小编Ere*_*ith的帖子

不知何故,EF在两个查询之间处理ObjectContext,没有任何进一步的通知,但显然不是随机的,也不是由于超时.

我添加了使用,所以示例是自包含的,但它与整个应用程序中使用的DbContext相同.

using (MyDbContext db = new MyDbContext ())
{
  //I am sure these are unique
  Employee emp = db.Employees.Single(e => e.FirstName == "Bob" && e.LastName == "Morane");
  Node node = db.Nodes.Single(n => n.ShortName == "stuff"); //Here the request throws
  // "ObjectContext instance has been disposed and can no longer be used for operations that require a connection"
}

通知db尚未使用,因此这是不可能的.错误也发生在.First()和.Where().Single/First().

反转这两个请求不起作用:

using (MyDbContext db = new MyDbContext ())
{
  Node node = db.Nodes.Single(n => …

嗨,我必须为系统调用编写2个函数,这些函数将管理操作系统中的任务执行.我找不到暂停/重启进程的方法.我找到了一个信号列表,我知道kill函数,这里是我的代码:

#include <stdlib.h>
#include <signal.h>

typedef struct File
{
  int pid;
  struct File *pids;
} *file;

file file1 = NULL;

//this fonction is to suspend a process using its pid number
int V(int pid_num)
{
  //does the kill fonction just kill the process or will it take into account the signal argument?
  kill(pid_num, SIGSTOP);
  file1 = ajouter(file1, pid_num);
  return 0;
}

//this is to restart the process
int C()
{
  if (file1 != NULL)
  {
    //I know the kill fonction …

使用过这个程序,如何计算回溯算法的时间复杂度？

/*
  Function to print permutations of string    This function takes three parameters:
  1. String
  2. Starting index of the string
  3. Ending index of the string.
*/ 
void swap (char *x, char *y)
{
  char temp;
  temp = *x;
  *x = *y;
  *y = temp;
}

void permute(char *a, int i, int n)
{  
  int j;

  if (i == n)
    printf("%s\n", a);
  else
  {
    for (j = i; j <= n; j++)
    {
      swap((a+i), (a+j));
      permute(a, i+1, n);
      swap((a+i), …

我有2个帖子.我的目标是第一个终止自己的执行,必须停止另一个线程.可能吗？

我有这个代码:

#include <stdio.h>
#include <pthread.h>
#include <sys/types.h>

void* start1(void* arg)
{
  printf("I'm just born 1\n");
  int i = 0;
  for (i = 0;i < 100;i++)
  {
    printf("Thread 1\n");
  }
  printf("I'm dead 1\n");
  pthread_exit(0);
}

void* start2(void* arg)
{
  printf("I'm just born 2\n");
  int i = 0;
  for (i = 0;i < 1000;i++)
  {
    printf("Thread 2\n");
  }
  printf("I'm dead 2\n");
  pthread_exit(0);
}

void* function()
{
  int k = 0;
  int i = 0;
  for (i = 0;i < 50;i++)
  { …