--- /dev/null
+/* Copyright (C) 2010-2020 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (nbio_linux.c).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <file/nbio.h>
+
+#if defined(__linux__)
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <time.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/syscall.h>
+#include <linux/aio_abi.h>
+
+struct nbio_linux_t
+{
+ void* ptr;
+ aio_context_t ctx;
+ struct iocb cb;
+ size_t len;
+ int fd;
+ bool busy;
+};
+
+/* there's also a Unix AIO thingy, but it's not in glibc
+ * and we don't want more dependencies */
+
+static int io_setup(unsigned nr, aio_context_t * ctxp)
+{
+ return syscall(__NR_io_setup, nr, ctxp);
+}
+
+static int io_destroy(aio_context_t ctx)
+{
+ return syscall(__NR_io_destroy, ctx);
+}
+
+static int io_submit(aio_context_t ctx, long nr, struct iocb ** cbp)
+{
+ return syscall(__NR_io_submit, ctx, nr, cbp);
+}
+
+static int io_cancel(aio_context_t ctx, struct iocb * iocb, struct io_event * result)
+{
+ return syscall(__NR_io_cancel, ctx, iocb, result);
+}
+
+static int io_getevents(aio_context_t ctx, long min_nr, long nr,
+ struct io_event * events, struct timespec * timeout)
+{
+ return syscall(__NR_io_getevents, ctx, min_nr, nr, events, timeout);
+}
+
+static void nbio_begin_op(struct nbio_linux_t* handle, uint16_t op)
+{
+ struct iocb * cbp = &handle->cb;
+
+ memset(&handle->cb, 0, sizeof(handle->cb));
+
+ handle->cb.aio_fildes = handle->fd;
+ handle->cb.aio_lio_opcode = op;
+
+ handle->cb.aio_buf = (uint64_t)(uintptr_t)handle->ptr;
+ handle->cb.aio_offset = 0;
+ handle->cb.aio_nbytes = handle->len;
+
+ if (io_submit(handle->ctx, 1, &cbp) != 1)
+ abort();
+
+ handle->busy = true;
+}
+
+static void *nbio_linux_open(const char * filename, unsigned mode)
+{
+ static const int o_flags[] = { O_RDONLY, O_RDWR|O_CREAT|O_TRUNC, O_RDWR, O_RDONLY, O_RDWR|O_CREAT|O_TRUNC };
+
+ aio_context_t ctx = 0;
+ struct nbio_linux_t* handle = NULL;
+ int fd = open(filename, o_flags[mode]|O_CLOEXEC, 0644);
+ if (fd < 0)
+ return NULL;
+
+ if (io_setup(128, &ctx) < 0)
+ {
+ close(fd);
+ return NULL;
+ }
+
+ handle = (struct nbio_linux_t*)malloc(sizeof(struct nbio_linux_t));
+ handle->fd = fd;
+ handle->ctx = ctx;
+ handle->len = lseek(fd, 0, SEEK_END);
+ handle->ptr = malloc(handle->len);
+ handle->busy = false;
+
+ return handle;
+}
+
+static void nbio_linux_begin_read(void *data)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (handle)
+ nbio_begin_op(handle, IOCB_CMD_PREAD);
+}
+
+static void nbio_linux_begin_write(void *data)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (handle)
+ nbio_begin_op(handle, IOCB_CMD_PWRITE);
+}
+
+static bool nbio_linux_iterate(void *data)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (!handle)
+ return false;
+ if (handle->busy)
+ {
+ struct io_event ev;
+ if (io_getevents(handle->ctx, 0, 1, &ev, NULL) == 1)
+ handle->busy = false;
+ }
+ return !handle->busy;
+}
+
+static void nbio_linux_resize(void *data, size_t len)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (!handle)
+ return;
+
+ /* This works perfectly fine if this check is removed, but it
+ * won't work on other nbio implementations */
+ /* therefore, it's blocked so nobody accidentally relies on it */
+ if (len < handle->len)
+ abort();
+
+ if (ftruncate(handle->fd, len) != 0)
+ abort(); /* this one returns void and I can't find any other way
+ for it to report failure */
+
+ handle->ptr = realloc(handle->ptr, len);
+ handle->len = len;
+}
+
+static void *nbio_linux_get_ptr(void *data, size_t* len)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (!handle)
+ return NULL;
+ if (len)
+ *len = handle->len;
+ if (!handle->busy)
+ return handle->ptr;
+ return NULL;
+}
+
+static void nbio_linux_cancel(void *data)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (!handle)
+ return;
+
+ if (handle->busy)
+ {
+ struct io_event ev;
+ io_cancel(handle->ctx, &handle->cb, &ev);
+ handle->busy = false;
+ }
+}
+
+static void nbio_linux_free(void *data)
+{
+ struct nbio_linux_t* handle = (struct nbio_linux_t*)data;
+ if (!handle)
+ return;
+
+ io_destroy(handle->ctx);
+ close(handle->fd);
+ free(handle->ptr);
+ free(handle);
+}
+
+nbio_intf_t nbio_linux = {
+ nbio_linux_open,
+ nbio_linux_begin_read,
+ nbio_linux_begin_write,
+ nbio_linux_iterate,
+ nbio_linux_resize,
+ nbio_linux_get_ptr,
+ nbio_linux_cancel,
+ nbio_linux_free,
+ "nbio_linux",
+};
+#else
+nbio_intf_t nbio_linux = {
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ "nbio_linux",
+};
+
+#endif
notaz.gp2x.de / pcsx_rearmed.git / blobdiff