Add cache logging property and file pieces.

7 files changed, 475 insertions, 10 deletions

diff --git a/src/H5Fint.c b/src/H5Fint.c
index 201dd65..fb05efc 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -642,6 +642,10 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
         /* For latest format, activate all latest version support */
         if(latest_format)
             f->shared->latest_flags |= H5F_LATEST_ALL_FLAGS;
+        if(H5P_get(plist, H5F_ACS_USE_MDC_LOGGING_NAME, &(f->shared->use_mdc_logging)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get 'use mdc logging' flag")
+        if(H5P_get(plist, H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME, &(f->shared->start_mdc_log_on_access)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get 'start mdc log on access' flag")
         if(H5P_get(plist, H5F_ACS_META_BLOCK_SIZE_NAME, &(f->shared->meta_aggr.alloc_size)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get metadata cache size")
         f->shared->meta_aggr.feature_flag = H5FD_FEAT_AGGREGATE_METADATA;
@@ -827,6 +831,10 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
             /* Push error, but keep going*/
             HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "problems closing file")
 
+        /* Clean up the metadata cache log location string */
+        if(f->shared->mdc_log_location)
+            f->shared->mdc_log_location = (char *)H5MM_xfree(f->shared->mdc_log_location);
+
         /*
          * Do not close the root group since we didn't count it, but free
          * the memory associated with it.
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 8ec2a93..4d324d1 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -259,6 +259,10 @@ struct H5F_file_t {
                                 /* metadata cache.  This structure is   */
                                 /* fixed at creation time and should    */
                                 /* not change thereafter.               */
+    hbool_t     use_mdc_logging; /* Set when metadata logging is desired */
+    hbool_t     start_mdc_log_on_access; /* set when mdc logging should  */
+                                /* begin on file access/create          */
+    char        *mdc_log_location; /* location of mdc log               */
     hid_t       fcpl_id;	/* File creation property list ID 	*/
     H5F_close_degree_t fc_degree;   /* File close behavior degree	*/
     hbool_t evict_on_close; /* If the file's objects should be evicted from the metadata cache on close */
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 40e5ff2..19a8117 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -319,6 +319,9 @@
 #ifdef H5_HAVE_PARALLEL
 #define H5F_COLL_MD_READ(F)     ((F)->coll_md_read)
 #endif /* H5_HAVE_PARALLEL */
+#define H5F_USE_MDC_LOGGING(F)  ((F)->shared->use_mdc_logging)
+#define H5F_START_MDC_LOG_ON_ACCESS(F)  ((F)->shared->start_mdc_log_on_access)
+#define H5F_MDC_LOG_LOCATION(F) ((F)->shared->mdc_log_location)
 #else /* H5F_MODULE */
 #define H5F_INTENT(F)           (H5F_get_intent(F))
 #define H5F_OPEN_NAME(F)        (H5F_get_open_name(F))
@@ -365,6 +368,9 @@
 #ifdef H5_HAVE_PARALLEL
 #define H5F_COLL_MD_READ(F)     (H5F_coll_md_read(F))
 #endif /* H5_HAVE_PARALLEL */
+#define H5F_USE_MDC_LOGGING(F)  (H5F_use_mdc_logging(F))
+#define H5F_START_MDC_LOG_ON_ACCESS(F)  (H5F_start_mdc_log_on_access(F))
+#define H5F_MDC_LOG_LOCATION(F) (H5F_mdc_log_location(F))
 #endif /* H5F_MODULE */
 
 
@@ -464,6 +470,9 @@
 #define H5F_ACS_OBJECT_FLUSH_CB_NAME     	"object_flush_cb" 	 /* Object flush callback */
 #define H5F_ACS_EFC_SIZE_NAME                   "efc_size"      /* Size of external file cache */
 #define H5F_ACS_FILE_IMAGE_INFO_NAME            "file_image_info" /* struct containing initial file image and callback info */
+#define H5F_ACS_USE_MDC_LOGGING_NAME            "use_mdc_logging" /* Whether to use metadata cache logging */
+#define H5F_ACS_MDC_LOG_LOCATION_NAME           "mdc_log_location" /* Name of metadata cache log location */
+#define H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME    "start_mdc_log_on_access" /* Whether logging starts on file create/open */
 #define H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME       "core_write_tracking_flag" /* Whether or not core VFD backing store write tracking is enabled */
 #define H5F_ACS_EVICT_ON_CLOSE_FLAG_NAME        "evict_on_close_flag" /* Whether or not the metadata cache will evict objects on close */
 #define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME  "core_write_tracking_page_size" /* The page size in kiB when core VFD write tracking is enabled */
@@ -680,6 +689,9 @@ H5_DLL hbool_t H5F_is_tmp_addr(const H5F_t *f, haddr_t addr);
 H5_DLL H5P_coll_md_read_flag_t H5F_coll_md_read(const H5F_t *f);
 H5_DLL void H5F_set_coll_md_read(H5F_t *f, H5P_coll_md_read_flag_t flag);
 #endif /* H5_HAVE_PARALLEL */
+H5_DLL hbool_t H5F_use_mdc_logging(const H5F_t *f);
+H5_DLL hbool_t H5F_start_mdc_log_on_access(const H5F_t *f);
+H5_DLL char *H5F_mdc_log_location(const H5F_t *f);
 
 /* Functions that retrieve values from VFD layer */
 H5_DLL hid_t H5F_get_driver_id(const H5F_t *f);
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index fcccf07..6db5a69 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -219,6 +219,11 @@ H5_DLL herr_t H5Fget_info2(hid_t obj_id, H5F_info2_t *finfo);
 H5_DLL ssize_t H5Fget_free_sections(hid_t file_id, H5F_mem_t type,
     size_t nsects, H5F_sect_info_t *sect_info/*out*/);
 H5_DLL herr_t H5Fclear_elink_file_cache(hid_t file_id);
+H5_DLL herr_t H5Fstart_mdc_logging(hid_t file_id);
+H5_DLL herr_t H5Fstop_mdc_logging(hid_t file_id);
+H5_DLL herr_t H5Fget_mdc_logging_status(hid_t file_id,
+                                        /*OUT*/ hbool_t *is_enabled,
+                                        /*OUT*/ hbool_t *is_currently_logging);
 H5_DLL herr_t H5Fformat_convert(hid_t fid);
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index f59a9b7..487eb85 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -1127,3 +1127,87 @@ H5F_coll_md_read(const H5F_t *f)
 } /* end H5F_coll_md_read() */
 #endif /* H5_HAVE_PARALLEL */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_use_mdc_logging
+ *
+ * Purpose:	Quick and dirty routine to determine if using MDC logging
+ *		is enabled for this file.
+ *          (Mainly added to stop non-file routines from poking about in the
+ *          H5F_t data structure)
+ *
+ * Return:	TRUE/FALSE on success/abort on failure (shouldn't fail)
+ *
+ * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
+ *		June  5, 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_use_mdc_logging(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->use_mdc_logging)
+} /* end H5F_use_mdc_logging() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_start_mdc_log_on_access
+ *
+ * Purpose:	Quick and dirty routine to determine if we should start MDC
+ *		logging on access for this file.
+ *          (Mainly added to stop non-file routines from poking about in the
+ *          H5F_t data structure)
+ *
+ * Return:	TRUE/FALSE on success/abort on failure (shouldn't fail)
+ *
+ * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
+ *		June  5, 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_start_mdc_log_on_access(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->start_mdc_log_on_access)
+} /* end H5F_start_mdc_log_on_access() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_mdc_log_location
+ *
+ * Purpose:	Quick and dirty routine to retrieve the MDC log location
+ *		for this file.
+ *          (Mainly added to stop non-file routines from poking about in the
+ *          H5F_t data structure)
+ *
+ * Return:	TRUE/FALSE on success/abort on failure (shouldn't fail)
+ *
+ * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
+ *		June  5, 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+char *
+H5F_mdc_log_location(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->mdc_log_location)
+} /* end H5F_mdc_log_location() */
+
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 8801061..9309ea9 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -181,6 +181,25 @@
 /* Definition for object flush callback */
 #define H5F_ACS_OBJECT_FLUSH_CB_SIZE		sizeof(H5F_object_flush_t)
 #define H5F_ACS_OBJECT_FLUSH_CB_DEF             {NULL, NULL}
+/* Definition for 'use metadata cache logging' flag */
+#define H5F_ACS_USE_MDC_LOGGING_SIZE            sizeof(hbool_t)
+#define H5F_ACS_USE_MDC_LOGGING_DEF             FALSE
+#define H5F_ACS_USE_MDC_LOGGING_ENC             H5P__encode_hbool_t
+#define H5F_ACS_USE_MDC_LOGGING_DEC             H5P__decode_hbool_t
+/* Definition for 'mdc log location' flag */
+#define H5F_ACS_MDC_LOG_LOCATION_SIZE           sizeof(char *)
+#define H5F_ACS_MDC_LOG_LOCATION_DEF            NULL /* default is no log location */
+#define H5F_ACS_MDC_LOG_LOCATION_ENC            H5P_facc_mdc_log_location_enc
+#define H5F_ACS_MDC_LOG_LOCATION_DEC            H5P_facc_mdc_log_location_dec
+#define H5F_ACS_MDC_LOG_LOCATION_DEL            H5P_facc_mdc_log_location_del
+#define H5F_ACS_MDC_LOG_LOCATION_COPY           H5P_facc_mdc_log_location_copy
+#define H5F_ACS_MDC_LOG_LOCATION_CMP            H5P_facc_mdc_log_location_cmp
+#define H5F_ACS_MDC_LOG_LOCATION_CLOSE          H5P_facc_mdc_log_location_close
+/* Definition for 'start metadata cache logging on access' flag */
+#define H5F_ACS_START_MDC_LOG_ON_ACCESS_SIZE    sizeof(hbool_t)
+#define H5F_ACS_START_MDC_LOG_ON_ACCESS_DEF     FALSE
+#define H5F_ACS_START_MDC_LOG_ON_ACCESS_ENC     H5P__encode_hbool_t
+#define H5F_ACS_START_MDC_LOG_ON_ACCESS_DEC     H5P__decode_hbool_t
 /* Definition for evict on close property */
 #define H5F_ACS_EVICT_ON_CLOSE_FLAG_SIZE                sizeof(hbool_t)
 #define H5F_ACS_EVICT_ON_CLOSE_FLAG_DEF                 FALSE
@@ -244,6 +263,14 @@ static herr_t H5P__facc_fclose_degree_dec(const void **pp, void *value);
 static herr_t H5P__facc_multi_type_enc(const void *value, void **_pp, size_t *size);
 static herr_t H5P__facc_multi_type_dec(const void **_pp, void *value);
 
+/* Metadata cache log location property callbacks */
+static herr_t H5P_facc_mdc_log_location_enc(const void *value, void **_pp, size_t *size);
+static herr_t H5P_facc_mdc_log_location_dec(const void **_pp, void *value);
+static herr_t H5P_facc_mdc_log_location_del(hid_t prop_id, const char *name, size_t size, void *value);
+static herr_t H5P_facc_mdc_log_location_copy(const char *name, size_t size, void *value);
+static int    H5P_facc_mdc_log_location_cmp(const void *value1, const void *value2, size_t size);
+static herr_t H5P_facc_mdc_log_location_close(const char *name, size_t size, void *value);
+
 
 /*********************/
 /* Package Variables */
@@ -301,6 +328,9 @@ static const H5FD_file_image_info_t H5F_def_file_image_info_g = H5F_ACS_FILE_IMA
 static const hbool_t H5F_def_core_write_tracking_flag_g = H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEF;              /* Default setting for core VFD write tracking */
 static const size_t H5F_def_core_write_tracking_page_size_g = H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEF;     /* Default core VFD write tracking page size */
 static const H5F_object_flush_t H5F_def_object_flush_cb_g = H5F_ACS_OBJECT_FLUSH_CB_DEF;      /* Default setting for object flush callback */
+static const hbool_t H5F_def_use_mdc_logging_g = H5F_ACS_USE_MDC_LOGGING_DEF;                 /* Default metadata cache logging flag */
+static const char *H5F_def_mdc_log_location_g = H5F_ACS_MDC_LOG_LOCATION_DEF;                 /* Default mdc log location */
+static const hbool_t H5F_def_start_mdc_log_on_access_g = H5F_ACS_START_MDC_LOG_ON_ACCESS_DEF; /* Default mdc log start on access flag */
 static const hbool_t H5F_def_evict_on_close_flag_g = H5F_ACS_EVICT_ON_CLOSE_FLAG_DEF;         /* Default setting for evict on close property */
 #ifdef H5_HAVE_PARALLEL
 static const H5P_coll_md_read_flag_t H5F_def_coll_md_read_flag_g = H5F_ACS_COLL_MD_READ_FLAG_DEF;  /* Default setting for the collective metedata read flag */
@@ -468,6 +498,22 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the metadata cache logging flag. */
+    if(H5P_register_real(pclass, H5F_ACS_USE_MDC_LOGGING_NAME, H5F_ACS_USE_MDC_LOGGING_SIZE, &H5F_def_use_mdc_logging_g,
+            NULL, NULL, NULL, H5F_ACS_USE_MDC_LOGGING_ENC, H5F_ACS_USE_MDC_LOGGING_DEC, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
+    /* Register the metadata cache log location. */
+    if(H5P_register_real(pclass, H5F_ACS_MDC_LOG_LOCATION_NAME, H5F_ACS_MDC_LOG_LOCATION_SIZE, &H5F_def_mdc_log_location_g,
+        NULL, NULL, NULL, H5F_ACS_MDC_LOG_LOCATION_ENC, H5F_ACS_MDC_LOG_LOCATION_DEC,
+        H5F_ACS_MDC_LOG_LOCATION_DEL, H5F_ACS_MDC_LOG_LOCATION_COPY, H5F_ACS_MDC_LOG_LOCATION_CMP, H5F_ACS_MDC_LOG_LOCATION_CLOSE) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
+    /* Register the flag that indicates whether mdc logging starts on file access. */
+    if(H5P_register_real(pclass, H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME, H5F_ACS_START_MDC_LOG_ON_ACCESS_SIZE, &H5F_def_start_mdc_log_on_access_g,
+            NULL, NULL, NULL, H5F_ACS_START_MDC_LOG_ON_ACCESS_ENC, H5F_ACS_START_MDC_LOG_ON_ACCESS_DEC, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register the evict on close flag */
     if(H5P_register_real(pclass, H5F_ACS_EVICT_ON_CLOSE_FLAG_NAME, H5F_ACS_EVICT_ON_CLOSE_FLAG_SIZE, &H5F_def_evict_on_close_flag_g, 
             NULL, NULL, NULL, H5F_ACS_EVICT_ON_CLOSE_FLAG_ENC, H5F_ACS_EVICT_ON_CLOSE_FLAG_DEC, 
@@ -2934,16 +2980,6 @@ H5P__facc_cache_config_cmp(const void *_config1, const void *_config2, size_t H5
     if(config1->rpt_fcn_enabled < config2->rpt_fcn_enabled) HGOTO_DONE(-1);
     if(config1->rpt_fcn_enabled > config2->rpt_fcn_enabled) HGOTO_DONE(1);
 
-    if(config1->open_trace_file < config2->open_trace_file) HGOTO_DONE(-1);
-    if(config1->open_trace_file > config2->open_trace_file) HGOTO_DONE(1);
-
-    if(config1->close_trace_file < config2->close_trace_file) HGOTO_DONE(-1);
-    if(config1->close_trace_file > config2->close_trace_file) HGOTO_DONE(1);
-
-    if((ret_value = HDstrncmp(config1->trace_file_name, config2->trace_file_name, 
-                              (size_t)(H5AC__MAX_TRACE_FILE_NAME_LEN + 1))) != 0)
-        HGOTO_DONE(ret_value);
-
     if(config1->evictions_enabled < config2->evictions_enabled) HGOTO_DONE(-1);
     if(config1->evictions_enabled > config2->evictions_enabled) HGOTO_DONE(1);
 
@@ -3619,6 +3655,320 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Pset_mdc_log_options
+ *
+ * Purpose:	Set metadata cache log options.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_mdc_log_options(hid_t plist_id, hbool_t is_enabled, const char *location,
+                       hbool_t start_on_access)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    char *      tmp_location;           /* Working location pointer */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE4("e", "ib*sb", plist_id, is_enabled, location, start_on_access);
+
+    /* Check arguments */
+    if(H5P_DEFAULT == plist_id)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "can't modify default property list")
+    if(!location)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "location cannot be NULL")
+
+    /* Get the property list structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "plist_id is not a file access property list")
+
+    /* Get the current location string and free it */
+    if(H5P_get(plist, H5F_ACS_MDC_LOG_LOCATION_NAME, &tmp_location) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get current log location")
+    H5MM_xfree(tmp_location);
+
+    /* Make a copy of the passed-in location */
+    if(NULL == (tmp_location = H5MM_xstrdup(location)))
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTCOPY, FAIL, "can't copy passed-in log location")
+
+    /* Set values */
+    if(H5P_set(plist, H5F_ACS_USE_MDC_LOGGING_NAME, &is_enabled) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set is_enabled flag")
+    if(H5P_set(plist, H5F_ACS_MDC_LOG_LOCATION_NAME, &tmp_location) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set log location")
+    if(H5P_set(plist, H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME, &start_on_access) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set start_on_access flag")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pset_mdc_log_options() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_mdc_log_options
+ *
+ * Purpose:	Get metadata cache log options. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_mdc_log_options(hid_t plist_id, hbool_t *is_enabled, char *location,
+                       size_t *location_size, hbool_t *start_on_access)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    char *location_ptr;                 /* Pointer to location string */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE5("e", "i*b*s*z*b", plist_id, is_enabled, location, location_size,
+             start_on_access);
+
+    /* Get the property list structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "plist_id is not a file access property list")
+
+    /* Get simple values */
+    if(is_enabled)
+        if(H5P_get(plist, H5F_ACS_USE_MDC_LOGGING_NAME, is_enabled) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get log location")
+    if(start_on_access)
+        if(H5P_get(plist, H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME, start_on_access) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get start_on_access flag")
+
+    /* Get the location */
+    if(location || location_size)
+        if(H5P_get(plist, H5F_ACS_MDC_LOG_LOCATION_NAME, &location_ptr) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get log location")
+
+    /* Copy log location to output buffer */
+    if(location_ptr && location)
+        HDmemcpy(location, location_ptr, *location_size);
+
+    /* Get location size, including terminating NULL */
+    if(location_size) {
+        if(location_ptr)
+            *location_size = HDstrlen(location_ptr) + 1;
+        else
+            *location_size = 0;
+    }
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pget_mdc_log_options() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5P_facc_mdc_log_location_enc
+ *
+ * Purpose:        Callback routine which is called whenever the metadata
+ *                 cache log location property in the file access property
+ *                 list is encoded.
+ *
+ * Return:         Success:     Non-negative
+ *                 Failure:     Negative
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P_facc_mdc_log_location_enc(const void *value, void **_pp, size_t *size)
+{
+    const char *log_location = *(const char * const *)value;
+    uint8_t **pp = (uint8_t **)_pp;
+    size_t len = 0;
+    uint64_t enc_value;
+    unsigned enc_size;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDcompile_assert(sizeof(size_t) <= sizeof(uint64_t));
+
+    /* calculate prefix length */
+    if(NULL != log_location)
+        len = HDstrlen(log_location);
+
+    enc_value = (uint64_t)len;
+    enc_size = H5VM_limit_enc_size(enc_value);
+    HDassert(enc_size < 256);
+
+    if(NULL != *pp) {
+        /* encode the length of the prefix */
+        *(*pp)++ = (uint8_t)enc_size;
+        UINT64ENCODE_VAR(*pp, enc_value, enc_size);
+
+        /* encode the prefix */
+        if(NULL != log_location) {
+            HDmemcpy(*(char **)pp, log_location, len);
+            *pp += len;
+        } /* end if */
+    } /* end if */
+
+    *size += (1 + enc_size);
+    if(NULL != log_location)
+        *size += len;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P_facc_mdc_log_location_enc() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5P_facc_mdc_log_location_dec
+ *
+ * Purpose:        Callback routine which is called whenever the metadata
+ *                 cache log location property in the file access property
+ *                 list is decoded.
+ *
+ * Return:         Success:     Non-negative
+ *                 Failure:     Negative
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P_facc_mdc_log_location_dec(const void **_pp, void *_value)
+{
+    char **log_location = (char **)_value;
+    const uint8_t **pp = (const uint8_t **)_pp;
+    size_t len;
+    uint64_t enc_value;                 /* Decoded property value */
+    unsigned enc_size;                  /* Size of encoded property */
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(pp);
+    HDassert(*pp);
+    HDassert(log_location);
+    HDcompile_assert(sizeof(size_t) <= sizeof(uint64_t));
+
+    /* Decode the size */
+    enc_size = *(*pp)++;
+    HDassert(enc_size < 256);
+
+    /* Decode the value */
+    UINT64DECODE_VAR(*pp, enc_value, enc_size);
+    len = enc_value;
+
+    if(0 != len) {
+        /* Make a copy of the user's prefix string */
+        if(NULL == (*log_location = (char *)H5MM_malloc(len + 1)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "memory allocation failed for prefix")
+        HDstrncpy(*log_location, *(const char **)pp, len);
+        (*log_location)[len] = '\0';
+
+        *pp += len;
+    } /* end if */
+    else
+        *log_location = NULL;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_facc_mdc_log_location_dec() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5P_facc_mdc_log_location_del
+ *
+ * Purpose:     Frees memory used to store the metadata cache log location.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P_facc_mdc_log_location_del(hid_t H5_ATTR_UNUSED prop_id, const char H5_ATTR_UNUSED *name,
+    size_t H5_ATTR_UNUSED size, void *value)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(value);
+
+    H5MM_xfree(*(void **)value);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P_facc_mdc_log_location_del() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5P_facc_mdc_log_location_copy
+ *
+ * Purpose:     Creates a copy of the metadata cache log location string.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P_facc_mdc_log_location_copy(const char H5_ATTR_UNUSED *name, size_t H5_ATTR_UNUSED size, void *value)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(value);
+
+    *(char **)value = H5MM_xstrdup(*(const char **)value);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P_facc_mdc_log_location_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5P_facc_mdc_log_location_cmp
+ *
+ * Purpose:        Callback routine which is called whenever the metadata
+ *                 cache log location property in the file creation property
+ *                 list is compared.
+ *
+ * Return:         zero if VALUE1 and VALUE2 are equal, non zero otherwise.
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5P_facc_mdc_log_location_cmp(const void *value1, const void *value2, size_t H5_ATTR_UNUSED size)
+{
+    const char *pref1 = *(const char * const *)value1;
+    const char *pref2 = *(const char * const *)value2;
+    int ret_value = 0;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    if(NULL == pref1 && NULL != pref2)
+        HGOTO_DONE(1);
+    if(NULL != pref1 && NULL == pref2)
+        HGOTO_DONE(-1);
+    if(NULL != pref1 && NULL != pref2)
+        ret_value = HDstrcmp(pref1, pref2);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_facc_mdc_log_location_cmp() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5P_facc_mdc_log_location_close
+ *
+ * Purpose:     Frees memory used to store the metadata cache log location
+ *              string
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P_facc_mdc_log_location_close(const char H5_ATTR_UNUSED *name, size_t H5_ATTR_UNUSED size, void *value)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(value);
+
+    H5MM_xfree(*(void **)value);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P_facc_mdc_log_location_close() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5Pset_evict_on_close
  *
  * Purpose:     Sets the evict_on_close property value.
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index b807a37..fc902a8 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -353,6 +353,8 @@ H5_DLL herr_t H5Pset_core_write_tracking(hid_t fapl_id, hbool_t is_enabled, size
 H5_DLL herr_t H5Pget_core_write_tracking(hid_t fapl_id, hbool_t *is_enabled, size_t *page_size);
 H5_DLL herr_t H5Pset_object_flush_cb(hid_t plist_id, H5F_flush_cb_t func, void *udata);
 H5_DLL herr_t H5Pget_object_flush_cb(hid_t plist_id, H5F_flush_cb_t *func, void **udata);
+H5_DLL herr_t H5Pset_mdc_log_options(hid_t plist_id, hbool_t is_enabled, const char *location, hbool_t start_on_access);
+H5_DLL herr_t H5Pget_mdc_log_options(hid_t plist_id, hbool_t *is_enabled, char *location, size_t *location_size, hbool_t *start_on_access);
 H5_DLL herr_t H5Pset_evict_on_close(hid_t fapl_id, hbool_t evict_on_close);
 H5_DLL herr_t H5Pget_evict_on_close(hid_t fapl_id, hbool_t *evict_on_close);
 #ifdef H5_HAVE_PARALLEL