pthread_rwlockattr_getpshared()
by Tracey Hughes, Cameron Hughes
Professional Multicore Programming: Design and Implementation for C++ Developers
- Copyright
- About the Authors
- Credits
- Acknowledgments
- Introduction
- 1. The New Architecture
- 2. Four Effective Multicore Designs
- 2.1. The AMD Multicore Opteron
- 2.2. The Sun UltraSparc T1 Multiprocessor
- 2.3. The IBM Cell Broadband Engine
- 2.4. Intel Core 2 Duo Processor
- 2.5. Summary
- 3. The Challenges of Multicore Programming
- 3.1. What Is the Sequential Model?
- 3.2. What Is Concurrency?
- 3.3. Software Development
- 3.3.1. Challenge #1: Software Decomposition
- 3.3.2. Challenge #2: Task-to-Task Communication
- 3.3.3. Challenge #3: Concurrent Access to Data or Resources by Multiple Tasks or Agents
- 3.3.4. Challenge #4: Identifying the Relationships between Concurrently Executing Tasks
- 3.3.5. Challenge #5: Controlling Resource Contention Between Tasks
- 3.3.6. Challenge #6: How Many Processes or Threads Are Enough?
- 3.3.7. Challenges #7 and #8: Finding Reliable and Reproducible Debugging and Testing
- 3.3.8. Challenge #9: Communicating a Design That Has Multiprocessing Components
- 3.3.9. Challenge #10: Implementing Multiprocessing and Multithreading in C++
- 3.4. C++ Developers Have to Learn New Libraries
- 3.5. Processor Architecture Challenges
- 3.6. Summary
- 4. The Operating System's Role
- 4.1. What Part Does the Operating System Play?
- 4.1.1. Providing a Consistent Interface
- 4.1.2. Managing Hardware Resources and Other Software Applications
- 4.1.3. The Developer's Interaction with the Operating System
- 4.1.4. Core Operating System Services
- 4.1.5. The Application Programmer's Interface
- 4.2. Decomposition and the Operating System's Role
- 4.3. Hiding the Operating System's Role
- 4.4. Summary
- 4.1. What Part Does the Operating System Play?
- 5. Processes, C++ Interface Classes, and Predicates
- 5.1. We Say Multicore, We Mean Multiprocessor
- 5.2. What Is a Process?
- 5.3. Why Processes and Not Threads?
- 5.4. Using posix_spawn()
- 5.5. Who Is the Parent? Who Is the Child?
- 5.6. Processes: A Closer Look
- 5.7. Monitoring Processes with the ps Utility
- 5.8. Setting and Getting Process Priorities
- 5.9. What Is a Context Switch?
- 5.10. The Activities in Process Creation
- 5.11. Working with Process Environment Variables
- 5.12. Using system() to Spawn Processes
- 5.13. Killing a Process
- 5.14. Process Resources
- 5.15. What Are Asynchronous and Synchronous Processes
- 5.16. The wait() Function Call
- 5.17. Predicates, Processes, and Interface Classes
- 5.18. Summary
- 6. Multithreading
- 6.1. What Is a Thread?
- 6.2. Comparing Threads to Processes
- 6.3. Setting Thread Attributes
- 6.4. The Architecture of a Thread
- 6.5. A Simple Threaded Program
- 6.6. Creating Threads
- 6.7. Managing Threads
- 6.8. Extending the Thread Interface Class
- 6.9. Summary
- 7. Communication and Synchronization of Concurrent Tasks
- 7.1. Communication and Synchronization
- 7.1.1. Dependency Relationships
- 7.1.2. Counting Tasks Dependencies
- 7.1.3. What Is Interprocess Communication?
- 7.1.4. What Are Interthread Communications?
- 7.2. Synchronizing Concurrency
- 7.2.1. Types of Synchronization
- 7.2.2. Synchronizing Access to Data
- 7.2.2.1. Critical Sections
- 7.2.2.2. PRAM Model
- 7.2.2.2.1. Concurrent and Exclusive Memory Access
- 7.2.2.2.2. Concurrent Tasks: Coordinating Order of Execution
- 7.2.2.2.3. Relationships between Cooperating Tasks
- 7.2.2.2.4. Start-to-Start (SS) Relationship
- 7.2.2.2.5. Finish-to-Start (FS) Relationship
- 7.2.2.2.6. Start-to-Finish Relationship
- 7.2.2.2.7. Finish-to-Finish Relationship
- 7.2.3. Synchronization Mechanisms
- 7.2.3.1. Semaphores
- 7.2.3.2. Program Profile 7-4
- 7.2.3.2.1. Program Name:
- 7.2.3.2.2. Description:
- 7.2.3.2.3. Libraries Required:
- 7.2.3.2.4. Headers Required:
- 7.2.3.2.5. Compile and Link Instructions:
- 7.2.3.2.6. Test Environment:
- 7.2.3.2.7. Processors:
- 7.2.3.2.8. Execution Instructions:
- 7.2.3.2.9. Notes:
- 7.2.3.2.10. Mutex Semaphores
- 7.2.3.2.11. Using the Mutex Attribute Object
- 7.2.3.2.12. Using Mutex Semaphores to Manage Critical Sections
- 7.2.3.3. Read-Write Locks
- 7.2.3.4. Program Profile 7-5
- 7.2.3.5. Condition Variables
- 7.2.3.6. Program Profile 7-6
- 7.2.3.7. Thread-Safe Data Structures
- 7.3. Thread Strategy Approaches
- 7.4. Decomposition and Encapsulation of Work
- 7.5. Summary
- 7.1. Communication and Synchronization
- 8. PADL and PBS: Approaches to Application Design
- 8.1. Designing Applications for Massive Multicore Processors
- 8.2. What Is PADL?
- 8.2.1. Layer 5: Application Architecture Selection
- 8.2.1.1. What Are Agents?
- 8.2.1.2. What Is a Multiagent Architecture?
- 8.2.1.3. From Problem Statements to Multiagent Architectures
- 8.2.1.4. Blackboard Architectures
- 8.2.1.5. Approaches to Structuring the Blackboard
- 8.2.1.5.1. A "Question and Answer Browser" Blackboard Example
- 8.2.1.5.2. Where's the Parallelism? Where's the Blackboard?
- 8.2.1.5.3. Components of the Solution
- 8.2.1.5.4. Knowledge Sources for the Browser Program
- 8.2.1.5.5. Is a Blackboard a Good Fit?
- 8.2.1.5.6. The Blackboard as an Iterative Shared Solution Space
- 8.2.1.6. The Anatomy of a Knowledge Source
- 8.2.1.7. Concurrency Flexibility of the Application Architecture
- 8.2.2. Layer 4: Concurrency Models in PADL
- 8.2.3. Layer 3: The Implementation Model of PADL
- 8.2.3.1. C++ Components to the Rescue
- 8.2.3.2. The Intel Threading Building Blocks
- 8.2.3.3. Program Profile 8-1
- 8.2.3.3.1. Program Name:
- 8.2.3.3.2. Description:
- 8.2.3.3.3. Libraries Required:
- 8.2.3.3.4. Additional Source Files Needed:
- 8.2.3.3.5. User-Defined Headers Required:
- 8.2.3.3.6. Compile and Link Instructions:
- 8.2.3.3.7. Test Environment:
- 8.2.3.3.8. Processors:
- 8.2.3.3.9. Notes:
- 8.2.3.3.10. Obtaining the TBB library
- 8.2.3.4. The Parallel STL Library
- 8.2.3.5. The "Implementation Layer" Mapping
- 8.2.3.6. PADL: Layer 3 Type Control Strategies
- 8.2.1. Layer 5: Application Architecture Selection
- 8.3. The Predicate Breakdown Structure (PBS)
- 8.4. Summary
- 9. Modeling Software Systems That Require Concurrency
- 9.1. What Is UML?
- 9.2. Modeling the Structure of a System
- 9.2.1. The Class Model
- 9.2.2. Visualizing Classes
- 9.2.3. Ordering the Attributes and Services
- 9.2.4. Visualizing Instances of a Class
- 9.2.5. Visualizing Template Classes
- 9.2.6. Showing the Relationship between Classes and Objects
- 9.2.7. Visualizing Interface Classes
- 9.2.8. The Organization of Interactive Objects
- 9.3. UML and Concurrent Behavior
- 9.4. Visualizing the Whole System
- 9.5. Summary
- 10. Testing and Logical Fault Tolerance for Parallel Programs
- 10.1. Can You Just Skip the Testing?
- 10.2. Five Concurrency Challenges That Must Be Checked during Testing
- 10.3. Failure: The Result of Defects and Faults
- 10.4. How Do You Approach Defect Removal for Parallel Programs?
- 10.4.1. The Problem Statement
- 10.4.2. A Simple Strategy and Rough-Cut Solution Model
- 10.4.3. A Revised Solution Model Using Layer 5 from PADL
- 10.4.4. The PBS of the Agent Solution Model
- 10.5. What Are the Standard Software Engineering Tests?
- 10.5.1. Software Verification and Validation
- 10.5.2. The Code Doesn't Work — Now What?
- 10.5.3. What Is Logical Fault Tolerance?
- 10.5.4. Predicate Exceptions and Possible Worlds
- 10.5.5. What Is Model Checking?
- 10.6. Summary
- A. UML for Concurrent Design
- B. Concurrency Models
- B.1. Interprocess and Interthread Communication
- B.2. Boss/Worker Approach 1 with Threads
- B.3. Boss/Worker Approach 1 with Processes
- B.4. Boss/Worker Approach 2 with Threads
- B.5. Boss/Worker Approach 3 with Threads
- B.6. Peer-to-Peer Approach 1 with Threads
- B.7. Peer-to-Peer Approach 1 with Processes
- B.8. Peer-to-Peer Approach 2 with Threads
- B.9. Peer-to-Peer Approach 2 with Processes
- B.10. Workpile Approach 1
- B.11. Workpile Approach 2
- B.12. Pipeline Approach with Threads
- B.13. Producer/Consumer Approach 1 with Threads
- B.14. Producer/Consumer Approach 2 with Threads
- B.15. Producer/Consumer Approach 3 with Threads
- B.16. Monitor Approach
- B.17. Blackboard Approach with Threads
- B.18. Data Level Parallelism: SIMD Approach
- B.19. Data Level Parallelism: MIMD Approach
- B.20. PRAM Model
- C. POSIX Standard for Thread Management
- pthread_atfork()
- pthread_attr_destroy()
- pthread_attr_getdetachstate()
- pthread_attr_getguardsize()
- pthread_attr_getinheritsched()
- pthread_attr_getschedparam()
- pthread_attr_getschedpolicy()
- pthread_attr_getscope()
- pthread_attr_getstack()
- pthread_attr_getstackaddr()
- pthread_attr_getstacksize()
- pthread_attr_init()
- pthread_attr_setdetachstate()
- pthread_attr_setguardsize()
- pthread_attr_setinheritsched()
- pthread_attr_setschedparam()
- pthread_attr_setschedpolicy()
- pthread_attr_setscope()
- pthread_attr_setstack()
- pthread_attr_setstackaddr()
- pthread_attr_setstacksize()
- pthread_cancel()
- pthread_cond_broadcast()
- pthread_cond_destroy()
- pthread_cond_signal()
- pthread_cond_timedwait()
- pthread_condattr_destroy()
- pthread_condattr_getclock()
- pthread_condattr_getpshared()
- pthread_condattr_init()
- pthread_condattr_setclock()
- pthread_condattr_setpshared()
- pthread_create()
- pthread_detach()
- pthread_equal()
- pthread_exit()
- pthread_getconcurrency()
- pthread_getcpuclockid()
- pthread_getschedparam()
- pthread_getspecific()
- pthread_join()
- pthread_kill()
- pthread_mutex_destroy()
- pthread_mutex_getprioceiling()
- pthread_mutex_init()
- pthread_mutex_lock()
- pthread_mutex_setprioceiling()
- pthread_mutex_timedlock()
- pthread_mutex_trylock()
- pthread_mutexattr_destroy()
- pthread_mutexattr_getprioceiling()
- pthread_mutexattr_getprotocol()
- pthread_mutexattr_getpshared()
- pthread_mutexattr_gettype()
- pthread_mutexattr_init()
- pthread_mutexattr_setprioceiling()
- pthread_mutexattr_setprotocol()
- pthread_mutexattr_setpshared()
- pthread_mutexattr_settype()
- pthread_once()
- pthread_rwlock_destroy()
- pthread_rwlock_rdlock()
- pthread_rwlock_timedrdlock()
- pthread_rwlock_timedwrlock()
- pthread_rwlock_tryrdlock()
- pthread_rwlock_trywrlock()
- pthread_rwlock_unlock()
- pthread_rwlock_wrlock()
- pthread_rwlockattr_destroy()
- pthread_rwlockattr_getpshared()
- pthread_rwlockattr_init()
- pthread_rwlockattr_setpshared()
- pthread_self()
- pthread_setcancelstate()
- pthread_setconcurrency()
- pthread_setschedparam()
- Pthread_setschedprio()
- pthread_setspecific()
- pthread_testcancel()
- D. POSIX Standard for Process Management
- posix_spawn()
- posix_spawn_file_actions_addclose()
- posix_spawn_file_actions_adddup2()
- posix_spawn_file_actions_addopen()
- posix_spawn_file_actions_destroy()
- posix_spawnattr_destroy()
- posix_spawnattr_getflags()
- posix_spawnattr_getpgroup()
- pisix_spawnattr_getschedparam()
- posix_spawnattr_getschedpolicy()
- Bibliography
Name
NAME
pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared — get and set the process-shared attribute of the read-write lock attributes object
SYNOPSIS
THR TSH #include <pthread.h>
int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *
restrict attr, int *restrict pshared);
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
int pshared) ;DESCRIPTION
The pthread_rwlockattr_getpshared() function shall obtain the value of the process-shared attribute from the initialized attributes object referenced by attr. The pthread_rwlockattr_setpshared() function shall set the process-shared attribute in an initialized attributes object referenced by attr.
The process-shared attribute shall be set to PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated upon by any thread that has access to the memory where the read-write lock is allocated, even if the read-write lock is allocated in memory that is shared by multiple processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock shall only be operated upon by threads created within the same process as the thread that initialized the read-write lock; if threads of differing processes attempt to operate on such a read-write lock, the behavior is undefined. The default value of the process-shared attribute shall be PTHREAD_PROCESS_PRIVATE.
Additional attributes, their default values, and the names of the associated functions to get and set those attribute values are implementation-defined.
RETURN VALUE
Upon successful completion, the pthread_rwlockattr_getpshared() function shall return zero and store the value of the process-shared attribute of attr into the object referenced by the pshared parameter. Otherwise, an error number shall be returned to indicate the error.
If successful, the pthread_rwlockattr_setpshared() function shall return zero; otherwise, an error number shall be returned to indicate the error.
ERRORS
The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions may fail if:
[EINVAL] | The value specified by attr is invalid. |
The pthread_rwlockattr_setpshared() function may fail if:
[EINVAL] | The new value specified for the attribute is outside the range of legal values for that attribute. |
These functions shall not return an error code of [EINTR].
SEE ALSO
pthread_rwlock_destroy(), pthread_rwlockattr_destroy(), pthread_rwlockattr_init(), the Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h>
Issue 6
The following changes are made for alignment with IEEE Std 1003.lj-2000:
The margin code in the SYNOPSIS is changed to THR to indicate that the functionality is now part of the Threads option (previously it was part of the Read-Write Locks option in IEEE Std 1003.lj-2000 and also part of the XSI extension).
The DESCRIPTION notes that additional attributes are implementation-defined.
The SEE ALSO section is updated.
The restrict keyword is added to the pthread_rwlockattr_getshared() prototype for alignment with the ISO/IEC 9899:1999 standard.
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