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#include "../plan9/lib.h"
#include "../plan9/sys9.h"
#include <signal.h>
#include <setjmp.h>
/* A stack to hold pcs when signals nest */
#define MAXSIGSTACK 20
typedef struct Pcstack Pcstack;
static struct Pcstack {
int sig;
void (*hdlr)(int, char*, Ureg*);
unsigned long restorepc;
Ureg *u;
} pcstack[MAXSIGSTACK];
static int nstack = 0;
static void notecont(Ureg*, char*);
void
_notetramp(int sig, void (*hdlr)(int, char*, Ureg*), Ureg *u)
{
Pcstack *p;
if(nstack >= MAXSIGSTACK)
_NOTED(1); /* nesting too deep; just do system default */
p = &pcstack[nstack];
p->restorepc = u->pc;
p->sig = sig;
p->hdlr = hdlr;
p->u = u;
nstack++;
u->pc = (unsigned long) notecont;
_NOTED(2); /* NSAVE: clear note but hold state */
}
static void
notecont(Ureg *u, char *s)
{
Pcstack *p;
void(*f)(int, char*, Ureg*);
p = &pcstack[nstack-1];
f = p->hdlr;
u->pc = p->restorepc;
nstack--;
(*f)(p->sig, s, u);
_NOTED(3); /* NRSTR */
}
#define JMPBUFPC 1
#define JMPBUFSP 0
extern sigset_t _psigblocked;
void
siglongjmp(sigjmp_buf j, int ret)
{
struct Ureg *u;
if(j[0])
_psigblocked = j[1];
if(nstack == 0 || pcstack[nstack-1].u->sp > j[2+JMPBUFSP])
longjmp(j+2, ret);
u = pcstack[nstack-1].u;
nstack--;
u->r1 = ret;
if(ret == 0)
u->r1 = 1;
u->pc = j[2+JMPBUFPC];
u->sp = j[2+JMPBUFSP];
_NOTED(3); /* NRSTR */
}
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