fifo

net_device结构体 相对于linux做了相当大简化，其结构及含义如下： struct net_device { char name[MAX_NETDEV_NAME_LEN]; //用于存放网络设备的设备名称 struct vmm_device *dev; //？？？ const struct net_device_ops *netdev_ops; //上层ops接口 const struct ethtool_ops *ethtool_ops; //可选ops接口 unsigned int state; //网络设备接口的状态 unsigned int link_state; //链接状态 void *priv; /* Driver specific private data */ void *nsw_priv; /* VMM virtual packet switching layer specific private data.*/ void *net_priv; /* VMM specific private data -Usecase is currently undefined */ unsigned char dev_addr[MAX_NDEV_HW_ADDRESS]; //硬件接口地址 unsigned int hw_addr_len; //硬件地址长度

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I'm trying to write to FIFO file locate on NFS mount and it blocks. What could be the problem? My /etc/export: /tmp/ test / 10.0 . 0.0 / 24 ( rw , no_root_squash , async ) ls /tmp/test on NFS server and client is the same prw -- w -- w - 1 root root 0 2009 - 06 - 24 17 : 28 ui - input and I'm writing as root Thanks. 回答1: A FIFO is meant to be an inter-process communication mechanism. By trying to export the FIFO via NFS, you are asking the kernel to treat the local inter-process communication as more of a network communication

I create a ThreadPoolExecutor with this line of code : private ExecutorService executor = new ThreadPoolExecutor(5, 10, 120, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(20, true)); Then, I run 25 tasks (T01 to T25) so the situation is : 5 tasks currently running (T01 to T05) 20 tasks waiting in the Queue (T06 to T25) When I put 1 more task (T26), as the queue is full, I expected that the older task (T06) is removed to be launched (because MaxPoolSize is not reached) and the new task (T26) is placed at the end of the queue. But in real life, if Queue is full and MaxPoolSize is not

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: need something similiar with java's LinkedBlockingQueue . method of interest: messageQueue.poll(120000, TimeUnit.MILLISECONDS); meaning ..try to get item..and if in X unit of time you still have no item..return null that + i must be FIFO after some googling (but havent yet tested): i found ConcurrentQueue (has FIFO behaviour), BlockingCollection (FiFO OR no FIFO??) 回答1: BlockingCollection can be used with any number of different types of collections. If you don't manually pass in a specific type of concurrent collection it will uses a

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm doing a bash script that interacts with a MySQL datatabase using the mysql command line programme. I want to use table locks in my SQL. Can I do this? mysql -e "LOCK TABLES mytable" # do some bash stuff mysql -u "UNLOCK TABLES" The reason I ask, is because table locks are only kept for the session, so wouldn't the lock be released as soon as that mysql programme finishes? 回答1: [EDIT] nos had the basic idea -- only run "mysql" once, and the solution nos provided should work, but it left the FIFO on disk. nos was also correct that I

一、用到的函数 umask linux中的 umask 函数主要用于：在创建新文件或目录时 屏蔽掉新文件或目录不应有的访问允许权限。 文件的访问允许权限共有9种，分别是：r w x r w x r w x（它们分别代表：用户读 用户写 用户执行 组读 组写 组执行 其它读 其它写 其它执行） 其实这个函数的作用，就是设置允许当前进程创建文件或者目录最大可操作的权限，比如这里设置为0，它的意思就是0取反再创建文件时权限相与，也就是：(~0) & mode 等于八进制的值0777 & mode了，这样就是给后面的代码调用函数mkdir给出最大的权限，避免了创建目录或文件的权限不确定性 第一位代表了一项特别的安全特性，叫作粘着位（sticky bit），后面的3位表示文件或目录对应的umask八进制值。要理解umask是怎么工作的，得先理解八进制模式的安全性设置。 八进制模式的安全性设置先获取这3个rwx权限的值，然后将其转换成3位二进制值，用一个八进制值来表示。在这个二进制表示中，每个位置代表一个二进制位。因此，如果读权限是唯一置位的权限，权限值就是r--，转换成二进制值就是100，代表的八进制值是4。下表列出了可 能会遇到的组合。 原文链接： https://blog.csdn.net/qq_32767041/article/details/81191866 S_IFIFO|0666

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How can you create a temporary FIFO (named pipe) in Python? This should work: import tempfile temp_file_name = mktemp() os.mkfifo(temp_file_name) open(temp_file_name, os.O_WRONLY) # ... some process, somewhere, will read it ... However, I'm hesitant because of the big warning in Python Docs 11.6 and potential removal because it's deprecated. EDIT : It's noteworthy that I've tried tempfile.NamedTemporaryFile (and by extension tempfile.mkstemp ), but os.mkfifo throws: OSError -17: File already exists when you run it on the files that mkstemp

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a table of invoices being prepared, and then ready for printing. [STATUS] column is Draft, Print, Printing, Printed I need to get the ID of the first (FIFO) record to be printed, and change the record status. The operation must be threadsafe so that another process does not select the same InvoiceID Can I do this (looks atomic to me, but maybe not ...): 1: WITH CTE AS ( SELECT TOP(1) [InvoiceID], [Status] FROM INVOICES WHERE [Status] = 'Print' ORDER BY [PrintRequestedDate], [InvoiceID] ) UPDATE CTE SET [Status] = 'Printing' ,

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm looking for a FIFO stream in Scala, i.e., something that provides the functionality of immutable.Stream (a stream that can be finite and memorizes the elements that have already been read) mutable.Queue (which allows for added elements to the FIFO) The stream should be closable and should block access to the next element until the element has been added or the stream has been closed. Actually I'm a bit surprised that the collection library does not (seem to) include such a data structure, since it is IMO a quite classical one. My