static void* thread_start_mark(void *arg){
tar_threadstart threadstart=(tar_threadstart)arg;
#if (!NO_SNAPSHOT)
bound_thread_to_cpu(MARK_CPU);
#else
bound_thread_to_cpu(NONSNAPSHOT_MARK_CPU);
#endif
threadstart();
return NULL;
}
static void* thread_start_free(void *arg){
tar_threadstart threadstart=(tar_threadstart)arg;
bound_thread_to_cpu(FREE_CPU);
threadstart();
return NULL;
}
static void* thread_start_snapshot(void *arg){
tar_threadstart threadstart=(tar_threadstart)arg;
threadstart();
return NULL;
}
int
ctlproc(int id, char *msg)
{
Thread *t;
int status;
// Hang/attached dance is for debugging newly exec'ed programs.
// After fork, the child does ctlproc("hang") before exec,
// and the parent does ctlproc("attached") and then waitstop.
// Using these requires the BSD ptrace interface, unlike everything
// else we do, which uses only the Mach interface. Our goal here
// is to do as little as possible using ptrace and then flip over to Mach.
if(strcmp(msg, "hang") == 0)
return ptrace(PT_TRACE_ME, 0, 0, 0);
if(strcmp(msg, "attached") == 0){
// The pid "id" has done a ctlproc "hang" and then
// exec, so we should find it stoppped just before exec
// of the new program.
#undef waitpid
if(waitpid(id, &status, WUNTRACED) < 0){
fprint(2, "ctlproc attached waitpid: %r\n");
return -1;
}
if(WIFEXITED(status) || !WIFSTOPPED(status)){
fprint(2, "ctlproc attached: bad process state\n");
return -1;
}
// Find Mach thread for pid and suspend it.
t = addpid(id, 1);
if(t == nil)
return -1;
if(me(thread_suspend(t->thread)) < 0){
fprint(2, "ctlproc attached: thread_suspend: %r\n");
return -1;
}
// Let ptrace tell the process to keep going:
// then ptrace is out of the way and we're back in Mach land.
return ptrace(PT_CONTINUE, id, (caddr_t)1, 0);
}
// All the other control messages require a Thread structure.
if((t = idtotable(id)) == nil){
werrstr("no such thread");
return -1;
}
if(strcmp(msg, "kill") == 0)
return ptrace(PT_KILL, t->pid, 0, 0);
if(strcmp(msg, "start") == 0)
return threadstart(t, 0);
if(strcmp(msg, "stop") == 0)
return threadstop(t);
if(strcmp(msg, "startstop") == 0){
if(threadstart(t, 0) < 0)
return -1;
return waitstop(t);
}
if(strcmp(msg, "step") == 0){
if(threadstart(t, 1) < 0)
return -1;
return waitstop(t);
}
if(strcmp(msg, "waitstop") == 0)
return waitstop(t);
// sysstop not available on OS X
werrstr("unknown control message");
return -1;
}