mutex

For example I want to create 5 threads and print them. How do I make the fourth one execute before the second one? I tried locking it with a mutex, but I don't know how to make only the second one locked, so it gives me segmentation fault. Normally, you define the order of operations , not the threads that do those operations. It may sound like a trivial distinction, but when you start implementing it, you'll see it makes for a major difference. It is also more efficient approach, because you don't think of the number of threads you need, but the number of operations or tasks to be done, and

I tried to use Mutex module, such as Mutex.create(), but compiler says Unbound module Mutex. Does it require some special namespace? Thanks For toplevel : ocaml -I +threads # #load "unix.cma";; # #load "threads.cma";; # Mutex.create ();; - : Mutex.t = <abstr> For ocamlc : ocamlc -thread unix.cma threads.cma src.ml For ocamlopt : ocamlopt -thread unix.cmxa threads.cmxa src.ml For findlib : ocamlfind ocamlc -thread -package threads -linkpkg src.ml 来源： https://stackoverflow.com/questions/17188866/ocaml-mutex-module-cannot-be-found

So in my ilumination days, i started to think about how the hell do windows/linux implement the mutex, i've implemented this synchronizer in 100... different ways, in many diferent arquitectures but never think how it is really implemented in big ass OS, for example in the ARM world i made some of my synchronizers disabling the interrupts but i always though that it wasn't a really good way to do it. I tried to "swim" throgh the linux kernel but just like a though i can't see nothing that satisfies my curiosity. I'm not an expert in threading, but i have solid all the basic and intermediate

i am facing a deadlock in one of my c application(its a big code) and I was able to debug down the stage where I printed a mutex. It looks like below - {__data = {__lock = 2, __count = 0, __owner = 15805, __nusers = 1, __kind = 0, __spins = 0, __list = {__prev = 0x0, __next = 0x0} }, __size = "\002\000\000\000\000\000\000\000½=\000\000\001", '\0' <repeats 26 times>, __align = 2 } Now i could understand that __owner is thread id of thread holding this mutex, same thread ends up in deadlock for this mutex. Does anyone know meaning of rest of fields such as _ lock, _count,__spins etc which could

I'm trying to wrap a general map (with interface{} as both key and value) as in-memory key-value store that I named MemStore . But it is not thread-safe, despite my use of a sync.RWMutex to lock access to the underlying map. I did verify that it works fine when used from a single goroutine. However, just two concurrent goroutines accessing it results in panic: runtime error: invalid memory address or nil pointer dereference . What is causing this problem, and what is the proper way to achieve thread-safety in Go? Whilst in this example, channels to a single goroutine interacting with the map

I've made this question: PHP mutual exclusion (mutex) As said there, I want several sources to send their stats once in a while, and these stats will be showed at the website's main page. My problem is that I want this to be done in an atomic manner, so no update of the stats will overlap another one running in the background. Now, I came up with this solution and I want you PHP experts to judge it. stats.php <?php define("my_counter", 12); ?> index.php <?php include "stats.php"; echo constant("my_counter"); ?> update.php <?php $old_error_reporting = error_reporting(0); include "stats.php";

From what I have learned about Mutexes - they generally provide a locking capability on a shared resources. So if a new thread wants to access this locked shared resource - it either quits or has to continually poll the lock (and wastes processor cycles in waiting for the lock). However, a monitor has condition variables which provides a more asynchronous way for waiting threads - by putting them on wait queue and thereby not making them consume processor cycles. Would this be the only advantage of monitors over mutexes (or any general locking mechanism without condition variables) ? Mutexes