/* ----------------------------------------------------------------------------
 * Copyright (c) Huawei Technologies Co., Ltd. 2013-2019. All rights reserved.
 * Description: Basic definitions
 * Author: Huawei LiteOS Team
 * Create: 2013-01-01
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 * of conditions and the following disclaimer in the documentation and/or other materials
 * provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific prior written
 * permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * --------------------------------------------------------------------------- */

/**
 * @defgroup kernel Kernel
 * @defgroup los_base Basic definitions
 * @ingroup kernel
 */

#ifndef _LOS_BASE_H
#define _LOS_BASE_H

#include "los_builddef.h"
#include "los_typedef.h"
#include "los_config.h"
#include "los_printf.h"
#include "los_list.h"
#include "los_err.h"
#include "los_errno.h"
#include "los_hw.h"
#include "los_tick.h"
#include "securec.h"
#ifdef LOSCFG_LIB_LIBCMINI
#include "stdarg.h"
#endif
#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/**
 * @ingroup los_base
 * @brief Assertion.
 *
 * @par Description:
 * When the program runs to the assertion position, the corresponding expression should
 * be true. If the expression is not true, the program stops running and gives an error
 * message. The LOS_ASSERT_COND function is same with #LOS_ASSERT function.
 *
 * @attention
 * The function is effective only LOSCFG_DEBUG_VERSION is defined.
 *
 * @param expression  [IN] The judgement expression of the assertion.
 *
 * @retval None.
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_ASSERT
 * @since Huawei LiteOS V100R001C00
 */
#define LOS_ASSERT_COND(expression) LOS_ASSERT(expression)
//这是一个宏函数，它接受一个表达式作为参数，并将该表达式作为参数传递给另一个名为LOS_ASSERT的宏函数。它的作用是在满足给定条件时执行断言。
/**
 * @ingroup los_base
 * Define the timeout interval as LOS_NO_WAIT.
 */
#define LOS_NO_WAIT                                 0
//这是一个常量，被定义为0。它表示一个超时时间间隔，即表示不等待，立即返回。
/**
 * @ingroup los_base
 * Define the timeout interval as LOS_WAIT_FOREVER.
 */
#define LOS_WAIT_FOREVER                            0xFFFFFFFF
//这是另一个常量，被定义为0xFFFFFFFF。它表示一个超时时间间隔，即表示永远等待，直到条件满足或者被中断。
/**
 * @ingroup los_base
 * @brief Align the value (addr) by some bytes (boundary).
 *
 * @par Description:
 * Align the beginning of the object with the base address, with boundary bytes being
 * the smallest unit of alignment. The ALIGN function is same with #LOS_Align function.
 *
 * @attention
 * <ul>
 * <li>the value of boundary usually is 4,8,16,32.</li>
 * <li>users should avoid overflows due to alignment.</li>
 * </ul>
 *
 * @param addr     [IN] Type #UINTPTR The address you want to align.
 * @param boundary [IN] Type #UINT32 The alignment size.
 *
 * @retval #UINTPTR The address which have been aligned.
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_Align | TRUNCATE
 * @since Huawei LiteOS V100R001C00
 */
#ifndef ALIGN//判断ALIGN是否已经被定义过，如果没有被定义过，则执行接下来的代码。
#define ALIGN(addr, boundary)                       LOS_Align(addr, boundary)//分别表示需要对齐的地址和对齐边界。在函数体内部，它调用了LOS_Align函数进行地址对齐操作，将addr地址向上对齐到最接近的boundary的倍数。
#endif

/**
 * @ingroup los_base
 * @brief Align the value (addr) by some bytes (size).
 *
 * @par Description:
 * Align the tail of the object with the base address, with size bytes being the
 * smallest unit of alignment.
 *
 * @attention
 * <ul>
 * <li>the value of size usually is 4,8,16,32.</li>
 * <li>users should avoid overflows due to alignment.</li>
 * </ul>
 *
 * @param addr     [IN] Type #UINTPTR The address you want to align.
 * @param size     [IN] Type #UINT32  The alignment size.
 *
 * @retval #UINTPTR The address which have been aligned.
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_Align | ALIGN
 * @since Huawei LiteOS V100R001C00
 */
#define TRUNCATE(addr, size)                        ((UINTPTR)(addr) & ~((size) - 1))
//宏接受两个参数 addr 和 size，返回一个截断后的地址。具体而言，该宏将地址 addr 按照 size 的大小进行对齐，并将低位多余的位置为零。例如，如果 addr 是 0x12345678，size 是 4，则截断后的地址是 0x12345670。
/**
 * Read a UINT8 value from addr and stroed in value.
 */
/*READ_UINT8(value, addr)、READ_UINT16(value, addr) 和 READ_UINT32(value, addr) 
分别用于从地址 addr 中读取 8 位、16 位和 32 位的数值，
并将结果存储到变量 value 中。这几个宏的实现方式类似，
都是通过指针间接读取内存中的数值，并使用 dsb() 函数进行数据同步操作，
以确保读取的数据正确。其中，dsb() 函数是一个汇编指令，
用于进行数据同步操作，防止出现数据不一致的情况。*/
#define READ_UINT8(value, addr)                     ({ (value) = *((volatile UINT8 *)((UINTPTR)(addr))); dsb(); })

/**
 * Read a UINT16 value from addr and stroed in addr.
 */
#define READ_UINT16(value, addr)                    ({ (value) = *((volatile UINT16 *)((UINTPTR)(addr))); dsb(); })

/**
 * Read a UINT32 value from addr and stroed in value.
 */
#define READ_UINT32(value, addr)                    ({ (value) = *((volatile UINT32 *)((UINTPTR)(addr))); dsb(); })


//判断编译环境是否为 64 位。如果是 64 位环境，则定义了 READ_UINT64 和 WRITE_UINT64 宏。否则，这两个宏将被忽略。
//宏用于从地址 addr 中读取一个 64 位的整数值，并将结果存储到变量 value 中。这里使用了和之前类似的操作，通过指针间接读取内存中的值，并使用 dsb() 函数进行数据同步操作。
#ifdef __LP64__
/**
 * Read a UINT64 value from addr and stroed in value.
 */
#define READ_UINT64(value, addr)                    ({ (value) = *((volatile UINT64 *)((UINTPTR)(addr))); dsb(); })
#endif


/*WRITE_UINT8(value, addr)、WRITE_UINT16(value, addr) 和 WRITE_UINT32(value, addr) 宏
分别用于将 8 位、16 位和 32 位的整数值 value 写入到地址 addr 中。
这些宏也使用了和之前类似的操作，使用 dsb() 函数进行数据同步操作，
并通过指针间接写入内存中的值。*/
/**
 * Write a UINT8 value to addr.
 */
#define WRITE_UINT8(value, addr)                    ({ dsb(); *((volatile UINT8 *)((UINTPTR)(addr))) = (value); })

/**
 * Write a UINT16 value to addr.
 */
#define WRITE_UINT16(value, addr)                   ({ dsb(); *((volatile UINT16 *)((UINTPTR)(addr))) = (value); })

/**
 * Write a UINT32 value to addr.
 */
#define WRITE_UINT32(value, addr)                   ({ dsb(); *((volatile UINT32 *)((UINTPTR)(addr))) = (value); })


//在 64 位环境下，还定义了 WRITE_UINT64 宏，用于将 64 位的整数值 value 写入到地址 addr 中。
#ifdef __LP64__
/**
 * Write a UINT64 addr to addr.
 */
#define WRITE_UINT64(value, addr)                   ({ dsb(); *((volatile UINT64 *)((UINTPTR)(addr))) = (value); })
#endif

/**
 * Get a UINT8 value from addr.
 */
//宏用于从地址 addr 中读取一个 8 位的无符号整数值，并返回读取到的结果。在读取之后，使用 dsb() 函数进行数据同步操作，以确保读取的数据正确。
#define GET_UINT8(addr)                             ({ UINT8 r = *((volatile UINT8 *)((UINTPTR)(addr))); dsb(); r; })

/**
 * Get a UINT16 value from addr.
 */
//GET_UINT16(addr) 和 GET_UINT32(addr) 宏分别用于从地址 addr 中读取 16 位和 32 位的无符号整数值，并返回读取到的结果。同样地，在读取之后也进行数据同步操作。
#define GET_UINT16(addr)                            ({ UINT16 r = *((volatile UINT16 *)((UINTPTR)(addr))); dsb(); r; })

/**
 * Get a UINT32 value from addr.
 */
#define GET_UINT32(addr)                            ({ UINT32 r = *((volatile UINT32 *)((UINTPTR)(addr))); dsb(); r; })


//在 64 位环境下，还定义了 GET_UINT64(addr) 宏，用于从地址 addr 中读取一个 64 位的无符号整数值，并返回读取到的结果。
#ifdef __LP64__
/**
 * Get a UINT64 value from addr.
 */
#define GET_UINT64(addr)                            ({ UINT64 r = *((volatile UINT64 *)((UINTPTR)(addr))); dsb(); r; })
#endif

/**
 * @ingroup los_base
 * @brief Assertion.
 *
 * @par Description:
 * When the program runs to the assertion position, the corresponding expression should
 * be true. If the expression is not true, the program stops running and gives an error
 * message. The function is same with #LOS_ASSERT_COND function.
 *
 * @attention
 * The function is effective only LOSCFG_DEBUG_VERSION is defined.
 *
 * @param judge [IN] The judgement expression of the assertion.
 *
 * @retval None.
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_ASSERT_COND
 * @since Huawei LiteOS V100R001C00
 */
#ifdef LOSCFG_DEBUG_VERSION//首先，通过条件编译指令 #ifdef LOSCFG_DEBUG_VERSION 来判断是否处于调试版本。如果定义了 LOSCFG_DEBUG_VERSION 宏，则表示处于调试版本，代码块 #ifdef 和 #endif 之间的内容将会生效；否则，代码块 #else 和 #endif 之间的内容将会生效。
#define LOS_ASSERT(judge) do {                                                     \
    if ((UINTPTR)(judge) == 0) {                                                    \
        (VOID)LOS_IntLock();                                                       \
        PRINT_ERR("ASSERT ERROR! %s, %d, %s\n", __FILE__, __LINE__, __FUNCTION__); \
        while (1) {}                                                               \
    }                                                                              \
} while (0)
//在调试版本下，宏定义的代码块中，LOS_ASSERT 宏被定义为一个带有参数 judge 的宏函数。它的作用是进行断言检查，如果 judge 表达式的结果为零（即假），则执行以上操作
//调用 LOS_IntLock() 函数，该函数可能是一个用于禁止中断的操作，以确保在断言失败时不会中断处理。
//使用 PRINT_ERR 打印一条错误信息，其中包含了出错的文件名、行号和函数名。
//进入一个无限循环 while (1)，程序会一直停留在这个循环中。
#else
#define LOS_ASSERT(judge)//在非调试版本下，宏定义的代码块中，LOS_ASSERT 宏被定义为空，即不进行任何操作。
#endif

/**
 * @ingroup los_base
 * @brief Align the address (addr) by some bytes (boundary) you specify.
 *
 * @par Description:
 * This API is used to align the address (addr) by some bytes (boundary) you specify.
 *
 * @attention
 * <ul>
 * <li>the value of boundary usually is 4,8,16,32.</li>
 * <li>users should avoid overflows due to alignment.</li>
 * </ul>
 *
 * @param addr     [IN] Type #UINTPTR The address you want to align.
 * @param boundary [IN] Type #UINT32  The alignment size.
 *
 * @retval #UINTPTR The address which have been aligned.
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see ALIGN | TRUNCATE
 * @since Huawei LiteOS V100R001C00
 */
extern UINTPTR LOS_Align(UINTPTR addr, UINT32 boundary);
//具体而言，函数的功能是将 addr 按照 boundary 边界进行对齐，并返回对齐后的地址。例如，如果 addr 是 12，boundary 是 8，那么对齐后的地址就是 16。
//extern 关键字表示该函数是在其他地方定义的，这里只是对其进行声明。这样做的目的是在当前文件中使用该函数时能够正确引用它，而不需要提供函数的具体实现。
/**
 * @ingroup los_base
 * @brief Sleep the current task.
 *
 * @par Description:
 * This API is used to delay the execution of the current task. The task is able to be scheduled after it is delayed
 * for a specified milliseconds.
 *
 * @attention
 * <ul>
 * <li>The task fails to be delayed if it is being delayed during interrupt processing or it is locked.</li>
 * <li>If 0 is passed in and the task scheduling is not locked, execute the next task in the queue of tasks with the
 * priority of the current task.
 * If no ready task with the priority of the current task is available, the task scheduling will not occur, and the
 * current task continues to be executed.</li>
 * <li>The parameter passed in can not be equal to LOS_WAIT_FOREVER(0xFFFFFFFF).
 * If that happens, the task will not sleep 0xFFFFFFFF milliseconds or sleep forever but sleep 0xFFFFFFFF Ticks.</li>
 * <li>This API is not an accurate delay function. The actual delay time is longer than that of parameter msecs.</li>
 * </ul>
 *
 * @param msecs [IN] Type #UINT32 Milliseconds for which the task is delayed.
 *
 * @retval None
 * @par Dependency:
 * <ul><li>los_base.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_Mdelay | LOS_TaskDelay
 * @since Huawei LiteOS V100R001C00
 */
extern VOID LOS_Msleep(UINT32 msecs);

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* _LOS_BASE_H */
