Process synchronization and communication
Contact between processes
relationship
- Resource sharing relationship
- Mutual cooperation relations
Critical Resources
A time only allows a process to access resources
Critical section
Access to critical resources in the process of that code is called the critical zone
Synchronization mechanism to be followed
- Idle let into
- Busy waiting
- Limited waiting
- Let the right to wait
Interprocess communication
definition
- It refers to exchange of information between processes
Types of
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Low-level communication
-
Exclusive
- Software Method
- Hardware method
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Synchronize
- Semaphore mechanism
- Synchronization issues
-
-
Advanced Communications
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Shared memory system
- Communication mode based on shared data structures
- Communication mode based on the shared storage area
-
Messaging system
- Direct communication
- Indirect communication
-
Pipeline Communication System
- The definition of pipeline
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Deadlock
definition
- Refers to the multi-channel programming system, a set of processes in each process are wait indefinitely for the process to be another set of processes in the occupied resources and never released, called this phenomenon the system is in deadlock status
the reason
- Competition for resources
- Improper order to promote the process
A necessary condition for the
- Exclusive
- Request and hold
- Do not deprive
- Loop waiting
The basic method to solve deadlock
-
Deadlock prevention
-
Avoid deadlock
- Security status
- Banker's algorithm
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Deadlock Detection
- Resource allocation map
- Deadlock Theorem
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Lift the deadlock
- Deprived of resources
- Revocation process
