linux_emul_base/trace.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <ureg.h>
   4 #include "dat.h"
   5 #include "fns.h"
   6
   7 #undef trace
   8
   9 static char magic[] = "TRACEBUF";
  10
  11 typedef struct Tracebuf Tracebuf;
  12 struct Tracebuf
  13 {
  14         char            magic[8];
  15         int             wp;
  16         char            lines[256][80];
  17 };
  18
  19 static void*
  20 alloctrace(void)
  21 {
  22         Tracebuf *t;
  23
  24         t = kmallocz(sizeof(*t), 1);
  25         memmove(t->magic, magic, sizeof(t->magic));
  26         return t;
  27 }
  28
  29 static void
  30 checktrace(Tracebuf *t)
  31 {
  32         if(memcmp(t->magic, magic, sizeof(t->magic)) != 0)
  33                 panic("tracebuffer corrupted");
  34 }
  35
  36 static void
  37 freetrace(Tracebuf *t)
  38 {
  39         if(t == nil)
  40                 return;
  41         checktrace(t);
  42         memset(t, 0, sizeof(*t));
  43         free(t);
  44 }
  45
  46 static void
  47 vputtrace(Tracebuf *t, char *fmt, va_list a)
  48 {
  49         char *s;
  50
  51         checktrace(t);
  52         s = t->lines[t->wp++ %  nelem(t->lines)];
  53         vsnprint(s, sizeof(t->lines[0]), fmt, a);
  54         if(debug > 1)
  55                 fprint(2, "%d\t%s\n", (current != nil) ? current->tid : 0, s);
  56 }
  57
  58 void inittrace(void)
  59 {
  60         if(debug > 0)
  61                 current->trace = alloctrace();
  62 }
  63
  64 void exittrace(Uproc *proc)
  65 {
  66         Tracebuf *t;
  67
  68         if(t = proc->trace){
  69                 proc->trace = nil;
  70                 freetrace(t);
  71         }
  72 }
  73
  74 void clonetrace(Uproc *new, int copy)
  75 {
  76         Tracebuf *t;
  77
  78         if((t = current->trace) == nil){
  79                 new->trace = nil;
  80                 return;
  81         }
  82
  83         if(copy){
  84                 Tracebuf *x;
  85
  86                 x = kmalloc(sizeof(*t));
  87                 memmove(x, t, sizeof(*t));
  88                 new->trace = x;
  89
  90                 return;
  91         }
  92
  93         new->trace = alloctrace();
  94 }
  95
  96 void tprint(char *fmt, ...)
  97 {
  98         va_list a;
  99         Uproc *p;
 100
 101         p = current;
 102         if(p && p->trace){
 103                 va_start(a, fmt);
 104                 vputtrace((Tracebuf*)p->trace, fmt, a);
 105                 va_end(a);
 106         }
 107 }