pthread_rdwr.h File Reference

functions that provide a read-write locking mechanism More...

#include <pthread.h>
#include <unistd.h>

Go to the source code of this file.

Data Structures
struct	pthread_rdwrattr_t
	pthread_rdwr_t attribute structure More...
struct	pthread_rdwr_t
	pthread_rdwr_t structure More...
Defines
#define	PTHREAD_RDWR_PREFER_READER   PTHREAD_RDWR_PREFER_READER
	reader preference enumeration
#define	PTHREAD_RDWR_PREFER_WRITER   PTHREAD_RDWR_PREFER_WRITER
	writer preference enumeration
#define	PTHREAD_RDWR_PREFER_TOGGLE   PTHREAD_RDWR_PREFER_TOGGLE
	toggle preference enumeration
#define	PTHREAD_RDWR_PREFER_DEFAULT   PTHREAD_RDWR_PREFER_DEFAULT
	default preference enumeration
#define	PTHREAD_RDWR_NORMAL   PTHREAD_RDWR_NORMAL
	normal type enumeration
#define	PTHREAD_RDWR_ERRORCHECK   PTHREAD_RDWR_ERRORCHECK
	error checking type enumeration
#define	PTHREAD_RDWR_DEFAULT   PTHREAD_RDWR_DEFAULT
	default type enumeration
#define	PTHREAD_RDWR_INITIALIZER
	static initializer for pthread_rdwr_t
Enumerations
enum	{ PTHREAD_RDWR_PREFER_READER, PTHREAD_RDWR_PREFER_WRITER, PTHREAD_RDWR_PREFER_TOGGLE, PTHREAD_RDWR_PREFER_DEFAULT = PTHREAD_RDWR_PREFER_TOGGLE }
	enumeration for rdwr preference More...
enum	{ PTHREAD_RDWR_NORMAL, PTHREAD_RDWR_ERRORCHECK, PTHREAD_RDWR_DEFAULT = PTHREAD_RDWR_NORMAL }
	enumeration for rdwr type More...
Functions
int	pthread_rdwr_init (pthread_rdwr_t *rdwr, const pthread_rdwrattr_t *attr)
	initialize pthread_rdwr_t structure
int	pthread_rdwr_destroy (pthread_rdwr_t *rdwr)
	initialize pthread_rdwr_t structure
int	pthread_rdwr_rdlock (pthread_rdwr_t *rdwr)
	to obtain a read lock
int	pthread_rdwr_timedrdlock (pthread_rdwr_t *rdwr, const struct timespec *timeout)
	to try to obtain a read lock for at least timeout duration
int	pthread_rdwr_tryrdlock (pthread_rdwr_t *rdwr)
	to obtain a read lock if no write lock
int	pthread_rdwr_wrlock (pthread_rdwr_t *rdwr)
	to obtain a write lock
int	pthread_rdwr_timedwrlock (pthread_rdwr_t *rdwr, const struct timespec *timeout)
	try to obtain a write lock for at least timeout duration
int	pthread_rdwr_trywrlock (pthread_rdwr_t *rdwr)
	try to obtain a write lock if no read lock or write lock
int	pthread_rdwr_unlock (pthread_rdwr_t *rdwr)
	unlock current thread
int	pthread_rdwrattr_init (pthread_rdwrattr_t *attr)
	initialize pthread_rdwr_t attribute structure
int	pthread_rdwrattr_destroy (pthread_rdwrattr_t *attr)
	destroy pthread_rdwr_t attribute structure
int	pthread_rdwrattr_getkind (const pthread_rdwrattr_t *attr, int *pref)
	assign kind the current kind attribute
int	pthread_rdwrattr_setkind (pthread_rdwrattr_t *attr, const int pref)
	assign current kind attribute
int	pthread_rdwrattr_gettype (const pthread_rdwrattr_t *attr, int *type)
	assign type the current type attribute
int	pthread_rdwrattr_settype (pthread_rdwrattr_t *attr, const int type)
	assign current type attribute

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Detailed Description

functions that provide a read-write locking mechanism

A barrier causes the calling thread to wait until a set number of threads reach a point, then those threads may continue.

Warning:

• not async-cancel safe

• cancellation has not been tested

---

Define Documentation

#define PTHREAD_RDWR_INITIALIZER

Value:

{ PTHREAD_MUTEX_INITIALIZER, \
        PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, \
        0, 0, 0, 0, 0, PTHREAD_RDWR_PREFER_DEFAULT, PTHREAD_RDWR_DEFAULT }

static initializer for pthread_rdwr_t

---

Enumeration Type Documentation

anonymous enum

enumeration for rdwr preference

Enumerator:

PTHREAD_RDWR_PREFER_READER	reader preference enumeration
PTHREAD_RDWR_PREFER_WRITER	writer preference enumeration
PTHREAD_RDWR_PREFER_TOGGLE	toggle preference enumeration
PTHREAD_RDWR_PREFER_DEFAULT	default preference enumeration

anonymous enum

enumeration for rdwr type

Enumerator:

PTHREAD_RDWR_NORMAL	normal type enumeration
PTHREAD_RDWR_ERRORCHECK	error checking type enumeration
PTHREAD_RDWR_DEFAULT	default type enumeration

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Function Documentation

int pthread_rdwr_destroy

(

pthread_rdwr_t *

rdwr

)

initialize pthread_rdwr_t structure

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_init	(	pthread_rdwr_t *	rdwr,
		const pthread_rdwrattr_t *	attr
	)

initialize pthread_rdwr_t structure

Parameters:

	rdwr	pointer to pthread_rdwr_t structure
	attr	pointer to pthread_rdwr_t attribute structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_rdlock

(

pthread_rdwr_t *

rdwr

)

to obtain a read lock

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_timedrdlock	(	pthread_rdwr_t *	rdwr,
		const struct timespec *	timeout
	)

to try to obtain a read lock for at least timeout duration

Parameters:

	rdwr	pointer to pthread_rdwr_t structure
	timeout	pointer to timespec structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_timedwrlock	(	pthread_rdwr_t *	rdwr,
		const struct timespec *	timeout
	)

try to obtain a write lock for at least timeout duration

Parameters:

	rdwr	pointer to pthread_rdwr_t structure
	timeout	pointer to timespec structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_tryrdlock

(

pthread_rdwr_t *

rdwr

)

to obtain a read lock if no write lock

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_trywrlock

(

pthread_rdwr_t *

rdwr

)

try to obtain a write lock if no read lock or write lock

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_unlock

(

pthread_rdwr_t *

rdwr

)

unlock current thread

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwr_wrlock

(

pthread_rdwr_t *

rdwr

)

to obtain a write lock

Parameters:

rdwr

pointer to pthread_rdwr_t structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_destroy

(

pthread_rdwrattr_t *

attr

)

destroy pthread_rdwr_t attribute structure

Parameters:

attr

pointer to pthread_rdwr_t attribute structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_getkind	(	const pthread_rdwrattr_t *	attr,
		int *	pref
	)

assign kind the current kind attribute

Parameters:

	attr	pointer to pthread_rdwr_t attribute structure
	pref	pointer to kind attribute

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_gettype	(	const pthread_rdwrattr_t *	attr,
		int *	type
	)

assign type the current type attribute

Parameters:

	attr	pointer to pthread_rdwr_t attribute structure
	type	pointer to type attribute

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_init

(

pthread_rdwrattr_t *

attr

)

initialize pthread_rdwr_t attribute structure

Parameters:

attr

pointer to pthread_rdwr_t attribute structure

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_setkind	(	pthread_rdwrattr_t *	attr,
		const int	pref
	)

assign current kind attribute

Parameters:

	attr	pointer to pthread_rdwr_t attribute structure
	pref	kind attribute

Returns:

0 is returned on success
non-zero error code is returned on failure

int pthread_rdwrattr_settype	(	pthread_rdwrattr_t *	attr,
		const int	type
	)

assign current type attribute

Parameters:

	attr	pointer to pthread_rdwr_t attribute structure
	type	type attribute

Returns:

0 is returned on success
non-zero error code is returned on failure

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