diff options
Diffstat (limited to 'src/device.c')
| -rw-r--r-- | src/device.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/device.c b/src/device.c index 1335c7fd2c..75b88bf6eb 100644 --- a/src/device.c +++ b/src/device.c @@ -1,7 +1,7 @@ /* * File : device.c * This file is part of RT-Thread RTOS - * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team + * COPYRIGHT (C) 2006 - 2013, RT-Thread Development Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -24,6 +24,7 @@ * 2012-10-20 Bernard add device check in register function, * provided by Rob <[email protected]> * 2012-12-25 Bernard return RT_EOK if the device interface not exist. + * 2013-07-09 Grissiom add ref_count support */ #include <rtthread.h> @@ -51,6 +52,7 @@ rt_err_t rt_device_register(rt_device_t dev, rt_object_init(&(dev->parent), RT_Object_Class_Device, name); dev->flag = flags; + dev->ref_count = 0; return RT_EOK; } @@ -237,6 +239,11 @@ rt_err_t rt_device_open(rt_device_t dev, rt_uint16_t oflag) return -RT_EBUSY; } + dev->ref_count++; + /* don't let bad things happen silently. If you are bitten by this assert, + * please set the ref_count to a bigger type. */ + RT_ASSERT(dev->ref_count != 0); + /* call device open interface */ if (dev->open != RT_NULL) { @@ -264,6 +271,14 @@ rt_err_t rt_device_close(rt_device_t dev) RT_ASSERT(dev != RT_NULL); + if (dev->ref_count == 0) + return -RT_ERROR; + + dev->ref_count--; + + if (dev->ref_count != 0) + return RT_EOK; + /* call device close interface */ if (dev->close != RT_NULL) { @@ -297,6 +312,12 @@ rt_size_t rt_device_read(rt_device_t dev, { RT_ASSERT(dev != RT_NULL); + if (dev->ref_count == 0) + { + rt_set_errno(-RT_ERROR); + return 0; + } + /* call device read interface */ if (dev->read != RT_NULL) { @@ -329,6 +350,12 @@ rt_size_t rt_device_write(rt_device_t dev, { RT_ASSERT(dev != RT_NULL); + if (dev->ref_count == 0) + { + rt_set_errno(-RT_ERROR); + return 0; + } + /* call device write interface */ if (dev->write != RT_NULL) { |