Novell Doc: NDK: Libraries for C (LibC), Volume 2

43.9 Interface Comparison Tables

The synchronization functions manipulate mutexes, reader-writer locks, semaphores, and condition variables. The following sections group the functions by these tasks, briefly describe them, and list the NKS, pthread, and UI equivalent functions.

43.9.1 Mutex Interface Comparison

The following functions manage mutexes:

NKS Function	NKS Description	Pthread Equivalent	UI Equivalent
NXLock	Locks the specified mutex	pthread_mutex_lock	mutex_lock
NX_LOCK_INFO_ALLOC	Declares and initializes a variable of type NXLockInfo_t
NXMutexAlloc	Allocates and initializes a mutex
NXMutexDeinit	Deinitializes the specified mutex	pthread_mutex_destroy	mutex_destroy
NXMutexFree	Deallocates the specified mutex
NXMutexInit	Initializes a mutex	pthread_mutex_init	mutex_init
NXMutexIsOwned	Checks to see if the thread owns the specified mutex
NXTryLock	Makes a single attempt to acquire the specified mutex	pthread_mutex_trylock	mutex_trylock
NXUnlock	Unlocks the specified mutex	pthread_mutex_unlock	mutex_unlock

When NDEBUG is not defined, the following functions help you debug recursive mutexes. These are only available for NKS mutexes:

NKS Function	NKS Description
NXMutexDepth	Determines the depth of a recursive mutex.
NXMutexTestFlag	Determines whether the mutex is a recursive mutex.

43.9.2 Reader-Writer Lock Interface Comparison

The following functions manage reader-writer locks.

NKS Function	NKS Description	PThread Equivalent	UI Equivalent
NXRdLock	Locks the specified reader-writer lock in the read mode	pthread_rwlock_rdlock	rw_rdlock
NXRwLockAlloc	Allocates and initializes a reader-writer lock
NXRwLockDeinit	Deinitializes the specified reader-writer lock	pthread_rwlock_destroy	rwlock_destroy
NXRwLockFree	Frees the specified reader-writer lock
NXRwLockInit	Initializes a reader-writer lock	pthread_rwlock_init	rwlock_init
NXRwLockIsOwned	Checks to see if the thread owns the specified reader-writer lock
NXTryRdLock	Makes a single attempt to acquire the specified reader-writer lock in the read mode	pthread_rwlock_tryrdlock	rw_tryrdlock
NXTryWrLock	Makes a single attempt to acquire the specified reader-writer lock in the write mode	pthread_rwlock_trywrlock	rw_trywrlock
NXWrLock	Locks the specified reader-writer lock in the write mode	pthread_rwlock_wrlock	rw_wrlock
NXRwUnlock	Unlocks the specified reader-writer lock	pthread_rwlock_unlock	rw_unlock
NXRwLockUpgrade	Converts the specified reader-writer lock from read mode to write mode.

43.9.3 Semaphore Interface Comparison

The following functions manage semaphores:

NKS Function	NKS Description	POSIX Equivalent	UI Equivalent
NXSemaAlloc	Allocates and initializes a semaphore
NXSemaDeinit	Deinitializes the specified semaphore	sem_destroy	sema_destroy
NXSemaFree	Frees the specified semaphore
NXSemaInit	Initializes a semaphore	sem_init	sema_init
NXSemaPost	Releases the resource protected by the specified semaphore	sem_post	sema_post
NXSemaTryWait	Makes a single attempt to acquire the resource protected by a semaphore	sem_trywait	sema_trywait
NXSemaWait	Acquires the resource protected by a semaphore	sem_wait	sema_wait

For System-V semaphores, which create shareable semaphores, see System-V Semaphore Functions

43.9.4 Condition Variable Interface Comparison

The following functions manage condition variables:

NKS Function	NKS Description	Pthread Equivalent	UI Equivalent
NXCondAlloc	Allocates and initializes a condition variable
NXCondBroadcast	Wakes up all the threads blocked on the condition variable	pthread_cond_broadcast	cond_broadcast
NXCondDeinit	Deinitializes the condition variable	pthread_cond_destroy	cond_destroy
NXCondFree	Deallocates the condition variable
NXCondInit	Initializes a specified condition variable	pthread_cond_init	cond_init
NXCondSignal	Signals on the condition variable	pthread_cond_signal	cond_signal
NXCondTimedWait	Waits on the condition variable for a limited time	pthread_cond_timedwait	cond_timedwait
NXCondWait	Waits on the condition variable	pthread_cond_wait	cond_wait