Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
#include "../plan9/lib.h"
2 
#include "../plan9/sys9.h"
3 
#include <signal.h>
4 
#include <setjmp.h>
5 
 
6 
/* A stack to hold pcs when signals nest */
7 
#define MAXSIGSTACK 20
8 
typedef struct Pcstack Pcstack;
9 
static struct Pcstack {
10 
	int sig;
11 
	void (*hdlr)(int, char*, Ureg*);
12 
	unsigned long restorepc;
13 
	unsigned long restorenpc;
14 
	Ureg *u;
15 
} pcstack[MAXSIGSTACK];
16 
static int nstack = 0;
17 
 
18 
static void notecont(Ureg*, char*);
19 
 
20 
void
21 
_notetramp(int sig, void (*hdlr)(int, char*, Ureg*), Ureg *u)
22 
{
23 
	Pcstack *p;
24 
 
25 
	if(nstack >= MAXSIGSTACK)
26 
		_NOTED(1);	/* nesting too deep; just do system default */
27 
	p = &pcstack[nstack];
28 
	p->restorepc = u->pc;
29 
	p->restorenpc = u->npc;
30 
	p->sig = sig;
31 
	p->hdlr = hdlr;
32 
	p->u = u;
33 
	nstack++;
34 
	u->pc = (unsigned long) notecont;
35 
	u->npc = u->pc+4;
36 
	_NOTED(2);	/* NSAVE: clear note but hold state */
37 
}
38 
 
39 
static void
40 
notecont(Ureg *u, char *s)
41 
{
42 
	Pcstack *p;
43 
	void(*f)(int, char*, Ureg*);
44 
 
45 
	p = &pcstack[nstack-1];
46 
	f = p->hdlr;
47 
	u->pc = p->restorepc;
48 
	u->npc = p->restorenpc;
49 
	nstack--;
50 
	(*f)(p->sig, s, u);
51 
	_NOTED(3);	/* NRSTR */
52 
}
53 
 
54 
int	__noterestore(void);
55 
 
56 
#define JMPBUFPC 1
57 
#define JMPBUFSP 0
58 
#define	JMPBUFDPC (-8)
59 
 
60 
extern sigset_t	_psigblocked;
61 
 
62 
void
63 
siglongjmp(sigjmp_buf j, int ret)
64 
{
65 
	struct Ureg *u;
66 
 
67 
	if(j[0])
68 
		_psigblocked = j[1];
69 
	if(nstack == 0 || pcstack[nstack-1].u->sp > j[2+JMPBUFSP])
70 
		longjmp(j+2, ret);
71 
	u = pcstack[nstack-1].u;
72 
	nstack--;
73 
	u->r8 = ret;
74 
	if(ret == 0)
75 
		u->r8 = 1;
76 
	u->r9 = j[JMPBUFPC] - JMPBUFDPC;
77 
	u->pc = (unsigned long)__noterestore;
78 
	u->npc = (unsigned long)__noterestore + 4;
79 
	u->sp = j[JMPBUFSP];
80 
	_NOTED(3);	/* NRSTR */
81 
}