1 files changed, 169 insertions, 0 deletions
diff --git a/include/dnsjit/core/channel.c b/include/dnsjit/core/channel.c
new file mode 100644
index 0000000..691ad1a
--- /dev/null
+++ b/include/dnsjit/core/channel.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2018-2021, OARC, Inc.
+ * All rights reserved.
+ *
+ * This file is part of dnsjit.
+ *
+ * dnsjit is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dnsjit is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dnsjit.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "core/channel.h"
+#include "core/assert.h"
+
+#include <sched.h>
+
+static core_log_t     _log      = LOG_T_INIT("core.channel");
+static core_channel_t _defaults = {
+    LOG_T_INIT_OBJ("core.channel"),
+    0, { 0 }, 0, 0,
+    0, 0
+};
+
+core_log_t* core_channel_log()
+{
+    return &_log;
+}
+
+static inline bool _is_pow2(size_t num)
+{
+    while (num != 1) {
+        if (num % 2 != 0)
+            return false;
+        num = num / 2;
+    }
+    return true;
+}
+
+void core_channel_init(core_channel_t* self, size_t capacity)
+{
+    mlassert_self();
+    if (capacity < 4 || !_is_pow2(capacity)) {
+        mlfatal("invalid capacity");
+    }
+
+    *self          = _defaults;
+    self->capacity = capacity;
+
+    lfatal_oom(self->ring_buf = malloc(sizeof(ck_ring_buffer_t) * capacity));
+    ck_ring_init(&self->ring, capacity);
+}
+
+void core_channel_destroy(core_channel_t* self)
+{
+    mlassert_self();
+    free(self->ring_buf);
+}
+
+void core_channel_put(core_channel_t* self, const void* obj)
+{
+    mlassert_self();
+    lassert(self->ring_buf, "ring_buf is nil");
+
+    while (!ck_ring_enqueue_spsc(&self->ring, self->ring_buf, (void*)obj)) {
+        sched_yield();
+    }
+}
+
+int core_channel_try_put(core_channel_t* self, const void* obj)
+{
+    mlassert_self();
+    lassert(self->ring_buf, "ring_buf is nil");
+
+    if (!ck_ring_enqueue_spsc(&self->ring, self->ring_buf, (void*)obj)) {
+        return -1;
+    }
+
+    return 0;
+}
+
+void* core_channel_get(core_channel_t* self)
+{
+    void* obj = 0;
+    mlassert_self();
+    lassert(self->ring_buf, "ring_buf is nil");
+
+    while (!ck_ring_dequeue_spsc(&self->ring, self->ring_buf, &obj)) {
+        sched_yield();
+        if (ck_pr_load_int(&self->closed)) {
+            linfo("channel closed");
+            return 0;
+        }
+    }
+
+    return obj;
+}
+
+void* core_channel_try_get(core_channel_t* self)
+{
+    void* obj = 0;
+    mlassert_self();
+    lassert(self->ring_buf, "ring_buf is nil");
+
+    if (!ck_ring_dequeue_spsc(&self->ring, self->ring_buf, &obj)) {
+        return 0;
+    }
+
+    return obj;
+}
+
+int core_channel_size(core_channel_t* self)
+{
+    mlassert_self();
+    return ck_ring_size(&self->ring);
+}
+
+bool core_channel_full(core_channel_t* self)
+{
+    mlassert_self();
+
+    /* ck_ring can only hold capacity minus one enties at a time */
+    if (ck_ring_size(&self->ring) < (self->capacity - 1)) {
+        return false;
+    }
+    return true;
+}
+
+void core_channel_close(core_channel_t* self)
+{
+    mlassert_self();
+    ck_pr_store_int(&self->closed, 1);
+}
+
+core_receiver_t core_channel_receiver()
+{
+    return (core_receiver_t)core_channel_put;
+}
+
+void core_channel_run(core_channel_t* self)
+{
+    void* obj = 0;
+    mlassert_self();
+    lassert(self->ring_buf, "ring_buf is nil");
+    if (!self->recv) {
+        lfatal("no receiver set");
+    }
+
+    for (;;) {
+        while (!ck_ring_dequeue_spsc(&self->ring, self->ring_buf, &obj)) {
+            sched_yield();
+            if (ck_pr_load_int(&self->closed)) {
+                linfo("channel closed");
+                return;
+            }
+        }
+        self->recv(self->ctx, obj);
+    }
+}