In computer science, a lock convoy is a performance problem that can occur when using locks for concurrency control in a multithreaded application. A lock convoy occurs when multiple threads of equal priority contend repeatedly for the same lock. Unlike deadlock and livelock situations, the threads in a lock convoy do progress; however, each time a thread attempts to acquire the lock and fails, it relinquishes the remainder of its scheduling quantum and forces a context switch. The overhead of repeated context switches and underutilization of scheduling quanta degrade overall performance. Lock convoys often occur when concurrency control primitives such as locks serialize access to a commonly used resource, such as a memory heap or a thread pool. They can sometimes be addressed by using non-locking alternatives such as lock-free algorithms or by altering the relative priorities of the contending threads. (Wikipedia).
Combination Locks - Intro to Algorithms
This video is part of an online course, Intro to Algorithms. Check out the course here: https://www.udacity.com/course/cs215.
From playlist Introduction to Algorithms
Samsung Galaxy S5 customization - set up lock screen
In this video we teach you how to set up the Samsung Galaxy S5 lock screen to provide some security for your phone.
From playlist Technology
The Connecting Europe Express: Frankfurt to Berlin
The Connecting Europe Express was a special train which travelled 20,000 km across 26 countries promoting rail's potential in the EU Year of Rail, 2021. I joined the train between Frankfurt, Leipzig & Berlin. The train is composed of a sleeping-car from ÖBB, a panorama car from SBB, rest
From playlist Train Travel In Europe
Muon-g-2 ring on land for final transport
After a long water journey, a large crowd gathers to watch the muon-g-2 ring being placed onto the Emmert transporter for its journey to Fermilab.
From playlist Muon g-2
This LOCK is NOT What it Seems!! - Solving the CHALLENGING Lock Puzzle!
B Lock Puzzle: http://bit.ly/2Fx8urh Today I'm attempting to solve the infamous B Lock puzzle by Boaz Feldman. This lock puzzle is very difficult and can be used as an actual lock! The secret to opening is contained within the lock and key. Enjoy! OTHER LOCK PUZZLE VIDEO: https://www.you
From playlist Puzzles!
Lecture 9: Privatizing Government II: Prisons and the Military
In this lecture, Prof. Shapiro discusses the privatization of two core government functions, providing military and prisons. He talks about host nation trucking in Afghanistan and provides background on the emergence of U.S. private prisons before he draws useful comparisons between the mi
From playlist Power and Politics in Today’s World
What Really Happened at the Suez Canal?
Exploring the engineering principles behind the recent obstruction of the Suez Canal, which caused a weeklong disruption in global shipping traffic. I give a brief overview of the bank effect and dilatancy of coarse-grained soils. Hopefully, the video helps you understand a few of the engi
From playlist Civil Engineering
London to Paris by Eurostar train
A guide to the Eurostar train from London to Paris. A journey from London St Pancras by Eurostar e320 across Kent, through the Channel Tunnel & across France to Paris Gare du Nord. It shows standard class, cafe-bar, standard premier & food. For more info see https://www.seat61.com/train
From playlist Train Travel In Europe
Lec 15 | MIT 6.172 Performance Engineering of Software Systems, Fall 2010
Lecture 15: Nondeterministic Programming Instructor: Charles Leiserson View the complete course: http://ocw.mit.edu/6-172F10 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT 6.172 Performance Engineering of Software Systems
Installing A Massive Control Tower At Heathrow Airport | Huge Moves | Spark
At Britain's busiest airport, Heathrow, a team of international engineers have to dodge aircraft, passengers and their luggage, racing against time to move a gleaming, state of the art Air Traffic Control Tower across the world's busiest runway into position in a brand new terminal. Find o
From playlist Huge Moves
Plus qu’une semaine avant la collision entre le #CERN et ses voisins pendant les @Automnales ! http://cern.ch/go/CERNautomnales #CERNvoisins
From playlist Français
FRONTLINE VIETNAM: Armored Cavalry
The use of armor in the jungles by the United States Eleventh Cavalry in the 1960's.
From playlist FRONTLINE VIETNAM 1-30
Border Wars: Cartel Corridor.Border patrol at the train station finds a large stash of bundles hidden in a train car. ➡ Subscribe: http://bit.ly/NatGeoSubscribe About National Geographic: National Geographic is the world's premium destination for science, exploration, and adventure. Throu
From playlist Border Wars: Season 3
USS Buckley vs U-66 during the Battle of the Atlantic
The Battle of the Atlantic was the longest campaign of the Second World War. The campaign encompassed more than a thousand different ship to ship engagements. The engagement between the Destroyer Escort USS Buckley and the German Submarine U-66 was one of the most interesting. The episo
From playlist Submariners
The Triple Threat That Eliminated 1600+ Russian Tanks in Ukraine: Javelin, NLAW & TOW
According to US officials, Russia has likely lost half of its main battle tanks, if not more, during the fighting in Ukraine. Most sources agree that since the beginning of the invasion the Ukrainians destroyed or captured more than 1,600 T-72s. The lack of sufficient infantry support or
From playlist Combat Tech
The Kill Zone | Locked Up Abroad
Locked Up Abroad: Highway to Hell : Thomas' convoy is attacked in the streets of Baghdad. ➡ Subscribe: http://bit.ly/NatGeoSubscribe ➡ Get More Locked Up Abroad: https://on.natgeo.com/2mdU6QB About National Geographic: National Geographic is the world's premium destination for science, ex
From playlist Locked Up Abroad: Season 6
Loose the screw for moving the stopper to new position and then tighten it. The stopper is kept immobile by wedge mechnism.
From playlist Mechanisms
Building And Delivering A Luxury Floating Home Along 70 Miles of Dutch Canals | Huge Moves | Spark
This Week On Huge Moves - A team of engineers attempts to build and haul a titanic town of brand new floating homes 70 miles across the Netherlands. Wim Jelsma and Carin Koning is a couple on a mission to build and move their ultimate dream home - one of seven floating mansions that will b
From playlist Huge Moves
Geneva Wheel for Precise Indexing
A modified type of Geneva wheel that was developed to obtain precise intermittent indexing movements. This special mechanism was designed to eliminate any backlash or over-running action of the driven member at the end or beginning of each indexing movement. It uses a double locking, with
From playlist Geneva Mechanisms
DIRTY SECRETS of WW2: The Defense of Alaska
Aleutian Islands Pacific theater campaign beginning June 3, 1942 was a lightly defended outpost.
From playlist Dirty Secrets of WW2