current->pid 如何为 linux 工作？
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how does current->pid work for linux?
提问by randomizertech
Do I need to include a library? Can anyone please elaborate in it?
我需要包含一个库吗？任何人都可以请详细说明吗？
I know is used to get the process id of the current task where is being called from
我知道用于获取正在调用的当前任务的进程 ID
But I want to printk something with current->pid
但我想用 current->pid 打印一些东西
printk("My current process id/pid is %d\n", current->pid);
printk("My current process id/pid is %d\n", current->pid);
...and is giving me an error
...并给我一个错误
error: dereferencing pointer to incomplete type
error: dereferencing pointer to incomplete type
采纳答案by cnicutar
You're looking for #include <linux/sched.h>. That's where task_structis declared.
您正在寻找#include <linux/sched.h>. 这task_struct就是声明的地方。
回答by Rob I
回答by betabandido
Your code should work. You are probably missing some header.
您的代码应该可以工作。您可能缺少一些标题。
currentis a per-cpu variable defined in linux/arch/x86/include/asm/current.h(all the code is for the case of x86):
current是一个 per-cpu 变量定义在linux/arch/x86/include/asm/current.h（所有代码都是针对 x86 的情况）：
DECLARE_PER_CPU(struct task_struct *, current_task);
static __always_inline struct task_struct *get_current(void)
{
return percpu_read_stable(current_task);
}
#define current get_current()
currentpoints to the task running on a CPU at a given moment. Its type is struct task_structand it is defined in linux/include/linux/sched.h:
current指向在给定时刻在 CPU 上运行的任务。它的类型是struct task_struct，定义在linux/include/linux/sched.h：
struct task_struct {
...
pid_t pid; // process identifier
pid_t tgid; // process thread group id
...
};
You can browse the code for these files in the Linux Cross Reference:
您可以在Linux 交叉参考中浏览这些文件的代码：
