deadlock

问题 I understand there's a TPL deadlock trap when calling async method within a sync MVC method, while using .Wait() or .Result to wait till the task complete. But we just found a strange behaviour in our MVC application: The sync action calls an async method, but since it's a trigger, we never waited it complete. Still, the async method seems stucked. Code is like below, this strange issue not 100% happens. It just happens sometime. When it happens: The HomeController.Index() action completed

问题 This question is related to this post in SI forum, but as the forum is closed, I post it here to continue the thread: http://forum.spring.io/forum/spring-projects/integration/748192-messages-not-flowing-when-using-jms-channels To sum up, I have an aggregator with a Redis message store and a reaper scheduled every 60 secs. Messages are sent to the aggregator using a JMS-Channel. Here's the config: <bean id="jedisPoolConfigBean" class="redis.clients.jedis.JedisPoolConfig"> <property name=

问题 I just have started to program with java rmi and I face the following problem in my code: My server has two Remote methods which are implemented in general as follows: public class ServerImpl extends UnicastRemoteObject implements Server{ .... Synchronized void foo(){ aClient.Foo3();} Synchronized void foo1(){ .... } } My clients have one remote method which is implemented as follows: public class ClientImpl extends UnicastRemoteObject implements Client{ .... void Foo3(){theServer.foo1();} }

问题 I have a class which contains a mutex and an object, each time I need to access the contained object, a method is called to lock the mutex and return te contained object, let's see the code: template <typename MUTEX, typename RESOURCE> class LockedResource { using mutex_t = MUTEX; using resource_t = RESOURCE; mutex_t m_mutex; resource_t m_resource; public: template <typename ... ARGS> LockedResource(ARGS &&... args) : m_resource(std::forward<ARGS>(args) ...) {} class Handler { std::unique

问题 Is there any useful reason why the GHC allows the following to block forever: list = 1 : tail list It seems with a bit of sophistication in the list iterator/generator we should be able to do something more useful: Return error "Infinitely blocking list" Return [1,1] Explaining 2: it seems possible that when entering the generator to get element N , we could then make all self references inside the generator limited to the list but ending at N-1 (we notice the read N inside the scope generate

问题 I have a program that deadlocks when one of the threads calls pthread_cond_siganl (or broadcast). The problem is reproducible 100% in the main program. I could not figure out what is wrong with it and thus extracted the piece of code that wait and signal are called. However, the deadlock cannot be reproduced with the extracted problem. Running valgrind on the main program does not report any invalid reads/writes or memory leaks. I want to know what are the possible reasons for a deadlock when

问题 Assume there are two objects of the following Account class - account1 and account2. And there are two threads T1 and T2. T1 is transferring amount 100 from account1 to account2 as follows: account1.transfer(account2, 100); Similarly, T2 is transferring amount 50 from account2 to account1: account2.transfer(account1, 50); The transfer() method is obviously prone to deadlock as two threads T1 and T2 would be trying to acquire lock in the reverse order. (Thread T1 will try acquiring lock on

问题 To make sure that a Lock is unlocked, it is adviced to call the unlock() method from inside a finally-clause: lock.lock(); try{ // critical section which may throw exceptions } finally { lock.unlock(); } This is to avoid a possible deadlock, in case an exception is thrown from the code in the critical section. Why isn't the same practice adviced for binary semaphores in equivalent scenarios? mutex.acquire(); try{ // critical section which may throw exceptions } finally { mutex.release(); }

问题 I have a deadlock problem with two transactions that do not access any common records. There is also no lock escalation. So I can't explain why a deadlock is possible. The deadlock occurs when two such transactions are executed at the same time: begin transaction update A set [value] = [value] where id = 1; /* resp. 2 */ /* synchronize transactions here */ SELECT * FROM A inner join B on A.B_FK = B.id inner join C on C.A_FK = A.id WHERE A.[value] = 1; /* resp. 2 */ rollback; These are the

问题 Lets say I open a transaction and run update queries. BEGIN TRANSACTION UPDATE x SET y = z WHERE w = v The query returns successfully and the transaction stays open deliberately for a period of time before I decide to commit. While I'm sitting on the transaction is it ever possible the MSSQL deadlock machinary would be able to preempt my open transaction that is not actually executing anything to either clear a deadlock or free resources as system memory/resource limits are reached? I know