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more debugging

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This commit is contained in:
rsc 2004-10-22 17:12:38 +00:00
parent aa200fe309
commit 32116738e1
1 changed files with 33 additions and 7 deletions
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40
src/lib9/rfork.c
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@ -4,6 +4,12 @@
#include <libc.h>
#undef rfork
static void
nop(int x)
{
USED(x);
}
int
p9rfork(int flags)
{
@ -21,6 +27,13 @@ p9rfork(int flags)
return -1;
}
if(flags&RFNOWAIT){
/*
* BUG - should put the signal handler back after we
* finish, but I just don't care. If a program calls with
* NOWAIT once, they're not likely to want child notes
* after that.
*/
signal(SIGCHLD, nop);
if(pipe(p) < 0)
return -1;
}
@ -35,20 +48,33 @@ p9rfork(int flags)
* Then read pid from pipe. Assume pipe buffer can absorb the write.
*/
close(p[1]);
wait4(pid, &status, 0, 0);
status = 0;
if(wait4(pid, &status, 0, 0) < 0){
werrstr("pipe dance - wait4 - %r");
close(p[0]);
return -1;
}
n = readn(p[0], buf, sizeof buf-1);
close(p[0]);
if(!WIFEXITED(status) || WEXITSTATUS(status)!=0 || n <= 0){
werrstr("pipe dance failed in rfork");
if(!WIFEXITED(status))
werrstr("pipe dance - !exited 0x%ux", status);
else if(WEXITSTATUS(status) != 0)
werrstr("pipe dance - non-zero status 0x%ux", status);
else if(n < 0)
werrstr("pipe dance - pipe read error - %r");
else if(n == 0)
werrstr("pipe dance - pipe read eof");
else
werrstr("pipe dance - unknown failure");
return -1;
}
buf[n] = 0;
n = strtol(buf, &q, 0);
if(*q != 0){
werrstr("%s", q);
if(buf[0] == 'x'){
werrstr("%s", buf+2);
return -1;
}
pid = n;
pid = strtol(buf, &q, 0);
}else{
/*
* Child - fork a new child whose wait message can't
@ -62,7 +88,7 @@ p9rfork(int flags)
if(pid > 0)
fprint(p[1], "%d", pid);
else
fprint(p[1], " %r");
fprint(p[1], "x %r");
close(p[1]);
_exit(0);
}else{