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Diffstat (limited to 'src/ssx/ssx/ssx_timer_init.c')
| -rwxr-xr-x | src/ssx/ssx/ssx_timer_init.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/src/ssx/ssx/ssx_timer_init.c b/src/ssx/ssx/ssx_timer_init.c new file mode 100755 index 0000000..6c35ea6 --- /dev/null +++ b/src/ssx/ssx/ssx_timer_init.c @@ -0,0 +1,124 @@ +// $Id: ssx_timer_init.c,v 1.2 2014/02/03 01:30:44 daviddu Exp $ +// $Source: /afs/awd/projects/eclipz/KnowledgeBase/.cvsroot/eclipz/chips/p8/working/procedures/ssx/ssx/ssx_timer_init.c,v $ +//----------------------------------------------------------------------------- +// *! (C) Copyright International Business Machines Corp. 2013 +// *! All Rights Reserved -- Property of IBM +// *! *** IBM Confidential *** +//----------------------------------------------------------------------------- + +/// \file ssx_timer_init.c +/// \brief SSX timer initialization +/// +/// The entry points in this file might only be used during initialization of +/// the application. In this case the code space for these routines could be +/// recovered and reused after initialization. + +#include "ssx.h" + +// Implementation of timer creation + +static int +_ssx_timer_create(SsxTimer *timer, + SsxTimerCallback callback, + void *arg, + int options) +{ + if (SSX_ERROR_CHECK_API) { + SSX_ERROR_IF((timer == 0), SSX_INVALID_TIMER_AT_CREATE); + } + + ssx_deque_element_create((SsxDeque*)timer); + timer->timeout = 0; + timer->period = 0; + timer->callback = callback; + timer->arg = arg; + timer->options = options; + + return SSX_OK; +} + + +/// Create (initialize) a preemptible timer. +/// +/// \param timer The SsxTimer to initialize. +/// +/// \param callback The timer callback +/// +/// \param arg Private data provided to the callback. +/// +/// Once created with ssx_timer_create() a timer can be scheduled with +/// ssx_timer_schedule() or ssx_timer_schedule_absolute(), which queues the +/// timer in the kernel time queue. Timers can be cancelled by a call of +/// ssx_timer_cancel(). +/// +/// Timers created with ssx_timer_create() are always run as noncritical +/// interrupt handlers with interrupt preemption enabled. Timer callbacks are +/// free to enter critical sections of any priorioty if required, but must +/// always exit with noncritical interrupts enabled. +/// +/// Caution: SSX has no way to know if an SsxTimer structure provided to +/// ssx_timer_create() is safe to use as a timer, and will silently modify +/// whatever memory is provided. +/// +/// Return values other then SSX_OK (0) are errors; see \ref ssx_errors +/// +/// \retval 0 Successful completion +/// +/// \retval -SSX_INVALID_TIMER_AT_CREATE The \a timer is a null (0) pointer. + +int +ssx_timer_create(SsxTimer *timer, + SsxTimerCallback callback, + void *arg) +{ + return _ssx_timer_create(timer, callback, arg, + SSX_TIMER_CALLBACK_PREEMPTIBLE); +} + + +/// Create (initialize) a nonpreemptible timer. +/// +/// \param timer The SsxTimer to initialize. +/// +/// \param callback The timer callback +/// +/// \param arg Private data provided to the callback. +/// +/// Once created with ssx_timer_create_preemptible() a timer can be scheduled +/// with ssx_timer_schedule() or ssx_timer_schedule_absolute(), which queues +/// the timer in the kernel time queue. Timers can be cancelled by a call of +/// ssx_timer_cancel(). +/// +/// Timers created with ssx_timer_create_nonpreemptible() are always run as +/// noncritical interrupt handlers with interrupt preemption disabled. Timer +/// callbacks are free to later enable preemption if desired, but must always +/// exit with noncritical interrupts disabled. +/// +/// \note The use of ssx_timer_create_nonpreemptible() should be rare, and the +/// timer callbacks should be short and sweet to avoid long interrupt +/// latencies for other interrupts. This API was initially introduced for use +/// by the SSX kernel itself when scheduling thread-timer callbacks to avoid +/// potential race conditions with other interrupts that may modify thread +/// state or the state of the time queue. Applications may also require this +/// facility to guarantee a consistent state in the event that other +/// interrupts may cancel the timer. +/// +/// Caution: SSX has no way to know if an SsxTimer structure provided to +/// ssx_timer_create() is safe to use as a timer, and will silently modify +/// whatever memory is provided. +/// +/// Return values other then SSX_OK (0) are errors; see \ref ssx_errors +/// +/// \retval 0 Successful completion +/// +/// \retval -SSX_INVALID_TIMER_AT_CREATE The \a timer is a null (0) pointer. + +int +ssx_timer_create_nonpreemptible(SsxTimer *timer, + SsxTimerCallback callback, + void *arg) +{ + return _ssx_timer_create(timer, callback, arg, 0); +} + + |
