This is exactly what we want to happen. Our thread is sleeping, waiting for a particular condition to become true, without performing any kind of busy polling that would waste CPU time. From our thread's perspective, it's simply waiting for the pthread_cond_wait() call to return.

"dead list" that contains all stopped threads and then have a special cleanup thread that simply waits for an item to be added to the list. The cleanup thread calls pthread_join() to merge it with itself. Now your entire cleanup will be handled neatly and efficiently in a single thread.

mutexes are used to serialize access to *shared data*. Don't use them for non-shared data, and don't use them if your program's logic ensures that only one thread is accessing a particular data structure at a single time.

if you are using shared data, use mutexes for both reading and writing. Surround your read and write sections with pthread_mutex_lock() and pthread_mutex_unlock(), or use them any time a program's invariant is temporarily broken.

pthread_mutex_destroy() does not free the memory used to store the pthread_mutex_t. It's up to you to free() your own memory. Also remember that both pthread_mutex_init() and pthread_mutex_destroy() return zero on success.

pthread_mutex_lock() accepts a single pointer to a mutex to lock. If the mutex already happens to be locked, the caller will go to sleep. When the function returns, the caller will be woken up (obviously), and the caller will also now hold the lock. This call either returns zero on success.

You should always unlock a mutex that you've locked as soon as safely possible (to increase performance). And you should never unlock a mutex that you don't hold a lock for

When you call pthread_mutex_trylock() you'll attempt to lock the mutex. If the mutex is currently unlocked you'll get the lock, and this function will return zero. However, if the mutex is locked this call won't block. Rather, it will return a non-zero EBUSY error value.

pthread_cond_wait() simultaneously unlock the mutex (so that other threads can modify the linked list) and wait on the condition (so that pthread_cond_wait() will wake up when it is "signalled" by another thread). Now that the mutex is unlocked, other threads can access and modify the linked list, possibly adding items

pthread_cond_wait() call has not yet returned. Unlocking the mutex happens immediately, but waiting on the condition mycond is normally a blocking operation, meaning that our thread will go to sleep, consuming no CPU cycles until it is woken up.

Immediately after unlocking the mutex, thread 2 calls the function pthread_cond_broadcast(&mycond). By doing so, thread 2 will cause all threads waiting on the mycond condition variable to immediately wake up. This means that our first thread (which is in the middle of a pthread_cond_wait() call) will now wake up.

After thread 2 called pthread_cond_broadcast(&mymutex) you might think that thread 1's pthread_cond_wait() will immediately return. Not so! Instead, pthread_cond_wait() will perform one last operation: relock mymutex. Once pthread_cond_wait() has the lock, it will then return and allow thread 1 to continue execution.

Men should have more time with their newborn babies.

China and India are close neighbours linked by mountains and rivers and the Chinese and Indian peoples have enjoyed friendly exchanges for thousands of years.

We were the first urban school system in the country to wire all of our schools for the Internet.

My sister listened to reggae, and my homies listened to trap music.

Whom the Gods love die young

The lesson of Good Friday is to never lose hope or at least give it 48 hours.

Advertising is totally unnecessary. Unless you hope to make money.

We live in a world of shifting values. The family is falling apart. Parents failing in what they ought to do.

In the case of the Japanese, they usually commit suicide before they make any apology.

This dilettante notion that the global economy is evil because big corporate leaders make too much money... they do make too much money, but the only way we've figured out how to generate wealth in this world is through the market economy.

London has the advantage of one of the most gloomy atmospheres in the world.

I would say that I have an aspect of my personality which is that I have no personality. That's why I work as an agent. I have the assumed personality of the people I represent. I am like a sponge.

The American flag is an enduring symbol of liberty, democracy, and justice. It is fitting that the House act to protect it as we approach our nation's birthday, and as our men and women in uniform rally behind it in Iraq's battlefields.

A modern democracy is a tyranny whose borders are undefined; one discovers how far one can go only by traveling in a straight line until one is stopped.

When a company is charging money for a product - as Evernote does for all above its most basic service, and same for Dropbox and SugarSync - you understand its incentive for sticking with that product.

Who bothers to cook TV dinners? I suck them frozen.

I enjoy meat, but I can do without it.

I speak onstage to try to establish some method of communication. The songs are supposed to be a way of communicating. But speech and drinks and sometimes chocolates are also a way of communicating.

In order to deal with all the medical cost demands and other challenges in the U.S., as we look to raise that revenue, the rich will have to pay slightly more. That's quite clear.

Illness sets the mind free sometimes to roam and surmise.

As a little kid, I used to lock myself in my room and put on my Whitney Houston CD's and pretend to be her and try and hit every single note that she hit. I used to dream that one day that would be me.

I've always found teenagers really interesting. I think they've got so much going on in their lives, so that lends itself really well to fiction because there's so much drama, so much activity, so much growth.

Progress can be unglamorous.

There are far too many silent sufferers. Not because they dont yearn to reach out but because theyve tried and found no one who cares.