Data.Primitive.PVar.Unsafe · pvar-1.0.0.0

datadata PVar a s

#

Mutable variable with primitive value.

Constructors

PVar (MutableByteArray# s)

Instances2Storable, NFData

Prim a => Storable (PVar a RealWorld)Defined in pvar-1.0.0.0 · Data.Primitive.PVar.Internal
poke+peek will result in a new copy of a PVar
NFData (PVar a s)Defined in pvar-1.0.0.0 · Data.Primitive.PVar.Internal
Values are already written into PVar in NF, this instance is trivial.

Creation

5 declarations

valuerawPVar :: (MonadPrim s m, Prim a) => m (PVar a s)

#

Create a mutable variable in unpinned and unititialized memory

valuerawPinnedPVar :: (MonadPrim s m, Prim a) => m (PVar a s)

#

Create a mutable variable in pinned memory with uninitialized memory.

valuerawAlignedPinnedPVar :: (MonadPrim s m, Prim a) => m (PVar a s)

#

Create a mutable variable in pinned uninitialized memory.

valuerawStorablePVar :: (MonadPrim s m, Storable a) => m (PVar a s)

#

Create a mutable variable in pinned uninitialized memory using Storable interface for getting the number of bytes for memory allocation.

valuerawAlignedStorablePVar :: (MonadPrim s m, Storable a) => m (PVar a s)

#

Create a mutable variable in pinned uninitialized memory using Storable interface for getting the number of bytes for memory allocation and alignement.

Access

2 declarations

valuepeekPrim :: (Storable a, MonadPrim s m) => Ptr a -> m a

#

Use Storable reading functionality inside the PrimMonad.

valuepokePrim :: (Storable a, MonadPrim s m) => Ptr a -> a -> m ()

#

Use Storable wrting functionality inside the PrimMonad.

Conversion

3 declarations

valuetoPtrPVar :: PVar a s -> Maybe (Ptr a)

#

Extract the address to the mutable variable, but only if it is backed by pinned memory. It is unsafe because even for pinned memory memory can be deallocated if associated PVar goes out of scope. Use withPtrPVar or Data.Primitive.PVar.toForeignPtr instead.

valueunsafeToPtrPVar :: PVar a s -> Ptr a

#

Get the address to the contents. This is highly unsafe, espcially if memory is not pinned

valueunsafeToForeignPtrPVar :: PVar a s -> ForeignPtr a

#

Convert PVar into a ForeignPtr, very unsafe if not backed by pinned memory.

Reset

1 declaration

valuezeroPVar :: (MonadPrim s m, Prim a) => PVar a s -> m ()

#

Reset contents of a mutable variable to zero.

Unpacked opartions

3 declarations

valuesizeOfPVar# :: Prim a => PVar a s -> Int#

#

Get the size of the mutable variable in bytes as an unpacked integer

valuealignmentPVar# :: Prim a => PVar a s -> Int#

#

Get the alignment of the mutable variable in bytes as an unpacked integer

valuesetPVar#

:: (MonadPrim s m, Prim a)
=> PVar a s
-> Int#
Byte value to fill the PVar with
-> m ()

#

Fill the contents of mutable variable with byte c

ByteArray

0 declarations

Atomic operations

valueatomicModifyIntArray#

:: MutableByteArray# d
Array to be mutated
-> Int#
Index in number of Int# elements into the MutableByteArray#
-> (Int# -> (# Int#, b #))
Function to be applied atomically to the element
-> State# d
Starting state
-> (# State# d, b #)

#

Using casIntArray# perform atomic modification of an integer element in a MutableByteArray#. Implies a full memory barrier.

valueatomicModifyIntArray_#

:: MutableByteArray# d
Array to be mutated
-> Int#
Index in number of Int# elements into the MutableByteArray#
-> (Int# -> Int#)
Function to be applied atomically to the element
-> State# d
Starting state
-> State# d

#

Uses casIntArray# to perform atomic modification of an integer element in a MutableByteArray#. Implies a full memory barrier.

Memory copying

valuecopyFromByteArrayPVar

:: (MonadPrim s m, Prim a)
=> ByteArray
Source array
-> Int
Offset in number of elements into the array
-> PVar a s
-> m ()

#

Copy the value from a frozen ByteArray into a mutable variable at specified index. Index of array is not checked and can result in an unchecked exception when incorrect

valuecopyFromMutableByteArrayPVar

:: (MonadPrim s m, Prim a)
=> MutableByteArray s
-> Int
Offset in number of elements into the array
-> PVar a s
-> m ()

#

Copy the value from MutableByteArray at specified index into the mutable variable. Index of array is not checked and can result in an unchecked exception when incorrect

valuecopyPVarToMutableByteArray

:: (MonadPrim s m, Prim a)
=> PVar a s
-> MutableByteArray s
-> Int
Offset in number of elements into the array
-> m ()

#

Copy the value from a mutable variable into a mutable array at the specified index. Index of array is not checked and can result in an unchecked exception when incorrect