Collaboration diagram for Binary Semaphores:

Detailed Description

Macros
#define	_BSEMAPHORE_DATA(name, taken) {_SEMAPHORE_DATA(name.sem, ((taken) ? 0 : 1))}
	Data part of a static semaphore initializer. More...

#define	BSEMAPHORE_DECL(name, taken) binary_semaphore_t name = _BSEMAPHORE_DATA(name, taken)
	Static semaphore initializer. More...

Typedefs
typedef struct ch_binary_semaphore	binary_semaphore_t
	Binary semaphore type. More...

Data Structures
struct	ch_binary_semaphore
	Binary semaphore type. More...

Functions
static void	chBSemObjectInit (binary_semaphore_t *bsp, bool taken)
	Initializes a binary semaphore. More...

static msg_t	chBSemWait (binary_semaphore_t *bsp)
	Wait operation on the binary semaphore. More...

static msg_t	chBSemWaitS (binary_semaphore_t *bsp)
	Wait operation on the binary semaphore. More...

static msg_t	chBSemWaitTimeoutS (binary_semaphore_t *bsp, sysinterval_t timeout)
	Wait operation on the binary semaphore. More...

static msg_t	chBSemWaitTimeout (binary_semaphore_t *bsp, sysinterval_t timeout)
	Wait operation on the binary semaphore. More...

static void	chBSemResetI (binary_semaphore_t *bsp, bool taken)
	Reset operation on the binary semaphore. More...

static void	chBSemReset (binary_semaphore_t *bsp, bool taken)
	Reset operation on the binary semaphore. More...

static void	chBSemSignalI (binary_semaphore_t *bsp)
	Performs a signal operation on a binary semaphore. More...

static void	chBSemSignal (binary_semaphore_t *bsp)
	Performs a signal operation on a binary semaphore. More...

static bool	chBSemGetStateI (const binary_semaphore_t *bsp)
	Returns the binary semaphore current state. More...

Macro Definition Documentation

#define _BSEMAPHORE_DATA	(	name,
		taken
	)	{_SEMAPHORE_DATA(name.sem, ((taken) ? 0 : 1))}

Data part of a static semaphore initializer.

This macro should be used when statically initializing a semaphore that is part of a bigger structure.

Parameters

[in]	name	the name of the semaphore variable
[in]	taken	the semaphore initial state

Definition at line 91 of file chbsem.h.

#define BSEMAPHORE_DECL	(	name,
		taken
	)	binary_semaphore_t name = _BSEMAPHORE_DATA(name, taken)

Static semaphore initializer.

Statically initialized semaphores require no explicit initialization using chBSemInit().

Parameters

[in]	name	the name of the semaphore variable
[in]	taken	the semaphore initial state

Definition at line 102 of file chbsem.h.

Typedef Documentation

typedef struct ch_binary_semaphore binary_semaphore_t

Binary semaphore type.

Function Documentation

static void chBSemObjectInit	(	binary_semaphore_t *	bsp,
		bool	taken
	)

inlinestatic

Initializes a binary semaphore.

Parameters

[out]	bsp	pointer to a `binary_semaphore_t` structure
[in]	taken	initial state of the binary semaphore: false, the initial state is not taken. true, the initial state is taken.

Function Class:Initializer, this function just initializes an object and can be invoked before the kernel is initialized.

Definition at line 124 of file chbsem.h.

References chSemObjectInit().

Here is the call graph for this function:

static msg_t chBSemWait ( binary_semaphore_t * bsp )

inlinestatic

Wait operation on the binary semaphore.

Parameters

[in] bsp pointer to a binary_semaphore_t structure

Returns: A message specifying how the invoking thread has been released from the semaphore.

Return values

MSG_OK	if the binary semaphore has been successfully taken.
MSG_RESET	if the binary semaphore has been reset using `bsemReset()`.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 141 of file chbsem.h.

References chSemWait().

Here is the call graph for this function:

static msg_t chBSemWaitS ( binary_semaphore_t * bsp )

inlinestatic

Wait operation on the binary semaphore.

Parameters

[in] bsp pointer to a binary_semaphore_t structure

Returns: A message specifying how the invoking thread has been released from the semaphore.

Return values

MSG_OK	if the binary semaphore has been successfully taken.
MSG_RESET	if the binary semaphore has been reset using `bsemReset()`.

Function Class:This is an S-Class API, this function can be invoked from within a system lock zone by threads only.

Definition at line 158 of file chbsem.h.

References chSemWaitS().

Here is the call graph for this function:

static msg_t chBSemWaitTimeoutS	(	binary_semaphore_t *	bsp,
		sysinterval_t	timeout
	)

inlinestatic

Wait operation on the binary semaphore.

Parameters

[in]	bsp	pointer to a `binary_semaphore_t` structure
[in]	timeout	the number of ticks before the operation timeouts, the following special values are allowed: TIME_IMMEDIATE immediate timeout. TIME_INFINITE no timeout.

Returns: A message specifying how the invoking thread has been released from the semaphore.

Return values

MSG_OK	if the binary semaphore has been successfully taken.
MSG_RESET	if the binary semaphore has been reset using `bsemReset()`.
MSG_TIMEOUT	if the binary semaphore has not been signaled or reset within the specified timeout.

Function Class:This is an S-Class API, this function can be invoked from within a system lock zone by threads only.

Definition at line 184 of file chbsem.h.

References chSemWaitTimeoutS().

Here is the call graph for this function:

static msg_t chBSemWaitTimeout	(	binary_semaphore_t *	bsp,
		sysinterval_t	timeout
	)

inlinestatic

Wait operation on the binary semaphore.

Parameters

[in]	bsp	pointer to a `binary_semaphore_t` structure
[in]	timeout	the number of ticks before the operation timeouts, the following special values are allowed: TIME_IMMEDIATE immediate timeout. TIME_INFINITE no timeout.

Returns: A message specifying how the invoking thread has been released from the semaphore.

Return values

MSG_OK	if the binary semaphore has been successfully taken.
MSG_RESET	if the binary semaphore has been reset using `bsemReset()`.
MSG_TIMEOUT	if the binary semaphore has not been signaled or reset within the specified timeout.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 211 of file chbsem.h.

References chSemWaitTimeout().

Here is the call graph for this function:

static void chBSemResetI	(	binary_semaphore_t *	bsp,
		bool	taken
	)

inlinestatic

Reset operation on the binary semaphore.

Note: The released threads can recognize they were waked up by a reset rather than a signal because the bsemWait() will return MSG_RESET instead of MSG_OK.; This function does not reschedule.

Parameters

[in]	bsp	pointer to a `binary_semaphore_t` structure
[in]	taken	new state of the binary semaphore false, the new state is not taken. true, the new state is taken.

Function Class:This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 232 of file chbsem.h.

References chSemResetI().

Here is the call graph for this function:

static void chBSemReset	(	binary_semaphore_t *	bsp,
		bool	taken
	)

inlinestatic

Reset operation on the binary semaphore.

Note: The released threads can recognize they were waked up by a reset rather than a signal because the bsemWait() will return MSG_RESET instead of MSG_OK.

Parameters

[in]	bsp	pointer to a `binary_semaphore_t` structure
[in]	taken	new state of the binary semaphore false, the new state is not taken. true, the new state is taken.