pid_t vfork_and_run(void (*fn)(void*) /*NORETURN*/, void *arg) {
/* GNO's fork2 call will return immediately and allow the parent and
* child processes to execute concurrently using the same memory
* space. To prevent them stomping on each other, we want to get
* behavior like a traditional vfork() implementation, where the
* parent blocks until the child terminates or execs.
*
* Our approach is to check the process tables to make sure the
* child has actually finished or exec'd. If not, we loop and try again.
* We can't just rely on the fact that the child signaled us, because
* it may still be running in libc's implementation of exec*.
*/
long oldmask;
pid_t pid;
kvmt *kvm_context;
struct pentry *proc_entry;
int done = 0;
/* Isolate child process's environment from parent */
if (environPush() != 0)
return -1;
/* Block all signals for now */
oldmask = sigblock(-1);
pid = fork2(fork_thunk, CHILD_STACKSIZE, 0, forked_child_name,
(sizeof(fn) + sizeof(arg) + sizeof(oldmask) + 1) / 2,
fn, arg, oldmask);
if (pid < 0)
goto ret;
while (!done) {
/* Wait for ~100 ms. If procsend worked, the child could send a
* message with it to end the waiting earlier, but this isn't
* possible in GNO 2.0.6 because procsend is broken. This isn't
* too big an issue, since 100ms isn't very long to wait anyhow. */
procrecvtim(1);
/* Check if the child is really dead or forked by inspecting
* the kernel's process entry for it. */
kvm_context = kvm_open();
if (kvm_context == NULL)
break;
proc_entry = kvmgetproc(kvm_context, pid);
if (proc_entry == NULL
|| (proc_entry->args != NULL
&& strcmp(forked_child_name, proc_entry->args + 8) != 0))
done = 1;
kvm_close(kvm_context);
}
ret:
sigsetmask(oldmask);
environPop();
return pid;
}
int
main (int argc, char **argv) {
int i=1; /* the number of the test */
unsigned int result;
if (argc > 1) {
use_environ = 1;
} else {
use_environ = 0;
printf("NOT ");
}
printf("using environ global variable\n");
/*
* initial Test 1:1
*/
result = test_environ();
if (result != NONE_SET) {
printf("Please unset the variable \"%s\" for this test.\n",
string1);
return -1;
}
printf("Test %d passed.\n",i);
i++;
#define FAIL(fmt) { printf(fmt, i, string1); exit(1); }
/*
* environInit(); Test :2
*/
if (use_environ) {
environInit();
result = test_environ();
switch (result) {
case BOTH_SET: FAIL("Test %d failed. %s prematurely set\n");
case ORCA_SET: FAIL("Test %d failed. %s set internally\n");
case UNIX_SET: FAIL("Test %d failed. %s set in environ\n");
case NONE_SET:
printf("Test %d passed.\n",i);
i++;
break;
default:
printf("Test internal error: test %d returned %ud\n",
i, result);
return -1;
}
}
/*
* setenv(); Test 2:3
*/
if (setenv(string1,string2,1) != 0) {
printf("Test %d: setenv() failed\n",i);
return -1;
}
result = test_environ();
if (use_environ) {
switch (result) {
case BOTH_SET:
printf("Test %d passed.\n",i);
i++;
break;
case ORCA_SET:
FAIL("Test %d failed. %s not set in environ\n");
case UNIX_SET:
FAIL("Test %d failed. %s not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
printf("Test internal error: test %d returned %ud\n",
i, result);
return -1;
}
} else {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set in environ\n");
case ORCA_SET:
printf("Test %d passed.\n", i);
i++;
break;
case UNIX_SET:
FAIL("Test %d failed. %s set in environ, not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
printf("Test internal error: test %d returned %ud\n",
i, result);
return -1;
}
}
/*
* unsetenv() Test 3:4
*/
unsetenv(string1);
result = test_environ();
if (use_environ) {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set\n");
case ORCA_SET:
FAIL("Test %d failed. %s set internally\n");
case UNIX_SET:
FAIL("Test %d failed. %s set in in environ\n");
case NONE_SET:
printf("Test %d passed.\n",i);
i++;
break;
default:
printf("Test internal error: test %d returned %ud\n",
i, result);
return -1;
}
} else {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set\n");
case ORCA_SET:
FAIL("Test %d failed. %s set internally\n");
case UNIX_SET:
FAIL("Test %d failed. %s set in environ\n");
case NONE_SET:
printf("Test %d passed.\n",i);
i++;
break;
default:
printf("Test internal error: test %d returned %ud\n",
i, result);
return -1;
}
}
/*
* environPush() Test 4:5 bork
*/
if (setenv(string1,string2,1) != 0) {
printf("Test %d: setenv() failed\n",i);
return -1;
}
if (environPush() != 0) {
printf("Test %d: environPush() failed\n",i);
return -1;
}
result = test_environ();
if (use_environ) {
switch (result) {
case BOTH_SET:
printf("Test %d passed.\n",i);
i++;
break;
case ORCA_SET:
FAIL("Test %d failed. %s not set in environ\n");
case UNIX_SET:
FAIL("Test %d failed. %s not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
} else {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set in environ\n");
case ORCA_SET:
printf("Test %d passed.\n",i);
i++;
break;
case UNIX_SET:
FAIL("Test %d failed. %s set in environ, not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
}
/*
* environPop() Test 5:6
*/
unsetenv(string1);
environPop();
result = test_environ();
if (use_environ) {
switch (result) {
case BOTH_SET:
printf("Test %d passed.\n",i);
i++;
break;
case ORCA_SET:
FAIL("Test %d failed. %s not set in environ\n");
case UNIX_SET:
FAIL("Test %d failed. %s not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
} else {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set in environ\n");
case ORCA_SET:
printf("Test %d passed.\n",i);
i++;
break;
case UNIX_SET:
FAIL("Test %d failed. %s set in environ, not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
}
/*
* putenv() Test 6:7
*/
unsetenv(string1);
if (putenv(string3) != 0) {
printf("Test %d: putenv() failed\n",i);
return -1;
}
result = test_environ();
if (use_environ) {
switch (result) {
case BOTH_SET:
printf("Test %d passed.\n",i);
i++;
break;
case ORCA_SET:
FAIL("Test %d failed. %s not set in environ\n");
case UNIX_SET:
FAIL("Test %d failed. %s not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
} else {
switch (result) {
case BOTH_SET:
FAIL("Test %d failed. %s set in environ\n");
case ORCA_SET:
printf("Test %d passed.\n",i);
i++;
break;
case UNIX_SET:
FAIL("Test %d failed. %s set in environ, not set internally\n");
case NONE_SET:
FAIL("Test %d failed. %s not set\n");
default:
assert(0);
}
}
unsetenv(string1);
printf("Tests done.\n");
return 0;
}