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-rw-r--r--io_context.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/io_context.c b/io_context.c
new file mode 100644
index 0000000..38a7d13
--- /dev/null
+++ b/io_context.c
@@ -0,0 +1,304 @@
+/*
+ * Copyright (C) 2024 Mikhail Burakov. This file is part of streamer.
+ *
+ * streamer 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.
+ *
+ * streamer 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 streamer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "io_context.h"
+
+#include <arpa/inet.h>
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <threads.h>
+#include <unistd.h>
+
+#include "proto.h"
+#include "queue.h"
+#include "util.h"
+
+struct IoContext {
+ int fd;
+ atomic_bool running;
+ struct Queue prio;
+ struct Queue queue;
+
+ mtx_t mutex;
+ cnd_t cond;
+ thrd_t thread;
+};
+
+struct ProtoImpl {
+ struct Proto proto;
+ struct ProtoHeader header;
+ uint8_t data[];
+};
+
+static bool IsPrioProto(const struct Proto* proto) {
+ return proto->header->type == kProtoTypePing ||
+ proto->header->type == kProtoTypePong;
+}
+
+static void ProtoDestroy(struct Proto* proto) { free(proto); }
+
+static bool ReadAll(int fd, void* buffer, size_t size) {
+ for (uint8_t* ptr = buffer; size;) {
+ ssize_t result = read(fd, ptr, size);
+ if (result <= 0) {
+ LOG("Failed to read socket (%s)", strerror(errno));
+ return false;
+ }
+ size -= (size_t)result;
+ ptr += result;
+ }
+ return true;
+}
+
+static bool WriteAll(int fd, struct iovec* iov, size_t count) {
+ while (count) {
+ int max_count = (int)MIN(count, UIO_MAXIOV);
+ ssize_t result = writev(fd, iov, max_count);
+ if (result <= 0) {
+ LOG("Failed to write socket (%s)", strerror(errno));
+ return false;
+ }
+
+ for (;;) {
+ if ((size_t)result < iov->iov_len) {
+ iov->iov_len -= (size_t)result;
+ iov->iov_base = (uint8_t*)iov->iov_base + result;
+ break;
+ }
+ result -= (ssize_t)iov->iov_len;
+ count--;
+ iov++;
+ }
+ }
+ return true;
+}
+
+static bool IoContextDequeue(struct IoContext* io_context,
+ struct Proto** pproto) {
+ if (mtx_lock(&io_context->mutex) != thrd_success) {
+ LOG("Failed to lock mutex (%s)", strerror(errno));
+ return false;
+ }
+
+ void* item = NULL;
+ while (!QueuePop(&io_context->prio, &item) &&
+ !QueuePop(&io_context->queue, &item) &&
+ atomic_load_explicit(&io_context->running, memory_order_relaxed)) {
+ assert(cnd_wait(&io_context->cond, &io_context->mutex) == thrd_success);
+ }
+
+ assert(mtx_unlock(&io_context->mutex) == thrd_success);
+ *pproto = item;
+ return true;
+}
+
+static int IoContextThreadProc(void* arg) {
+ struct IoContext* io_context = arg;
+ for (;;) {
+ struct Proto* proto;
+ if (!IoContextDequeue(io_context, &proto)) {
+ LOG("Failed to dequeue proto");
+ goto leave;
+ }
+
+ if (!proto) {
+ // mburakov: running was set to false externally.
+ return 0;
+ }
+
+ struct iovec iov[] = {
+ {.iov_base = (void*)(uintptr_t)(proto->header),
+ .iov_len = sizeof(struct ProtoHeader)},
+ {.iov_base = (void*)(uintptr_t)(proto->data),
+ .iov_len = proto->header->size},
+ };
+ bool result = WriteAll(io_context->fd, iov, LENGTH(iov));
+ proto->Destroy(proto);
+ if (!result) {
+ LOG("Failed to write proto");
+ goto leave;
+ }
+ }
+
+leave:
+ atomic_store_explicit(&io_context->running, false, memory_order_relaxed);
+ return 0;
+}
+
+struct IoContext* IoContextCreate(uint16_t port) {
+ int sock = socket(AF_INET, SOCK_STREAM, 0);
+ if (sock == -1) {
+ LOG("Failed to create socket (%s)", strerror(errno));
+ return NULL;
+ }
+
+ if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int))) {
+ LOG("Failed to reuse socket address (%s)", strerror(errno));
+ goto rollback_sock;
+ }
+
+ const struct sockaddr_in sa = {
+ .sin_family = AF_INET,
+ .sin_port = htons(port),
+ .sin_addr = INADDR_ANY,
+ };
+ if (bind(sock, (const struct sockaddr*)&sa, sizeof(sa))) {
+ LOG("Failed to bind socket (%s)", strerror(errno));
+ goto rollback_sock;
+ }
+
+ if (listen(sock, SOMAXCONN)) {
+ LOG("Failed to listen socket (%s)", strerror(errno));
+ goto rollback_sock;
+ }
+
+ struct IoContext* io_context = malloc(sizeof(struct IoContext));
+ if (!io_context) {
+ LOG("Failed to allocate io context (%s)", strerror(errno));
+ goto rollback_sock;
+ }
+
+ io_context->fd = accept(sock, NULL, NULL);
+ if (io_context->fd == -1) {
+ LOG("Failed to accept socket (%s)", strerror(errno));
+ goto rollback_io_context;
+ }
+
+ if (setsockopt(io_context->fd, IPPROTO_TCP, TCP_NODELAY, &(int){1},
+ sizeof(int))) {
+ LOG("Failed to set TCP_NODELAY (%s)", strerror(errno));
+ goto rollback_fd;
+ }
+
+ atomic_init(&io_context->running, true);
+ QueueCreate(&io_context->prio);
+ QueueCreate(&io_context->queue);
+ if (mtx_init(&io_context->mutex, mtx_plain) != thrd_success) {
+ LOG("Failed to init mutex (%s)", strerror(errno));
+ goto rollback_fd;
+ }
+
+ if (cnd_init(&io_context->cond) != thrd_success) {
+ LOG("Failed to init condition variable (%s)", strerror(errno));
+ goto rollback_mutex;
+ }
+
+ if (thrd_create(&io_context->thread, &IoContextThreadProc, io_context) !=
+ thrd_success) {
+ LOG("Failed to create thread (%s)", strerror(errno));
+ goto rollback_cond;
+ }
+
+ assert(!close(sock));
+ return io_context;
+
+rollback_cond:
+ cnd_destroy(&io_context->cond);
+rollback_mutex:
+ mtx_destroy(&io_context->mutex);
+rollback_fd:
+ assert(!close(io_context->fd));
+rollback_io_context:
+ free(io_context);
+rollback_sock:
+ assert(!close(sock));
+ return NULL;
+}
+
+struct Proto* IoContextRead(struct IoContext* io_context) {
+ struct ProtoHeader header;
+ if (!ReadAll(io_context->fd, &header, sizeof(header))) {
+ LOG("Failed to read proto header");
+ return NULL;
+ }
+
+ struct ProtoImpl* proto_impl = malloc(sizeof(struct ProtoImpl) + header.size);
+ if (!proto_impl) {
+ LOG("Failed to allocate proto (%s)", strerror(errno));
+ return NULL;
+ }
+
+ if (!ReadAll(io_context->fd, &proto_impl->data, header.size)) {
+ LOG("Failed to read proto body");
+ goto rollback_proto_impl;
+ }
+
+ proto_impl->header = header;
+ const struct Proto proto = {
+ .Destroy = ProtoDestroy,
+ .header = &proto_impl->header,
+ .data = proto_impl->data,
+ };
+ memcpy(proto_impl, &proto, sizeof(proto));
+ return &proto_impl->proto;
+
+rollback_proto_impl:
+ free(proto_impl);
+ return NULL;
+}
+
+bool IoContextWrite(struct IoContext* io_context, struct Proto* proto) {
+ if (!atomic_load_explicit(&io_context->running, memory_order_relaxed)) {
+ LOG("Io context is not running");
+ goto rollback_proto;
+ }
+
+ struct Queue* queue =
+ IsPrioProto(proto) ? &io_context->prio : &io_context->queue;
+ if (mtx_lock(&io_context->mutex) != thrd_success) {
+ LOG("Failed to lock mutex (%s)", strerror(errno));
+ goto rollback_proto;
+ }
+
+ if (!QueuePush(queue, proto)) {
+ LOG("Failed to queue proto");
+ goto rollback_lock;
+ }
+
+ assert(cnd_broadcast(&io_context->cond) == thrd_success);
+ assert(mtx_unlock(&io_context->mutex) == thrd_success);
+ return true;
+
+rollback_lock:
+ assert(mtx_unlock(&io_context->mutex) == thrd_success);
+rollback_proto:
+ proto->Destroy(proto);
+ return false;
+}
+
+void IoContextDestroy(struct IoContext* io_context) {
+ atomic_store_explicit(&io_context->running, false, memory_order_relaxed);
+ assert(cnd_broadcast(&io_context->cond) == thrd_success);
+ assert(thrd_join(io_context->thread, NULL) == thrd_success);
+ cnd_destroy(&io_context->cond);
+ mtx_destroy(&io_context->mutex);
+ for (void* item; QueuePop(&io_context->prio, &item); free(item));
+ QueueDestroy(&io_context->prio);
+ for (void* item; QueuePop(&io_context->queue, &item); free(item));
+ QueueDestroy(&io_context->queue);
+ assert(!close(io_context->fd));
+ free(io_context);
+}
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