locking

来源： https://stackoverflow.com/questions/14962030/why-do-i-have-a-lock-here

来源： https://stackoverflow.com/questions/60854328/mysql-exclusive-lock

来源： https://stackoverflow.com/questions/59760841/how-can-i-facilitate-concurrent-users-on-a-google-apps-script-webapp

来源： https://stackoverflow.com/questions/59760841/how-can-i-facilitate-concurrent-users-on-a-google-apps-script-webapp

来源： https://stackoverflow.com/questions/63268087/atomic-struct-containing-pointer

来源： https://stackoverflow.com/questions/63268087/atomic-struct-containing-pointer

问题 O wise interwebs We have an impasse between two colleagues that we could use your help resolving in the proper C++ way. Basically we have a set of utility classes, two of which are a Mutex and SpinLock class which both have the following abridged interface: class Mutex { public: Mutex(); ~Mutex(); void Lock(); void Unlock(); // ... }; Obviously this is similar to, but differently-cased than the BasicLockable concept used by std::lock_guard, so we want something similar (assume that the Mutex

问题 In old synchronized block, we used same object to synchronize on, also used wait and notify methods. So they can all refer to same lock. Makes sense. So when I use class ReentrantLock, why can't I also use same variable to call lock , unlock as well as await and signal ? Why do I need to make additional Condition variable? That is, why I need to do this: Lock lock = new ReentrantLock(); Condition condition = lock.newCondition(); void doSomething() { lock.lock(); //some code condition.await();

问题 I have a script in Google Sheets, which runs a function when a user clicks on an image. The function modifies content in cells and in order to avoid simultaneous modifications I need to use lock for this function. I cannot get, why this doesn't work (I still can invoke same function several times from different clients): function placeBidMP1() { var lock = LockService.getScriptLock(); lock.waitLock(10000) placeBid('MP1', 'I21:J25'); lock.releaseLock(); } placeBid() function is below: function

问题 #include <atomic> #include <iostream> using namespace std; struct Simple{ int a = 0; int b = 0; }; struct WithPointer{ int *a = nullptr; int b = 0; }; int main(int argc, char const *argv[]) { atomic<Simple> simple; cout<<simple.is_lock_free()<<"\n"; atomic<Simple*> simple_p; cout<<simple_p.is_lock_free()<<"\n"; atomic<WithPointer> with_pointer; cout<<with_pointer.is_lock_free()<<"\n"; return 0; } This example works fine for the Simple struct but not for the WithPointer struct. I get the