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

Tony Nemo

Threads in C

pthreads library and threaded programming in C

#programming

#threads

#CS

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"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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

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.

Tony Nemo

I never had trouble getting an agent. I went out and got my first couple roles, and literally within six months I never had to have another job other than acting.

Dean Norris

When you've done the technical part, you're then into the joy, the zen, into being. Technology no longer exists for you. You're then into the mystery of the thing you're doing.

William Shatner

I definitely make time for music.

Hayley Orrantia

I think I'm a pretty open book. We're all a work in progress, and I'm not ashamed to say that I don't have it all together - I don't really think anyone does.

Adrienne Bailon

Be good to others, that will protect you against evil.

Abu Bakr

I have a reputation for being pretty much of a wild man.

Bill Hunter

When you change everything will change for you.When you get better everything will get better for you.

Jim Rohn

I'll always be chasing you... Glory.

Sidney Poitier

Cupcakes are sweet and even sweeter when shared.

Marie Williams Johnstone

I don't mind my eyebrows. They add... something to me. I wouldn't say they were my best feature, though. People tell me they like my eyes. They distract from the eyebrows.

Nicholas Hoult

The intellectuals' chief cause of anguish are one another's works.

Jacques Barzun

Corporeal death is not the whole story.

Tom Stoppard

If I thought about it before I went on, I would have never went on. So, therefore, you don't think about it; you have to talk yourself then into, 'Listen, this is it. This is the gig. Broadway or no Broadway, you've got to do your job.'

Rachel Tucker

I refuse to answer on the ground that this might be incriminating.

Ethel Rosenberg

I have scars on the backs of my arms from dressers in Paris scraping me with pins as I was taking a shirt or gown off.

Tyra Banks

I am not a socialist.

Emmanuel Macron

I'm a little superstitious.

Bill Parcells

In reality, I've always been an actor - since I was a kid. I did theater growing up in New York. I was always in the plays in school. I was either going to be an actor or an athlete or a soldier. Those were kind of the three paths that I always kind of embarked on.

Zach McGowan

Well, I tell you... the first chorus, I plays the melody. The second chorus, I plays the melody round the melody, and the third chorus, I routines.

Louis Armstrong

As for futuristic costumes, I loved doing 'Gattaca' because I'm a minimalist at heart, and it's a very minimal film. Plus, with Uma Thurman, Ethan Hawke and Jude Law, how could you go wrong?

Colleen Atwood

At the crash of economic collapse of which the rumblings can already be heard the sleeping soldiers of the proletariat will awake as at the fanfare of the Last Judgment and the corpses of the victims of the struggle will arise and demand an accounting from those who are loaded down with curses.

Karl Liebknecht

Film has to be reflecting the world that we live in, and that's all you want to be a part of. Actors inhabit the same planet as everyone else. It's a weird thing that happens when you're an actor because people hold you up because you somehow embody in parts groups of people or people's hopes or something.

Alan Rickman

I can't tell you how hard it is to make a dark-humored movie in Hollywood.

Michael Lehmann

I'm not turning my back on music anytime soon, but it's just a blessing to have options open. A lot of artists just have rap, and that's it. But once rap stops, it's hard to get into that Hollywood circle; it really is. It's a whole 'nother beast that people think they're ready for, but they're really not.

Bow Wow