Synchronization

As explained in Python Concurrency with asyncio

Synchronization is the coordination of concurrent operations to control their ordering and access to shared state.

Synchronization coordinates concurrent operations so shared state changes occur in a consistent order. It prevents race conditions by controlling access, blocking competing operations when necessary. section 6.5.2 section 11.0

Choose the mechanism according to the coordination problem:

• Use a lock, or mutex, to protect a critical section; acquire it before changing shared data and release it afterward. section 6.5.2
• Use a semaphore to limit concurrent access to a resource such as a database connection pool. section 11.0
• Use events and conditions to notify tasks when data or another required state becomes available. section 11.0

Protecting a shared counter

Two processes incrementing the same integer can produce an incorrect result. Locking the increment makes one process wait while the other reads, updates, and releases the shared value; a context manager expresses the same acquire-and-release pattern. section 6.5.2

Figure 6.5 Process 2 is blocked from reading shared data until Process 1 releases the lock.

A process-level diagram makes the waiting behavior visible: one process holds the lock while another is blocked from reading shared data. section 6.5.2

How Python Concurrency with asyncio covers it

How deep it goes

Defines race prevention and lock operations, then demonstrates protected updates; it stops short of implementation internals.

Examples

Uses a multiprocessing counter, lock acquisition and release, a context manager, database pools, and vendor request limits.

What it assumes

Assumes concurrent operations and shared resources, while explaining race conditions and synchronization from concrete counter examples.

What you can do after

Apply it via Python multiprocessing and asyncio primitives to protect updates, constrain concurrency, and coordinate tasks.

How it connects

Connects race conditions, shared state, locks, mutexes, critical sections, semaphores, events, conditions, and asyncio.

liveBookmanning.com

Read Python Concurrency with asyncio on liveBook Get the book at manning.com

Also explained in

• 

  liveBookmanning.com
  Grokking ConcurrencySynchronization is coordination that controls access to shared resources and orders task execution so required exclusivity or dependencies are respected.
• 

  liveBookmanning.com
  Modern C, Third EditionA synchronization event is an operation or occurrence that coordinates concurrent execution and can establish an ordering relationship between threads.
• 

  liveBookmanning.com
  100 Go Mistakes and How to Avoid ThemSynchronization is the coordination of concurrent execution so that access to shared state occurs according to required ordering or exclusivity constraints.
• 

  liveBookmanning.com
  Troubleshooting Java, Second EditionThread synchronization is the coordination of concurrent threads to control their access to shared state and operations.
• 

  liveBookmanning.com
  LatencyA synchronization primitive is an execution mechanism that coordinates concurrent operations and controls access to shared resources.
• 

  liveBookmanning.com
  Go in Action, Second EditionSynchronization is the coordination of concurrent computations to control their interactions and access to shared state.
• 

  liveBookmanning.com
  C# Concurrency: Asynchronous and multithreaded programmingSynchronization is the coordination of concurrent operations so that they occur in a controlled sequential order rather than simultaneously.
• 

  liveBookmanning.com
  Modern CSynchronization is the coordination of concurrent execution so that specified operations or events have defined ordering and visibility relationships.
• 

  liveBookmanning.com
  Advanced Algorithms and Data StructuresSynchronization is the coordination of concurrent operations to control access to shared state and preserve required execution properties.

Compare how 10 books explain synchronization →

Related concepts

• channelproduced by · A channel is a medium, mechanism, or pathway through which information or messages are conveyed between participants or endpoints.
• race conditionaddresses · A race condition is a concurrency defect in which program behavior or results depend on the relative timing or ordering of interacting operations.
• lockingincludes · Locking is a concurrency-control technique that restricts access to a shared resource or protected operation to prevent conflicting concurrent access.
• atomicityincludes · Atomicity is the property that an operation or group of operations takes effect as an indivisible, all-or-nothing unit, without observable partial effects.
• parallelismcontrasts with · Parallelism is the concurrent execution or progress of multiple computational operations or tasks.
• shared resourceuses · A shared resource is data, an object, or another resource that multiple people, components, or execution contexts can access or use.

This explainer was generated by Manning's knowledge graph from the text of Python Concurrency with asyncio. The section links point to the parts of the book it draws on.