285 lines
6.6 KiB
C
285 lines
6.6 KiB
C
/*
|
|
* Copyright (c) 2006-2023, RT-Thread Development Team
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Change Logs:
|
|
* Date Author Notes
|
|
* 2023-07-20 zmq810150896 first version
|
|
*/
|
|
|
|
#include <rtthread.h>
|
|
#include <fcntl.h>
|
|
#include <rtdevice.h>
|
|
#include <stdint.h>
|
|
#include <unistd.h>
|
|
#include <dfs_file.h>
|
|
#include "poll.h"
|
|
#include "eventfd.h"
|
|
|
|
#define EFD_SEMAPHORE (1 << 0)
|
|
#define EFD_CLOEXEC O_CLOEXEC
|
|
#define EFD_NONBLOCK O_NONBLOCK
|
|
|
|
#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
|
|
#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)
|
|
|
|
#define ULLONG_MAX (~0ULL)
|
|
|
|
#define EVENTFD_MUTEX_NAME "eventfd"
|
|
|
|
struct eventfd_ctx
|
|
{
|
|
rt_wqueue_t reader_queue;
|
|
rt_wqueue_t writer_queue;
|
|
rt_uint64_t count;
|
|
unsigned int flags;
|
|
struct rt_mutex lock;
|
|
};
|
|
|
|
#ifndef RT_USING_DFS_V2
|
|
static int eventfd_close(struct dfs_file *file);
|
|
static int eventfd_poll(struct dfs_file *file, struct rt_pollreq *req);
|
|
static ssize_t eventfd_read(struct dfs_file *file, void *buf, size_t count);
|
|
static ssize_t eventfd_write(struct dfs_file *file, const void *buf, size_t count);
|
|
#else
|
|
static int eventfd_close(struct dfs_file *file);
|
|
static int eventfd_poll(struct dfs_file *file, struct rt_pollreq *req);
|
|
static ssize_t eventfd_read(struct dfs_file *file, void *buf, size_t count, off_t *pos);
|
|
static ssize_t eventfd_write(struct dfs_file *file, const void *buf, size_t count, off_t *pos);
|
|
#endif
|
|
|
|
static const struct dfs_file_ops eventfd_fops =
|
|
{
|
|
.close = eventfd_close,
|
|
.poll = eventfd_poll,
|
|
.read = eventfd_read,
|
|
.write = eventfd_write,
|
|
};
|
|
|
|
static int eventfd_close(struct dfs_file *file)
|
|
{
|
|
struct eventfd_ctx *ctx = file->vnode->data;
|
|
|
|
if (file->vnode->ref_count == 1)
|
|
{
|
|
rt_mutex_detach(&ctx->lock);
|
|
rt_free(ctx);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int eventfd_poll(struct dfs_file *file, struct rt_pollreq *req)
|
|
{
|
|
struct eventfd_ctx *ctx = (struct eventfd_ctx *)file->vnode->data;
|
|
int events = 0;
|
|
rt_uint64_t count;
|
|
|
|
count = ctx->count;
|
|
|
|
rt_poll_add(&ctx->reader_queue, req);
|
|
|
|
if (count > 0)
|
|
events |= POLLIN;
|
|
|
|
if (count == ULLONG_MAX)
|
|
events |= POLLERR;
|
|
|
|
if ((ULLONG_MAX - 1) > count)
|
|
events |= POLLOUT;
|
|
|
|
return events;
|
|
}
|
|
|
|
#ifndef RT_USING_DFS_V2
|
|
static ssize_t eventfd_read(struct dfs_file *file, void *buf, size_t count)
|
|
#else
|
|
static ssize_t eventfd_read(struct dfs_file *file, void *buf, size_t count, off_t *pos)
|
|
#endif
|
|
{
|
|
struct eventfd_ctx *ctx = (struct eventfd_ctx *)file->vnode->data;
|
|
rt_uint64_t counter_num = 0;
|
|
rt_uint64_t *buffer;
|
|
|
|
if (count < sizeof(counter_num))
|
|
return -EINVAL;
|
|
|
|
buffer = (rt_uint64_t *)buf;
|
|
|
|
rt_mutex_take(&ctx->lock, RT_WAITING_FOREVER);
|
|
|
|
if (ctx->count <= 0)
|
|
{
|
|
if (file->flags & O_NONBLOCK)
|
|
{
|
|
rt_wqueue_wakeup(&ctx->writer_queue, (void*)POLLOUT);
|
|
rt_mutex_release(&ctx->lock);
|
|
return -EAGAIN;
|
|
}
|
|
else
|
|
{
|
|
/* In this case, when the data is read in blocked mode, when ctx->count is 0, the mutex needs to be released and wait for writing */
|
|
rt_mutex_release(&ctx->lock);
|
|
rt_wqueue_wakeup(&ctx->writer_queue, (void*)POLLOUT);
|
|
rt_wqueue_wait(&ctx->reader_queue, 0, RT_WAITING_FOREVER);
|
|
rt_mutex_take(&ctx->lock, RT_WAITING_FOREVER);
|
|
}
|
|
}
|
|
|
|
if (ctx->flags & EFD_SEMAPHORE)
|
|
{
|
|
counter_num = 1;
|
|
}
|
|
else
|
|
{
|
|
counter_num = ctx->count;
|
|
}
|
|
|
|
ctx->count -= counter_num;
|
|
(*buffer) = counter_num;
|
|
|
|
rt_mutex_release(&ctx->lock);
|
|
|
|
return sizeof(counter_num);
|
|
}
|
|
|
|
#ifndef RT_USING_DFS_V2
|
|
static ssize_t eventfd_write(struct dfs_file *file, const void *buf, size_t count)
|
|
#else
|
|
static ssize_t eventfd_write(struct dfs_file *file, const void *buf, size_t count, off_t *pos)
|
|
#endif
|
|
{
|
|
struct eventfd_ctx *ctx = (struct eventfd_ctx *)file->vnode->data;
|
|
rt_ssize_t ret = 0;
|
|
|
|
rt_uint64_t counter_num;
|
|
|
|
if (count < sizeof(counter_num))
|
|
return -EINVAL;
|
|
|
|
counter_num = *(rt_uint64_t *)buf;
|
|
|
|
if (counter_num == ULLONG_MAX)
|
|
return -EINVAL;
|
|
|
|
ret = -EAGAIN;
|
|
|
|
rt_mutex_take(&ctx->lock, RT_WAITING_FOREVER);
|
|
|
|
if ((ULLONG_MAX - ctx->count) > counter_num)
|
|
{
|
|
ret = sizeof(counter_num);
|
|
}
|
|
else if (!(file->flags & O_NONBLOCK))
|
|
{
|
|
for (;;)
|
|
{
|
|
if ((ULLONG_MAX - ctx->count) >= counter_num)
|
|
{
|
|
ret = sizeof(counter_num);
|
|
break;
|
|
}
|
|
/* Release the mutex to avoid a deadlock */
|
|
rt_mutex_release(&ctx->lock);
|
|
rt_wqueue_wait(&ctx->writer_queue, 0, RT_WAITING_FOREVER);
|
|
rt_mutex_take(&ctx->lock, RT_WAITING_FOREVER);
|
|
}
|
|
}
|
|
|
|
if (ret > 0)
|
|
{
|
|
ctx->count += counter_num;
|
|
rt_wqueue_wakeup(&ctx->reader_queue, (void *)POLLIN);
|
|
}
|
|
|
|
rt_mutex_release(&ctx->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int rt_eventfd_create(struct dfs_file *df, unsigned int count, int flags)
|
|
{
|
|
struct eventfd_ctx *ctx = RT_NULL;
|
|
rt_err_t ret = 0;
|
|
|
|
ctx = (struct eventfd_ctx *)rt_malloc(sizeof(struct eventfd_ctx));
|
|
if (ctx == RT_NULL)
|
|
{
|
|
ret = -ENOMEM;
|
|
}
|
|
else
|
|
{
|
|
ctx->count = count;
|
|
ctx->flags = flags;
|
|
flags &= EFD_SHARED_FCNTL_FLAGS;
|
|
flags |= O_RDWR;
|
|
|
|
rt_mutex_init(&ctx->lock, EVENTFD_MUTEX_NAME, RT_IPC_FLAG_FIFO);
|
|
rt_wqueue_init(&ctx->reader_queue);
|
|
rt_wqueue_init(&ctx->writer_queue);
|
|
|
|
df->vnode = (struct dfs_vnode *)rt_malloc(sizeof(struct dfs_vnode));
|
|
if (df->vnode)
|
|
{
|
|
dfs_vnode_init(df->vnode, FT_NONLOCK, &eventfd_fops);
|
|
df->vnode->data = ctx;
|
|
df->flags = flags;
|
|
}
|
|
else
|
|
{
|
|
rt_mutex_detach(&ctx->lock);
|
|
rt_free(ctx);
|
|
ret = -ENOMEM;
|
|
}
|
|
|
|
#ifdef RT_USING_DFS_V2
|
|
df->fops = &eventfd_fops;
|
|
#endif
|
|
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int do_eventfd(unsigned int count, int flags)
|
|
{
|
|
struct dfs_file *file;
|
|
int fd;
|
|
int status;
|
|
rt_ssize_t ret = 0;
|
|
|
|
if (flags & ~EFD_FLAGS_SET)
|
|
{
|
|
rt_set_errno(EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
fd = fd_new();
|
|
if (fd >= 0)
|
|
{
|
|
ret = fd;
|
|
file = fd_get(fd);
|
|
|
|
status = rt_eventfd_create(file, count, flags);
|
|
if (status < 0)
|
|
{
|
|
fd_release(fd);
|
|
rt_set_errno(-status);
|
|
ret = -1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
rt_set_errno(-fd);
|
|
ret = -1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int eventfd(unsigned int count, int flags)
|
|
{
|
|
return do_eventfd(count, flags);
|
|
}
|