1 files changed, 85 insertions, 0 deletions
diff --git a/crypto/openssl/ssl/quic/quic_reactor_wait_ctx.c b/crypto/openssl/ssl/quic/quic_reactor_wait_ctx.c
new file mode 100644
index 000000000000..00efac715603
--- /dev/null
+++ b/crypto/openssl/ssl/quic/quic_reactor_wait_ctx.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2024-2025 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 "internal/quic_reactor_wait_ctx.h"
+#include "internal/common.h"
+#include "internal/thread_arch.h"
+#include <assert.h>
+
+struct quic_reactor_wait_slot_st {
+    OSSL_LIST_MEMBER(quic_reactor_wait_slot, QUIC_REACTOR_WAIT_SLOT);
+    QUIC_REACTOR            *rtor;              /* primary key */
+    size_t                  blocking_count;     /* datum */
+};
+
+DEFINE_LIST_OF_IMPL(quic_reactor_wait_slot, QUIC_REACTOR_WAIT_SLOT);
+
+void ossl_quic_reactor_wait_ctx_init(QUIC_REACTOR_WAIT_CTX *ctx)
+{
+    ossl_list_quic_reactor_wait_slot_init(&ctx->slots);
+}
+
+static void slot_activate(QUIC_REACTOR_WAIT_SLOT *slot)
+{
+    if (++slot->blocking_count == 1)
+        ossl_quic_reactor_enter_blocking_section(slot->rtor);
+}
+
+static void slot_deactivate(QUIC_REACTOR_WAIT_SLOT *slot)
+{
+    assert(slot->blocking_count > 0);
+
+    if (--slot->blocking_count > 0)
+        return;
+
+    ossl_quic_reactor_leave_blocking_section(slot->rtor);
+}
+
+int ossl_quic_reactor_wait_ctx_enter(QUIC_REACTOR_WAIT_CTX *ctx,
+                                     QUIC_REACTOR *rtor)
+{
+    QUIC_REACTOR_WAIT_SLOT *slot;
+
+    OSSL_LIST_FOREACH(slot, quic_reactor_wait_slot, &ctx->slots)
+        if (slot->rtor == rtor)
+            break;
+
+    if (slot == NULL) {
+        if ((slot = OPENSSL_zalloc(sizeof(QUIC_REACTOR_WAIT_SLOT))) == NULL)
+            return 0;
+
+        slot->rtor = rtor;
+        ossl_list_quic_reactor_wait_slot_insert_tail(&ctx->slots, slot);
+    }
+
+    slot_activate(slot);
+    return 1;
+}
+
+void ossl_quic_reactor_wait_ctx_leave(QUIC_REACTOR_WAIT_CTX *ctx,
+                                      QUIC_REACTOR *rtor)
+{
+    QUIC_REACTOR_WAIT_SLOT *slot;
+
+    OSSL_LIST_FOREACH(slot, quic_reactor_wait_slot, &ctx->slots)
+        if (slot->rtor == rtor)
+            break;
+
+    assert(slot != NULL);
+    slot_deactivate(slot);
+}
+
+void ossl_quic_reactor_wait_ctx_cleanup(QUIC_REACTOR_WAIT_CTX *ctx)
+{
+    QUIC_REACTOR_WAIT_SLOT *slot, *nslot;
+
+    OSSL_LIST_FOREACH_DELSAFE(slot, nslot, quic_reactor_wait_slot, &ctx->slots) {
+        assert(slot->blocking_count == 0);
+        OPENSSL_free(slot);
+    }
+}