Questions about techniques for enforcing an agreed order of events between several concurrently executing threads. Specific synchronization mechanisms include mutexes (locks), condition variables, semaphores and monitors.

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4
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0answers
16 views

Emulations of atomic registers and read-modify-write (RMW) primitives in message-passing systems

The well-known ABD algorithm in Sharing Memory Robustly in Message-Passing Systems can emulate atomic, single-writer multi-reader registers in message-passing systems, in the presence of processor or ...
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1answer
27 views

How are lamport clocks implemented in real world distributed systems?

Can anyone explain, how lamport clocks implementations are used in modern distributed systems? Can you name an open source package which implements this algorithm?
3
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1answer
144 views

How do locks work?

Suppose I have an application with two threads, which both use the same resource. Normally, a synchronized block keeps these threads from messing with the resource in a way the user doesn't expect. I ...
1
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1answer
52 views

How to synchronize a 2d cellular automaton in $\Theta(\sqrt{n} \log n)$ steps

Let's assume we have given a two dimensional cellular automaton with an initial configuration where alls cells are in an quiescent state, expect for one square of cells. Let $n$ be the number of cells ...
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0answers
23 views

How can I talk about priority inversion if it's impossible to specify priority?

In the paper: Leslie Lamport: What It Means for a Concurrent Program to Satisfy a Specification: Why No One Has Specified Priority; ACM Symp Principles of Programming Languages, (POPL-12):78-83, ...
3
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0answers
213 views

totally ordered multicast with Lamport timestamp

I'm studying Distributed Systems and synchronization and I didn't catch this solution of totally ordered multicast with Lamport timestamps. I read that it doesn't need ack to deliver a message to the ...
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1answer
48 views

Issue with Multithreading spin locks

a spin lock solution to the critical path problem is shown below . my question is will this or will this not result in starvation ? ...
2
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1answer
46 views

Finding issues in concurrent implementation of carpark overflow control

Firstly, I am revising for my Concurrent Programming exam and have come across the following question from a previous exam paper. I have attempted to answer it, and will try and convey this effort; ...
1
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1answer
69 views

How to present ping data from ICMP timestamp

The ICMP timestamp protocol is useful for determining which path — forward or reverse — is contributing to the jitter on the line. In an ideal world, all computers would have an excellent ntpd, and ...
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0answers
55 views

NTP: synchronisation of time between two machines for ICMP timestamping

Some guy on the internet recommends using the same ntp server when it is required to troubleshoot asymmetric routes through ICMP, and it's somewhat important to have synchronised time between the two ...
4
votes
3answers
389 views

Solutions to synchronization problem need to be executed in critical section

I was reading about synchronization problems for cooperating processes and i learned that only hardware solutions like test_and_wait() and ...
1
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1answer
53 views

Good “serializer” ADT implementations for Synchronization

I am looking for a library which provides a "serializer" ADT for synchronization. (http://courses.cs.vt.edu/~cs5204/fall99/Summaries/Concurrency/serializers2.html) Googling leads me to nowhere, ...
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votes
2answers
138 views

What is the impact of synchronisation overhead on parallel speedup? [closed]

When implementing a parallel version of an algorithm, what is the impact of synchronization delays on speedup efficiency? Does this depend on the platform used? Is coarse-grained parallelism better ...
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1answer
86 views

Synchronization using serialization

How can someone synchronize two or more threads using serialization? According to my professor's slides and code assignments you can use serialization to solve the synchronization problem. (He doesn't ...
3
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1answer
460 views

What is a linearization point?

With respect concurrent programming, what is a linearization point? They seem to occur at a compare-and-swap instruction apparently. The best definition I could find is here. All function calls ...
3
votes
1answer
170 views

Distributed algorithms - $\alpha, \beta$ synchronizers

I experience a difficulty in solving exercises in distributed algorithm. Below is the the exercise I try to solve, it looks like I miss basic idea. Exercise. Consider a 15-processor asynchronous ...
6
votes
1answer
170 views

Variation of the dining philosophers: is the standard solution still valid?

I have a problem that is almost equal to the standard one of the dining philosophers, but has a quirk: while a philosopher thinks, he still holds the fork on his left. If after the period of thinking ...