * This function will return the state of the global flag.
+ *
+ * Return: Zero if all plugin types are disabled, negative if all
+ * plugin types are enabled, positive if one or more of the plugin types are enabled.
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PLget_loading_state(unsigned int *plugin_type)
+{
+    herr_t ret_value = SUCCEED; /* Return value */
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("e", "*Iu", plugin_type);
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5PL_no_plugin() */
+    if(plugin_type)
+        *plugin_type = H5PL_plugin_g;
+    done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5PLget_loading_state() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL_term_interface
+ * Function:    H5PL_term_interface
  *
- * Purpose:	Terminate the H5PL interface: release all memory, reset all
- *		global variables to initial values. This only happens if all
- *		types have been destroyed from other interfaces.
+ * Purpose:     Terminate the H5PL interface: release all memory, reset all
+ *              global variables to initial values. This only happens if all
+ *              types have been destroyed from other interfaces.
  *
- * Return:	Success:	Positive if any action was taken that might
- *				affect some other interface; zero otherwise.
+ * Return:      Success:    Positive if any action was taken that might
+ *                          affect some other interface; zero otherwise.
  *
- * 		Failure:	Negative.
+ *              Failure:    Negative.
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              20 February 2013
  *
  *-------------------------------------------------------------------------
@@ -238,13 +277,13 @@ H5PL_term_interface(void)
     if(H5_interface_initialize_g) {
         size_t u;       /* Local index variable */
 
-	/* Close opened dynamic libraries */
+        /* Close opened dynamic libraries */
         for(u = 0; u < H5PL_table_used_g; u++)
             H5PL__close((H5PL_table_g[u]).handle);
 
-	/* Free the table of dynamic libraries */
-	H5PL_table_g = (H5PL_table_t *)H5MM_xfree(H5PL_table_g);
-	H5PL_table_used_g = H5PL_table_alloc_g = 0;
+        /* Free the table of dynamic libraries */
+        H5PL_table_g = (H5PL_table_t *)H5MM_xfree(H5PL_table_g);
+        H5PL_table_used_g = H5PL_table_alloc_g = 0;
 
         /* Free the table of search paths */
         for(u = 0; u < H5PL_num_paths_g; u++)
@@ -253,7 +292,7 @@ H5PL_term_interface(void)
         H5PL_num_paths_g = 0;
         H5PL_path_found_g = FALSE;
 
-	H5_interface_initialize_g = 0;
+        H5_interface_initialize_g = 0;
         i = 1;
     } /* end if */
 
@@ -262,15 +301,15 @@ H5PL_term_interface(void)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL_load
+ * Function:    H5PL_load
  *
- * Purpose:	Given the plugin type and identifier, this function searches
+ * Purpose:     Given the plugin type and identifier, this function searches
  *              and/or loads a dynamic plugin library first among the already
  *              opened libraries then in the designated location paths.
  *
- * Return:	Non-NULL on success/NULL on failure
+ * Return:      Non-NULL on success/NULL on failure
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              13 February 2013
  *
  *-------------------------------------------------------------------------
@@ -284,9 +323,14 @@ H5PL_load(H5PL_type_t type, int id)
 
     FUNC_ENTER_NOAPI(NULL)
 
-    /* Check for "no plugins" indicated" */
-    if(H5PL_no_plugin_g)
-        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "required dynamically loaded plugin filter '%d' is not available", id)
+    switch (type) {
+    case H5PL_TYPE_FILTER:
+        if((H5PL_plugin_g & H5PL_FILTER_PLUGIN) == 0)
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "required dynamically loaded plugin filter '%d' is not available", id)
+        break;
+    default:
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "required dynamically loaded plugin '%d' is not valid", id)
+    }
 
     /* Initialize the location paths for dynamic libraries, if they aren't
      * already set up.
@@ -325,13 +369,13 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL__init_path_table
+ * Function:    H5PL__init_path_table
  *
- * Purpose:	Initialize the path table.
+ * Purpose:     Initialize the path table.
  *
- * Return:	Non-negative on success/Negative on failure
+ * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:	Quincey Koziol
+ * Programmer:  Quincey Koziol
  *              18 March 2013
  *
  *-------------------------------------------------------------------------
@@ -380,18 +424,18 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL__find
+ * Function:    H5PL__find
  *
  * Purpose:     Given a path, this function opens the directory and envokes
  *              another function to go through all files to find the right 
  *              plugin library. Two function definitions are for Unix and 
  *              Windows.
  *
- * Return:	TRUE on success, 
+ * Return:      TRUE on success, 
  *              FALSE on not found,
  *              negative on failure
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              13 February 2013
  *
  *-------------------------------------------------------------------------
@@ -491,7 +535,7 @@ H5PL__find(H5PL_type_t plugin_type, int type_id, char *dir, const void **info)
 
             /* Allocate & initialize the path name */
             pathname_len = HDstrlen(dir) + HDstrlen(fdFile.cFileName) + 2;
-	    if(NULL == (pathname = (char *)H5MM_malloc(pathname_len)))
+            if(NULL == (pathname = (char *)H5MM_malloc(pathname_len)))
                 HGOTO_ERROR(H5E_PLUGIN, H5E_CANTALLOC, FAIL, "can't allocate memory for path")
             HDsnprintf(pathname, pathname_len, "%s\\%s", dir, fdFile.cFileName);
 
@@ -506,7 +550,7 @@ H5PL__find(H5PL_type_t plugin_type, int type_id, char *dir, const void **info)
                 HGOTO_DONE(TRUE)
             } /* end if */
             else
-	        HDassert(pathname);
+                HDassert(pathname);
                 pathname = (char *)H5MM_xfree(pathname);
         } /* end if */
     } while(FindNextFileA(hFind, &fdFile)); /* Find the next file. */
@@ -523,17 +567,17 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL__open
+ * Function:    H5PL__open
  *
  * Purpose:     Iterates through all files to find the right plugin library.
  *              It loads the dynamic plugin library and keeps it on the list 
- *              of loaded libraries. 	
+ *              of loaded libraries.
  *
- * Return:	TRUE on success, 
+ * Return:      TRUE on success, 
  *              FALSE on not found,
  *              negative on failure
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              13 February 2013
  *
  *-------------------------------------------------------------------------
@@ -611,16 +655,16 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL__search_table
+ * Function:    H5PL__search_table
  *
  * Purpose:     Search in the list of already opened dynamic libraries
  *              to see if the one we are looking for is already opened.
  *
- * Return:	TRUE on success, 
+ * Return:      TRUE on success, 
  *              FALSE on not found,
  *              Negative on failure
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              13 February 2013
  *
  *-------------------------------------------------------------------------
@@ -642,12 +686,12 @@ H5PL__search_table(H5PL_type_t plugin_type, int type_id, const void **info)
                 const H5Z_class2_t   *plugin_info;
 
                 if(NULL == (get_plugin_info = (H5PL_get_plugin_info_t)H5PL_GET_LIB_FUNC((H5PL_table_g[i]).handle, "H5PLget_plugin_info")))
-		    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get function for H5PLget_plugin_info")
+                HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get function for H5PLget_plugin_info")
 
-	        if(NULL == (plugin_info = (const H5Z_class2_t *)(*get_plugin_info)()))
-		    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get plugin info")
+                if(NULL == (plugin_info = (const H5Z_class2_t *)(*get_plugin_info)()))
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get plugin info")
 
-	        *info = plugin_info;
+                *info = plugin_info;
                 HGOTO_DONE(TRUE)
             } /* end if */
         } /* end for */
@@ -659,13 +703,13 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5PL__close
+ * Function:    H5PL__close
  *
  * Purpose:     Closes the handle for dynamic library	
  *
- * Return:	Non-negative on success/Negative on failure
+ * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              13 February 2013
  *
  *-------------------------------------------------------------------------
diff --git a/src/H5PLextern.h b/src/H5PLextern.h
index 7f10575..3264435 100644
--- a/src/H5PLextern.h
+++ b/src/H5PLextern.h
@@ -22,20 +22,6 @@
 /* Include HDF5 header */
 #include "hdf5.h"
 
-#ifndef H5_VMS
-
-/*******************/
-/* Public Typedefs */
-/*******************/
-
-/* Plugin type */
-typedef enum H5PL_type_t {
-    H5PL_TYPE_ERROR        = -1,  /*error                    */
-    H5PL_TYPE_FILTER       = 0,   /*filter                   */
-    H5PL_TYPE_NONE         = 1    /*this must be last!       */
-} H5PL_type_t;
-
-
 /* plugins always export */
 #if defined (_MSC_VER)  /* MSVC Compiler Case */
   #define H5PLUGIN_DLL __declspec(dllexport)
@@ -55,7 +41,6 @@ H5PLUGIN_DLL const void *H5PLget_plugin_info(void);
 #ifdef __cplusplus
 }
 #endif
-#endif /*H5_VMS*/
 
 #endif /* _H5PLextern_H */
 
diff --git a/src/H5PLprivate.h b/src/H5PLprivate.h
index a1b77ea..77e115b 100644
--- a/src/H5PLprivate.h
+++ b/src/H5PLprivate.h
@@ -19,23 +19,12 @@
 #ifndef _H5PLprivate_H
 #define _H5PLprivate_H
 
-/* Keep the following in sync with the package's "external" header */
-
-/*******************/
-/* Public Typedefs */
-/*******************/
-
-/* Plugin type */
-typedef enum H5PL_type_t {
-    H5PL_TYPE_ERROR        = -1,  /*error                    */
-    H5PL_TYPE_FILTER       = 0,   /*filter                   */
-    H5PL_TYPE_NONE         = 1    /*this must be last!       */
-} H5PL_type_t;
+/* Include package's public header */
+#include "H5PLpublic.h"
 
 /* Private headers needed by this file */
 #include "H5private.h"          /* Generic Functions                    */
 
-#ifndef H5_VMS
 
 /**************************/
 /* Library Private Macros */
@@ -58,8 +47,6 @@ typedef enum H5PL_type_t {
 
 /* Internal API routines */
 H5_DLL const void *H5PL_load(H5PL_type_t plugin_type, int type_id);
-H5_DLL htri_t H5PL_no_plugin(void);
-#endif /*H5_VMS*/
 
 #endif /* _H5PLprivate_H */
 
diff --git a/src/H5PLpublic.h b/src/H5PLpublic.h
new file mode 100644
index 0000000..0296819
--- /dev/null
+++ b/src/H5PLpublic.h
@@ -0,0 +1,53 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5. The full HDF5 copyright notice, including      *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic document set and is     *
+ * linked from the top-level documents page.  It can also be found at        *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have access   *
+ * to either file, you may request a copy from help@hdfgroup.org.            *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer:  Raymond Lu <songyulu@hdfgroup.org>
+ *              13 February 2013
+ */
+
+#ifndef _H5PLpublic_H
+#define _H5PLpublic_H
+
+/* Public headers needed by this file */
+#include "H5public.h"          /* Generic Functions                    */
+
+/*******************/
+/* Public Typedefs */
+/*******************/
+
+/* Plugin type used by the plugin library */
+typedef enum H5PL_type_t {
+    H5PL_TYPE_ERROR        = -1,  /*error                    */
+    H5PL_TYPE_FILTER       = 0,   /*filter                   */
+    H5PL_TYPE_NONE         = 1    /*this must be last!       */
+} H5PL_type_t;
+
+/* Common dynamic plugin type flags used by the set/get_loading_state functions */
+#define H5PL_FILTER_PLUGIN 0x0001
+#define H5PL_ALL_PLUGIN 0xFFFF
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* plugin state */
+H5_DLL herr_t H5PLset_loading_state(unsigned int plugin_type);
+H5_DLL herr_t H5PLget_loading_state(unsigned int *plugin_type/*out*/);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _H5PLpublic_H */
+
diff --git a/src/Makefile.am b/src/Makefile.am
index 004a01b..bc94252 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -114,7 +114,7 @@ include_HEADERS = hdf5.h H5api_adpt.h H5overflow.h H5pubconf.h H5public.h H5vers
         H5FDmulti.h H5FDsec2.h  H5FDstdio.h \
         H5Gpublic.h  H5Ipublic.h H5Lpublic.h \
         H5MMpublic.h H5Opublic.h H5Ppublic.h \
-        H5PLextern.h \
+        H5PLextern.h H5PLpublic.h \
         H5Rpublic.h H5Spublic.h \
         H5Tpublic.h H5Zpublic.h
 
diff --git a/src/Makefile.in b/src/Makefile.in
index 31335c8..10a307e 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -813,7 +813,7 @@ include_HEADERS = hdf5.h H5api_adpt.h H5overflow.h H5pubconf.h H5public.h H5vers
         H5FDmulti.h H5FDsec2.h  H5FDstdio.h \
         H5Gpublic.h  H5Ipublic.h H5Lpublic.h \
         H5MMpublic.h H5Opublic.h H5Ppublic.h \
-        H5PLextern.h \
+        H5PLextern.h H5PLpublic.h \
         H5Rpublic.h H5Spublic.h \
         H5Tpublic.h H5Zpublic.h
 
diff --git a/src/hdf5.h b/src/hdf5.h
index ef15063..fb41007 100644
--- a/src/hdf5.h
+++ b/src/hdf5.h
@@ -33,7 +33,8 @@
 #include "H5Lpublic.h"		/* Links				*/
 #include "H5MMpublic.h"		/* Memory management			*/
 #include "H5Opublic.h"		/* Object headers			*/
-#include "H5Ppublic.h"		/* Property lists			*/
+#include "H5Ppublic.h"      /* Property lists           */
+#include "H5PLpublic.h"     /* Plugins           */
 #include "H5Rpublic.h"		/* References				*/
 #include "H5Spublic.h"		/* Dataspaces				*/
 #include "H5Tpublic.h"		/* Datatypes				*/
diff --git a/test/plugin.c b/test/plugin.c
index 86bc952..02007d5 100644
--- a/test/plugin.c
+++ b/test/plugin.c
@@ -456,14 +456,14 @@ error:
 }
 
 /*-------------------------------------------------------------------------
- * Function:	test_read_with_filters
+ * Function:    test_read_with_filters
  *
- * Purpose:	Tests reading dataset created with dynamically loaded filters
+ * Purpose: Tests reading dataset created with dynamically loaded filters
  *
- * Return:	Success:	0
- *		Failure:	-1
+ * Return:  Success:    0
+ *      Failure:    -1
  *
- * Programmer:	Raymond Lu
+ * Programmer:  Raymond Lu
  *              14 March 2013
  *
  *-------------------------------------------------------------------------
@@ -471,7 +471,7 @@ error:
 static herr_t
 test_read_with_filters(hid_t file)
 {
-    hid_t	dset;                 /* Dataset ID */
+    hid_t   dset;                 /* Dataset ID */
 
     /*----------------------------------------------------------
      * STEP 1: Test deflation by itself.
@@ -526,6 +526,76 @@ error:
 }
 
 /*-------------------------------------------------------------------------
+ * Function:    test_noread_data
+ *
+ * Purpose: Tests not reading data
+ *
+ * Return:  Success:    0
+ *      Failure:    -1
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_noread_data(hid_t dataset, int *origin_data)
+{
+    int                 check[DSET_DIM1][DSET_DIM2];
+    const hsize_t   size[2] = {DSET_DIM1, DSET_DIM2};           /* Dataspace dimensions */
+    int                 *data_p = origin_data;
+    size_t      i, j;        /* Local index variables */
+
+    /* Read the dataset back */
+    if(H5Dread(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, check) >= 0)
+        TEST_ERROR;
+
+    PASSED();
+    return 0;
+
+error:
+    return -1;
+}
+
+/*-------------------------------------------------------------------------
+ * Function:	test_noread_with_filters
+ *
+ * Purpose:	Tests reading dataset created with dynamically loaded filters disabled
+ *
+ * Return:	Success:	0
+ *		Failure:	-1
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_noread_with_filters(hid_t file)
+{
+    hid_t	dset;                 /* Dataset ID */
+    unsigned     plugin_state;         /* status of plugins */
+    TESTING("Testing DYNLIB1 filter with plugins disabled");
+
+    /* disable filter plugin */
+    if(H5PLget_loading_state(&plugin_state) < 0) TEST_ERROR
+    plugin_state = plugin_state & ~H5PL_FILTER_PLUGIN;
+    if(H5PLset_loading_state(plugin_state) < 0) TEST_ERROR
+
+    if((dset = H5Dopen2(file,DSET_DYNLIB1_NAME,H5P_DEFAULT)) < 0) TEST_ERROR
+
+    if(test_noread_data(dset, (int *)points_dynlib1) < 0) TEST_ERROR
+
+    if(H5Dclose(dset) < 0) TEST_ERROR
+
+    /* re-enable filter plugin */
+    plugin_state = plugin_state | H5PL_FILTER_PLUGIN;
+    if(H5PLset_loading_state(plugin_state) < 0) TEST_ERROR
+
+    return 0;
+
+error:
+    /* re-enable filter plugin */
+    plugin_state = plugin_state | H5PL_FILTER_PLUGIN;
+    if(H5PLset_loading_state(plugin_state) < 0) TEST_ERROR
+    return -1;
+}
+
+/*-------------------------------------------------------------------------
  * Function:	test_filters_for_groups
  *
  * Purpose:	Tests creating group with dynamically loaded filters
@@ -713,6 +783,17 @@ main(void)
     /* Open the groups with filters */
     nerrors += (test_groups_with_filters(file) < 0	? 1 : 0);
 
+    /* Close the library so that all loaded plugin libraries are unloaded */
+    h5_reset();
+    fapl = h5_fileaccess();
+
+    /* Reopen the file for testing data reading */
+    if((file = H5Fopen(filename, H5F_ACC_RDONLY, fapl)) < 0)
+        TEST_ERROR
+
+    /* Read the data with disabled filters */
+    nerrors += (test_noread_with_filters(file) < 0  ? 1 : 0);
+
     if(H5Fclose(file) < 0)
         TEST_ERROR