71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
/* Filter driver - utility functions */
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#include "inc.h"
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#include <sys/mman.h>
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#include <signal.h>
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static clock_t next_alarm;
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/*===========================================================================*
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* flt_malloc *
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*===========================================================================*/
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char *flt_malloc(size_t size, char *sbuf, size_t ssize)
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{
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/* Allocate a buffer for 'size' bytes. If 'size' is equal to or less
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* than 'ssize', return the static buffer 'sbuf', otherwise, use
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* malloc() to allocate memory dynamically.
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*/
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char *p;
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if (size <= ssize)
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return sbuf;
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if(!(p = alloc_contig(size, 0, NULL)))
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panic("out of memory: %d", size);
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return p;
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}
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/*===========================================================================*
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* flt_free *
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*===========================================================================*/
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void flt_free(char *buf, size_t size, const char *sbuf)
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{
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/* Free a buffer previously allocated with flt_malloc().
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*/
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if(buf != sbuf)
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free_contig(buf, size);
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}
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/*===========================================================================*
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* flt_alarm *
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*===========================================================================*/
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clock_t flt_alarm(clock_t dt)
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{
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int r;
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if(dt < 0)
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return next_alarm;
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r = sys_setalarm(dt, 0);
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if(r != OK)
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panic("sys_setalarm failed: %d", r);
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if(dt == 0) {
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if(!next_alarm)
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panic("clearing unset alarm: %d", r);
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next_alarm = 0;
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} else {
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if(next_alarm)
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panic("overwriting alarm: %d", r);
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if ((r = getuptime(&next_alarm)) != OK)
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panic("getuptime failed: %d", r);
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next_alarm += dt;
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}
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return next_alarm;
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}
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