OS Threading Level Abstraction.

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Detailed Description

See OS Threading Abstraction (and Independence) Layer.

Classes
struct	Wefts::tag_ThreadAndReturn
	Utility structure to pass around a thread object along with its return. More...
class	Wefts::OSMutexBase
	Implements an OS specific mutex This mutex class is not supposed to be reentrant, but it is supposed to have an trylock() feature at OS level. More...
class	Wefts::OSConditionBase
	This class implement an os-dependant condition. More...
class	Wefts::OSThreadBase
	Thread OS layer abstraction This class can be rewritten in other header files to implement different os specific threading system. More...
class	Wefts::OSSpecificDataBase
	Wrapper class for thread specific data access (tsd/tls). More...
class	Wefts::OSMutexPthread
class	Wefts::OSConditionPthread
	This class implement an os-dependant condition. More...
class	Wefts::OSThreadPthread
	Wraps Posix threads. More...
class	Wefts::OSSpecificDataPthread
	Wrapper class for pthread specific data access (tsd/tls). More...
Typedefs
typedef Wefts::tag_ThreadAndReturn	Wefts::ThreadAndReturn
	Utility structure to pass around a thread object along with its return.
typedef OSSpecificDataPthread	Wefts::OSSpecificData
	Function to execute the thread RUN procedure guarded by OS cleanup.
typedef OSThreadPthread	Wefts::OSThread
typedef OSConditionPthread	Wefts::OSCondition
typedef OSMutexPthread	Wefts::OSMutex
Enumerations
enum	Wefts::OSPriority {   Wefts::PrioRealTime = 0, Wefts::PrioHigh = 1, Wefts::PrioNormal = 2, Wefts::PrioLow = 3,   Wefts::PrioIdle = 4 }
	Portable priority concept. More...
Functions
std::string	Wefts::OSErrorDescription (int osCode)
	Function to report OS specific error.
bool	Wefts::OSSleep (long nSeconds, long nNanoseconds)
	Function to provide a wefts-interruptable wait.
void *	Wefts::getCurrentThreadObject ()
	Function that returns the thread object running in the current OS thread.
void	Wefts::setCurrentThreadObject (void *thread)
	Function used to set current thread object.
void	Wefts::wefts_pthread_cond_guard (void *param)
	This function is used internally by pthread module to safely guard the condition on async cancellation.
void	Wefts::wefts_pthread_cond_reset (void *param)

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Typedef Documentation

typedef OSConditionWindows Wefts::OSCondition

typedef OSMutexWindows Wefts::OSMutex

typedef OSSpecificDataWindows Wefts::OSSpecificData

Function to execute the thread RUN procedure guarded by OS cleanup.

typedef OSThreadWindows Wefts::OSThread

typedef struct Wefts::tag_ThreadAndReturn Wefts::ThreadAndReturn

Utility structure to pass around a thread object along with its return. As the only function able to know if a thread is detached, and that then can rightfully delete the thread object, is the cancellation cleanup handler, it is also the only function that is able to set the thread run return value member if the thread is NOT detached. To let the cleanup handler have this value, this structure holds a pointer to the thread and a pointer to the run return value (or zero, if the run() method had not a chance to return). OSThreadBase::osRun() is responsible to fill correctly this value and let the cleanup routine have it.

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Enumeration Type Documentation

enum Wefts::OSPriority

Portable priority concept. This is a set of priorities that can be used to modify a thread priority in the internal scheduling policy. Enumeration values: PrioRealTime  Realtime priority. Theads in this class should be rescheduled and executed as fast as the operating system is able to do, pre-empting even the Kernel, if the OS is able to cope with this. PrioHigh  High priority. Theads in this class should be rescheduled and executed as fast as the operating system is able to do, but the kernel is not pre-empted under any condition. PrioNormal  Normal priority. The thread is just scheduled in the normal thread queues, which means that it's waken as soon as possible, after that system kernel, interrupts/signal handlers and device driver/service routines have completed or are considered "idle". PrioLow  Low priority. Threads in this class are considered low priority, and awaken only if/when the normal priority threads are idle; anyhow, care is taken not to starve this thread class, so a little space should be found for them anyway, maybe with big delays. PrioIdle  Idle threads. Threads in this class are waken up only during the system Idle cycle, so that they are actually running only if no other process (including the kernel) is actively demanding CPU. Idle thread class may be starved indefinitely, if the CPU is so intensely exploited that it never enters the idle loop.

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Function Documentation

void* getCurrentThreadObject (   )

Function that returns the thread object running in the current OS thread. It may be null if current OS thread has not be started with Thread::run(); tipically calling this from the main thread will return 0. If you use only Wefts to start threads, you can safely use the return vaule of 0 as a marker for the main application thread. Returns: a pointer that can be casted into a Wefts::Thread object.

std::string OSErrorDescription (  int  osCode  )

Function to report OS specific error.

bool OSSleep (  long  nSeconds, long  nNanoseconds )

Function to provide a wefts-interruptable wait.

void setCurrentThreadObject (  void *  thread  )

Function used to set current thread object. OSTAIL providers must provide this function, that is called by threads right before calling the Thread::run() method. This is used internally for various reasons.a Parameters: thread  the object whose Thread::run() method is going to be called.

void wefts_pthread_cond_guard (  void *  param  )

This function is used internally by pthread module to safely guard the condition on async cancellation.

void wefts_pthread_cond_reset (  void *  param  )

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