{-# LANGUAGE TypeApplications #-}


-- | Copyright  : Will Thompson, Iñaki García Etxebarria and Jonas Platte
-- License    : LGPL-2.1
-- Maintainer : Iñaki García Etxebarria
-- 
-- The GRWLock struct is an opaque data structure to represent a
-- reader-writer lock. It is similar to a t'GI.GLib.Unions.Mutex.Mutex' in that it allows
-- multiple threads to coordinate access to a shared resource.
-- 
-- The difference to a mutex is that a reader-writer lock discriminates
-- between read-only (\'reader\') and full (\'writer\') access. While only
-- one thread at a time is allowed write access (by holding the \'writer\'
-- lock via 'GI.GLib.Structs.RWLock.rWLockWriterLock'), multiple threads can gain
-- simultaneous read-only access (by holding the \'reader\' lock via
-- 'GI.GLib.Structs.RWLock.rWLockReaderLock').
-- 
-- It is unspecified whether readers or writers have priority in acquiring the
-- lock when a reader already holds the lock and a writer is queued to acquire
-- it.
-- 
-- Here is an example for an array with access functions:
-- 
-- === /C code/
-- >
-- >  GRWLock lock;
-- >  GPtrArray *array;
-- >
-- >  gpointer
-- >  my_array_get (guint index)
-- >  {
-- >    gpointer retval = NULL;
-- >
-- >    if (!array)
-- >      return NULL;
-- >
-- >    g_rw_lock_reader_lock (&lock);
-- >    if (index < array->len)
-- >      retval = g_ptr_array_index (array, index);
-- >    g_rw_lock_reader_unlock (&lock);
-- >
-- >    return retval;
-- >  }
-- >
-- >  void
-- >  my_array_set (guint index, gpointer data)
-- >  {
-- >    g_rw_lock_writer_lock (&lock);
-- >
-- >    if (!array)
-- >      array = g_ptr_array_new ();
-- >
-- >    if (index >= array->len)
-- >      g_ptr_array_set_size (array, index+1);
-- >    g_ptr_array_index (array, index) = data;
-- >
-- >    g_rw_lock_writer_unlock (&lock);
-- >  }
-- > 
-- 
-- This example shows an array which can be accessed by many readers
-- (the @/my_array_get()/@ function) simultaneously, whereas the writers
-- (the @/my_array_set()/@ function) will only be allowed one at a time
-- and only if no readers currently access the array. This is because
-- of the potentially dangerous resizing of the array. Using these
-- functions is fully multi-thread safe now.
-- 
-- If a t'GI.GLib.Structs.RWLock.RWLock' is allocated in static storage then it can be used
-- without initialisation.  Otherwise, you should call
-- 'GI.GLib.Structs.RWLock.rWLockInit' on it and 'GI.GLib.Structs.RWLock.rWLockClear' when done.
-- 
-- A GRWLock should only be accessed with the g_rw_lock_ functions.
-- 
-- /Since: 2.32/

#if (MIN_VERSION_haskell_gi_overloading(1,0,0) && !defined(__HADDOCK_VERSION__))
#define ENABLE_OVERLOADING
#endif

module GI.GLib.Structs.RWLock
    (

-- * Exported types
    RWLock(..)                              ,
    newZeroRWLock                           ,
    noRWLock                                ,


 -- * Methods
-- ** Overloaded methods #method:Overloaded methods#

#if defined(ENABLE_OVERLOADING)
    ResolveRWLockMethod                     ,
#endif


-- ** clear #method:clear#

#if defined(ENABLE_OVERLOADING)
    RWLockClearMethodInfo                   ,
#endif
    rWLockClear                             ,


-- ** init #method:init#

#if defined(ENABLE_OVERLOADING)
    RWLockInitMethodInfo                    ,
#endif
    rWLockInit                              ,


-- ** readerLock #method:readerLock#

#if defined(ENABLE_OVERLOADING)
    RWLockReaderLockMethodInfo              ,
#endif
    rWLockReaderLock                        ,


-- ** readerTrylock #method:readerTrylock#

#if defined(ENABLE_OVERLOADING)
    RWLockReaderTrylockMethodInfo           ,
#endif
    rWLockReaderTrylock                     ,


-- ** readerUnlock #method:readerUnlock#

#if defined(ENABLE_OVERLOADING)
    RWLockReaderUnlockMethodInfo            ,
#endif
    rWLockReaderUnlock                      ,


-- ** writerLock #method:writerLock#

#if defined(ENABLE_OVERLOADING)
    RWLockWriterLockMethodInfo              ,
#endif
    rWLockWriterLock                        ,


-- ** writerTrylock #method:writerTrylock#

#if defined(ENABLE_OVERLOADING)
    RWLockWriterTrylockMethodInfo           ,
#endif
    rWLockWriterTrylock                     ,


-- ** writerUnlock #method:writerUnlock#

#if defined(ENABLE_OVERLOADING)
    RWLockWriterUnlockMethodInfo            ,
#endif
    rWLockWriterUnlock                      ,




    ) where

import Data.GI.Base.ShortPrelude
import qualified Data.GI.Base.ShortPrelude as SP
import qualified Data.GI.Base.Overloading as O
import qualified Prelude as P

import qualified Data.GI.Base.Attributes as GI.Attributes
import qualified Data.GI.Base.ManagedPtr as B.ManagedPtr
import qualified Data.GI.Base.GClosure as B.GClosure
import qualified Data.GI.Base.GError as B.GError
import qualified Data.GI.Base.GVariant as B.GVariant
import qualified Data.GI.Base.GValue as B.GValue
import qualified Data.GI.Base.GParamSpec as B.GParamSpec
import qualified Data.GI.Base.CallStack as B.CallStack
import qualified Data.GI.Base.Properties as B.Properties
import qualified Data.GI.Base.Signals as B.Signals
import qualified Data.Text as T
import qualified Data.ByteString.Char8 as B
import qualified Data.Map as Map
import qualified Foreign.Ptr as FP
import qualified GHC.OverloadedLabels as OL


-- | Memory-managed wrapper type.
newtype RWLock = RWLock (ManagedPtr RWLock)
    deriving (Eq)
instance WrappedPtr RWLock where
    wrappedPtrCalloc = callocBytes 12
    wrappedPtrCopy = \p -> withManagedPtr p (copyBytes 12 >=> wrapPtr RWLock)
    wrappedPtrFree = Just ptr_to_g_free

-- | Construct a `RWLock` struct initialized to zero.
newZeroRWLock :: MonadIO m => m RWLock
newZeroRWLock = liftIO $ wrappedPtrCalloc >>= wrapPtr RWLock

instance tag ~ 'AttrSet => Constructible RWLock tag where
    new _ attrs = do
        o <- newZeroRWLock
        GI.Attributes.set o attrs
        return o


-- | A convenience alias for `Nothing` :: `Maybe` `RWLock`.
noRWLock :: Maybe RWLock
noRWLock = Nothing


#if defined(ENABLE_OVERLOADING)
instance O.HasAttributeList RWLock
type instance O.AttributeList RWLock = RWLockAttributeList
type RWLockAttributeList = ('[ ] :: [(Symbol, *)])
#endif

-- method RWLock::clear
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "an initialized #GRWLock"
--                 , sinceVersion = Nothing
--                 }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_clear" g_rw_lock_clear ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Frees the resources allocated to a lock with 'GI.GLib.Structs.RWLock.rWLockInit'.
-- 
-- This function should not be used with a t'GI.GLib.Structs.RWLock.RWLock' that has been
-- statically allocated.
-- 
-- Calling 'GI.GLib.Structs.RWLock.rWLockClear' when any thread holds the lock
-- leads to undefined behaviour.
-- 
-- Sine: 2.32
rWLockClear ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: an initialized t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockClear rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_clear rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockClearMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockClearMethodInfo RWLock signature where
    overloadedMethod = rWLockClear

#endif

-- method RWLock::init
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "an uninitialized #GRWLock"
--                 , sinceVersion = Nothing
--                 }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_init" g_rw_lock_init ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Initializes a t'GI.GLib.Structs.RWLock.RWLock' so that it can be used.
-- 
-- This function is useful to initialize a lock that has been
-- allocated on the stack, or as part of a larger structure.  It is not
-- necessary to initialise a reader-writer lock that has been statically
-- allocated.
-- 
-- 
-- === /C code/
-- >
-- >  typedef struct {
-- >    GRWLock l;
-- >    ...
-- >  } Blob;
-- >
-- >Blob *b;
-- >
-- >b = g_new (Blob, 1);
-- >g_rw_lock_init (&b->l);
-- 
-- 
-- To undo the effect of 'GI.GLib.Structs.RWLock.rWLockInit' when a lock is no longer
-- needed, use 'GI.GLib.Structs.RWLock.rWLockClear'.
-- 
-- Calling 'GI.GLib.Structs.RWLock.rWLockInit' on an already initialized t'GI.GLib.Structs.RWLock.RWLock' leads
-- to undefined behaviour.
-- 
-- /Since: 2.32/
rWLockInit ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: an uninitialized t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockInit rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_init rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockInitMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockInitMethodInfo RWLock signature where
    overloadedMethod = rWLockInit

#endif

-- method RWLock::reader_lock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_reader_lock" g_rw_lock_reader_lock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Obtain a read lock on /@rwLock@/. If another thread currently holds
-- the write lock on /@rwLock@/, the current thread will block. If another thread
-- does not hold the write lock, but is waiting for it, it is implementation
-- defined whether the reader or writer will block. Read locks can be taken
-- recursively.
-- 
-- It is implementation-defined how many threads are allowed to
-- hold read locks on the same lock simultaneously. If the limit is hit,
-- or if a deadlock is detected, a critical warning will be emitted.
-- 
-- /Since: 2.32/
rWLockReaderLock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockReaderLock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_reader_lock rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockReaderLockMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockReaderLockMethodInfo RWLock signature where
    overloadedMethod = rWLockReaderLock

#endif

-- method RWLock::reader_trylock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Just (TBasicType TBoolean)
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_reader_trylock" g_rw_lock_reader_trylock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO CInt

-- | Tries to obtain a read lock on /@rwLock@/ and returns 'P.True' if
-- the read lock was successfully obtained. Otherwise it
-- returns 'P.False'.
-- 
-- /Since: 2.32/
rWLockReaderTrylock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m Bool
    -- ^ __Returns:__ 'P.True' if /@rwLock@/ could be locked
rWLockReaderTrylock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    result <- g_rw_lock_reader_trylock rwLock'
    let result' = (/= 0) result
    touchManagedPtr rwLock
    return result'

#if defined(ENABLE_OVERLOADING)
data RWLockReaderTrylockMethodInfo
instance (signature ~ (m Bool), MonadIO m) => O.MethodInfo RWLockReaderTrylockMethodInfo RWLock signature where
    overloadedMethod = rWLockReaderTrylock

#endif

-- method RWLock::reader_unlock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_reader_unlock" g_rw_lock_reader_unlock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Release a read lock on /@rwLock@/.
-- 
-- Calling 'GI.GLib.Structs.RWLock.rWLockReaderUnlock' on a lock that is not held
-- by the current thread leads to undefined behaviour.
-- 
-- /Since: 2.32/
rWLockReaderUnlock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockReaderUnlock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_reader_unlock rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockReaderUnlockMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockReaderUnlockMethodInfo RWLock signature where
    overloadedMethod = rWLockReaderUnlock

#endif

-- method RWLock::writer_lock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_writer_lock" g_rw_lock_writer_lock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Obtain a write lock on /@rwLock@/. If any thread already holds
-- a read or write lock on /@rwLock@/, the current thread will block
-- until all other threads have dropped their locks on /@rwLock@/.
-- 
-- /Since: 2.32/
rWLockWriterLock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockWriterLock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_writer_lock rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockWriterLockMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockWriterLockMethodInfo RWLock signature where
    overloadedMethod = rWLockWriterLock

#endif

-- method RWLock::writer_trylock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Just (TBasicType TBoolean)
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_writer_trylock" g_rw_lock_writer_trylock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO CInt

-- | Tries to obtain a write lock on /@rwLock@/. If any other thread holds
-- a read or write lock on /@rwLock@/, it immediately returns 'P.False'.
-- Otherwise it locks /@rwLock@/ and returns 'P.True'.
-- 
-- /Since: 2.32/
rWLockWriterTrylock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m Bool
    -- ^ __Returns:__ 'P.True' if /@rwLock@/ could be locked
rWLockWriterTrylock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    result <- g_rw_lock_writer_trylock rwLock'
    let result' = (/= 0) result
    touchManagedPtr rwLock
    return result'

#if defined(ENABLE_OVERLOADING)
data RWLockWriterTrylockMethodInfo
instance (signature ~ (m Bool), MonadIO m) => O.MethodInfo RWLockWriterTrylockMethodInfo RWLock signature where
    overloadedMethod = rWLockWriterTrylock

#endif

-- method RWLock::writer_unlock
-- method type : OrdinaryMethod
-- Args: [ Arg
--           { argCName = "rw_lock"
--           , argType =
--               TInterface Name { namespace = "GLib" , name = "RWLock" }
--           , direction = DirectionIn
--           , mayBeNull = False
--           , argDoc =
--               Documentation
--                 { rawDocText = Just "a #GRWLock" , sinceVersion = Nothing }
--           , argScope = ScopeTypeInvalid
--           , argClosure = -1
--           , argDestroy = -1
--           , argCallerAllocates = False
--           , transfer = TransferNothing
--           }
--       ]
-- Lengths: []
-- returnType: Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_rw_lock_writer_unlock" g_rw_lock_writer_unlock ::
    Ptr RWLock ->                           -- rw_lock : TInterface (Name {namespace = "GLib", name = "RWLock"})
    IO ()

-- | Release a write lock on /@rwLock@/.
-- 
-- Calling 'GI.GLib.Structs.RWLock.rWLockWriterUnlock' on a lock that is not held
-- by the current thread leads to undefined behaviour.
-- 
-- /Since: 2.32/
rWLockWriterUnlock ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    RWLock
    -- ^ /@rwLock@/: a t'GI.GLib.Structs.RWLock.RWLock'
    -> m ()
rWLockWriterUnlock rwLock = liftIO $ do
    rwLock' <- unsafeManagedPtrGetPtr rwLock
    g_rw_lock_writer_unlock rwLock'
    touchManagedPtr rwLock
    return ()

#if defined(ENABLE_OVERLOADING)
data RWLockWriterUnlockMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo RWLockWriterUnlockMethodInfo RWLock signature where
    overloadedMethod = rWLockWriterUnlock

#endif

#if defined(ENABLE_OVERLOADING)
type family ResolveRWLockMethod (t :: Symbol) (o :: *) :: * where
    ResolveRWLockMethod "clear" o = RWLockClearMethodInfo
    ResolveRWLockMethod "init" o = RWLockInitMethodInfo
    ResolveRWLockMethod "readerLock" o = RWLockReaderLockMethodInfo
    ResolveRWLockMethod "readerTrylock" o = RWLockReaderTrylockMethodInfo
    ResolveRWLockMethod "readerUnlock" o = RWLockReaderUnlockMethodInfo
    ResolveRWLockMethod "writerLock" o = RWLockWriterLockMethodInfo
    ResolveRWLockMethod "writerTrylock" o = RWLockWriterTrylockMethodInfo
    ResolveRWLockMethod "writerUnlock" o = RWLockWriterUnlockMethodInfo
    ResolveRWLockMethod l o = O.MethodResolutionFailed l o

instance (info ~ ResolveRWLockMethod t RWLock, O.MethodInfo info RWLock p) => OL.IsLabel t (RWLock -> p) where
#if MIN_VERSION_base(4,10,0)
    fromLabel = O.overloadedMethod @info
#else
    fromLabel _ = O.overloadedMethod @info
#endif

#endif