Differenze tra le versioni di "Creare un Timer con le funzioni esterne delle librerie standard C "signal.h" e "time.h""

Da Gambas-it.org - Wikipedia.
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Usando alcune funzioni esterne delle librerie standard C "''signal.h''" e "''time.h''", è possibile creare ed utilizzare un ''Timer''
 
Usando alcune funzioni esterne delle librerie standard C "''signal.h''" e "''time.h''", è possibile creare ed utilizzare un ''Timer''
  
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E' necessario avere installata nel sistema e richiamare in Gambas la libreria condivisa: "''/usr/lib/x86_64-linux-gnu/libvlccore.so.9.0.0'' " o altra, purché contenente le funzioni esterne "timer_create()", "timer_settime()" e "timer_delete()".
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E' necessario avere installata nel sistema e richiamare in Gambas la libreria condivisa: "''/usr/lib/x86_64-linux-gnu/libvlccore.so.9.0.1'' " o altra, purché contenente le funzioni esterne "timer_create()", "timer_settime()" e "timer_delete()".
  
 
Mostriamo un esempio:
 
Mostriamo un esempio:
Riga 17: Riga 17:
 
   
 
   
 
   
 
   
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  Library "/usr/lib/x86_64-linux-gnu/libvlccore:9.0.0"
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  Library "/usr/lib/x86_64-linux-gnu/libvlccore:9.0.1"
 
   
 
   
 
  Public Struct timespec
 
  Public Struct timespec
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  '''Public''' Sub Main()
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  Public Sub Main()
 
    
 
    
 
   signal(SIGALRM, timer_callback)
 
   signal(SIGALRM, timer_callback)
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   timer_delete(id)
 
   timer_delete(id)
 
    
 
    
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  '''End'''
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  End
 
   
 
   
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  '''Private''' Procedure Start_Timer(vlr As Long)
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Private Procedure Start_Timer(vlr As Long)
 
    
 
    
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  Dim spec As New Itimerspec
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  Dim spec As New Itimerspec
 
      
 
      
 
   With spec
 
   With spec
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   timer_settime(id, 0, spec, Null)
 
   timer_settime(id, 0, spec, Null)
 
    
 
    
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  '''End'''
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  End
 
    
 
    
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  '''Private''' Procedure timer_callback(signum As Integer)
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Private Procedure timer_callback(signum As Integer)
 
    
 
    
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  Print num; "  Intercettato segnale Timer: "; signum
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  Print num; "  Intercettato segnale Timer: "; signum
 
    
 
    
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  Inc num
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  Inc num
 
    
 
    
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  '''End'''
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  End
 
   
 
   
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  '''Private''' Procedure Stop_Timer()
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Private Procedure Stop_Timer()
 
    
 
    
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  Dim spec As New Itimerspec
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  Dim spec As New Itimerspec
 
   
 
   
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  With spec
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  With spec
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    .it_value.tv_sec = 0
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    .it_value.tv_sec = 0
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    .it_value.tv_nsec = 0
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    .it_value.tv_nsec = 0
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    .it_interval.tv_sec = 0
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    .it_interval.tv_sec = 0
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    .it_interval.tv_nsec = 0
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    .it_interval.tv_nsec = 0
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  End With
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  End With
 
    
 
    
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  timer_settime(id, 0, spec, Null)
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  timer_settime(id, 0, spec, Null)
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  timer_delete(id)
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  timer_delete(id)
 
    
 
    
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  '''End'''
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  End
  
  

Versione delle 08:59, 1 lug 2024

Usando alcune funzioni esterne delle librerie standard C "signal.h" e "time.h", è possibile creare ed utilizzare un Timer

E' necessario avere installata nel sistema e richiamare in Gambas la libreria condivisa: "/usr/lib/x86_64-linux-gnu/libvlccore.so.9.0.1 " o altra, purché contenente le funzioni esterne "timer_create()", "timer_settime()" e "timer_delete()".

Mostriamo un esempio: 

Private id As Long
Private num As Byte


Library "libc:6"

Private Const SIGALRM As Integer = 14      ' Alarm clock (POSIX)

' __sighandler_t signal (int __sig, __sighandler_t __handler)
' Set the handler for the signal SIG to HANDLER.
Private Extern signal(__sig As Integer, __handler As Pointer) As Pointer


Library "/usr/lib/x86_64-linux-gnu/libvlccore:9.0.1"

Public Struct timespec
  tv_sec As Long
  tv_nsec As Long
End Struct

Public Struct itimerspec
  it_interval As Struct Timespec
  it_value As Struct Timespec
End Struct

Private Enum CLOCK_REALTIME = 0, CLOCK_MONOTONIC, CLOCK_PROCESS_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID, CLOCK_MONOTONIC_RAW,
             CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_COARSE, CLOCK_BOOTTIME, CLOCK_REALTIME_ALARM, CLOCK_BOOTTIME_ALARM

' int timer_create (clockid_t __clock_id, struct sigevent *__restrict __evp, timer_t *__restrict __timerid)
' Create new per-process timer using CLOCK_ID.
Private Extern timer_create(__clock_id As Integer, __evp As Pointer, __timerid As Pointer) As Integer

' int timer_settime (timer_t __timerid, int __flags, const struct itimerspec *__restrict __value, struct itimerspec *__restrict __ovalue)
' Set timer TIMERID to VALUE, returning old value in OVALUE.
Private Extern timer_settime(__timerid As Long, __flags As Integer, __value As Itimerspec, __ovalue As Itimerspec) As Integer

' int timer_delete (timer_t __timerid)
' Delete timer TIMERID.
Private Extern timer_delete(__timerid As Long) As Integer


Public Sub Main()
  
  signal(SIGALRM, timer_callback)
  
  Start_Timer(300000000)
  
  While num < 99
    Sleep 0.01
  Wend
   
  Stop_Timer()
   
  timer_delete(id)
  
End


Private Procedure Start_Timer(vlr As Long)
 
  Dim spec As New Itimerspec
   
  With spec
    .it_value.tv_sec = 0
    .it_value.tv_nsec = vlr     ' Attende 300.000.000 di nanosecondi prima di inviare un segnale Timer
    .it_interval.tv_sec = 0
    .it_interval.tv_nsec = vlr  ' Invia un segnale Timer ogni 300.000.000 nanosecondi
  End With
  
  timer_create(CLOCK_REALTIME, 0, VarPtr(id))
  timer_settime(id, 0, spec, Null)
 
End
  

Private Procedure timer_callback(signum As Integer)
 
  Print num; "   Intercettato segnale Timer: "; signum
 
  Inc num
 
End


Private Procedure Stop_Timer()
 
  Dim spec As New Itimerspec

  With spec
    .it_value.tv_sec = 0
    .it_value.tv_nsec = 0
    .it_interval.tv_sec = 0
    .it_interval.tv_nsec = 0
  End With
  
  timer_settime(id, 0, spec, Null)
  timer_delete(id)
  
End


Riferimenti

Estratto da "https://www.gambas-it.org/wiki/index.php?title=Creare_un_Timer_con_le_funzioni_esterne_delle_librerie_standard_C_%22signal.h%22_e_%22time.h%22&oldid=37751"