thread-safety

问题 Can I safely attempt to create the same directory from two different threads, without having one of them throw an exception, or run into other issues? Note that according to MSDN, it is OK to call CreateDirectory() on a directory which already exists, in which case the method is expected to do nothing. 回答1: The Directory.CreateDirectory call itself is safe to make from multiple threads. It will not corrupt program or file system state if you do so. However it's not possible to call Directory

问题 Can I safely attempt to create the same directory from two different threads, without having one of them throw an exception, or run into other issues? Note that according to MSDN, it is OK to call CreateDirectory() on a directory which already exists, in which case the method is expected to do nothing. 回答1: The Directory.CreateDirectory call itself is safe to make from multiple threads. It will not corrupt program or file system state if you do so. However it's not possible to call Directory

问题 Can I safely attempt to create the same directory from two different threads, without having one of them throw an exception, or run into other issues? Note that according to MSDN, it is OK to call CreateDirectory() on a directory which already exists, in which case the method is expected to do nothing. 回答1: The Directory.CreateDirectory call itself is safe to make from multiple threads. It will not corrupt program or file system state if you do so. However it's not possible to call Directory

问题 I have recently been discussing the initialisation of multiple random number generators of the same type in the comments of another post and in that discussion we asked the following questions: 1) Is it a good idea to create multiple instances of the same random number generator with different seeds and use these random number generators in different parts of the program? 2) In particular, can the technique of creating random number generators using the .Net Random class, seeded as below, and

问题 I have recently been discussing the initialisation of multiple random number generators of the same type in the comments of another post and in that discussion we asked the following questions: 1) Is it a good idea to create multiple instances of the same random number generator with different seeds and use these random number generators in different parts of the program? 2) In particular, can the technique of creating random number generators using the .Net Random class, seeded as below, and

问题 Let's say I have a Concurrent Map that is high-read, low-write, and needs to store application data: ConcurrentMap<UUID, Data> map = new ConcurrentHashMap<UUID, Data>(); Then, during startup and through user input, data is added to the map: public void createData(Data newData) { map.put(newId, newData); // etc... } If I then need to change the data, should I: A) Make the Data class objects immutable, and then conduct a put operation every time a change is needed for a Data object: public void

问题 I thought thread safe, in particular, means it must satisfy the need for multiple threads to access the same shared data. But, it seems this definition is not enough. Can anyone please list out the things to be done or taken care of to make an application thread safe . If possible, give an answer with respect to C/C++ language. 回答1: There are several ways in which a function can be thread safe. It can be reentrant . This means that a function has no state, and does not touch any global or

问题 I would like to know if C# automatically implemented properties, like public static T Prop { get; set; } , are thread-safe or not. Thanks! 回答1: It appears not. This is the decompilation with Reflector: private static string Test { [CompilerGenerated] get { return <Test>k__BackingField; } [CompilerGenerated] set { <Test>k__BackingField = value; } } 回答2: Section 10.7.4 of the C# specification states: When a property is specified as an automatically implemented property, a hidden backing field

问题 i'm having issues reading input from a serial port in C#. The device, that is connected via usb, is a ELM327-Chip for reading the OBD-port of the car. My Code consist of two threads: A Write- and a Read-Thread. It looks like the following: static volatile SerialPort moPort; ... moPort = new SerialPort("COM3"); moPort.BaudRate = 38400; moPort.Parity = Parity.None; moPort.DataBits = 8; moPort.StopBits = StopBits.One; moPort.NewLine = "\r"; moPort.ReadTimeout = 5000; moPort.Open(); Write-Thread:

问题 I was pointed last week about a piece of code like this: #include <pthread.h> namespace NSTest { class SingletonClass { public: static SingletonClass & getInstance() { static pthread_mutex_t mutex; pthread_mutex_lock(&mutex); if(singletonPtr==nullptr) { createInstence(); } return (*singletonPtr); pthread_mutex_unlock(&mutex); } private: static void createInstence() { static SingletonClass static_SingletonClass; singletonPtr=&static_SingletonClass; } static SingletonClass * singletonPtr; };