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The timer management provides functions to start and stop asynchronous timers, determine the CPU speed and let a thread give up the CPU for a specified time period.
Functions | |
void | NutTimerInit (void) |
Initialize system timer. | |
void | NutMicroDelay (u_long us) |
Loop for a specified number of microseconds. | |
void | NutDelay (u_char ms) |
Loop for a specified number of milliseconds. | |
void | NutTimerInsert (NUTTIMERINFO *tn) |
Insert a new timer in the global timer list. | |
void | NutTimerProcessElapsed (void) |
Process elapsed timers. | |
NUTTIMERINFO * | NutTimerCreate (u_long ticks, void(*callback)(HANDLE, void *), void *arg, u_char flags) |
Create a new system timer. | |
HANDLE | NutTimerStartTicks (u_long ticks, void(*callback)(HANDLE, void *), void *arg, u_char flags) |
Start a system timer. | |
HANDLE | NutTimerStart (u_long ms, void(*callback)(HANDLE, void *), void *arg, u_char flags) |
Start a system timer. | |
void | NutSleep (u_long ms) |
Temporarily suspends the current thread. | |
void | NutTimerStop (HANDLE handle) |
Stop a specified timer. | |
u_long | NutGetTickCount (void) |
Return the number of system timer ticks. | |
u_long | NutGetSeconds (void) |
Return the seconds counter value. | |
u_long | NutGetMillis (void) |
Return the milliseconds counter value. | |
Variables | |
NUTTIMERINFO * | nutTimerList |
Double linked list of all system timers. | |
volatile u_long | nut_ticks |
System tick counter. | |
volatile u_long | nut_delay_loops |
Loops per microsecond. |
void NutTimerInit | ( | void | ) |
Initialize system timer.
This function is automatically called by Nut/OS during system initialization. It calls the hardware dependent layer to initialze the timer hardware and register a timer interrupt handler.
Definition at line 278 of file timer.c.
References nut_delay_loops, NutEnableTimerIrq, NutGetTickCount(), and NutRegisterTimer().
Referenced by NutIdle().
void NutMicroDelay | ( | u_long | us | ) |
Loop for a specified number of microseconds.
This call will not release the CPU and will not switch to another thread. However, interrupts are not disabled and introduce some jitter. Furthermore, unless NUT_DELAYLOOPS is not defined, the deviation may be greater than 10%.
If you need exact timing, use timer/counter hardware instead.
us | Delay time in microseconds. Values above 255 milliseconds may not work. |
Definition at line 327 of file timer.c.
References _NOP, and nut_delay_loops.
Referenced by NutDelay().
void NutDelay | ( | u_char | ms | ) |
Loop for a specified number of milliseconds.
This call will not release the CPU and will not switch to another thread. Because of absent thread switching, the delay time is more exact than with NutSleep().
ms | Delay time in milliseconds, maximum is 255. |
Definition at line 351 of file timer.c.
References NutMicroDelay().
Referenced by cs8900Init(), CSNicInit(), CSSoftwareWakeup(), SpiFlashErase(), SpiFlashWriteByte(), VsBeep(), VsMemoryTest(), VsPlayerInit(), and VsPlayerReset().
void NutTimerInsert | ( | NUTTIMERINFO * | tn | ) |
Insert a new timer in the global timer list.
Applications should not call this function.
tn | Pointer to the timer structure to insert. |
Definition at line 365 of file timer.c.
References _NUTTIMERINFO::tn_next, _NUTTIMERINFO::tn_prev, and _NUTTIMERINFO::tn_ticks_left.
Referenced by NutTimerProcessElapsed(), NutTimerStartTicks(), and NutTimerStop().
void NutTimerProcessElapsed | ( | void | ) |
Process elapsed timers.
This routine is called during context switch processing. Applications should not use this function.
Definition at line 396 of file timer.c.
References NutGetTickCount(), NutHeapFree(), NutTimerInsert(), _NUTTIMERINFO::tn_arg, _NUTTIMERINFO::tn_callback, _NUTTIMERINFO::tn_next, _NUTTIMERINFO::tn_prev, _NUTTIMERINFO::tn_ticks, and _NUTTIMERINFO::tn_ticks_left.
Referenced by NutThreadResume().
NUTTIMERINFO* NutTimerCreate | ( | u_long | ticks, | |
void(*)(HANDLE, void *) | callback, | |||
void * | arg, | |||
u_char | flags | |||
) |
Create a new system timer.
Applications should not call this function.
ticks | Specifies the timer interval in system ticks. | |
callback | Identifies the function to be called on each timer interval. | |
arg | The argument passed to the callback function. | |
flags | If set to TM_ONESHOT, the timer will be stopped after the first interval. Set to 0 for periodic timers. |
Definition at line 463 of file timer.c.
References NutGetTickCount(), NutHeapAlloc(), TM_ONESHOT, _NUTTIMERINFO::tn_arg, _NUTTIMERINFO::tn_callback, _NUTTIMERINFO::tn_ticks, and _NUTTIMERINFO::tn_ticks_left.
Referenced by NutTimerStartTicks().
HANDLE NutTimerStartTicks | ( | u_long | ticks, | |
void(*)(HANDLE, void *) | callback, | |||
void * | arg, | |||
u_char | flags | |||
) |
Start a system timer.
The function returns immediately, while the timer runs asynchronously in the background.
The timer counts for a specified number of ticks, then calls the callback routine with a given argument.
Even after the timer elapsed, the callback function is not executed before the currently running thread is ready to give up the CPU. Thus, system timers may not fulfill the required accuracy. For precise or high resolution timing, native timer interrupt routines are a better choice.
ticks | Specifies the timer interval in system ticks. | |
callback | Identifies the function to be called on each timer interval. | |
arg | The argument passed to the callback function. | |
flags | If set to TM_ONESHOT, the timer will be stopped after the first interval. Set to 0 for periodic timers. |
Definition at line 514 of file timer.c.
References NutTimerCreate(), and NutTimerInsert().
Referenced by NutTimerStart().
Start a system timer.
The function returns immediately, while the timer runs asynchronously in the background.
The timer counts for a specified number of milliseconds, then calls the callback routine with a given argument.
Even after the timer elapsed, the callback function is not executed before the currently running thread is ready to give up the CPU. Thus, system timers may not fulfill the required accuracy. For precise or high resolution timing, native timer interrupt routines are a better choice.
ms | Specifies the timer interval in milliseconds. The resolution is limited to the granularity of the system timer. | |
callback | Identifies the function to be called on each timer interval. | |
arg | The argument passed to the callback function. | |
flags | If set to TM_ONESHOT, the timer will be stopped after the first interval. Set to 0 for periodic timers. |
Definition at line 554 of file timer.c.
References NutTimerMillisToTicks(), and NutTimerStartTicks().
Referenced by main(), NutEventWait(), NutMsgQStartTimer(), and NutSleep().
void NutSleep | ( | u_long | ms | ) |
Temporarily suspends the current thread.
Causes the current thread to wait for a specified interval or, if the specified interval is zero, to give up the CPU for another thread with higher or same priority.
This function may switch to another application thread, that got the same or a higher priority and is ready to run.
ms | Milliseconds to sleep. If 0, the current thread will not sleep, but may give up the CPU. The resolution is limited to the granularity of the system timer. |
Definition at line 580 of file timer.c.
References NutThreadRemoveQueue(), NutThreadResume(), NutThreadWake(), NutThreadYield(), NutTimerStart(), runningThread, runQueue, _NUTTHREADINFO::td_qnxt, _NUTTHREADINFO::td_queue, _NUTTHREADINFO::td_state, _NUTTHREADINFO::td_timer, TDS_RUNNING, TDS_SLEEP, TM_ONESHOT, TRACE_ADD_ITEM, and TRACE_TAG_THREAD_SLEEP.
Referenced by AhdlcRx(), At45dbWaitReady(), AvrTargetPollReady(), CFChange(), CSNICrx(), DiscoveryResponder(), EmacRxThread(), FeederThread(), High(), Low(), main(), NicInit(), NicRx(), NicRxAsix(), NicRxLanc(), NutDhcpIfConfig(), NutPppInput(), NutPppOutput(), NutPppSm(), Scanner(), Service(), Sleeper1(), Sleeper2(), Sleeper3(), Sleeper4(), SNTP_resync(), Thread1(), Thread2(), TwMasterTransact(), wlandrv_ProbeDevice(), and X12Init().
void NutTimerStop | ( | HANDLE | handle | ) |
Stop a specified timer.
Only periodic timers need to be stopped. One-shot timers are automatically stopped by the timer management after ther first timer interval. Anyway, long running one-shot timers may be stopped to release the occupied memory.
handle | Identifies the timer to be stopped. This handle must have been created by calling NutTimerStart() or NutTimerStartTicks(). |
Definition at line 617 of file timer.c.
References NutTimerInsert(), _NUTTIMERINFO::tn_callback, _NUTTIMERINFO::tn_next, _NUTTIMERINFO::tn_prev, _NUTTIMERINFO::tn_ticks, and _NUTTIMERINFO::tn_ticks_left.
Referenced by main(), NutEventPostAsync(), and NutMsgQStopTimer().
u_long NutGetTickCount | ( | void | ) |
Return the number of system timer ticks.
This function returns the number of system ticks since the system was started.
Definition at line 649 of file timer.c.
References nut_ticks, NutEnterCritical, and NutExitCritical.
Referenced by DiscoveryResponder(), main(), NutGetMillis(), NutGetSeconds(), NutTcpCreateSocket(), NutTimerCreate(), NutTimerInit(), and NutTimerProcessElapsed().
u_long NutGetSeconds | ( | void | ) |
Return the seconds counter value.
This function returns the value of a counter, which is incremented every second. During system start, the counter is cleared to zero.
Definition at line 682 of file timer.c.
References NutGetTickClock(), and NutGetTickCount().
Referenced by NutDhcpClient(), stime(), and time().
u_long NutGetMillis | ( | void | ) |
Return the milliseconds counter value.
This function returns the value of a counter, which is incremented every system timer tick. During system start, the counter is cleared to zero and will overflow with the 32 bit tick counter (4294967296). With the default 1024 ticks/s this will happen after 7.9 years. The resolution is also given by the system ticks.
Definition at line 703 of file timer.c.
References NutGetTickClock(), and NutGetTickCount().
Referenced by NutConditionTimedWait(), NutDhcpClient(), NutTcpCalcRtt(), NutTcpOutput(), NutTcpSm(), and NutTcpStateRetranTimeout().
Double linked list of all system timers.
Definition at line 227 of file timer.c.
Referenced by NutDumpTimerList(), and ProcessRequests().
volatile u_long nut_delay_loops |
Loops per microsecond.
Definition at line 247 of file timer.c.
Referenced by NutMicroDelay(), and NutTimerInit().