struct sigaction act, oact; act.sa_flags = 0; sigemptyset(&act.sa_mask); act.sa_handler = handler;

我可以回答这个问题。这段代码是定义了一个结构体 sigaction，其中包含两个成员变量 act 和 oact。act.sa_flags 被设置为 0，表示不需要特殊处理信号。sigemptyset() 函数用于初始化一个信号集，将其中所有信号都设置为未决状态。

相关问题

void watch_signal() { //signal(SIGSEGV, signal_handler); struct sigaction act; sigemptyset(&act.sa_mask); act.sa_flags = SA_SIGINFO | SA_RESETHAND; act.sa_sigaction = signal_handler; sigaction(SIGSEGV, &act, NULL); }

这段代码是用来注册一个信号处理函数(signal handler)来处理程序收到 SIGSEGV 信号的情况。SIGSEGV 信号通常表示程序访问了一个非法内存地址，或者试图写入只读内存等错误情况。在这种情况下，操作系统会向程序发送SIGSEGV信号，如果程序没有注册信号处理函数，那么就会直接崩溃退出。

这段代码的作用是在程序运行时，当程序收到 SIGSEGV 信号时，会执行signal_handler 函数来处理这个信号。在这个函数中，你可以对这个错误进行处理，比如记录日志，打印错误信息，或者进行内存保护等操作，以保证程序能够正常运行下去。

在保持原来的代码逻辑的条件下，根据STM32F407的特性，把下面STM32F1的代码移植到STM32F407。void ExtiGpioInit(void) { GPIO_InitTypeDef GPIO_InitStruct; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC|RCC_APB2Periph_AFIO, ENABLE); GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5 ; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOC, &GPIO_InitStruct); } void ExtiNvicInit(void) { NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn ; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); } void ExtiModeInit(void) { EXTI_InitTypeDef EXTI_InitStructure; GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource4); EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_Line = EXTI_Line4; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource5); EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_Line = EXTI_Line5; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); }

void ExtiGpioInit(void)
{
GPIO_InitTypeDef GPIO_InitStruct;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5 ;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStruct);

}

void ExtiNvicInit(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

void ExtiModeInit(void)
{
EXTI_InitTypeDef EXTI_InitStructure;

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource4);
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_Line = EXTI_Line4;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource5);
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_Line = EXTI_Line5;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
}