Articles contenant le tag C++
Why does std::for_each return the Functor ?
Posté par Olivier dans Trucs & Astuces le 9 décembre 2010
In short: Because the provided Functor is copied by for_each. A bit longer: the functor has to be copied so that for_each can use a reference to it in the loopage as the functor is copied, the context of the functor would be lost at end of for_each if it was not returned class Object […]
Bad idea: get a read lock while holding a write lock
Posté par Olivier dans Trucs & Astuces le 4 novembre 2009
Under Linux, the following code hangs in the second execution of the loop at the time the write lock is acquired. pthread_rwlock_t lock; fprintf(stderr, « Init\n »); pthread_rwlock_init(&lock, NULL); for(int i = 0; i < 2; ++i) { fprintf(stderr, « Get Write lock\n »); pthread_rwlock_wrlock(&lock); fprintf(stderr, « Get Read lock\n »); pthread_rwlock_rdlock(&lock); fprintf(stderr, « Release Read lock\n »); pthread_rwlock_unlock(&lock); fprintf(stderr, « Release Write lock\n »); […]