synchronization

How can you ensure in java that a block of code can not be interrupted by any other thread

由 吃可爱长大的小学妹 提交于 2019-11-30 18:14:03
exampl: new Thread(new Runnable() { public void run() { while(condition) { *code that must not be interrupted* *some more code* } } }).start(); SomeOtherThread.start(); YetAntherThread.start(); How can you ensure that code that must not be interrupted won't be interrupted? You can't - at least not with normal Java, running on a normal, non-real-time operating system. Even if other threads don't interrupt yours, other processes might well do so. Basically you won't be able to guarantee that you get a CPU all to yourself until you're done. If you want this sort of guarantee you should use

Synchronize access to static variables in sql server SQLCLR

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-30 17:50:55
问题 I have written an assembly which is integrated in sql server, providing some stored procedures written in C#. The assembly has a readonly static variable holding some configuration data. This data is manipulated via stored procedures, which are also provided by the assembly. Obviously I have to synchronize access to this static variable. I tried to use lock(someGuard) { // ... access static configuration } inside my configuration class. But then I get a HostProtectionException, telling me,

SQL Server 2005 - Syncing development/production databases

由 徘徊边缘 提交于 2019-11-30 17:38:04
问题 I've got a rather large SQL Server 2005 database that is under constant development. Every so often, I either get a new developer or need to deploy wide-scale schema changes to the production server. My main concern is deploying schema + data updates to developer machines from the "master" development copy. Is there some built-in functionality or tools for publishing schema + data in such a fashion? I'd like it to take as little time as possible. Can it be done from within SSMS? Thanks in

Small footprint clock synchronization without NTP

由 允我心安 提交于 2019-11-30 17:31:36
I'm looking for a simple clock synchronization protocol that would be easy to implement with small footprint and that would work also in the absence of internet connection, so that it could be used e.g. within closed laboratory networks. To be clear, I'm not looking for something that can be used just to order events (like vector clocks), but something that would enable processes on different nodes to synchronize their actions based on local clocks. As far as I understand, this would require a solution that can take clock drift into account. Presence of TCP/IP or similar relatively low-latency

Guaranteeing mutex safety with async signals

由 落花浮王杯 提交于 2019-11-30 17:12:59
问题 First, I am aware that the mutexes are not considered async-safe normally. This question concerns the use of sigprocmask to make mutexes safe in a multithreaded program with async signals and signal handlers. I have some code conceptually like the following: struct { int a, b; } gvars; void sigfoo_handler(int signo, siginfo_t *info, void *context) { if(gvars.a == 42 || gvars.b == 13) { /* run a chained signal handler */ } } /* called from normal code */ void update_gvars(int a, int b) { gvars

Java: how to synchronize array accesses and what are the limitations on what goes in a synchronized condition

由 我只是一个虾纸丫 提交于 2019-11-30 16:51:32
问题 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

Difference between getAndSet and compareAndSet in AtomicBoolean

由 旧街凉风 提交于 2019-11-30 16:42:54
问题 The thread title should be self-explnatory... I'm a bit confused between the specification of below methos from AtomicBoolean class: java.util.concurrent.atomic.AtomicBoolean#compareAndSet java.util.concurrent.atomic.AtomicBoolean#getAndSet My assemption is that both would result in the same behavior when used as a boolean clause in an if condition: public class Test { private AtomicBoolean flag = AtomicBoolean(false); public void processSomeAction() { if (flag.getAndSet(false)) { // Shouldn

Small footprint clock synchronization without NTP

由 百般思念 提交于 2019-11-30 16:39:45
问题 I'm looking for a simple clock synchronization protocol that would be easy to implement with small footprint and that would work also in the absence of internet connection, so that it could be used e.g. within closed laboratory networks. To be clear, I'm not looking for something that can be used just to order events (like vector clocks), but something that would enable processes on different nodes to synchronize their actions based on local clocks. As far as I understand, this would require

Sync list with outlook only with items in current view

由 夙愿已清 提交于 2019-11-30 16:19:33
问题 Currently outlook takes all list data and synchronises it with outlook. Is it possible and how to synchronise only items in a specific view? I`m only interested in my items in the list. 回答1: Unfortunately this is not possible out-of-the-box. When connecting a list to Outlook it occurs at the list level, not at the view level. There may be a product you can purchase that will do this. I've had a quick look around for you without success but hopefully someone else can help. 回答2: I don't think

Save CKServerChangeToken to Core Data

由 馋奶兔 提交于 2019-11-30 16:01:56
问题 I use CloudKit and Core Data with Swift to synchronize my data. Therefore I created Subscriptions and after getting a notification I fetch the new data from the cloud to update my Core Data. This is the recommended way to handle this update. For fetching data changes I can insert a CKServerChangeToken to fetch just the new stuff. My question is how to save the token to Core Data for later fetch requests? For CKRecords there is a method to save only the metadata but there isn't anything like
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