diff options
| author | bernard <[email protected]> | 2017-10-15 22:56:46 +0800 |
|---|---|---|
| committer | bernard <[email protected]> | 2017-10-15 22:56:46 +0800 |
| commit | d7087fdd3b998192afb03b34fd8034071d06bde7 (patch) | |
| tree | 6a99d97408c4b3bc708b3a0601bff80907d8beac /components/drivers/include/ipc/ringbuffer.h | |
| parent | 0f5a68a55e2a3c44f1e85029d22de6180ad30390 (diff) | |
[DeviceDrivers] change cmd type.
1. Change 'rt_uint8_t' type of cmd to 'int';
2. Add waitqueue;
3. Split device ipc header files;
Diffstat (limited to 'components/drivers/include/ipc/ringbuffer.h')
| -rw-r--r-- | components/drivers/include/ipc/ringbuffer.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/components/drivers/include/ipc/ringbuffer.h b/components/drivers/include/ipc/ringbuffer.h new file mode 100644 index 0000000000..4cfab6d69c --- /dev/null +++ b/components/drivers/include/ipc/ringbuffer.h @@ -0,0 +1,88 @@ +#ifndef RINGBUFFER_H__ +#define RINGBUFFER_H__ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rtthread.h> + +/* ring buffer */ +struct rt_ringbuffer +{ + rt_uint8_t *buffer_ptr; + /* use the msb of the {read,write}_index as mirror bit. You can see this as + * if the buffer adds a virtual mirror and the pointers point either to the + * normal or to the mirrored buffer. If the write_index has the same value + * with the read_index, but in a different mirror, the buffer is full. + * While if the write_index and the read_index are the same and within the + * same mirror, the buffer is empty. The ASCII art of the ringbuffer is: + * + * mirror = 0 mirror = 1 + * +---+---+---+---+---+---+---+|+~~~+~~~+~~~+~~~+~~~+~~~+~~~+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 ||| 0 | 1 | 2 | 3 | 4 | 5 | 6 | Full + * +---+---+---+---+---+---+---+|+~~~+~~~+~~~+~~~+~~~+~~~+~~~+ + * read_idx-^ write_idx-^ + * + * +---+---+---+---+---+---+---+|+~~~+~~~+~~~+~~~+~~~+~~~+~~~+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 ||| 0 | 1 | 2 | 3 | 4 | 5 | 6 | Empty + * +---+---+---+---+---+---+---+|+~~~+~~~+~~~+~~~+~~~+~~~+~~~+ + * read_idx-^ ^-write_idx + * + * The tradeoff is we could only use 32KiB of buffer for 16 bit of index. + * But it should be enough for most of the cases. + * + * Ref: http://en.wikipedia.org/wiki/Circular_buffer#Mirroring */ + rt_uint16_t read_mirror : 1; + rt_uint16_t read_index : 15; + rt_uint16_t write_mirror : 1; + rt_uint16_t write_index : 15; + /* as we use msb of index as mirror bit, the size should be signed and + * could only be positive. */ + rt_int16_t buffer_size; +}; + +enum rt_ringbuffer_state +{ + RT_RINGBUFFER_EMPTY, + RT_RINGBUFFER_FULL, + /* half full is neither full nor empty */ + RT_RINGBUFFER_HALFFULL, +}; + +/** + * RingBuffer for DeviceDriver + * + * Please note that the ring buffer implementation of RT-Thread + * has no thread wait or resume feature. + */ +void rt_ringbuffer_init(struct rt_ringbuffer *rb, rt_uint8_t *pool, rt_int16_t size); +void rt_ringbuffer_reset(struct rt_ringbuffer *rb); +rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb, const rt_uint8_t *ptr, rt_uint16_t length); +rt_size_t rt_ringbuffer_put_force(struct rt_ringbuffer *rb, const rt_uint8_t *ptr, rt_uint16_t length); +rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer *rb, const rt_uint8_t ch); +rt_size_t rt_ringbuffer_putchar_force(struct rt_ringbuffer *rb, const rt_uint8_t ch); +rt_size_t rt_ringbuffer_get(struct rt_ringbuffer *rb, rt_uint8_t *ptr, rt_uint16_t length); +rt_size_t rt_ringbuffer_getchar(struct rt_ringbuffer *rb, rt_uint8_t *ch); +rt_size_t rt_ringbuffer_data_len(struct rt_ringbuffer *rb); + +#ifdef RT_USING_HEAP +struct rt_ringbuffer* rt_ringbuffer_create(rt_uint16_t length); +void rt_ringbuffer_destroy(struct rt_ringbuffer *rb); +#endif + +rt_inline rt_uint16_t rt_ringbuffer_get_size(struct rt_ringbuffer *rb) +{ + RT_ASSERT(rb != RT_NULL); + return rb->buffer_size; +} + +/** return the size of empty space in rb */ +#define rt_ringbuffer_space_len(rb) ((rb)->buffer_size - rt_ringbuffer_data_len(rb)) + + +#ifdef __cplusplus +} +#endif + +#endif |
