!2312 增加队列支持变长读取的说明

Merge pull request !2312 from chenliming_kh/master

en/device-dev/kernel/kernel-mini-basic-ipc-queue.md

@@ -155,6 +155,7 @@ The preceding figure illustrates how to write data to the tail node only. Writin
 >-   The input parameter  **timeOut**  in the queue interface function is relative time.
 >-   **LOS\_QueueReadCopy**,  **LOS\_QueueWriteCopy**, and  **LOS\_QueueWriteHeadCopy**  are a group of APIs that must be used together.  **LOS\_QueueRead**,  **LOS\_QueueWrite**, and  **LOS\_QueueWriteHead**  are a group of APIs that must be used together.
 >-   As  **LOS\_QueueWrite**,  **LOS\_QueueWriteHead**, and  **LOS\_QueueRead**  are used to manage data addresses, you must ensure that the memory directed by the pointer obtained by calling  **LOS\_QueueRead**  is not modified or released abnormally when the queue is being read. Otherwise, unpredictable results may occur.
+>-   If the input parameter bufferSize in **LOS\_QueueReadCopy** is less than the actual length of the message, the message will be truncated.
 >-   **LOS\_QueueWrite**,  **LOS\_QueueWriteHead**, and  **LOS\_QueueRead**  are called to manage data addresses, which means that the actual data read or written is pointer data. Therefore, before using these APIs, ensure that the message node size is the pointer length during queue creation, to avoid waste and read failures.
 
 ## Development Example<a name="section460018317164"></a>

en/device-dev/kernel/kernel-small-basic-trans-queue.md

@@ -156,6 +156,7 @@ The preceding figure illustrates how to write data to the tail node only. Writin
 >-   The input parameter  **timeOut**  in the queue interface function is relative time.
 >-   **LOS\_QueueReadCopy**,  **LOS\_QueueWriteCopy**, and  **LOS\_QueueWriteHeadCopy**  are a group of APIs that must be used together.  **LOS\_QueueRead**,  **LOS\_QueueWrite**, and  **LOS\_QueueWriteHead**  are a group of APIs that must be used together.
 >-   As  **LOS\_QueueWrite**,  **LOS\_QueueWriteHead**, and  **LOS\_QueueRead**  are used to manage data addresses, you must ensure that the memory directed by the pointer obtained by calling  **LOS\_QueueRead**  is not modified or released abnormally when the queue is being read. Otherwise, unpredictable results may occur.
+>-   If the input parameter bufferSize in **LOS\_QueueRead**and**LOS\_QueueReadCopy** is less than the actual length of the message, the message will be truncated.
 >-   **LOS\_QueueWrite**,  **LOS\_QueueWriteHead**, and  **LOS\_QueueRead**  are called to manage data addresses, which means that the actual data read or written is pointer data. Therefore, before using these APIs, ensure that the message node size is the pointer length during queue creation, to avoid waste and read failures.
 
 ## Development Example<a name="section27132341285"></a>

zh-cn/device-dev/kernel/kernel-mini-basic-ipc-queue.md

@@ -126,6 +126,8 @@ typedef struct
 > 
 > - 鉴于LOS_QueueWrite和LOS_QueueWriteHead和LOS_QueueRead这组接口实际操作的是数据地址，用户必须保证调用LOS_QueueRead获取到的指针所指向的内存区域在读队列期间没有被异常修改或释放，否则可能导致不可预知的后果。
 > 
+> - LOS_QueueReadCopy接口的读取长度如果小于消息实际长度，消息将被截断。
+>
 > - 鉴于LOS_QueueWrite和LOS_QueueWriteHead和LOS_QueueRead这组接口实际操作的是数据地址，也就意味着实际写和读的消息长度仅仅是一个指针数据，因此用户使用这组接口之前，需确保创建队列时的消息节点大小，为一个指针的长度，避免不必要的浪费和读取失败。
 
 

zh-cn/device-dev/kernel/kernel-small-basic-trans-queue.md

@@ -125,6 +125,8 @@ typedef struct {
 > - LOS_QueueReadCopy和LOS_QueueWriteCopy及LOS_QueueWriteHeadCopy是一组接口，LOS_QueueRead和LOS_QueueWrite及LOS_QueueWriteHead是一组接口，每组接口需要配套使用。
 > 
 > - 鉴于LOS_QueueWrite和LOS_QueueWriteHead和LOS_QueueRead这组接口实际操作的是数据地址，用户必须保证调用LOS_QueueRead获取到的指针所指向的内存区域在读队列期间没有被异常修改或释放，否则可能导致不可预知的后果。
+>
+> - LOS_QueueRead和LOS_QueueReadCopy接口的读取长度如果小于消息实际长度，消息将被截断。
 > 
 > - 鉴于LOS_QueueWrite和LOS_QueueWriteHead和LOS_QueueRead这组接口实际操作的是数据地址，也就意味着实际写和读的消息长度仅仅是一个指针数据，因此用户使用这组接口之前，需确保创建队列时的消息节点大小，为一个指针的长度，避免不必要的浪费和读取失败。