#include <stdint.h>
#include <stdbool.h>
-/* These are the preferred versions of the atomic and synchronization operations.
+#include <Availability.h>
+
+/*! @header
+ * These are the preferred versions of the atomic and synchronization operations.
* Their implementation is customized at boot time for the platform, including
* late-breaking errata fixes as necessary. They are thread safe.
*
- * WARNING: all addresses passed to these functions must be "naturally aligned", ie
- * int32_t's must be 32-bit aligned (low 2 bits of address zero), and int64_t's
- * must be 64-bit aligned (low 3 bits of address zero.)
+ * WARNING: all addresses passed to these functions must be "naturally aligned",
+ * i.e. * <code>int32_t</code> pointers must be 32-bit aligned (low 2 bits of
+ * address are zeroes), and <code>int64_t</code> pointers must be 64-bit aligned
+ * (low 3 bits of address are zeroes.)
+ *
+ * Note that some versions of the atomic functions incorporate memory barriers
+ * and some do not. Barriers strictly order memory access on weakly-ordered
+ * architectures such as PPC. All loads and stores that appear (in sequential
+ * program order) before the barrier are guaranteed to complete before any
+ * load or store that appears after the barrier.
*
- * Note that some versions of the atomic functions incorporate memory barriers,
- * and some do not. Barriers strictly order memory access on a weakly-ordered
- * architecture such as PPC. All loads and stores executed in sequential program
- * order before the barrier will complete before any load or store executed after
- * the barrier. On a uniprocessor, the barrier operation is typically a nop.
- * On a multiprocessor, the barrier can be quite expensive on some platforms,
- * eg PPC.
+ * On a uniprocessor system, the barrier operation is typically a no-op. On a
+ * multiprocessor system, the barrier can be quite expensive on some platforms,
+ * such as PPC.
*
- * Most code will want to use the barrier functions to insure that memory shared
- * between threads is properly synchronized. For example, if you want to initialize
+ * Most code should use the barrier functions to ensure that memory shared between
+ * threads is properly synchronized. For example, if you want to initialize
* a shared data structure and then atomically increment a variable to indicate
- * that the initialization is complete, then you must use OSAtomicIncrement32Barrier()
- * to ensure that the stores to your data structure complete before the atomic add.
- * Likewise, the consumer of that data structure must use OSAtomicDecrement32Barrier(),
+ * that the initialization is complete, you must use {@link OSAtomicIncrement32Barrier}
+ * to ensure that the stores to your data structure complete before the atomic
+ * increment.
+ *
+ * Likewise, the consumer of that data structure must use {@link OSAtomicDecrement32Barrier},
* in order to ensure that their loads of the structure are not executed before
* the atomic decrement. On the other hand, if you are simply incrementing a global
- * counter, then it is safe and potentially faster to use OSAtomicIncrement32().
+ * counter, then it is safe and potentially faster to use {@link OSAtomicIncrement32}.
*
* If you are unsure which version to use, prefer the barrier variants as they are
* safer.
*
* The spinlock and queue operations always incorporate a barrier.
+ *
+ * For the kernel-space version of this header, see
+ * {@link //apple_ref/doc/header/OSAtomic.h OSAtomic.h (Kernel Framework)}
+ *
+ * @apiuid //apple_ref/doc/header/user_space_OSAtomic.h
*/
__BEGIN_DECLS
-/* Arithmetic functions. They return the new value.
+/*! @group Arithmetic functions
+ All functions in this group return the new value.
+ */
+
+/*! @abstract Atomically adds two 32-bit values.
+ @discussion
+ This function adds the value given by <code>__theAmount</code> to the
+ value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the new value.
*/
int32_t OSAtomicAdd32( int32_t __theAmount, volatile int32_t *__theValue );
+
+
+/*! @abstract Atomically adds two 32-bit values.
+ @discussion
+ This function adds the value given by <code>__theAmount</code> to the
+ value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicAdd32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
int32_t OSAtomicAdd32Barrier( int32_t __theAmount, volatile int32_t *__theValue );
-inline static
+
+/*! @abstract Atomically increments a 32-bit value.
+ */
+__inline static
int32_t OSAtomicIncrement32( volatile int32_t *__theValue )
{ return OSAtomicAdd32( 1, __theValue); }
-inline static
+
+
+/*! @abstract Atomically increments a 32-bit value with a barrier.
+ @discussion
+ This function is equivalent to {@link OSAtomicIncrement32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+__inline static
int32_t OSAtomicIncrement32Barrier( volatile int32_t *__theValue )
{ return OSAtomicAdd32Barrier( 1, __theValue); }
-inline static
+/*! @abstract Atomically decrements a 32-bit value. */
+__inline static
int32_t OSAtomicDecrement32( volatile int32_t *__theValue )
{ return OSAtomicAdd32( -1, __theValue); }
-inline static
+
+/*! @abstract Atomically increments a 32-bit value with a barrier.
+ @discussion
+ This function is equivalent to {@link OSAtomicDecrement32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+__inline static
int32_t OSAtomicDecrement32Barrier( volatile int32_t *__theValue )
{ return OSAtomicAdd32Barrier( -1, __theValue); }
-#if defined(__ppc64__) || defined(__i386__) || defined(__x86_64__)
+#if defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) || defined(__arm__)
+
+/*! @abstract Atomically adds two 64-bit values.
+ @discussion
+ This function adds the value given by <code>__theAmount</code> to the
+ value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ */
int64_t OSAtomicAdd64( int64_t __theAmount, volatile int64_t *__theValue );
-int64_t OSAtomicAdd64Barrier( int64_t __theAmount, volatile int64_t *__theValue );
-inline static
+
+/*! @abstract Atomically adds two 64-bit values with a barrier.
+ @discussion
+ This function adds the value given by <code>__theAmount</code> to the
+ value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicAdd64}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+int64_t OSAtomicAdd64Barrier( int64_t __theAmount, volatile int64_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_3_2);
+
+
+/*! @abstract Atomically increments a 64-bit value. */
+__inline static
int64_t OSAtomicIncrement64( volatile int64_t *__theValue )
{ return OSAtomicAdd64( 1, __theValue); }
-inline static
+
+/*! @abstract Atomically increments a 64-bit value with a barrier.
+ @discussion
+ This function is equivalent to {@link OSAtomicIncrement64}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+__inline static
int64_t OSAtomicIncrement64Barrier( volatile int64_t *__theValue )
{ return OSAtomicAdd64Barrier( 1, __theValue); }
-inline static
+
+/*! @abstract Atomically decrements a 64-bit value.
+ @discussion
+ This function is equivalent to {@link OSAtomicIncrement64}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+__inline static
int64_t OSAtomicDecrement64( volatile int64_t *__theValue )
{ return OSAtomicAdd64( -1, __theValue); }
-inline static
+
+
+/*! @abstract Atomically decrements a 64-bit value with a barrier.
+ @discussion
+ This function is equivalent to {@link OSAtomicDecrement64}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
+__inline static
int64_t OSAtomicDecrement64Barrier( volatile int64_t *__theValue )
{ return OSAtomicAdd64Barrier( -1, __theValue); }
-#endif /* defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) */
+#endif /* defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) || defined(__arm__) */
-/* Boolean functions (and, or, xor.) These come in four versions for each operation:
- * with and without barriers, and returning the old or new value of the operation.
- * The "Orig" versions return the original value, ie before the operation, the non-Orig
+
+/*! @group Boolean functions (AND, OR, XOR)
+ *
+ * @discussion Functions in this group come in four variants for each operation:
+ * with and without barriers, and functions that return the original value or
+ * the result value of the operation.
+ *
+ * The "Orig" versions return the original value, (before the operation); the non-Orig
* versions return the value after the operation. All are layered on top of
- * compare-and-swap.
+ * {@link OSAtomicCompareAndSwap32} and similar.
+ */
+
+/*! @abstract Atomic bitwise OR of two 32-bit values.
+ @discussion
+ This function performs the bitwise OR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the new value.
*/
int32_t OSAtomicOr32( uint32_t __theMask, volatile uint32_t *__theValue );
+
+
+/*! @abstract Atomic bitwise OR of two 32-bit values with barrier.
+ @discussion
+ This function performs the bitwise OR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicOr32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
int32_t OSAtomicOr32Barrier( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicOr32Orig( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicOr32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue );
+
+/*! @abstract Atomic bitwise OR of two 32-bit values returning original.
+ @discussion
+ This function performs the bitwise OR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicOr32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
+
+
+/*! @abstract Atomic bitwise OR of two 32-bit values returning original with barrier.
+ @discussion
+ This function performs the bitwise OR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicOr32Orig}
+ except that it also introduces a barrier.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicOr32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
+
+
+
+
+/*! @abstract Atomic bitwise AND of two 32-bit values.
+ @discussion
+ This function performs the bitwise AND of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the new value.
+ */
int32_t OSAtomicAnd32( uint32_t __theMask, volatile uint32_t *__theValue );
+
+
+/*! @abstract Atomic bitwise AND of two 32-bit values with barrier.
+ @discussion
+ This function performs the bitwise AND of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicAnd32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
int32_t OSAtomicAnd32Barrier( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicAnd32Orig( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicAnd32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue );
+
+/*! @abstract Atomic bitwise AND of two 32-bit values returning original.
+ @discussion
+ This function performs the bitwise AND of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicAnd32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
+
+
+/*! @abstract Atomic bitwise AND of two 32-bit values returning original with barrier.
+ @discussion
+ This function performs the bitwise AND of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicAnd32Orig}
+ except that it also introduces a barrier.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicAnd32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
+
+
+
+
+/*! @abstract Atomic bitwise XOR of two 32-bit values.
+ @discussion
+ This function performs the bitwise XOR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the new value.
+ */
int32_t OSAtomicXor32( uint32_t __theMask, volatile uint32_t *__theValue );
+
+
+/*! @abstract Atomic bitwise XOR of two 32-bit values with barrier.
+ @discussion
+ This function performs the bitwise XOR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicXor32}
+ except that it also introduces a barrier.
+ @result Returns the new value.
+ */
int32_t OSAtomicXor32Barrier( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicXor32Orig( uint32_t __theMask, volatile uint32_t *__theValue );
-int32_t OSAtomicXor32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue );
+
+
+/*! @abstract Atomic bitwise XOR of two 32-bit values returning original.
+ @discussion
+ This function performs the bitwise XOR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicXor32Orig( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
+
+
+/*! @abstract Atomic bitwise XOR of two 32-bit values returning original with barrier.
+ @discussion
+ This function performs the bitwise XOR of the value given by <code>__theMask</code>
+ with the value in the memory location referenced by <code>__theValue</code>,
+ storing the result back to that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicXor32Orig}
+ except that it also introduces a barrier.
+ @result Returns the original value referenced by <code>__theValue</code>.
+ */
+int32_t OSAtomicXor32OrigBarrier( uint32_t __theMask, volatile uint32_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_3_2);
-/* Compare and swap. They return true if the swap occured. There are several versions,
- * depending on data type and whether or not a barrier is used.
+/*! @group Compare and swap
+ * Functions in this group return true if the swap occured. There are several versions,
+ * depending on data type and on whether or not a barrier is used.
+ */
+
+
+/*! @abstract Compare and swap for 32-bit values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+ @result Returns TRUE on a match, FALSE otherwise.
*/
bool OSAtomicCompareAndSwap32( int32_t __oldValue, int32_t __newValue, volatile int32_t *__theValue );
+
+
+/*! @abstract Compare and swap for 32-bit values with barrier.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap32}
+ except that it also introduces a barrier.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
bool OSAtomicCompareAndSwap32Barrier( int32_t __oldValue, int32_t __newValue, volatile int32_t *__theValue );
-bool OSAtomicCompareAndSwapPtr( void *__oldValue, void *__newValue, void * volatile *__theValue );
-bool OSAtomicCompareAndSwapPtrBarrier( void *__oldValue, void *__newValue, void * volatile *__theValue );
-bool OSAtomicCompareAndSwapInt( int __oldValue, int __newValue, volatile int *__theValue );
-bool OSAtomicCompareAndSwapIntBarrier( int __oldValue, int __newValue, volatile int *__theValue );
-bool OSAtomicCompareAndSwapLong( long __oldValue, long __newValue, volatile long *__theValue );
-bool OSAtomicCompareAndSwapLongBarrier( long __oldValue, long __newValue, volatile long *__theValue );
-#if defined(__ppc64__) || defined(__i386__) || defined(__x86_64__)
+/*! @abstract Compare and swap pointers.
+ @discussion
+ This function compares the pointer stored in <code>__oldValue</code> to the pointer
+ in the memory location referenced by <code>__theValue</code>. If the pointers
+ match, this function stores the pointer from <code>__newValue</code> into
+ that memory location atomically.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapPtr( void *__oldValue, void *__newValue, void * volatile *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+/*! @abstract Compare and swap pointers with barrier.
+ @discussion
+ This function compares the pointer stored in <code>__oldValue</code> to the pointer
+ in the memory location referenced by <code>__theValue</code>. If the pointers
+ match, this function stores the pointer from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwapPtr}
+ except that it also introduces a barrier.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapPtrBarrier( void *__oldValue, void *__newValue, void * volatile *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+/*! @abstract Compare and swap for <code>int</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap32}.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapInt( int __oldValue, int __newValue, volatile int *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+/*! @abstract Compare and swap for <code>int</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwapInt}
+ except that it also introduces a barrier.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap32Barrier}.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapIntBarrier( int __oldValue, int __newValue, volatile int *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+/*! @abstract Compare and swap for <code>long</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap32} on 32-bit architectures,
+ or {@link OSAtomicCompareAndSwap64} on 64-bit architectures.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapLong( long __oldValue, long __newValue, volatile long *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+/*! @abstract Compare and swap for <code>long</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwapLong}
+ except that it also introduces a barrier.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap32} on 32-bit architectures,
+ or {@link OSAtomicCompareAndSwap64} on 64-bit architectures.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwapLongBarrier( long __oldValue, long __newValue, volatile long *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+
+
+#if defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) || defined(__arm__)
+
+/*! @abstract Compare and swap for <code>uint64_t</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
bool OSAtomicCompareAndSwap64( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue );
-bool OSAtomicCompareAndSwap64Barrier( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue );
-#endif /* defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) */
+
+/*! @abstract Compare and swap for <code>uint64_t</code> values.
+ @discussion
+ This function compares the value in <code>__oldValue</code> to the value
+ in the memory location referenced by <code>__theValue</code>. If the values
+ match, this function stores the value from <code>__newValue</code> into
+ that memory location atomically.
+
+ This function is equivalent to {@link OSAtomicCompareAndSwap64}
+ except that it also introduces a barrier.
+ @result Returns TRUE on a match, FALSE otherwise.
+ */
+bool OSAtomicCompareAndSwap64Barrier( int64_t __oldValue, int64_t __newValue, volatile int64_t *__theValue ) __OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_3_2);
+
+#endif /* defined(__ppc64__) || defined(__i386__) || defined(__x86_64__) || defined(__arm__) */
/* Test and set. They return the original value of the bit, and operate on bit (0x80>>(n&7))
* in byte ((char*)theAddress + (n>>3)).
*/
+/*! @abstract Atomic test and set
+ @discussion
+ This function tests a bit in the value referenced by <code>__theAddress</code>
+ and if it is not set, sets it. The bit is chosen by the value of <code>__n</code>.
+ The bits are numbered in order beginning with bit 1 as the lowest order bit.
+
+ For example, if <code>__theAddress</code> points to a 64-bit value,
+ to compare the value of the highest bit, you would specify <code>64</code> for
+ <code>__n</code>.
+ @result
+ Returns the original value of the bit being tested.
+ */
bool OSAtomicTestAndSet( uint32_t __n, volatile void *__theAddress );
+
+
+/*! @abstract Atomic test and set with barrier
+ @discussion
+ This function tests a bit in the value referenced by <code>__theAddress</code>
+ and if it is not set, sets it. The bit is chosen by the value of <code>__n</code>.
+ The bits are numbered in order beginning with bit 1 as the lowest order bit.
+
+ For example, if <code>__theAddress</code> points to a 64-bit value,
+ to compare the value of the highest bit, you would specify <code>64</code> for
+ <code>__n</code>.
+
+ This function is equivalent to {@link OSAtomicTestAndSet}
+ except that it also introduces a barrier.
+ @result
+ Returns the original value of the bit being tested.
+ */
+
bool OSAtomicTestAndSetBarrier( uint32_t __n, volatile void *__theAddress );
+
+
+
+/*! @abstract Atomic test and clear
+ @discussion
+ This function tests a bit in the value referenced by <code>__theAddress</code>
+ and if it is not cleared, clears it. The bit is chosen by the value of <code>__n</code>.
+ The bits are numbered in order beginning with bit 1 as the lowest order bit.
+
+ For example, if <code>__theAddress</code> points to a 64-bit value,
+ to compare the value of the highest bit, you would specify <code>64</code> for
+ <code>__n</code>.
+ @result
+ Returns the original value of the bit being tested.
+ */
bool OSAtomicTestAndClear( uint32_t __n, volatile void *__theAddress );
+
+
+/*! @abstract Atomic test and clear
+ @discussion
+ This function tests a bit in the value referenced by <code>__theAddress</code>
+ and if it is not cleared, clears it. The bit is chosen by the value of <code>__n</code>.
+ The bits are numbered in order beginning with bit 1 as the lowest order bit.
+
+ For example, if <code>__theAddress</code> points to a 64-bit value,
+ to compare the value of the highest bit, you would specify <code>64</code> for
+ <code>__n</code>.
+
+ This function is equivalent to {@link OSAtomicTestAndSet}
+ except that it also introduces a barrier.
+ @result
+ Returns the original value of the bit being tested.
+ */
bool OSAtomicTestAndClearBarrier( uint32_t __n, volatile void *__theAddress );
-/* Spinlocks. These use memory barriers as required to synchronize access to shared
- * memory protected by the lock. The lock operation spins, but employs various strategies
- * to back off if the lock is held, making it immune to most priority-inversion livelocks.
- * The try operation immediately returns false if the lock was held, true if it took the
- * lock. The convention is that unlocked is zero, locked is nonzero.
+/*! @group Spinlocks
+ * These spinlocks use memory barriers as required to synchronize access to shared
+ * memory protected by the lock.
+ */
+
+/*! @abstract The default value for an <code>OSSpinLock</code>.
+ @discussion
+ The convention is that unlocked is zero, locked is nonzero.
*/
#define OS_SPINLOCK_INIT 0
+
+/*! @abstract Data type for a spinlock.
+ @discussion
+ You should always initialize a spinlock to {@link OS_SPINLOCK_INIT} before
+ using it.
+ */
typedef int32_t OSSpinLock;
+
+/*! @abstract Locks a spinlock if it would not block
+ @result
+ Returns <code>false</code> if the lock was already held by another thread,
+ <code>true</code> if it took the lock successfully.
+ */
bool OSSpinLockTry( volatile OSSpinLock *__lock );
+
+
+/*! @abstract Locks a spinlock
+ @discussion
+ Although the lock operation spins, it employs various strategies
+ to back off if the lock is held, making it immune to most priority-inversion
+ livelocks.
+ */
void OSSpinLockLock( volatile OSSpinLock *__lock );
+
+
+/*! @abstract Unlocks a spinlock */
void OSSpinLockUnlock( volatile OSSpinLock *__lock );
-/* Lockless atomic enqueue and dequeue. These routines manipulate singly
- * linked LIFO lists. Ie, a dequeue will return the most recently enqueued
- * element, or NULL if the list is empty. The "offset" parameter is the offset
- * in bytes of the link field within the data structure being queued. The
- * link field should be a pointer type. Memory barriers are incorporated as
- * needed to permit thread-safe access to the queue element.
+/*! @group Lockless atomic enqueue and dequeue
+ * These routines manipulate singly-linked LIFO lists.
+ */
+
+/*! @abstract The data structure for a queue head.
+ @discussion
+ You should always initialize a queue head structure with the
+ initialization vector {@link OS_ATOMIC_QUEUE_INIT} before use.
*/
#if defined(__x86_64__)
typedef volatile struct {
void *opaque1;
long opaque2;
-} OSQueueHead __attribute__ ((aligned (16)));
+} __attribute__ ((aligned (16))) OSQueueHead;
#else
#endif
+/*! @abstract The initialization vector for a queue head. */
#define OS_ATOMIC_QUEUE_INIT { NULL, 0 }
-void OSAtomicEnqueue( OSQueueHead *__list, void *__new, size_t __offset);
-void* OSAtomicDequeue( OSQueueHead *__list, size_t __offset);
+/*! @abstract Enqueue an item onto a list.
+ @discussion
+ Memory barriers are incorporated as needed to permit thread-safe access
+ to the queue element.
+ @param __list
+ The list on which you want to enqueue the item.
+ @param __new
+ The item to add.
+ @param __offset
+ The "offset" parameter is the offset (in bytes) of the link field
+ from the beginning of the data structure being queued (<code>__new</code>).
+ The link field should be a pointer type.
+ The <code>__offset</code> value needs to be same for all enqueuing and
+ dequeuing operations on the same queue, even if different structure types
+ are enqueued on that queue. The use of <code>offsetset()</code>, defined in
+ <code>stddef.h</code> is the common way to specify the <code>__offset</code>
+ value.
+ */
+void OSAtomicEnqueue( OSQueueHead *__list, void *__new, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_4_0);
+
+
+/*! @abstract Dequeue an item from a list.
+ @discussion
+ Memory barriers are incorporated as needed to permit thread-safe access
+ to the queue element.
+ @param __list
+ The list on which you want to enqueue the item.
+ @param __offset
+ The "offset" parameter is the offset (in bytes) of the link field
+ from the beginning of the data structure being queued (<code>__new</code>).
+ The link field should be a pointer type.
+ The <code>__offset</code> value needs to be same for all enqueuing and
+ dequeuing operations on the same queue, even if different structure types
+ are enqueued on that queue. The use of <code>offsetset()</code>, defined in
+ <code>stddef.h</code> is the common way to specify the <code>__offset</code>
+ value.
+ @result
+ Returns the most recently enqueued element, or <code>NULL</code> if the
+ list is empty.
+ */
+void* OSAtomicDequeue( OSQueueHead *__list, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_4_0);
+#if defined(__x86_64__) || defined(__i386__)
-/* Memory barrier. It is both a read and write barrier.
+/*! @group Lockless atomic fifo enqueue and dequeue
+ * These routines manipulate singly-linked FIFO lists.
*/
-void OSMemoryBarrier( void );
+/*! @abstract The data structure for a fifo queue head.
+ @discussion
+ You should always initialize a fifo queue head structure with the
+ initialization vector {@link OS_ATOMIC_FIFO_QUEUE_INIT} before use.
+ */
+#if defined(__x86_64__)
+
+typedef volatile struct {
+ void *opaque1;
+ void *opaque2;
+ int opaque3;
+} __attribute__ ((aligned (16))) OSFifoQueueHead;
+
+#else
+
+typedef volatile struct {
+ void *opaque1;
+ void *opaque2;
+ int opaque3;
+} OSFifoQueueHead;
+
+#endif
+
+/*! @abstract The initialization vector for a fifo queue head. */
+#define OS_ATOMIC_FIFO_QUEUE_INIT { NULL, NULL, 0 }
+
+/*! @abstract Enqueue an item onto a list.
+ @discussion
+ Memory barriers are incorporated as needed to permit thread-safe access
+ to the queue element.
+ @param __list
+ The list on which you want to enqueue the item.
+ @param __new
+ The item to add.
+ @param __offset
+ The "offset" parameter is the offset (in bytes) of the link field
+ from the beginning of the data structure being queued (<code>__new</code>).
+ The link field should be a pointer type.
+ The <code>__offset</code> value needs to be same for all enqueuing and
+ dequeuing operations on the same queue, even if different structure types
+ are enqueued on that queue. The use of <code>offsetset()</code>, defined in
+ <code>stddef.h</code> is the common way to specify the <code>__offset</code>
+ value.
+ */
+void OSAtomicFifoEnqueue( OSFifoQueueHead *__list, void *__new, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);
+
+/*! @abstract Dequeue an item from a list.
+ @discussion
+ Memory barriers are incorporated as needed to permit thread-safe access
+ to the queue element.
+ @param __list
+ The list on which you want to enqueue the item.
+ @param __offset
+ The "offset" parameter is the offset (in bytes) of the link field
+ from the beginning of the data structure being queued (<code>__new</code>).
+ The link field should be a pointer type.
+ The <code>__offset</code> value needs to be same for all enqueuing and
+ dequeuing operations on the same queue, even if different structure types
+ are enqueued on that queue. The use of <code>offsetset()</code>, defined in
+ <code>stddef.h</code> is the common way to specify the <code>__offset</code>
+ value.
+ @result
+ Returns the oldest enqueued element, or <code>NULL</code> if the
+ list is empty.
+ */
+void* OSAtomicFifoDequeue( OSFifoQueueHead *__list, size_t __offset) __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_NA);
+
+#endif /* __i386__ || __x86_64__ */
+
+/*! @group Memory barriers */
+
+/*! @abstract Memory barrier.
+ @discussion
+ This function serves as both a read and write barrier.
+ */
+void OSMemoryBarrier( void );
__END_DECLS
projects / apple / libc.git / blobdiff