Remove the event queue code

PR #18345 added some code for an event queue. It also added a test for it.
Unfortunately this event queue code has never been used for anything.
Additionally the test was never integrated into a test recipe, so it never
actually gets invoked via "make test". This makes the code entirely dead,
unnecessarily bloats the size of libssl and causes a decrease in our
testing code coverage value.

We remove the dead code.

Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25100)

2 files changed, 1 insertions, 197 deletions

diff --git a/ssl/build.info b/ssl/build.info
index de28a0700a..adfc966379 100644
--- a/ssl/build.info
+++ b/ssl/build.info
@@ -32,5 +32,5 @@ IF[{- !$disabled{'deprecated-3.0'} -}]
 ENDIF
 
 IF[{- !$disabled{quic} -}]
-  SOURCE[../libssl]=priority_queue.c event_queue.c
+  SOURCE[../libssl]=priority_queue.c
 ENDIF
diff --git a/ssl/event_queue.c b/ssl/event_queue.c
deleted file mode 100644
index 50b38de4cd..0000000000
--- a/ssl/event_queue.c
+++ /dev/null
@@ -1,196 +0,0 @@
-/*
- * Copyright 2022-2023 The OpenSSL Project Authors. All Rights Reserved.
- *
- * Licensed under the Apache License 2.0 (the "License").  You may not use
- * this file except in compliance with the License.  You can obtain a copy
- * in the file LICENSE in the source distribution or at
- * https://www.openssl.org/source/license.html
- */
-
-#include <stdlib.h>
-#include "internal/event_queue.h"
-#include "ssl_local.h"
-
-struct ossl_event_queue_st {
-    PRIORITY_QUEUE_OF(OSSL_EVENT) *timed_events;
-    PRIORITY_QUEUE_OF(OSSL_EVENT) *now_events;
-};
-
-static int event_compare_times(const OSSL_EVENT *a, const OSSL_EVENT *b)
-{
-    return ossl_time_compare(a->when, b->when);
-}
-
-static int event_compare_priority(const OSSL_EVENT *a, const OSSL_EVENT *b)
-{
-    if (a->priority > b->priority)
-        return -1;
-    if (a->priority < b->priority)
-        return 1;
-    return 0;
-}
-
-OSSL_EVENT_QUEUE *ossl_event_queue_new(void)
-{
-    OSSL_EVENT_QUEUE *r = OPENSSL_malloc(sizeof(*r));
-
-    if (r != NULL) {
-        r->timed_events = ossl_pqueue_OSSL_EVENT_new(&event_compare_times);
-        r->now_events = ossl_pqueue_OSSL_EVENT_new(&event_compare_priority);
-        if (r->timed_events == NULL || r->now_events == NULL) {
-            ossl_event_queue_free(r);
-            return NULL;
-        }
-    }
-    return r;
-}
-
-void ossl_event_free(OSSL_EVENT *event)
-{
-    if (event != NULL) {
-        if (event->flag_dynamic)
-            OPENSSL_free(event);
-        else
-            event->queue = NULL;
-    }
-}
-
-static void event_queue_free(PRIORITY_QUEUE_OF(OSSL_EVENT) *queue)
-{
-    OSSL_EVENT *e;
-
-    if (queue != NULL) {
-        while ((e = ossl_pqueue_OSSL_EVENT_pop(queue)) != NULL)
-            ossl_event_free(e);
-        ossl_pqueue_OSSL_EVENT_free(queue);
-    }
-}
-
-void ossl_event_queue_free(OSSL_EVENT_QUEUE *queue)
-{
-    if (queue != NULL) {
-        event_queue_free(queue->now_events);
-        event_queue_free(queue->timed_events);
-        OPENSSL_free(queue);
-    }
-}
-
-static ossl_inline
-int event_queue_add(OSSL_EVENT_QUEUE *queue, OSSL_EVENT *event)
-{
-    PRIORITY_QUEUE_OF(OSSL_EVENT) *pq =
-            ossl_time_compare(event->when, ossl_time_now()) <= 0
-            ? queue->now_events
-            : queue->timed_events;
-
-    if (ossl_pqueue_OSSL_EVENT_push(pq, event, &event->ref)) {
-        event->queue = pq;
-        return 1;
-    }
-    return 0;
-}
-
-static ossl_inline
-void ossl_event_set(OSSL_EVENT *event, uint32_t type, uint32_t priority,
-                    OSSL_TIME when, void *ctx,
-                    void *payload, size_t payload_size)
-{
-    event->type = type;
-    event->priority = priority;
-    event->when = when;
-    event->ctx = ctx;
-    event->payload = payload;
-    event->payload_size = payload_size;
-}
-
-OSSL_EVENT *ossl_event_queue_add_new(OSSL_EVENT_QUEUE *queue,
-                                     uint32_t type, uint32_t priority,
-                                     OSSL_TIME when, void *ctx,
-                                     void *payload, size_t payload_size)
-{
-    OSSL_EVENT *e = OPENSSL_malloc(sizeof(*e));
-
-    if (e == NULL || queue == NULL) {
-        OPENSSL_free(e);
-        return NULL;
-    }
-
-    ossl_event_set(e, type, priority, when, ctx, payload, payload_size);
-    e->flag_dynamic = 1;
-    if (event_queue_add(queue, e))
-        return e;
-    OPENSSL_free(e);
-    return NULL;
-}
-
-int ossl_event_queue_add(OSSL_EVENT_QUEUE *queue, OSSL_EVENT *event,
-                         uint32_t type, uint32_t priority,
-                         OSSL_TIME when, void *ctx,
-                         void *payload, size_t payload_size)
-{
-    if (event == NULL || queue == NULL)
-        return 0;
-    ossl_event_set(event, type, priority, when, ctx, payload, payload_size);
-    event->flag_dynamic = 0;
-    return event_queue_add(queue, event);
-}
-
-int ossl_event_queue_remove(OSSL_EVENT_QUEUE *queue, OSSL_EVENT *event)
-{
-    if (event != NULL && event->queue != NULL) {
-        ossl_pqueue_OSSL_EVENT_remove(event->queue, event->ref);
-        event->queue = NULL;
-    }
-    return 1;
-}
-
-OSSL_TIME ossl_event_time_until(const OSSL_EVENT *event)
-{
-    if (event == NULL)
-        return ossl_time_infinite();
-    return ossl_time_subtract(event->when, ossl_time_now());
-}
-
-OSSL_TIME ossl_event_queue_time_until_next(const OSSL_EVENT_QUEUE *queue)
-{
-    if (queue == NULL)
-        return ossl_time_infinite();
-    if (ossl_pqueue_OSSL_EVENT_num(queue->now_events) > 0)
-        return ossl_time_zero();
-    return ossl_event_time_until(ossl_pqueue_OSSL_EVENT_peek(queue->timed_events));
-}
-
-int ossl_event_queue_postpone_until(OSSL_EVENT_QUEUE *queue,
-                                    OSSL_EVENT *event,
-                                    OSSL_TIME when)
-{
-    if (ossl_event_queue_remove(queue, event)) {
-        event->when = when;
-        return event_queue_add(queue, event);
-    }
-    return 0;
-}
-
-int ossl_event_queue_get1_next_event(OSSL_EVENT_QUEUE *queue,
-                                     OSSL_EVENT **event)
-{
-    OSSL_TIME now = ossl_time_now();
-    OSSL_EVENT *e;
-
-    /* Check for expired timer based events and convert them to now events */
-    while ((e = ossl_pqueue_OSSL_EVENT_peek(queue->timed_events)) != NULL
-           && ossl_time_compare(e->when, now) <= 0) {
-        e = ossl_pqueue_OSSL_EVENT_pop(queue->timed_events);
-        if (!ossl_pqueue_OSSL_EVENT_push(queue->now_events, e, &e->ref)) {
-            e->queue = NULL;
-            return 0;
-        }
-    }
-
-    /*
-     * Get next event from the now queue.
-     * The pop returns NULL when there is none.
-     */
-    *event = ossl_pqueue_OSSL_EVENT_pop(queue->now_events);
-    return 1;
-}