Merge pull request #621 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:h5pl_commit to develop

* commit '9bcf8b2f2568083449ae3f9b6c2efbf6ed7f413a':
  Minor tweaks in response to code review.
  Fixed a failing Java plugin test.
  Major rework of H5PL package code before bringing VOL changes over.

1 files changed, 381 insertions, 0 deletions

diff --git a/src/H5PLint.c b/src/H5PLint.c
new file mode 100644
index 0000000..bd6bf7d
--- /dev/null
+++ b/src/H5PLint.c
@@ -0,0 +1,381 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * 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 COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose: Internal routines for managing plugins.
+ *
+ */
+
+
+/****************/
+/* Module Setup */
+/****************/
+
+#include "H5PLmodule.h"          /* This source code file is part of the H5PL module */
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"      /* Generic Functions            */
+#include "H5Eprivate.h"     /* Error handling               */
+#include "H5MMprivate.h"    /* Memory management            */
+#include "H5PLpkg.h"        /* Plugin                       */
+#include "H5Zprivate.h"     /* Filter pipeline              */
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+/* Package initialization variable */
+hbool_t H5_PKG_INIT_VAR = FALSE;
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+/* Bitmask that controls whether classes of plugins
+ * (e.g.: filters, VOL drivers) can be loaded.
+ */
+static unsigned int     H5PL_plugin_control_mask_g = H5PL_ALL_PLUGIN;
+
+/* This flag will be set to FALSE if the HDF5_PLUGIN_PRELOAD
+ * environment variable was set to H5PL_NO_PLUGIN at
+ * package initialization.
+ */
+static hbool_t          H5PL_allow_plugins_g = TRUE;
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL__get_plugin_control_mask
+ *
+ * Purpose:     Gets the internal plugin control mask value.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PL__get_plugin_control_mask(unsigned int *mask /*out*/)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE_NOERR
+
+    /* Check args - Just assert on package functions */
+    HDassert(mask);
+
+    /* Return the mask */
+    *mask = H5PL_plugin_control_mask_g;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* end H5PL__get_plugin_control_mask() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL__set_plugin_control_mask
+ *
+ * Purpose:     Sets the internal plugin control mask value.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PL__set_plugin_control_mask(unsigned int mask)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE_NOERR
+
+    /* Only allow setting this if plugins have not been disabled.
+     * XXX: Note that we don't consider this an error, but instead
+     *      silently ignore it. We may want to consider this behavior
+     *      more carefully.
+     */
+    if (H5PL_allow_plugins_g)
+        H5PL_plugin_control_mask_g = mask;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* end H5PL__set_plugin_control_mask() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL__init_package
+ *
+ * Purpose:     Initialize any package-specific data and call any init
+ *              routines for the package.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PL__init_package(void)
+{
+    char        *env_var = NULL;
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Check the environment variable to determine if the user wants
+     * to ignore plugins. The special symbol H5PL_NO_PLUGIN (defined in
+     * H5PLpublic.h) means we don't want to load plugins.
+     */
+    if (NULL != (env_var = HDgetenv("HDF5_PLUGIN_PRELOAD")))
+        if (!HDstrcmp(env_var, H5PL_NO_PLUGIN)) {
+            H5PL_plugin_control_mask_g = 0;
+            H5PL_allow_plugins_g = FALSE;
+        }
+
+    /* Create the table of previously-loaded plugins */
+    if (H5PL__create_plugin_cache() < 0)
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINIT, FAIL, "can't create plugin cache")
+
+    /* Create the table of search paths for dynamic libraries */
+    if (H5PL__create_path_table() < 0)
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINIT, FAIL, "can't create plugin search path table")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PL__init_package() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL_term_package
+ *
+ * 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
+ *              Failure:    Negative
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5PL_term_package(void)
+{
+    hbool_t already_closed = FALSE;
+    int     ret_value = 0;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    if (H5_PKG_INIT_VAR) {
+
+        /* Close the plugin cache.
+         * We need to bump the return value if we did any real work here.
+         */
+        if (H5PL__close_plugin_cache(&already_closed) < 0)
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTFREE, (-1), "problem closing plugin cache")
+        if (!already_closed)
+            ret_value++;
+
+        /* Close the search path table and free the paths */
+        if (H5PL__close_path_table() < 0)
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTFREE, (-1), "problem closing search path table")
+
+        /* Mark the interface as uninitialized */
+        if (0 == ret_value)
+            H5_PKG_INIT_VAR = FALSE;
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PL_term_package() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL_load
+ *
+ * Purpose:     Given the plugin type and identifier, this function searches
+ *              for and, if found, loads a dynamic plugin library.
+ *
+ *              The function searches first in the cached plugins and then
+ *              in the paths listed in the path table.
+ *
+ * Return:      Success:    A pointer to the plugin info
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+const void *
+H5PL_load(H5PL_type_t type, int id)
+{
+    H5PL_search_params_t    search_params;
+    hbool_t                 found = FALSE;          /* Whether the plugin was found */
+    const void             *plugin_info = NULL;
+    const void             *ret_value = NULL;
+
+    FUNC_ENTER_NOAPI(NULL)
+
+    /* Check if plugins can be loaded for this plugin type */
+    switch (type) {
+        case H5PL_TYPE_FILTER:
+            if ((H5PL_plugin_control_mask_g & H5PL_FILTER_PLUGIN) == 0)
+                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "required dynamically loaded plugin filter '%d' is not available", id)
+            break;
+
+        case H5PL_TYPE_ERROR:
+        case H5PL_TYPE_NONE:
+        default:
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTLOAD, NULL, "required dynamically loaded plugin '%d' is not valid", id)
+    }
+
+    /* Set up the search parameters */
+    search_params.type = type;
+    search_params.id = id;
+
+    /* Search in the table of already loaded plugin libraries */
+    if(H5PL__find_plugin_in_cache(&search_params, &found, &plugin_info) < 0)
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache  failed")
+
+    /* If not found, try iterating through the path table to find an appropriate plugin */
+    if (!found)
+        if (H5PL__find_plugin_in_path_table(&search_params, &found, &plugin_info) < 0)
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in path table failed")
+
+    /* Set the return value we found the plugin */
+    if (found)
+        ret_value = plugin_info;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PL_load() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL__open
+ *
+ * Purpose:     Opens a plugin.
+ *
+ *              The success parameter will be set to TRUE and the plugin_info
+ *              parameter will be filled in on success. Otherwise, they
+ *              will be FALSE and NULL, respectively.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PL__open(const char *path, H5PL_type_t type, int id, hbool_t *success, const void **plugin_info)
+{
+    H5PL_HANDLE             handle = NULL;
+    H5PL_get_plugin_info_t  get_plugin_info = NULL;
+    htri_t                  ret_value = SUCCEED;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Check args - Just assert on package functions */
+    HDassert(path);
+    HDassert(success);
+    HDassert(plugin_info);
+
+    /* Initialize out parameters */
+    *success = FALSE;
+    *plugin_info = NULL;
+
+    /* There are different reasons why a library can't be open, e.g. wrong architecture.
+     * If we can't open the library, just return.
+     */
+    if (NULL == (handle = H5PL_OPEN_DLIB(path))) {
+        H5PL_CLR_ERROR; /* clear error */
+        HGOTO_DONE(SUCCEED);
+    }
+
+
+    /* Return a handle for the function H5PLget_plugin_info in the dynamic library.
+     * The plugin library is suppose to define this function.
+     *
+     * NOTE: We turn off -Wpedantic in gcc to quiet a warning about converting
+     *       object pointers to function pointers, which is undefined in ANSI C.
+     *       This is basically unavoidable due to the nature of dlsym() and *is*
+     *       defined in POSIX, so it's fine.
+     */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpedantic"
+    if (NULL != (get_plugin_info = (H5PL_get_plugin_info_t)H5PL_GET_LIB_FUNC(handle, "H5PLget_plugin_info"))) {
+#pragma GCC diagnostic pop
+
+        const H5Z_class2_t *info;
+
+        /* Get the plugin info */
+        if (NULL == (info = (const H5Z_class2_t *)(*get_plugin_info)()))
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get plugin info")
+
+        /* Check if the filter IDs match */
+        if (info->id == id) {
+
+            /* Store the plugin in the cache */
+            if (H5PL__add_plugin(type, id, handle))
+                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTINSERT, FAIL, "unable to add new plugin to plugin cache")
+
+            /* Set output parameters */
+            *success = TRUE;
+            *plugin_info = (const void *)info;
+        }
+    }
+
+done:
+    if (!success && handle)
+        if (H5PL__close(handle) < 0)
+            HDONE_ERROR(H5E_PLUGIN, H5E_CLOSEERROR, FAIL, "can't close dynamic library")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PL__open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PL__close
+ *
+ * Purpose:     Closes the handle for dynamic library
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PL__close(H5PL_HANDLE handle)
+{
+    FUNC_ENTER_PACKAGE_NOERR
+
+    H5PL_CLOSE_LIB(handle);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5PL__close() */
+