synchronization

I have a question regarding synchronization of code that is executed by several threads: As far as I know each thread has its own stack, hence, non-static variables exist in different locations in the memory for each thread (for X threads there are X stacks that include all non-static variables). So why there's a need to synchronize anything? I mean, if the code that the threads execute includes some class variable v1, then each thread has its own "instance" of v1 (different memory address), and no other thread can "touch" it... isn't it so? non-static variables exist in different locations in

HI everybody, i have a question if i have a computer run sqlite , and i want to make sqlite sync Mysql server in the external network. If the data in the sqlite have been (changed/ modified), how can I sync my MYSQL DB and sqlite so that the data in sqlite will be (changed/ modified) when the data in MYSQL DB is changed/ modified? thanks all. You can try greplicator geplicator is a real-time solution designed to replicate data from MySQL database to any other relational database, such as Oracle, Microsoft SQL Server, IBM DB2 UDB and MySQL. I have a similar problem of 2-way syncing between an

Let's say I have the following class that will be read heavily, but only written to occasionally. It will be used in a multi-threaded web app, so it needs to be thread safe: public class Foo { private volatile String foo; public String getFoo() { return foo; } public synchronized String setFoo(String in) { this.foo = in; } } Java Concurrency ( http://www.ibm.com/developerworks/java/library/j-jtp06197/index.html ) states that this is a fragile way to protect write access while improving read access. What is a stronger alternative to this pattern? Or any alternative if foo will need to mutable

what is the correct solution to be sure that file will never be corrupted while using many threads and processes. version for threads, which care about opening errors. lock = threading.RLock() with lock: try: f = open(file, 'a') try: f.write('sth') finally: f.close() # try close in any circumstances if open passed except: pass # when open failed for processes I guess must use multiprocessing.Lock but if I want 2 processes, and the first process own 2 threads (each one use file) there is just theory, but I want know how to mix synchronization with threads and processes. are threads "inherit" it

what is meant by vector in Java is thread safe and synchronized, how is it made thread safe. I'm looking at internal details of implementation It is made "thread-safe" by merit of all its methods being synchronized (via the synchronized keyword), see the OpenJDK source code . What the synchronized keyword does is that it prevents more than one thread from executing any of the synchronized methods at the same time. It is using a lock internally, that a thread has to obtain when entering of of those methods, and that the thread releases when it leaves the method. Note that this does not really

I use Eclipse. When I have an application like this: write 20 times 'Hello World\n' to stdout write 'ERROR\n' to stderr write 5 times 'Hello World\n' to stdout The output looks many times like this: Hello World Hello World Hello World Hello World Hello World Hello World ... Hello World Hello World Hello World ERROR Is there a way to synchronize these two output streams? Of course without waiting a few milliseconds after the block of 20 times Hello World and waiting a few milliseconds after printing ERROR . Believe it or not, flushing is not a solution here.... If a stream leads to "an

I had a 2x2 array that I had two threads operating on. it is possible to use a synchronized statement in java on an array? how does the locking work? the java tutorial thread said that the synchronized statement works on objects, so I wasn't sure what they meant. Another site said that I could make a statement like synchronized (array1[]){ } Does this synchronize accesses to everything in the array so that the array is locked to other threads? if I have a two-d Array can i use synchronized (array1[i]) to lock one of the rows of the array? and is it possible to lock individual array values with