Some scenarios on Windows
1. using a notepad to edit a txt file, at the same time, a java program is using BufferedReader to read it, what it read is the stale content.
2. when a lock is grabbed, trying to read file using bufferedReader will cause I/O exception, "java.io.IOException: The process cannot access the file because another process has locked a portion of the file".
3. two threads, writer periodically write content to a file(500ms), reader read content every 100ms, there are some times that reader read null.
so explicitly use file lock on windows makes a difference.
4. cannot get read lock from FileInputStream, use RandomAccessFile to get read lock.
and here is some comment from tryLock:
File locks are held on behalf of the entire Java virtual machine.
They are not suitable for controlling access to a file by multiple
threads within the same virtual machine.
分享到：
相关推荐
记录锁（Record locks）和文件锁（File locks）用于在文件系统的上下文中控制文件的访问权限。互斥量（Mutexes）确保一次只有一个进程访问资源，条件变量（Condition Variables）允许进程等待满足特定条件后再继续...
首先，我们要理解文件锁（File Locks）和记录锁（Record Locks）的区别。文件锁是对整个文件进行锁定，所有对文件的修改操作都会受到锁的影响。而记录锁，也称为范围锁（Range Locks），只锁定文件中的特定区域或...
2. **同步机制**：涵盖了互斥锁（Mutexes）、条件变量（Condition Variables）、读写锁（Read-Write Locks）、文件锁定（File Locks）和记录锁定（Record Locks），以及信号量（Semaphores）。这些工具确保了多线程...
7. **文件锁（File Locks）**：当多个线程或进程需要同时访问同一文件时，文件锁可以防止数据冲突。在C#中，`FileStream`类提供了锁定文件的方法，以确保数据的完整性。 8. **先进先出堆（FIFO Queues）**：这是一...
If the programmed hex file locks the Flash of the MCU, The MCU Production Programmer will not be able to serialize the device. Release Dates ------------- Production Programmer Version 2.50 - ...
7. **文件锁（File Locks）** - NIO提供了文件锁功能，可以在读写文件时确保数据的一致性和完整性。 8. **管道（Pipes）** - 管道是两个线程之间的单向数据连接，用于线程间通信。 9. **效率与并发** - Java ...
文件锁分为两种主要类型：记录锁（Record Locks）和文件锁（File Locks）。 1. **记录锁**：允许开发者对文件的特定部分设置读写锁。这种锁通常是由`fcntl`函数提供的更细粒度的锁定机制，能够针对文件的特定字节...
Lesson 1: Concepts – Locks and Lock Manager 3 Lesson 2: Concepts – Batch and Transaction 31 Lesson 3: Concepts – Locks and Applications 51 Lesson 4: Information Collection and Analysis 63 Lesson 5:...
锁具 锁是一种基于语言的命令式，动态类型化，面向过程的脚本语言。 Locks-py是python的锁实现。... 要运行程序，请通过File -> Open打开一个锁定文件，然后从菜单栏中选择Run -> Run(debug) 。 有关更多详细
user-level one locks the file so the password is requiored to open/view the file. If only "owner" password is set, decryption is being done instantly; decrypted file can be opened in any PDF viewer ...
cursor.execute("INSERT OR IGNORE INTO locks (file_id, locked) VALUES (?, 1)", (file_id,)) conn.commit() conn.close() def unlock_file(file_id): conn = sqlite3.connect('file_lock.db') cursor = ...
Bootstrap_FileUpload4.3.9+Drapper+IOC+MVC ,包含...)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO
Select the locks and click Unlock and you are done. It is recommended to Unlock wisely and to close open processes locking files or folder if any, but if only Explorer.exe is the culprit, do not ...
KeePass Password Safe is a free, open source, ... KeePass puts all your passwords in a highly encrypted database and locks them with one master key or a key file. As a result, you only have to remem
Supports features which are specific to the I/O-system of Windows: Byte Range Locks, Directory Notfication (so the Explorer updates the view of a directory on changes within that directory), Oplocks ...
port locks up in the Operating System, the error is still reported. - Corrected a bug, where in rare cases, the result summary could be duplicated in a log file. - Updated license management, in ...
Building a APK that depends on a static .jar file 16 Building a APK that should be signed with the platform key 16 Building a APK that should be signed with a specific vendor key 17 Adding a prebuilt ...
000 30,000 Database size 32 TB (also limited by file system and OS) 32 TB (also limited by file system and OS) Identifier length (in characters) 255 255 Locks per connection 2,147,483,647 N/A Rows per...
Do not use an include-guard. This file is included once to declare the locks and once in win32 to actually do the runtime initialization.
- **Locks and Conditions**: Overview of the `java.util.concurrent.locks` package, which provides more flexible locking mechanisms compared to traditional `synchronized` blocks. - **Fork/Join ...