Linux通过AIO进行异步读文件

Linux通过AIO进行异步读文件，下面列出源代码：#include <stdio.h>
#include <stdlib.h>
#include <string.h>#include <aio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/stat.h>
#include <fcntl.h>
static char *memBuffer;
static int sFileDesc;
static struct sigaction sOldSigAction;static void MySigQuitHandler（int sig）
{
printf（"Signal Quit！ The number is: %d ", sig）;
}static void MyFileReadCompleteProcedure（int sig, siginfo_t *si, void *ucontext）
{
printf（"The file length is: %zu, and the content is: %s ", strlen（memBuffer）, memBuffer）;
int status = close（sFileDesc）;
if（status == 0）
puts（"File closed successfully！"）;
else
printf（"The error code is: %d ", status）; free（memBuffer）; // 还原原来的SIGUSR1信号行为
if（sigaction（SIGUSR1, &sOldSigAction, NULL） == -1）
puts（"SIGUSR1 signal restore failed！"）;
}int main（void）
{
struct sigaction sigAction = { .sa_flags = SA_RESTART, .sa_handler = &MySigQuitHandler }; sigemptyset（&sigAction.sa_mask）; if （sigaction（SIGQUIT, &sigAction, NULL） == -1）
{
puts（"Signal failed！"）;
return -1;
} sigAction.sa_sigaction = &MyFileReadCompleteProcedure;
if（sigaction（SIGUSR1, &sigAction, &sOldSigAction） == -1）
{
puts（"Signal failed！"）;
return -1;
} const char *filePath = "myfile.txt"; const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
sFileDesc = open（filePath, O_RDONLY, mode）;
if（sFileDesc == -1）
{
printf（"The file: %s cannot be opened！ ", filePath）;
return -1;
} const long fileLength = lseek（sFileDesc, 0, SEEK_END）;
lseek（sFileDesc, 0, SEEK_SET）; memBuffer = malloc（fileLength + 1）;
memBuffer[fileLength] = ""; struct aiocb aioBuffer;
aioBuffer.aio_fildes = sFileDesc;
aioBuffer.aio_offset = 0;
aioBuffer.aio_buf = memBuffer;
aioBuffer.aio_nbytes = fileLength;
aioBuffer.aio_reqprio = 0;
aioBuffer.aio_sigevent = （struct sigevent）{.sigev_notify = SIGEV_SIGNAL, .sigev_signo = SIGUSR1, .sigev_value.sival_ptr = memBuffer }; aio_read（&aioBuffer）; getchar（）; return 0;
}其中，上述代码实现中采用SIGUSR1信号进行捕获文件读完成事件，当然，这里也可以用SIGIO信号。另外，在编译链接时必须添加-lrt命令选项，因为rt库才包含了系统底层的API。本文永久更新链接地址：http://www.linuxidc.com/Linux/2015-12/126212.htm