Shorten the type name `H5F_vfd_swmr_eot_queue_entry_t` to `eot_queue_entry_t`:

people have to read and type this stuff!

Use TAILQ_* macros instead of an unnecessary custom implementation of
doubly-linked lists.

3 files changed, 46 insertions, 86 deletions

diff --git a/src/H5FDvfd_swmr_private.h b/src/H5FDvfd_swmr_private.h
index c12239c..5351b07 100644
--- a/src/H5FDvfd_swmr_private.h
+++ b/src/H5FDvfd_swmr_private.h
@@ -12,13 +12,15 @@
 #ifndef _H5FDvfd_swmr_private_H
 #define _H5FDvfd_swmr_private_H
 
+#include "bsdqueue.h"   /* for TAILQ_* */
+
 /* Forward declaration */
 struct H5F_t;
 struct H5F_shared_t;
 struct H5FD_vfd_swmr_idx_entry_t;
 
 /* 
- *  struct H5F_vfd_eot_queue_entry_t
+ *  struct eot_queue_entry_t
  * 
  *  This is the structure for an entry on the end-of-tick queue (EOT queue) of files
  *  opened in either VFD SWMR write or VFD SWMR read mode.  This queue is maintained
@@ -27,7 +29,7 @@ struct H5FD_vfd_swmr_idx_entry_t;
  *  of tick has arrived for the specified file, and to initiate end of tick processing
  *  if it has.
  *
- *  The fields of H5F_vfd_eot_queue_entry_t are discussed below:
+ *  The fields of eot_queue_entry_t are discussed below:
  *
  *  vfd_swmr_file: Pointer to the instance of H5F_file_t containing the shared
  *      fields of the associated file that has been opened in VFD SWMR mode
@@ -41,31 +43,27 @@ struct H5FD_vfd_swmr_idx_entry_t;
  *
  *  end_of_tick: Expiration time of the current tick of the target file.
  *
- *  next: Pointer to the next element in the end of tick queue, or NULL if there
- *      is no next entry.  Note that if next is not NULL, next->end_of_tick 
- *      must be greater than or equal to end_of_tick.
- *
- *  prev: Pointer to the previous element in the end of tick queue, or NULL if 
- *      there is no previous entry.  Note that if prev is not NULL, 
- *      prev->end_of_tick must be less than or equal to end_of_tick.
- *
+ *  link: Forward and backward linkage between the next element and the previous
+ *  element (or the queue head).  Note that if there is a following entry,
+ *  `next`, then `next->end_of_tick` must be greater than or equal to
+ *  `end_of_tick`.
  */
-typedef struct H5F_vfd_swmr_eot_queue_entry_t {
+typedef struct eot_queue_entry {
     hbool_t     vfd_swmr_writer;
     uint64_t    tick_num;
     struct timespec end_of_tick;
     struct H5F_t  *vfd_swmr_file; /* NOTE: for the time being use H5F_t instead H5F_file_t */
-    struct H5F_vfd_swmr_eot_queue_entry_t *next;
-    struct H5F_vfd_swmr_eot_queue_entry_t *prev;
-} H5F_vfd_swmr_eot_queue_entry_t;
+    TAILQ_ENTRY(eot_queue_entry) link;
+} eot_queue_entry_t;
 
 extern unsigned int vfd_swmr_api_entries_g;
 extern hbool_t vfd_swmr_writer_g;
 extern struct timespec end_of_tick_g;
 
-/* The head and tail pointers of the EOT queue */
-extern H5F_vfd_swmr_eot_queue_entry_t *vfd_swmr_eot_queue_head_g;
-extern H5F_vfd_swmr_eot_queue_entry_t *vfd_swmr_eot_queue_tail_g;
+/* The head of the EOT queue */
+typedef TAILQ_HEAD(eot_queue, eot_queue_entry) eot_queue_t;
+
+extern eot_queue_t eot_queue_g;
 
 /***************************************/
 /* Library-private Function Prototypes */
diff --git a/src/H5Fvfd_swmr.c b/src/H5Fvfd_swmr.c
index 78f0dd6..f7ab9fd 100644
--- a/src/H5Fvfd_swmr.c
+++ b/src/H5Fvfd_swmr.c
@@ -76,20 +76,6 @@
     entry_ptr->prev = NULL;                                         \
 } /* H5F__LL_REMOVE() */
 
-/* Append an entry to the doubly linked list */
-#define H5F__LL_APPEND(entry_ptr, head_ptr, tail_ptr)               \
-{                                                                   \
-    if((head_ptr) == NULL ) {                                       \
-       (head_ptr) = (entry_ptr);                                    \
-       (tail_ptr) = (entry_ptr);                                    \
-    }                                                               \
-    else {                                                          \
-       (tail_ptr)->next = (entry_ptr);                              \
-       (entry_ptr)->prev = (tail_ptr);                              \
-       (tail_ptr) = (entry_ptr);                                    \
-    }                                                               \
-} /* H5F__LL_APPEND() */
-
 /* Prepend an entry to the doubly linked list */ 
 #define H5F__LL_PREPEND(entry_ptr, head_ptr, tail_ptr)              \
 {                                                                   \
@@ -103,27 +89,6 @@
     }                                                               \
 } /* H5F__LL_PREPEND() */
 
-/* Insert an entry after the predecessor entry "prec_ptr" on the EOT queue */
-#define H5F_EOT_INSERT_AFTER(entry_ptr, prec_ptr, head_ptr, tail_ptr)       \
-{                                                                           \
-    /* The list is empty or has no predecessor -- prepend */                \
-    if(prec_ptr == NULL)                                                    \
-        H5F__LL_PREPEND(entry_ptr, head_ptr, tail_ptr)                      \
-                                                                            \
-    /* The predecessor entry is at head of list -- append */                \
-    else if(prec_ptr->prev == NULL)                                         \
-        H5F__LL_APPEND(entry_ptr, head_ptr, tail_ptr)                       \
-                                                                            \
-    /* The predecessor entry is in the body of list -- insert after it */   \
-    else                                                                    \
-    {                                                                       \
-        entry_ptr->prev = prec_ptr;                                         \
-        entry_ptr->next = prec_ptr->next;                                   \
-        prec_ptr->next->prev = entry_ptr;                                   \
-        prec_ptr->next = entry_ptr;                                         \
-    }                                                                       \
-} /* H5F_EOT_INSERT_AFTER() */
-
 /********************/
 /* Local Prototypes */
 /********************/
@@ -154,11 +119,10 @@ unsigned int vfd_swmr_api_entries_g = 0;/* Times the library was entered
                                          * transitions.
                                          */
 /*
- *  The head and tail of the end of tick queue (EOT queue) for files opened in either
+ *  The head of the end of tick queue (EOT queue) for files opened in either
  *  VFD SWMR write or VFD SWMR read mode
  */
-H5F_vfd_swmr_eot_queue_entry_t *vfd_swmr_eot_queue_head_g = NULL;
-H5F_vfd_swmr_eot_queue_entry_t *vfd_swmr_eot_queue_tail_g = NULL;
+eot_queue_t eot_queue_g = TAILQ_HEAD_INITIALIZER(eot_queue_g);
 
 /*******************/
 /* Local Variables */
@@ -167,8 +131,8 @@ H5F_vfd_swmr_eot_queue_entry_t *vfd_swmr_eot_queue_tail_g = NULL;
 /* Declare a free list to manage the H5F_vfd_swmr_dl_entry_t struct */
 H5FL_DEFINE(H5F_vfd_swmr_dl_entry_t);
 
-/* Declare a free list to manage the H5F_vfd_swmr_eot_queue_entry_t struct */
-H5FL_DEFINE(H5F_vfd_swmr_eot_queue_entry_t);
+/* Declare a free list to manage the eot_queue_entry_t struct */
+H5FL_DEFINE(eot_queue_entry_t);
 
 
 /*-------------------------------------------------------------------------
@@ -839,7 +803,7 @@ H5F_vfd_swmr_writer_end_of_tick(H5F_t *f)
 
     /* When called from FUNC ENTER/EXIT, get the first entry on the EOT queue */
     if(f == NULL)
-        f = vfd_swmr_eot_queue_head_g->vfd_swmr_file;
+        f = TAILQ_FIRST(&eot_queue_g)->vfd_swmr_file;
 
     HDassert(f);
     HDassert(f->shared);
@@ -1116,7 +1080,7 @@ H5F_vfd_swmr_reader_end_of_tick(H5F_t *f)
 
     /* When called from FUNC ENTER/EXIT, get the first entry on the EOT queue */
     if(f == NULL)
-        f = vfd_swmr_eot_queue_head_g->vfd_swmr_file;
+        f = TAILQ_FIRST(&eot_queue_g)->vfd_swmr_file;
 
     HDassert(f);
     HDassert(f->shared);
@@ -1421,26 +1385,25 @@ done:
 herr_t
 H5F_vfd_swmr_remove_entry_eot(H5F_t *f)
 {
-    H5F_vfd_swmr_eot_queue_entry_t *curr;
+    eot_queue_entry_t *curr;
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
     /* Free the entry on the EOT queue that corresponds to f */
     
-    for (curr = vfd_swmr_eot_queue_head_g; curr != NULL; curr = curr->next) {
+    TAILQ_FOREACH(curr, &eot_queue_g, link) {
         if (curr->vfd_swmr_file == f)
             break;
     }
 
     if (curr != NULL) {
-        H5F__LL_REMOVE(curr, vfd_swmr_eot_queue_head_g,
-            vfd_swmr_eot_queue_tail_g)
-        curr = H5FL_FREE(H5F_vfd_swmr_eot_queue_entry_t, curr);
+        TAILQ_REMOVE(&eot_queue_g, curr, link);
+        curr = H5FL_FREE(eot_queue_entry_t, curr);
     }
 
-    if(vfd_swmr_eot_queue_head_g) {
-        vfd_swmr_writer_g = vfd_swmr_eot_queue_head_g->vfd_swmr_writer;
-        end_of_tick_g = vfd_swmr_eot_queue_head_g->end_of_tick;
+    if(!TAILQ_EMPTY(&eot_queue_g)) {
+        vfd_swmr_writer_g = TAILQ_FIRST(&eot_queue_g)->vfd_swmr_writer;
+        end_of_tick_g = TAILQ_FIRST(&eot_queue_g)->end_of_tick;
     } else
         vfd_swmr_writer_g = FALSE;
 
@@ -1464,14 +1427,14 @@ H5F_vfd_swmr_remove_entry_eot(H5F_t *f)
 herr_t
 H5F_vfd_swmr_insert_entry_eot(H5F_t *f)
 {
-    H5F_vfd_swmr_eot_queue_entry_t *entry_ptr;    /* An entry on the EOT end of tick queue */
-    H5F_vfd_swmr_eot_queue_entry_t *prec_ptr;     /* The predecessor entry on the EOT end of tick queue */
+    eot_queue_entry_t *entry_ptr;    /* An entry on the EOT end of tick queue */
+    eot_queue_entry_t *prec_ptr;     /* The predecessor entry on the EOT end of tick queue */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Allocate an entry to be inserted onto the EOT queue */
-    if (NULL == (entry_ptr = H5FL_CALLOC(H5F_vfd_swmr_eot_queue_entry_t)))
+    if (NULL == (entry_ptr = H5FL_CALLOC(eot_queue_entry_t)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "unable to allocate the end of tick queue entry")
 
     /* Initialize the entry */
@@ -1479,24 +1442,23 @@ H5F_vfd_swmr_insert_entry_eot(H5F_t *f)
     entry_ptr->tick_num = f->shared->tick_num;
     entry_ptr->end_of_tick = f->shared->end_of_tick;
     entry_ptr->vfd_swmr_file = f;
-    entry_ptr->next = NULL;
-    entry_ptr->prev = NULL;
 
     /* Found the position to insert the entry on the EOT queue */
-    for (prec_ptr = vfd_swmr_eot_queue_tail_g;
-         prec_ptr != NULL;
-         prec_ptr = prec_ptr->prev) {
+    TAILQ_FOREACH_REVERSE(prec_ptr, &eot_queue_g, eot_queue, link) {
         if (timespeccmp(&prec_ptr->end_of_tick, &entry_ptr->end_of_tick, <=))
             break;
     }
 
     /* Insert the entry onto the EOT queue */
-    H5F_EOT_INSERT_AFTER(entry_ptr, prec_ptr, vfd_swmr_eot_queue_head_g, vfd_swmr_eot_queue_tail_g);
+    if (prec_ptr != NULL)
+        TAILQ_INSERT_AFTER(&eot_queue_g, prec_ptr, entry_ptr, link);
+    else
+        TAILQ_INSERT_HEAD(&eot_queue_g, entry_ptr, link);
 
     /* Set up globals accordinly */
-    if(vfd_swmr_eot_queue_head_g) {
-        vfd_swmr_writer_g = vfd_swmr_eot_queue_head_g->vfd_swmr_writer;
-        end_of_tick_g = vfd_swmr_eot_queue_head_g->end_of_tick;
+    if(!TAILQ_EMPTY(&eot_queue_g)) {
+        vfd_swmr_writer_g = TAILQ_FIRST(&eot_queue_g)->vfd_swmr_writer;
+        end_of_tick_g = TAILQ_FIRST(&eot_queue_g)->end_of_tick;
     } else
         vfd_swmr_writer_g = FALSE;
 
@@ -1523,13 +1485,13 @@ herr_t
 H5F_dump_eot_queue(void)
 {
     int i;
-    H5F_vfd_swmr_eot_queue_entry_t *curr;
+    eot_queue_entry_t *curr;
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-    for (i = 0, curr = vfd_swmr_eot_queue_head_g;
+    for (curr = TAILQ_FIRST(&eot_queue_g), i = 0;
          curr != NULL;
-         curr = curr->next, i++) {
+         curr = TAILQ_NEXT(curr, link), i++) {
         HDfprintf(stderr, "%d: %s tick_num %" PRIu64
             ", end_of_tick %jd.%09ld, vfd_swmr_file %p\n", 
                   i, curr->vfd_swmr_writer ? "writer" : "not writer",
diff --git a/src/H5private.h b/src/H5private.h
index cbdccce..e40e5c1 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -2116,10 +2116,10 @@ H5_DLL herr_t H5CX_pop(void);
         ;   /* Do nothing: we are *re-*entering the API. */                   \
     } else if(err_occurred) {                                                 \
         ;   /* Do nothing: an error occurred. */                              \
-    } else if(vfd_swmr_eot_queue_head_g != NULL) {                            \
+    } else if(TAILQ_FIRST(&eot_queue_g) != NULL) {                            \
         const bool swmr_reader_exit = _swmr_reader_exit;                      \
         struct timespec curr_time;                                            \
-        struct H5F_vfd_swmr_eot_queue_entry_t *init_eot_queue_head = vfd_swmr_eot_queue_head_g; \
+        eot_queue_entry_t *init_eot_queue_head = TAILQ_FIRST(&eot_queue_g);   \
         do {                                                                  \
             if(HDclock_gettime(CLOCK_MONOTONIC, &curr_time) < 0) {            \
                 HGOTO_ERROR(H5E_FUNC, H5E_CANTGET, err,                       \
@@ -2136,8 +2136,8 @@ H5_DLL herr_t H5CX_pop(void);
                                 "end of tick error for VFD SWMR reader")      \
             } else                                                            \
                 break;                                                        \
-        } while ((vfd_swmr_eot_queue_head_g != NULL) &&                       \
-                 (vfd_swmr_eot_queue_head_g != init_eot_queue_head));         \
+        } while (TAILQ_FIRST(&eot_queue_g) != NULL &&                         \
+                 TAILQ_FIRST(&eot_queue_g) != init_eot_queue_head);           \
     }                                                                         \
 
 /* Use this macro for all "normal" API functions */