Plank AtomicF class

Atomic float. More...

Typedefs
typedef struct PlankAtomicF *	PlankAtomicFRef
	An opaque reference to the Plank AtomicF object (atomic float).
Functions
PlankAtomicFRef	pl_AtomicF_CreateAndInit ()
	Creates and initialises a Plank AtomicF object and return an oqaque reference to it.
PlankAtomicFRef	pl_AtomicF_Create ()
	Create a Plank AtomicF object and return an oqaque reference to it.
static PlankResult	pl_AtomicF_Init (PlankAtomicFRef p)
	Initialise a Plank AtomicF object.
static PlankResult	pl_AtomicF_DeInit (PlankAtomicFRef p)
	Deinitialise a Plank AtomicF object.
PlankResult	pl_AtomicF_Destroy (PlankAtomicFRef p)
	Destroy a Plank AtomicF object.
static PlankF	pl_AtomicF_Get (PlankAtomicFRef p)
	Get the current value.
static PlankF	pl_AtomicF_GetUnchecked (PlankAtomicFRef p)
	Get the current value nonatomically.
PlankUI	pl_AtomicF_GetExtra (PlankAtomicFRef p)
	Not used for this class.
PlankUI	pl_AtomicF_GetExtraUnchecked (PlankAtomicFRef p)
	Not used for this class.
static PlankF	pl_AtomicF_Swap (PlankAtomicFRef p, PlankF newValue)
	Swap the current value with a new value.
static void	pl_AtomicF_SwapOther (PlankAtomicFRef p1, PlankAtomicFRef p2)
	Swap over two values.
static void	pl_AtomicF_Set (PlankAtomicFRef p, PlankF newValue)
	Set the current value to a new value.
static PlankF	pl_AtomicF_Add (PlankAtomicFRef p, PlankF operand)
	Add a value to the current value.
static PlankF	pl_AtomicF_Subtract (PlankAtomicFRef p, PlankF operand)
	Subtract a value from the current value.
static PlankF	pl_AtomicF_Increment (PlankAtomicFRef p)
	Increment the current value by 1.
static PlankF	pl_AtomicF_Decrement (PlankAtomicFRef p)
	Decrement the current value by 1.
static PlankB	pl_AtomicF_CompareAndSwap (PlankAtomicFRef p, PlankF oldValue, PlankF newValue)
	Swap the current value with a new value if a specified old value is still the current value.

---

Detailed Description

Atomic float.

This will be a 32-bit float on all Plank-supported platforms.

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Typedef Documentation

typedef struct PlankAtomicF* PlankAtomicFRef

An opaque reference to the Plank AtomicF object (atomic float).

---

Function Documentation

static PlankF pl_AtomicF_Add	(	PlankAtomicFRef	p,
		PlankF	operand
	)		[static]

Add a value to the current value.

Parameters:

p	The Plank AtomicF object.
operand	The value to add.

Returns:

The new value.

static PlankB pl_AtomicF_CompareAndSwap	(	PlankAtomicFRef	p,
		PlankF	oldValue,
		PlankF	newValue
	)		[static]

Swap the current value with a new value if a specified old value is still the current value.

This is the most important atomic operation for each atomic class, many other operations are based on this. If the operation fails the user would generally try again by getting the old value again and retrying to write the new value (e.g., in a loop) until successful. If there are no other threads contending to write the value the operation should succeed without blocking.

NB A bit-level comparison is performed. e.g., -0.f and 0.f would not be considered equal but two identical NaNs would be. In both of these cases this is different behaviour than comparing the two floating point values (i.e., -0.f and 0.f are considered equal and NaNs are never equal to anything else even if there's another identical NaN with which you are comparing).

Parameters:

p	The Plank AtomicF object.
oldValue	The expected old value being currently stored.
newValue	The new value to attempt to store.

Returns:

true if the swap was successful, otherwise false.

PlankAtomicFRef pl_AtomicF_Create

(

)

Create a Plank AtomicF object and return an oqaque reference to it.

Returns:

A Plank AtomicF object as an opaque reference or PLANK_NULL.

PlankAtomicFRef pl_AtomicF_CreateAndInit

(

)

Creates and initialises a Plank AtomicF object and return an oqaque reference to it.

Returns:

A Plank AtomicF object as an opaque reference or PLANK_NULL.

static PlankF pl_AtomicF_Decrement

(

PlankAtomicFRef

p

)

[static]

Decrement the current value by 1.

Parameters:

p	The Plank AtomicF object.

Returns:

The new value.

static PlankResult pl_AtomicF_DeInit

(

PlankAtomicFRef

p

)

[inline, static]

Deinitialise a Plank AtomicF object.

Parameters:

p	The Plank AtomicF object.

Returns:

PlankResult_OK if successful, otherwise an error code.

PlankResult pl_AtomicF_Destroy

(

PlankAtomicFRef

p

)

Destroy a Plank AtomicF object.

Parameters:

p	The Plank AtomicF object.

Returns:

PlankResult_OK if successful, otherwise an error code.

static PlankF pl_AtomicF_Get

(

PlankAtomicFRef

p

)

[static]

Get the current value.

Parameters:

p	The Plank AtomicF object.

Returns:

The value.

PlankUI pl_AtomicF_GetExtra

(

PlankAtomicFRef

p

)

Not used for this class.

Parameters:

p	The Plank AtomicF object.

Returns:

Always returns 0.

PlankUI pl_AtomicF_GetExtraUnchecked

(

PlankAtomicFRef

p

)

Not used for this class.

Parameters:

p	The Plank AtomicF object.

Returns:

Always returns 0.

static PlankF pl_AtomicF_GetUnchecked

(

PlankAtomicFRef

p

)

[static]

Get the current value nonatomically.

Parameters:

p	The Plank AtomicF object.

Returns:

The value.

static PlankF pl_AtomicF_Increment

(

PlankAtomicFRef

p

)

[static]

Increment the current value by 1.

Parameters:

p	The Plank AtomicF object.

Returns:

The new value.

static PlankResult pl_AtomicF_Init

(

PlankAtomicFRef

p

)

[inline, static]

Initialise a Plank AtomicF object.

Parameters:

p	The Plank AtomicF object.

Returns:

PlankResult_OK if successful, otherwise an error code.

static void pl_AtomicF_Set	(	PlankAtomicFRef	p,
		PlankF	newValue
	)		[static]

Set the current value to a new value.

Parameters:

p	The Plank AtomicF object.
newValue	The new value to store.

static PlankF pl_AtomicF_Subtract	(	PlankAtomicFRef	p,
		PlankF	operand
	)		[static]

Subtract a value from the current value.

Parameters:

p	The Plank AtomicF object.
operand	The value to subtract.

Returns:

The new value.

static PlankF pl_AtomicF_Swap	(	PlankAtomicFRef	p,
		PlankF	newValue
	)		[static]

Swap the current value with a new value.

Parameters:

p	The Plank AtomicF object.
newValue	The new value to store.

Returns:

The previously stored value.

static void pl_AtomicF_SwapOther	(	PlankAtomicFRef	p1,
		PlankAtomicFRef	p2
	)		[static]

Swap over two values.

The contents of p1 is copied to p2 and p2 is copied to p1 in an atomic operation.

Parameters:

p1	One Plank AtomicF object.
p2	The other Plank AtomicF object.