multithreading - C# Lock Statement -


im going use c# lock statement , im wondering if call function while inside lock, , function lock on same object program freeze?

for example:

object object;  public void f0() {    f1(object); }  public void f1(object obj1) {    lock (obj1) {        f2(obj1);    } }  public void f2(object obj2) {   lock(obj2) {       /// operations using obj2   }  }

here function f0 calls function f1 lock, inside lock calls f2 lock. program freeze in f2 waiting object locked in f1?

i have big program functions calling each other passing objects around, , need lock objects, may happen function call may lock same object, may locked twice, causing possible deadlock.

it may difficult know if same objects gets passed around , may end getting locked twice.

also program has multi-threading , multiple classes.

also if 1 thread gets exception inside lock, somehow unwind , fix itself?

anybody knows proper way this? have big program before start changing decide better find out proper way it.

thanks

monitor (which used lock statement under covers) reentrant, it's technically ok same thread lock on object multiple times. lock released when outer lock scope completes. however, reentrant locks difficult reason , should avoided unless have no other option.

deadlocks not occur due reentrant locks. occur when take out locks on multiple objects while other thread locks same objects in different order.


Comments

Post a Comment

Popular posts from this blog

php - Vagrant up error - Uncaught Reflection Exception: Class DOMDocument does not exist -

i've set bento/ubuntu-16.04 vagrant box using php 5.6, , getting following error quite few times when try , run shell script: "uncaught reflection exception: class domdocument not exist". i've tried adding following top of script (not together), each no success: "sudo apt-get install php5.6-xml", "sudo apt-get install php5-xml", "sudo apt-get install php-dom" i've tried resetting server "sudo service apache2 restart". does have suggestions?
Read more

vue.js - Create hooks for automated testing -

Image
qa guys complained can't automate frontend testing. because our html looks same outside. lazy hack did this <template> <div :role="$options.name"> ... </div> </template> <script> export default { name: 'vmcomponentname' } </script> which takes name script , applies html. in browser get: <div role="vmcomponentname"> ... </div> line :role="$options.name" goes in every component. is there dry er solutions? please share. additional details i'll explain in details looking for. imagine have vmusercreate form creates user. test case can create user . to automatically test without role, have use following selector: .wrapper > .wrapper > .wrapper > .submit-button the test extremely brittle (will break lot). if use roles can use [role="vmusercreateform"] .submit-button selector. many folds less brittle. so basically, i'm ...
Read more

Add new key value to json node in java -

i have json file : { "id":1, "name":"abc", "addressdetails": { "city":"newyork" } } i wanted add 1 more key-value ("pincode" : "414141") node 'addressdetails'. i tried using : objectmapper mapper = new objectmapper(); jsonnode root = mapper.readtree(new file("d://test.json")); objectnode node = mapper.createobjectnode(); node.with("addressdetails").put("pincode", "414141"); but it's not getting added, there way can ? you can try you should modify file path objectmapper mapper = new objectmapper(); objectnode nodes = mapper.readvalue(new file("d:\\test.txt"), objectnode.class); nodes.with("addressdetails").put("pincode", "414141"); mapper.writer().writevalue(new file("d:\\test.txt"), nodes);
Read more