Refactor H5S__hyper_project_intersection to operate directly on span

trees, improving performance and removing the conditionn that the
extents be equal.

1 files changed, 719 insertions, 1 deletions

diff --git a/test/vds.c b/test/vds.c
index c3b6181..af052a8 100644
--- a/test/vds.c
+++ b/test/vds.c
@@ -1409,7 +1409,7 @@ test_basic_io(unsigned config, hid_t fapl)
     int         erbuf[10][26];  /* Expected read buffer */
     int         fill = -1;      /* Fill value */
     herr_t      ret;            /* Generic return value */
-    int         i, j;
+    int         i, j, u, v;
 
     TESTING("basic virtual dataset I/O")
 
@@ -3498,6 +3498,724 @@ test_basic_io(unsigned config, hid_t fapl)
     memspace = -1;
 
 
+    /*
+     * Test 8: For code coverage: Horizontal block virtual mappings, and file
+     * selection, grid memory selection
+     */
+    /* Clear virtual layout in DCPL */
+    if(H5Pset_layout(dcpl, H5D_VIRTUAL) < 0)
+        TEST_ERROR
+
+    /* Create memory dataspace */
+    if((memspace = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataspaces */
+    dims[0] = 8;
+    dims[1] = 15;
+    if((vspace[0] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+    if((vspace[1] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create source dataspace */
+    dims[0] = 4;
+    if((srcspace[0] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Select all in source space (should not be necessary, but just to be sure)
+     */
+    if(H5Sselect_all(srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Select hyperslabs in virtual spaces */
+    start[0] = 0;
+    start[1] = 0;
+    if(H5Sselect_hyperslab(vspace[0], H5S_SELECT_SET, start, NULL, dims, NULL) < 0)
+        TEST_ERROR
+    start[0] = 4;
+    if(H5Sselect_hyperslab(vspace[1], H5S_SELECT_SET, start, NULL, dims, NULL) < 0)
+        TEST_ERROR
+
+    /* Add virtual layout mappings */
+    if(H5Pset_virtual(dcpl, vspace[0], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset1", srcspace[0]) < 0)
+        TEST_ERROR
+    if(H5Pset_virtual(dcpl, vspace[1], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset2", srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Reset dims */
+    dims[0] = 10;
+    dims[1] = 26;
+
+    /* Create virtual file */
+    if((vfile = H5Fcreate(vfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR
+
+    /* Create source file if requested */
+    if(config & TEST_IO_DIFFERENT_FILE) {
+        if((srcfile[0] = H5Fcreate(srcfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+            TEST_ERROR
+    }
+    else {
+        srcfile[0] = vfile;
+        if(H5Iinc_ref(srcfile[0]) < 0)
+            TEST_ERROR
+    }
+
+    /* Create source datasets */
+    if((srcdset[0] = H5Dcreate2(srcfile[0], "src_dset1", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+    if((srcdset[1] = H5Dcreate2(srcfile[0], "src_dset2", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataset */
+    if((vdset = H5Dcreate2(vfile, "v_dset", H5T_NATIVE_INT, vspace[0], H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Reset erbuf */
+    HDmemset(erbuf[0], 0, sizeof(rbuf));
+
+    /* Populate write buffer */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            buf[i][j] = (i * (int)(sizeof(buf[0]) / sizeof(buf[0][0]))) + j;
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    count[0] = 4;
+    count[1] = 15;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to first source dataset */
+    if(H5Dwrite(srcdset[0], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    u = 0;
+    v = 0;
+    for(i = 2; i < 4; i++)
+        for(j = 0; j < 15; j++) {
+            erbuf[u][v] = buf[i][j];
+            v += 2;
+            if(v >= 24) {
+                u += 2;
+                v = 0;
+            }
+        }
+
+    /* Select hyperslab in memory */
+    start[0] = 4;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to second source dataset */
+    if(H5Dwrite(srcdset[1], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    for(i = 4; i < 6; i++)
+        for(j = 0; j < 15; j++) {
+            erbuf[u][v] = buf[i][j];
+            v += 2;
+            if(v >= 24) {
+                u += 2;
+                v = 0;
+            }
+        }
+
+    /* Close srcdsets and srcfile if config option specified */
+    if(config & TEST_IO_CLOSE_SRC) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+
+    /* Reopen virtual dataset and file if config option specified */
+    if(config & TEST_IO_REOPEN_VIRT) {
+        if(H5Dclose(vdset) < 0)
+            TEST_ERROR
+        vdset = -1;
+        if(H5Fclose(vfile) < 0)
+            TEST_ERROR
+        vfile = -1;
+        if((vfile = H5Fopen(vfilename, H5F_ACC_RDWR, fapl)) < 0)
+            TEST_ERROR
+        if((vdset = H5Dopen2(vfile, "v_dset", H5P_DEFAULT)) < 0)
+            TEST_ERROR
+    }
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    stride[0] = 2;
+    stride[1] = 2;
+    count[0] = 5;
+    count[1] = 12;
+    block[0] = 1;
+    block[1] = 1;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, stride, count, block) < 0)
+        TEST_ERROR
+
+    /* Select hyperslab in file */
+    start[0] = 2;
+    start[1] = 0;
+    count[0] = 4;
+    count[1] = 15;
+    if(H5Sselect_hyperslab(vspace[0], H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Read data through virtual dataset */
+    HDmemset(rbuf[0], 0, sizeof(rbuf));
+    if(H5Dread(vdset, H5T_NATIVE_INT, memspace, vspace[0], H5P_DEFAULT, rbuf[0]) < 0)
+        TEST_ERROR
+
+    /* Verify read data */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            if(rbuf[i][j] != erbuf[i][j])
+                TEST_ERROR
+
+    /* Close */
+    if(!(config & TEST_IO_CLOSE_SRC)) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+    if(H5Dclose(vdset) < 0)
+        TEST_ERROR
+    vdset = -1;
+    if(H5Fclose(vfile) < 0)
+        TEST_ERROR
+    vfile = -1;
+    if(H5Sclose(srcspace[0]) < 0)
+        TEST_ERROR
+    srcspace[0] = -1;
+    if(H5Sclose(vspace[0]) < 0)
+        TEST_ERROR
+    vspace[0] = -1;
+    if(H5Sclose(vspace[1]) < 0)
+        TEST_ERROR
+    vspace[1] = -1;
+    if(H5Sclose(memspace) < 0)
+        TEST_ERROR
+    memspace = -1;
+
+
+    /*
+     * Test 9: For code coverage: Horizontal block virtual mappings, and file
+     * selection, grid memory selection, 3 mappings, 3D memory space
+     */
+    /* Clear virtual layout in DCPL */
+    if(H5Pset_layout(dcpl, H5D_VIRTUAL) < 0)
+        TEST_ERROR
+
+    /* Create memory dataspace */
+    dims[1] = 13;
+    dims[2] = 2;
+    if((memspace = H5Screate_simple(3, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataspaces */
+    dims[0] = 6;
+    dims[1] = 10;
+    if((vspace[0] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+    if((vspace[1] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+    if((vspace[2] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create source dataspace */
+    dims[0] = 2;
+    if((srcspace[0] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Select all in source space (should not be necessary, but just to be sure)
+     */
+    if(H5Sselect_all(srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Select hyperslabs in virtual spaces */
+    start[0] = 0;
+    start[1] = 0;
+    if(H5Sselect_hyperslab(vspace[0], H5S_SELECT_SET, start, NULL, dims, NULL) < 0)
+        TEST_ERROR
+    start[0] = 2;
+    if(H5Sselect_hyperslab(vspace[1], H5S_SELECT_SET, start, NULL, dims, NULL) < 0)
+        TEST_ERROR
+    start[0] = 4;
+    if(H5Sselect_hyperslab(vspace[2], H5S_SELECT_SET, start, NULL, dims, NULL) < 0)
+        TEST_ERROR
+
+    /* Add virtual layout mappings */
+    if(H5Pset_virtual(dcpl, vspace[0], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset1", srcspace[0]) < 0)
+        TEST_ERROR
+    if(H5Pset_virtual(dcpl, vspace[1], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset2", srcspace[0]) < 0)
+        TEST_ERROR
+    if(H5Pset_virtual(dcpl, vspace[2], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset3", srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Reset dims */
+    dims[0] = 10;
+    dims[1] = 26;
+
+    /* Create virtual file */
+    if((vfile = H5Fcreate(vfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR
+
+    /* Create source file if requested */
+    if(config & TEST_IO_DIFFERENT_FILE) {
+        if((srcfile[0] = H5Fcreate(srcfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+            TEST_ERROR
+    }
+    else {
+        srcfile[0] = vfile;
+        if(H5Iinc_ref(srcfile[0]) < 0)
+            TEST_ERROR
+    }
+
+    /* Create source datasets */
+    if((srcdset[0] = H5Dcreate2(srcfile[0], "src_dset1", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+    if((srcdset[1] = H5Dcreate2(srcfile[0], "src_dset2", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+    if((srcdset[2] = H5Dcreate2(srcfile[0], "src_dset3", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataset */
+    if((vdset = H5Dcreate2(vfile, "v_dset", H5T_NATIVE_INT, vspace[0], H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Reset erbuf */
+    HDmemset(erbuf[0], 0, sizeof(rbuf));
+
+    /* Populate write buffer */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            buf[i][j] = (i * (int)(sizeof(buf[0]) / sizeof(buf[0][0]))) + j;
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    start[2] = 0;
+    count[0] = 2;
+    count[1] = 5;
+    count[2] = 2;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to first source dataset */
+    if(H5Dwrite(srcdset[0], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    u = 0;
+    v = 0;
+    for(i = 0; i < 2; i++)
+        for(j = 0; j < 10; j++) {
+            erbuf[u][v] = buf[i][j];
+            if(++v == 6)
+                v += 2;
+            else if(v == 14) {
+                u += 2;
+                v = 0;
+            }
+        }
+
+    /* Select hyperslab in memory */
+    start[0] = 2;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to second source dataset */
+    if(H5Dwrite(srcdset[1], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    for(i = 2; i < 4; i++)
+        for(j = 0; j < 10; j++) {
+            erbuf[u][v] = buf[i][j];
+            if(++v == 6)
+                v += 2;
+            else if(v == 14) {
+                u += 2;
+                v = 0;
+            }
+        }
+
+    /* Select hyperslab in memory */
+    start[0] = 4;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to third source dataset */
+    if(H5Dwrite(srcdset[2], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    for(i = 4; i < 6; i++)
+        for(j = 0; j < 10; j++) {
+            erbuf[u][v] = buf[i][j];
+            if(++v == 6)
+                v += 2;
+            else if(v == 14) {
+                u += 2;
+                v = 0;
+            }
+        }
+
+    /* Close srcdsets and srcfile if config option specified */
+    if(config & TEST_IO_CLOSE_SRC) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Dclose(srcdset[2]) < 0)
+            TEST_ERROR
+        srcdset[2] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+
+    /* Reopen virtual dataset and file if config option specified */
+    if(config & TEST_IO_REOPEN_VIRT) {
+        if(H5Dclose(vdset) < 0)
+            TEST_ERROR
+        vdset = -1;
+        if(H5Fclose(vfile) < 0)
+            TEST_ERROR
+        vfile = -1;
+        if((vfile = H5Fopen(vfilename, H5F_ACC_RDWR, fapl)) < 0)
+            TEST_ERROR
+        if((vdset = H5Dopen2(vfile, "v_dset", H5P_DEFAULT)) < 0)
+            TEST_ERROR
+    }
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    start[2] = 0;
+    stride[0] = 2;
+    stride[1] = 4;
+    stride[2] = 1;
+    count[0] = 5;
+    count[1] = 2;
+    count[2] = 1;
+    block[0] = 1;
+    block[1] = 3;
+    block[2] = 2;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, stride, count, block) < 0)
+        TEST_ERROR
+
+    /* Read data through virtual dataset */
+    HDmemset(rbuf[0], 0, sizeof(rbuf));
+    if(H5Dread(vdset, H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, rbuf[0]) < 0)
+        TEST_ERROR
+
+    /* Verify read data */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            if(rbuf[i][j] != erbuf[i][j])
+                TEST_ERROR
+
+    /* Close */
+    if(!(config & TEST_IO_CLOSE_SRC)) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Dclose(srcdset[2]) < 0)
+            TEST_ERROR
+        srcdset[2] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+    if(H5Dclose(vdset) < 0)
+        TEST_ERROR
+    vdset = -1;
+    if(H5Fclose(vfile) < 0)
+        TEST_ERROR
+    vfile = -1;
+    if(H5Sclose(srcspace[0]) < 0)
+        TEST_ERROR
+    srcspace[0] = -1;
+    if(H5Sclose(vspace[0]) < 0)
+        TEST_ERROR
+    vspace[0] = -1;
+    if(H5Sclose(vspace[1]) < 0)
+        TEST_ERROR
+    vspace[1] = -1;
+    if(H5Sclose(vspace[2]) < 0)
+        TEST_ERROR
+    vspace[2] = -1;
+    if(H5Sclose(memspace) < 0)
+        TEST_ERROR
+    memspace = -1;
+
+
+    /*
+     * Test 10: For code coverage: Vertical stripe virtual mappings, vertical
+     * block file selection, block memory selection, 3D VDS
+     */
+    /* Clear virtual layout in DCPL */
+    if(H5Pset_layout(dcpl, H5D_VIRTUAL) < 0)
+        TEST_ERROR
+
+    /* Create memory dataspace */
+    if((memspace = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataspaces */
+    dims[0] = 10;
+    dims[1] = 9;
+    dims[2] = 6;
+    if((vspace[0] = H5Screate_simple(3, dims, NULL)) < 0)
+        TEST_ERROR
+    if((vspace[1] = H5Screate_simple(3, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Create source dataspace */
+    dims[1] = 12;
+    if((srcspace[0] = H5Screate_simple(2, dims, NULL)) < 0)
+        TEST_ERROR
+
+    /* Select all in source space (should not be necessary, but just to be sure)
+     */
+    if(H5Sselect_all(srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Select hyperslabs in virtual spaces */
+    start[0] = 0;
+    start[1] = 0;
+    start[2] = 0;
+    count[0] = 1;
+    count[1] = 4;
+    count[2] = 3;
+    stride[0] = 1;
+    stride[1] = 2;
+    stride[2] = 2;
+    block[0] = 10;
+    block[1] = 1;
+    block[2] = 1;
+    if(H5Sselect_hyperslab(vspace[0], H5S_SELECT_SET, start, stride, count, block) < 0)
+        TEST_ERROR
+    start[2] = 1;
+    if(H5Sselect_hyperslab(vspace[1], H5S_SELECT_SET, start, stride, count, block) < 0)
+        TEST_ERROR
+
+    /* Add virtual layout mappings */
+    if(H5Pset_virtual(dcpl, vspace[0], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset1", srcspace[0]) < 0)
+        TEST_ERROR
+    if(H5Pset_virtual(dcpl, vspace[1], config & TEST_IO_DIFFERENT_FILE ? srcfilename_map : ".", "src_dset2", srcspace[0]) < 0)
+        TEST_ERROR
+
+    /* Reset dims */
+    dims[0] = 10;
+    dims[1] = 26;
+
+    /* Create virtual file */
+    if((vfile = H5Fcreate(vfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR
+
+    /* Create source file if requested */
+    if(config & TEST_IO_DIFFERENT_FILE) {
+        if((srcfile[0] = H5Fcreate(srcfilename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+            TEST_ERROR
+    }
+    else {
+        srcfile[0] = vfile;
+        if(H5Iinc_ref(srcfile[0]) < 0)
+            TEST_ERROR
+    }
+
+    /* Create source datasets */
+    if((srcdset[0] = H5Dcreate2(srcfile[0], "src_dset1", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+    if((srcdset[1] = H5Dcreate2(srcfile[0], "src_dset2", H5T_NATIVE_INT, srcspace[0], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Create virtual dataset */
+    if((vdset = H5Dcreate2(vfile, "v_dset", H5T_NATIVE_INT, vspace[0], H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        TEST_ERROR
+
+    /* Initialize erbuf */
+    HDmemset(erbuf[0], 0, sizeof(rbuf));
+    for(i = 0; i < 10; i++)
+        for(j = 0; j < 24; j += 6) {
+            erbuf[i][j] = -1;
+            erbuf[i][j + 1] = -1;
+        }
+
+    /* Populate write buffer */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            buf[i][j] = (i * (int)(sizeof(buf[0]) / sizeof(buf[0][0]))) + j;
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    count[0] = 10;
+    count[1] = 12;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to first source dataset */
+    if(H5Dwrite(srcdset[0], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    u = 0;
+    v = 0;
+    for(i = 0; i < 10; i++)
+        for(j = 0; j < 8; j++) {
+            if(v == 0 || v == 12)
+                erbuf[u][v] = buf[i][j];
+            v += 2;
+            if(!(v % 6))
+                v += 6;
+            if(v >= 28) {
+                u++;
+                v = 0;
+            }
+        }
+
+    /* Select hyperslab in memory */
+    start[1] = 8;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Write data directly to second source dataset */
+    if(H5Dwrite(srcdset[1], H5T_NATIVE_INT, memspace, H5S_ALL, H5P_DEFAULT, buf[0]) < 0)
+        TEST_ERROR
+
+    /* Update erbuf */
+    u = 0;
+    v = 1;
+    for(i = 0; i < 10; i++)
+        for(j = 8; j < 16; j++) {
+            if(v == 1 || v == 13)
+                erbuf[u][v] = buf[i][j];
+            v += 2;
+            if(!((v - 1) % 6))
+                v += 6;
+            if(v >= 28) {
+                u++;
+                v = 1;
+            }
+        }
+
+    /* Close srcdsets and srcfile if config option specified */
+    if(config & TEST_IO_CLOSE_SRC) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+
+    /* Reopen virtual dataset and file if config option specified */
+    if(config & TEST_IO_REOPEN_VIRT) {
+        if(H5Dclose(vdset) < 0)
+            TEST_ERROR
+        vdset = -1;
+        if(H5Fclose(vfile) < 0)
+            TEST_ERROR
+        vfile = -1;
+        if((vfile = H5Fopen(vfilename, H5F_ACC_RDWR, fapl)) < 0)
+            TEST_ERROR
+        if((vdset = H5Dopen2(vfile, "v_dset", H5P_DEFAULT)) < 0)
+            TEST_ERROR
+    }
+
+    /* Select hyperslab in memory */
+    start[0] = 0;
+    start[1] = 0;
+    stride[0] = 1;
+    stride[1] = 6;
+    count[0] = 1;
+    count[1] = 4;
+    block[0] = 10;
+    block[1] = 2;
+    if(H5Sselect_hyperslab(memspace, H5S_SELECT_SET, start, stride, count, block) < 0)
+        TEST_ERROR
+
+    /* Select hyperslab in file */
+    start[0] = 0;
+    start[1] = 0;
+    start[2] = 0;
+    count[0] = 10;
+    count[1] = 4;
+    count[2] = 2;
+    if(H5Sselect_hyperslab(vspace[0], H5S_SELECT_SET, start, NULL, count, NULL) < 0)
+        TEST_ERROR
+
+    /* Read data through virtual dataset */
+    HDmemset(rbuf[0], 0, sizeof(rbuf));
+    if(H5Dread(vdset, H5T_NATIVE_INT, memspace, vspace[0], H5P_DEFAULT, rbuf[0]) < 0)
+        TEST_ERROR
+
+    /* Verify read data */
+    for(i = 0; i < (int)(sizeof(buf) / sizeof(buf[0])); i++)
+        for(j = 0; j < (int)(sizeof(buf[0]) / sizeof(buf[0][0])); j++)
+            if(rbuf[i][j] != erbuf[i][j])
+                TEST_ERROR
+
+    /* Close */
+    if(!(config & TEST_IO_CLOSE_SRC)) {
+        if(H5Dclose(srcdset[0]) < 0)
+            TEST_ERROR
+        srcdset[0] = -1;
+        if(H5Dclose(srcdset[1]) < 0)
+            TEST_ERROR
+        srcdset[1] = -1;
+        if(H5Fclose(srcfile[0]) < 0)
+            TEST_ERROR
+        srcfile[0] = -1;
+    }
+    if(H5Dclose(vdset) < 0)
+        TEST_ERROR
+    vdset = -1;
+    if(H5Fclose(vfile) < 0)
+        TEST_ERROR
+    vfile = -1;
+    if(H5Sclose(srcspace[0]) < 0)
+        TEST_ERROR
+    srcspace[0] = -1;
+    if(H5Sclose(vspace[0]) < 0)
+        TEST_ERROR
+    vspace[0] = -1;
+    if(H5Sclose(vspace[1]) < 0)
+        TEST_ERROR
+    vspace[1] = -1;
+    if(H5Sclose(memspace) < 0)
+        TEST_ERROR
+    memspace = -1;
+
+
     /* Close */
     if(H5Pclose(dcpl) < 0)
         TEST_ERROR