/rpython/translator/c/test/test_newgc.py

import gc
import inspect
import os
import sys
import subprocess
import random

import py

from rpython.conftest import option
from rpython.rlib import rgc
from rpython.rlib.objectmodel import keepalive_until_here, compute_hash, compute_identity_hash
from rpython.rlib.rstring import StringBuilder
from rpython.rtyper.lltypesystem import lltype, llmemory, rffi
from rpython.rtyper.lltypesystem.lloperation import llop
from rpython.memory.test import snippet
from rpython.tool.udir import udir
from rpython.translator.interactive import Translation


class UsingFrameworkTest(object):
    #gcpolicy = ... specified by subclasses
    should_be_moving = False
    removetypeptr = False
    taggedpointers = False
    GC_CAN_MOVE = False
    GC_CAN_SHRINK_ARRAY = False

    _isolated_func = None
    c_allfuncs = None

    @classmethod
    def _makefunc_str_int(cls, f):
        def main(argv):
            arg0 = argv[1]
            arg1 = int(argv[2])
            try:
                res = f(arg0, arg1)
            except MemoryError:
                print "MEMORY-ERROR"
            else:
                print res
            return 0

        t = Translation(main, gc=cls.gcpolicy,
                        taggedpointers=cls.taggedpointers,
                        gcremovetypeptr=cls.removetypeptr)
        t.disable(['backendopt'])
        t.set_backend_extra_options(c_debug_defines=True)
        t.rtype()
        if option.view:
            t.viewcg()
        exename = t.compile()

        def run(s, i, runner=subprocess.check_output):
            data = runner([str(exename), str(s), str(i)])
            data = data.strip()
            if data == 'MEMORY-ERROR':
                raise MemoryError
            return data

        return run

    def setup_class(cls):
        funcs0 = []
        funcs1 = []
        funcsstr = []
        name_to_func = {}
        for fullname in dir(cls):
            if not fullname.startswith('define'):
                continue
            keyword = option.keyword
            if keyword.startswith('test_') and not keyword.endswith(':'):
                keyword = keyword[len('test_'):]
                if keyword not in fullname:
                    continue
            prefix, name = fullname.split('_', 1)
            definefunc = getattr(cls, fullname)
            func = definefunc.im_func(cls)
            func.func_name = 'f_' + name
            if prefix == 'definestr':
                funcsstr.append(func)
                funcs0.append(None)
                funcs1.append(None)
            else:
                numargs = len(inspect.getargspec(func)[0])
                funcsstr.append(None)
                if numargs == 0:
                    funcs0.append(func)
                    funcs1.append(None)
                else:
                    assert numargs == 1
                    funcs0.append(None)
                    funcs1.append(func)
            assert name not in name_to_func
            name_to_func[name] = len(name_to_func)
        assert name_to_func

        def allfuncs(name, arg):
            num = name_to_func[name]
            func0 = funcs0[num]
            if func0:
                return str(func0())
            func1 = funcs1[num]
            if func1:
                return str(func1(arg))
            funcstr = funcsstr[num]
            if funcstr:
                return funcstr(arg)
            assert 0, 'unreachable'
        cls.funcsstr = funcsstr
        cls.c_allfuncs = staticmethod(cls._makefunc_str_int(allfuncs))
        cls.allfuncs = staticmethod(allfuncs)
        cls.name_to_func = name_to_func

    def teardown_class(cls):
        if hasattr(cls.c_allfuncs, 'close_isolate'):
            cls.c_allfuncs.close_isolate()
            cls.c_allfuncs = None

    def run(self, name, *args, **kwds):
        if not args:
            args = (-1, )
        print 'Running %r)' % name
        res = self.c_allfuncs(name, *args, **kwds)
        num = self.name_to_func[name]
        if self.funcsstr[num]:
            return res
        return int(res)

    def run_orig(self, name, *args):
        if not args:
            args = (-1, )
        res = self.allfuncs(name, *args)
        num = self.name_to_func[name]
        if self.funcsstr[num]:
            return res
        return int(res)

    def define_empty_collect(cls):
        def f():
            llop.gc__collect(lltype.Void)
            return 41
        return f

    def test_empty_collect(self):
        res = self.run('empty_collect')
        assert res == 41

    def define_framework_simple(cls):
        def g(x): # cannot cause a collect
            return x + 1
        class A(object):
            pass
        def make():
            a = A()
            a.b = g(1)
            return a
        make._dont_inline_ = True
        def f():
            a = make()
            llop.gc__collect(lltype.Void)
            return a.b
        return f

    def test_framework_simple(self):
        res = self.run('framework_simple')
        assert res == 2

    def define_framework_safe_pushpop(cls):
        class A(object):
            pass
        class B(object):
            pass
        def g(x): # cause a collect
            llop.gc__collect(lltype.Void)
        g._dont_inline_ = True
        global_a = A()
        global_a.b = B()
        global_a.b.a = A()
        global_a.b.a.b = B()
        global_a.b.a.b.c = 1
        def make():
            global_a.b.a.b.c = 40
            a = global_a.b.a
            b = a.b
            b.c = 41
            g(1)
            b0 = a.b
            b0.c = b.c = 42
        make._dont_inline_ = True
        def f():
            make()
            llop.gc__collect(lltype.Void)
            return global_a.b.a.b.c
        return f

    def test_framework_safe_pushpop(self):
        res = self.run('framework_safe_pushpop')
        assert res == 42

    def define_framework_protect_getfield(cls):
        class A(object):
            pass
        class B(object):
            pass
        def prepare(b, n):
            a = A()
            a.value = n
            b.a = a
            b.othervalue = 5
        def g(a):
            llop.gc__collect(lltype.Void)
            for i in range(1000):
                prepare(B(), -1)    # probably overwrites collected memory
            return a.value
        g._dont_inline_ = True
        def f():
            b = B()
            prepare(b, 123)
            a = b.a
            b.a = None
            return g(a) + b.othervalue
        return f

    def test_framework_protect_getfield(self):
        res = self.run('framework_protect_getfield')
        assert res == 128

    def define_framework_varsized(cls):
        S = lltype.GcStruct("S", ('x', lltype.Signed))
        T = lltype.GcStruct("T", ('y', lltype.Signed),
                                 ('s', lltype.Ptr(S)))
        ARRAY_Ts = lltype.GcArray(lltype.Ptr(T))

        def f():
            r = 0
            for i in range(30):
                a = lltype.malloc(ARRAY_Ts, i)
                for j in range(i):
                    a[j] = lltype.malloc(T)
                    a[j].y = i
                    a[j].s = lltype.malloc(S)
                    a[j].s.x = 2 * i
                    r += a[j].y + a[j].s.x
                    a[j].s = lltype.malloc(S)
                    a[j].s.x = 3 * i
                    r -= a[j].s.x
                for j in range(i):
                    r += a[j].y
            return r
        return f

    def test_framework_varsized(self):
        res = self.run('framework_varsized')
        assert res == self.run_orig('framework_varsized')

    def define_framework_using_lists(cls):
        class A(object):
            pass
        N = 1000
        def f():
            static_list = []
            for i in range(N):
                a = A()
                a.x = i
                static_list.append(a)
            r = 0
            for a in static_list:
                r += a.x
            return r
        return f

    def test_framework_using_lists(self):
        N = 1000
        res = self.run('framework_using_lists')
        assert res == N * (N - 1) / 2

    def define_framework_static_roots(cls):
        class A(object):
            def __init__(self, y):
                self.y = y
        a = A(0)
        a.x = None
        def make():
            a.x = A(42)
        make._dont_inline_ = True
        def f():
            make()
            llop.gc__collect(lltype.Void)
            return a.x.y
        return f

    def test_framework_static_roots(self):
        res = self.run('framework_static_roots')
        assert res == 42

    def define_framework_nongc_static_root(cls):
        S = lltype.GcStruct("S", ('x', lltype.Signed))
        T = lltype.Struct("T", ('p', lltype.Ptr(S)))
        t = lltype.malloc(T, immortal=True)
        def f():
            t.p = lltype.malloc(S)
            t.p.x = 43
            for i in range(2500000):
                s = lltype.malloc(S)
                s.x = i
            return t.p.x
        return f

    def test_framework_nongc_static_root(self):
        res = self.run('framework_nongc_static_root')
        assert res == 43

    def define_framework_void_array(cls):
        A = lltype.GcArray(lltype.Void)
        a = lltype.malloc(A, 44)
        def f():
            return len(a)
        return f

    def test_framework_void_array(self):
        res = self.run('framework_void_array')
        assert res == 44

    def define_framework_malloc_failure(cls):
        def f():
            a = [1] * (sys.maxint // 2)
            return len(a) + a[0]
        return f

    def test_framework_malloc_failure(self):
        py.test.raises(MemoryError, self.run, 'framework_malloc_failure')

    def define_framework_array_of_void(cls):
        def f():
            a = [None] * 43
            b = []
            for i in range(1000000):
                a.append(None)
                b.append(len(a))
            return b[-1]
        return f

    def test_framework_array_of_void(self):
        res = self.run('framework_array_of_void')
        assert res == 43 + 1000000

    def define_framework_opaque(cls):
        A = lltype.GcStruct('A', ('value', lltype.Signed))
        O = lltype.GcOpaqueType('test.framework')

        def gethidden(n):
            a = lltype.malloc(A)
            a.value = -n * 7
            return lltype.cast_opaque_ptr(lltype.Ptr(O), a)
        gethidden._dont_inline_ = True
        def reveal(o):
            return lltype.cast_opaque_ptr(lltype.Ptr(A), o)
        def overwrite(a, i):
            a.value = i
        overwrite._dont_inline_ = True
        def f():
            o = gethidden(10)
            llop.gc__collect(lltype.Void)
            for i in range(1000):    # overwrite freed memory
                overwrite(lltype.malloc(A), i)
            a = reveal(o)
            return a.value
        return f

    def test_framework_opaque(self):
        res = self.run('framework_opaque')
        assert res == -70

    def define_framework_finalizer(cls):
        class B(object):
            pass
        b = B()
        b.nextid = 0
        b.num_deleted = 0
        class A(object):
            def __init__(self):
                self.id = b.nextid
                b.nextid += 1
            def __del__(self):
                b.num_deleted += 1
        def f():
            a = A()
            i = 0
            while i < 5:
                i += 1
                a = A()
            llop.gc__collect(lltype.Void)
            llop.gc__collect(lltype.Void)
            return b.num_deleted
        return f

    def test_framework_finalizer(self):
        res = self.run('framework_finalizer')
        assert res == 6

    def define_del_catches(cls):
        def g():
            pass
        class A(object):
            def __del__(self):
                try:
                    g()
                except:
                    pass #os.write(1, "hallo")
        def f1(i):
            if i:
                raise TypeError
        def f(i):
            a = A()
            f1(i)
            a.b = 1
            llop.gc__collect(lltype.Void)
            return a.b
        def h(x):
            try:
                return f(x)
            except TypeError:
                return 42
        return h

    def test_del_catches(self):
        res = self.run('del_catches', 0)
        assert res == 1
        res = self.run('del_catches', 1)
        assert res == 42

    def define_del_raises(cls):
        class B(object):
            def __del__(self):
                raise TypeError
        def func():
            b = B()
            return 0
        return func

    def test_del_raises(self):
        self.run('del_raises') # does not raise

    def define_custom_trace(cls):
        from rpython.rtyper.annlowlevel import llhelper
        #
        S = lltype.GcStruct('S', ('x', llmemory.Address))
        offset_of_x = llmemory.offsetof(S, 'x')
        def customtrace(gc, obj, callback, arg):
            gc._trace_callback(callback, arg, obj + offset_of_x)
        lambda_customtrace = lambda: customtrace
        #
        def setup():
            rgc.register_custom_trace_hook(S, lambda_customtrace)
            s = lltype.nullptr(S)
            for i in range(10000):
                t = lltype.malloc(S)
                t.x = llmemory.cast_ptr_to_adr(s)
                s = t
            return s
        def measure_length(s):
            res = 0
            while s:
                res += 1
                s = llmemory.cast_adr_to_ptr(s.x, lltype.Ptr(S))
            return res
        def f(n):
            s1 = setup()
            llop.gc__collect(lltype.Void)
            return measure_length(s1)
        return f

    def test_custom_trace(self):
        res = self.run('custom_trace', 0)
        assert res == 10000

    def define_custom_light_finalizer(cls):
        from rpython.rtyper.annlowlevel import llhelper
        #
        T = lltype.Struct('T', ('count', lltype.Signed))
        t = lltype.malloc(T, zero=True, immortal=True, flavor='raw')
        #
        S = lltype.GcStruct('S', rtti=True)
        def customlightfinlz(addr):
            t.count += 1
        lambda_customlightfinlz = lambda: customlightfinlz
        #
        def setup():
            rgc.register_custom_light_finalizer(S, lambda_customlightfinlz)
            for i in range(10000):
                lltype.malloc(S)
        def f(n):
            setup()
            llop.gc__collect(lltype.Void)
            return t.count
        return f

    def test_custom_light_finalizer(self):
        res = self.run('custom_light_finalizer', 0)
        assert res == 10000

    def define_weakref(cls):
        import weakref

        class A:
            pass

        keepalive = []
        def fn():
            n = 7000
            weakrefs = []
            a = None
            for i in range(n):
                if i & 1 == 0:
                    a = A()
                    a.index = i
                assert a is not None
                weakrefs.append(weakref.ref(a))
                if i % 7 == 6:
                    keepalive.append(a)
            rgc.collect()
            count_free = 0
            for i in range(n):
                a = weakrefs[i]()
                if i % 7 == 6:
                    assert a is not None
                if a is not None:
                    assert a.index == i & ~1
                else:
                    count_free += 1
            return count_free
        return fn

    def test_weakref(self):
        res = self.run('weakref')
        # more than half of them should have been freed, ideally up to 6000
        assert 3500 <= res <= 6000

    def define_prebuilt_weakref(cls):
        import weakref
        class A:
            pass
        a = A()
        a.hello = 42
        refs = [weakref.ref(a), weakref.ref(A())]
        rgc.collect()
        def fn():
            result = 0
            for i in range(2):
                a = refs[i]()
                rgc.collect()
                if a is None:
                    result += (i + 1)
                else:
                    result += a.hello * (i + 1)
            return result
        return fn

    def test_prebuilt_weakref(self):
        res = self.run('prebuilt_weakref')
        assert res == self.run_orig('prebuilt_weakref')

    def define_framework_malloc_raw(cls):
        A = lltype.Struct('A', ('value', lltype.Signed))

        def f():
            p = lltype.malloc(A, flavor='raw')
            p.value = 123
            llop.gc__collect(lltype.Void)
            res = p.value
            lltype.free(p, flavor='raw')
            return res
        return f

    def test_framework_malloc_raw(self):
        res = self.run('framework_malloc_raw')
        assert res == 123

    def define_framework_del_seeing_new_types(cls):
        class B(object):
            pass
        class A(object):
            def __del__(self):
                B()
        def f():
            A()
            return 42
        return f

    def test_framework_del_seeing_new_types(self):
        res = self.run('framework_del_seeing_new_types')
        assert res == 42

    def define_framework_late_filling_pointers(cls):
        A = lltype.GcStruct('A', ('x', lltype.Signed))
        B = lltype.GcStruct('B', ('a', lltype.Ptr(A)))

        def f():
            p = lltype.malloc(B)
            llop.gc__collect(lltype.Void)
            p.a = lltype.malloc(A)
            return p.a.x
        return f

    def test_framework_late_filling_pointers(self):
        # the point is just not to segfault
        self.run('framework_late_filling_pointers')

    def define_zero_raw_malloc(cls):
        S = lltype.Struct('S', ('x', lltype.Signed), ('y', lltype.Signed))
        def f():
            for i in range(100):
                p = lltype.malloc(S, flavor='raw', zero=True)
                if p.x != 0 or p.y != 0:
                    return -1
                p.x = i
                p.y = i
                lltype.free(p, flavor='raw')
            return 42

        return f

    def test_zero_raw_malloc(self):
        res = self.run('zero_raw_malloc')
        assert res == 42

    def define_object_alignment(cls):
        # all objects returned by the GC should be properly aligned.
        from rpython.rtyper.lltypesystem import rffi
        mylist = ['a', 'bc', '84139871', 'ajkdh', '876']
        def f():
            result = 0
            buffer = ""
            for j in range(100):
                for s in mylist:
                    buffer += s
                    addr = rffi.cast(lltype.Signed, buffer)
                    result |= addr
            return result

        return f

    def test_object_alignment(self):
        res = self.run('object_alignment')
        from rpython.rtyper.tool import rffi_platform
        expected_alignment = rffi_platform.memory_alignment()
        assert (res & (expected_alignment - 1)) == 0

    def define_void_list(cls):
        class E:
            def __init__(self):
                self.l = []
        def f():
            e = E()
            return len(e.l)
        return f

    def test_void_list(self):
        assert self.run('void_list') == 0

    filename = str(udir.join('test_open_read_write_close.txt'))
    def define_open_read_write_seek_close(cls):
        filename = cls.filename
        def does_stuff():
            fd = os.open(filename, os.O_WRONLY | os.O_CREAT, 0777)
            count = os.write(fd, "hello world\n")
            assert count == len("hello world\n")
            os.close(fd)
            fd = os.open(filename, os.O_RDONLY, 0777)
            result = os.lseek(fd, 1, 0)
            assert result == 1
            data = os.read(fd, 500)
            assert data == "ello world\n"
            os.close(fd)
            return 0

        return does_stuff

    def test_open_read_write_seek_close(self):
        self.run('open_read_write_seek_close')
        with open(self.filename, 'r') as fid:
            assert fid.read() == "hello world\n"
        os.unlink(self.filename)

    def define_callback_with_collect(cls):
        from rpython.rlib.clibffi import ffi_type_pointer, cast_type_to_ffitype,\
             CDLL, ffi_type_void, CallbackFuncPtr, ffi_type_sint
        ffi_size_t = cast_type_to_ffitype(rffi.SIZE_T)

        from rpython.rlib.clibffi import get_libc_name

        def callback(ll_args, ll_res, stuff):
            gc.collect()
            p_a1 = rffi.cast(rffi.VOIDPP, ll_args[0])[0]
            p_a2 = rffi.cast(rffi.VOIDPP, ll_args[1])[0]
            a1 = rffi.cast(rffi.SIGNEDP, p_a1)[0]
            a2 = rffi.cast(rffi.SIGNEDP, p_a2)[0]
            # related to libffi issue on s390x, we MUST
            # overwrite the full ffi result which is 64 bit
            # if not, this leaves garbage in the return value
            # and qsort does not sort correctly
            res = rffi.cast(rffi.SIGNEDP, ll_res)
            if a1 > a2:
                res[0] = 1
            else:
                res[0] = -1

        def f():
            libc = CDLL(get_libc_name())
            qsort = libc.getpointer('qsort', [ffi_type_pointer, ffi_size_t,
                                              ffi_size_t, ffi_type_pointer],
                                    ffi_type_void)

            ptr = CallbackFuncPtr([ffi_type_pointer, ffi_type_pointer, ffi_type_pointer],
                                  ffi_type_sint, callback)

            TP = rffi.CArray(lltype.Signed)
            to_sort = lltype.malloc(TP, 4, flavor='raw')
            to_sort[0] = 4
            to_sort[1] = 3
            to_sort[2] = 1
            to_sort[3] = 2
            qsort.push_arg(rffi.cast(rffi.VOIDP, to_sort))
            qsort.push_arg(rffi.cast(rffi.SIZE_T, 4))
            qsort.push_arg(rffi.cast(rffi.SIZE_T, rffi.sizeof(lltype.Signed)))
            qsort.push_arg(rffi.cast(rffi.VOIDP, ptr.ll_closure))
            qsort.call(lltype.Void)
            result = [to_sort[i] for i in range(4)] == [1, 2, 3, 4]
            lltype.free(to_sort, flavor='raw')
            keepalive_until_here(ptr)
            return int(result)

        return f

    def test_callback_with_collect(self):
        assert self.run('callback_with_collect')

    def define_can_move(cls):
        class A:
            pass
        def fn():
            return rgc.can_move(A())
        return fn

    def test_can_move(self):
        assert self.run('can_move') == self.GC_CAN_MOVE

    def define_resizable_buffer(cls):
        from rpython.rtyper.lltypesystem.rstr import STR

        def f():
            ptr = lltype.malloc(STR, 3)
            ptr.hash = 0x62
            ptr.chars[0] = '0'
            ptr.chars[1] = 'B'
            ptr.chars[2] = 'C'
            ptr2 = rgc.ll_shrink_array(ptr, 2)
            return ((ptr == ptr2)             +
                     ord(ptr2.chars[0])       +
                    (ord(ptr2.chars[1]) << 8) +
                    (len(ptr2.chars)   << 16) +
                    (ptr2.hash         << 24))
        return f

    def test_resizable_buffer(self):
        res = self.run('resizable_buffer')
        if self.GC_CAN_SHRINK_ARRAY:
            expected = 0x62024231
        else:
            expected = 0x62024230
        assert res == expected

    def define_hash_preservation(cls):
        class C:
            pass
        class D(C):
            pass
        c = C()
        d = D()
        h_d = compute_hash(d)     # force to be cached on 'd', but not on 'c'
        h_t = compute_hash(("Hi", None, (7.5, 2, d)))
        S = lltype.GcStruct('S', ('x', lltype.Signed),
                                 ('a', lltype.Array(lltype.Signed)))
        s = lltype.malloc(S, 15, zero=True)
        h_s = compute_identity_hash(s)   # varsized: hash not saved/restored
        #
        def f():
            if compute_hash(c) != compute_identity_hash(c):
                return 12
            if compute_hash(d) != h_d:
                return 13
            if compute_hash(("Hi", None, (7.5, 2, d))) != h_t:
                return 14
            c2 = C()
            h_c2 = compute_hash(c2)
            if compute_hash(c2) != h_c2:
                return 15
            if compute_identity_hash(s) == h_s:
                return 16   # unlikely
            i = 0
            while i < 6:
                rgc.collect()
                if compute_hash(c2) != h_c2:
                    return i
                i += 1
            return 42
        return f

    def test_hash_preservation(self):
        res = self.run('hash_preservation')
        assert res == 42

    def define_hash_overflow(self):
        class X(object):
            pass

        def g(n):
            "Make a chain of n objects."
            x1 = None
            i = 0
            while i < n:
                x2 = X()
                x2.prev = x1
                x1 = x2
                i += 1
            return x1

        def build(xr, n):
            "Build the identity hashes of all n objects of the chain."
            i = 0
            while i < n:
                xr.hash = compute_identity_hash(xr)
                # ^^^ likely to trigger a collection
                xr = xr.prev
                i += 1
            assert xr is None

        def check(xr, n, step):
            "Check that the identity hashes are still correct."
            i = 0
            while i < n:
                if xr.hash != compute_identity_hash(xr):
                    os.write(2, "wrong hash! i=%d, n=%d, step=%d\n" % (i, n,
                                                                       step))
                    raise ValueError
                xr = xr.prev
                i += 1
            assert xr is None

        def h(n):
            x3 = g(3)
            x4 = g(3)
            x1 = g(n)
            build(x1, n)       # can collect!
            check(x1, n, 1)
            build(x3, 3)
            x2 = g(n // 2)       # allocate more and try again
            build(x2, n // 2)
            check(x1, n, 11)
            check(x2, n // 2, 12)
            build(x4, 3)
            check(x3, 3, 13)   # check these old objects too
            check(x4, 3, 14)   # check these old objects too
            rgc.collect()
            check(x1, n, 21)
            check(x2, n // 2, 22)
            check(x3, 3, 23)
            check(x4, 3, 24)

        def f():
            # numbers optimized for a 8MB space
            for n in [100000, 225000, 250000, 300000, 380000,
                      460000, 570000, 800000]:
                os.write(2, 'case %d\n' % n)
                rgc.collect()
                h(n)
            return -42

        return f

    def test_hash_overflow(self):
        res = self.run('hash_overflow')
        assert res == -42

    def define_hash_varsized(self):
        S = lltype.GcStruct('S', ('abc', lltype.Signed),
                                 ('def', lltype.Array(lltype.Signed)))
        s = lltype.malloc(S, 3, zero=True)
        h_s = lltype.identityhash(s)
        def f():
            return lltype.identityhash(s) - h_s    # != 0 (so far),
                                # because S is a varsized structure.
        return f

    def test_hash_varsized(self):
        res = self.run('hash_varsized')
        assert res != 0

    def define_arraycopy_writebarrier_int(cls):
        TP = lltype.GcArray(lltype.Signed)
        S = lltype.GcStruct('S')
        def fn():
            l = lltype.malloc(TP, 100)
            for i in range(100):
                l[i] = i * 3
            l2 = lltype.malloc(TP, 50)
            rgc.ll_arraycopy(l, l2, 40, 0, 50)
            # force a nursery collect
            x = []
            for i in range(20):
                x.append((1, lltype.malloc(S)))
            for i in range(50):
                assert l2[i] == (40 + i) * 3
            return 0

        return fn

    def test_arraycopy_writebarrier_int(self):
        self.run("arraycopy_writebarrier_int")

    def define_arraycopy_writebarrier_ptr(cls):
        TP = lltype.GcArray(lltype.Ptr(lltype.GcArray(lltype.Signed)))
        def fn():
            l = lltype.malloc(TP, 100)
            for i in range(100):
                l[i] = lltype.malloc(TP.OF.TO, i)
            l2 = lltype.malloc(TP, 50)
            rgc.ll_arraycopy(l, l2, 40, 0, 50)
            rgc.collect()
            for i in range(50):
                assert l2[i] == l[40 + i]
            return 0

        return fn

    def test_arraycopy_writebarrier_ptr(self):
        self.run("arraycopy_writebarrier_ptr")

    def define_get_rpy_roots(self):
        U = lltype.GcStruct('U', ('x', lltype.Signed))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))

        def g(s):
            lst = rgc.get_rpy_roots()
            found = False
            for x in lst:
                if x == lltype.cast_opaque_ptr(llmemory.GCREF, s):
                    found = True
                if x == lltype.cast_opaque_ptr(llmemory.GCREF, s.u):
                    os.write(2, "s.u should not be found!\n")
                    assert False
            return found == 1

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            found = g(s)
            if not found:
                os.write(2, "not found!\n")
                assert False
            s.u.x = 42
            return 0

        return fn

    def test_get_rpy_roots(self):
        self.run("get_rpy_roots")

    def define_get_rpy_referents(self):
        U = lltype.GcStruct('U', ('x', lltype.Signed))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            gcref1 = lltype.cast_opaque_ptr(llmemory.GCREF, s)
            gcref2 = lltype.cast_opaque_ptr(llmemory.GCREF, s.u)
            lst = rgc.get_rpy_referents(gcref1)
            assert gcref2 in lst
            assert gcref1 not in lst
            s.u.x = 42
            return 0

        return fn

    def test_get_rpy_referents(self):
        self.run("get_rpy_referents")

    def define_is_rpy_instance(self):
        class Foo:
            pass
        S = lltype.GcStruct('S', ('x', lltype.Signed))

        def check(gcref, expected):
            result = rgc._is_rpy_instance(gcref)
            assert result == expected

        def fn():
            s = lltype.malloc(S)
            gcref1 = lltype.cast_opaque_ptr(llmemory.GCREF, s)
            check(gcref1, False)

            f = Foo()
            gcref3 = rgc.cast_instance_to_gcref(f)
            check(gcref3, True)

            return 0

        return fn

    def test_is_rpy_instance(self):
        self.run("is_rpy_instance")

    def define_try_cast_gcref_to_instance(self):
        class Foo:
            pass
        class FooBar(Foo):
            pass
        class Biz(object):
            pass
        S = lltype.GcStruct('S', ('x', lltype.Signed))

        def fn():
            foo = Foo()
            gcref1 = rgc.cast_instance_to_gcref(foo)
            assert rgc.try_cast_gcref_to_instance(Foo,    gcref1) is foo
            assert rgc.try_cast_gcref_to_instance(FooBar, gcref1) is None
            assert rgc.try_cast_gcref_to_instance(Biz,    gcref1) is None

            foobar = FooBar()
            gcref2 = rgc.cast_instance_to_gcref(foobar)
            assert rgc.try_cast_gcref_to_instance(Foo,    gcref2) is foobar
            assert rgc.try_cast_gcref_to_instance(FooBar, gcref2) is foobar
            assert rgc.try_cast_gcref_to_instance(Biz,    gcref2) is None

            s = lltype.malloc(S)
            gcref3 = lltype.cast_opaque_ptr(llmemory.GCREF, s)
            assert rgc.try_cast_gcref_to_instance(Foo,    gcref3) is None
            assert rgc.try_cast_gcref_to_instance(FooBar, gcref3) is None
            assert rgc.try_cast_gcref_to_instance(Biz,    gcref3) is None

            return 0

        return fn

    def test_try_cast_gcref_to_instance(self):
        self.run("try_cast_gcref_to_instance")

    def define_get_rpy_memory_usage(self):
        U = lltype.GcStruct('U', ('x1', lltype.Signed),
                                 ('x2', lltype.Signed),
                                 ('x3', lltype.Signed),
                                 ('x4', lltype.Signed),
                                 ('x5', lltype.Signed),
                                 ('x6', lltype.Signed),
                                 ('x7', lltype.Signed),
                                 ('x8', lltype.Signed))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))
        A = lltype.GcArray(lltype.Ptr(S))

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            a = lltype.malloc(A, 1000)
            gcref1 = lltype.cast_opaque_ptr(llmemory.GCREF, s)
            int1 = rgc.get_rpy_memory_usage(gcref1)
            assert 8 <= int1 <= 32
            gcref2 = lltype.cast_opaque_ptr(llmemory.GCREF, s.u)
            int2 = rgc.get_rpy_memory_usage(gcref2)
            assert 4 * 9 <= int2 <= 8 * 12
            gcref3 = lltype.cast_opaque_ptr(llmemory.GCREF, a)
            int3 = rgc.get_rpy_memory_usage(gcref3)
            assert 4 * 1001 <= int3 <= 8 * 1010
            return 0

        return fn

    def test_get_rpy_memory_usage(self):
        self.run("get_rpy_memory_usage")

    def define_get_rpy_type_index(self):
        U = lltype.GcStruct('U', ('x', lltype.Signed))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))
        A = lltype.GcArray(lltype.Ptr(S))

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            a = lltype.malloc(A, 1000)
            s2 = lltype.malloc(S)
            gcref1 = lltype.cast_opaque_ptr(llmemory.GCREF, s)
            int1 = rgc.get_rpy_type_index(gcref1)
            gcref2 = lltype.cast_opaque_ptr(llmemory.GCREF, s.u)
            int2 = rgc.get_rpy_type_index(gcref2)
            gcref3 = lltype.cast_opaque_ptr(llmemory.GCREF, a)
            int3 = rgc.get_rpy_type_index(gcref3)
            gcref4 = lltype.cast_opaque_ptr(llmemory.GCREF, s2)
            int4 = rgc.get_rpy_type_index(gcref4)
            assert int1 != int2
            assert int1 != int3
            assert int2 != int3
            assert int1 == int4
            return 0

        return fn

    def test_get_rpy_type_index(self):
        self.run("get_rpy_type_index")

    filename1_dump = str(udir.join('test_dump_rpy_heap.1'))
    filename2_dump = str(udir.join('test_dump_rpy_heap.2'))
    def define_dump_rpy_heap(self):
        U = lltype.GcForwardReference()
        U.become(lltype.GcStruct('U', ('next', lltype.Ptr(U)),
                                 ('x', lltype.Signed)))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))
        A = lltype.GcArray(lltype.Ptr(S))
        filename1 = self.filename1_dump
        filename2 = self.filename2_dump

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            s.u.next = lltype.malloc(U)
            s.u.next.next = lltype.malloc(U)
            a = lltype.malloc(A, 1000)
            s2 = lltype.malloc(S)
            #
            fd1 = os.open(filename1, os.O_WRONLY | os.O_CREAT, 0666)
            fd2 = os.open(filename2, os.O_WRONLY | os.O_CREAT, 0666)
            # try to ensure we get twice the exact same output below
            gc.collect(); gc.collect(); gc.collect()
            rgc.dump_rpy_heap(fd1)
            rgc.dump_rpy_heap(fd2)      # try twice in a row
            keepalive_until_here(s2)
            keepalive_until_here(s)
            keepalive_until_here(a)
            os.close(fd1)
            os.close(fd2)
            return 0

        return fn

    def test_dump_rpy_heap(self):
        self.run("dump_rpy_heap")
        for fn in [self.filename1_dump, self.filename2_dump]:
            assert os.path.exists(fn)
            assert os.path.getsize(fn) > 64
        f = open(self.filename1_dump)
        data1 = f.read()
        f.close()
        f = open(self.filename2_dump)
        data2 = f.read()
        f.close()
        assert data1 == data2

    filename_dump_typeids_z = str(udir.join('test_typeids_z'))
    def define_write_typeids_z(self):
        U = lltype.GcForwardReference()
        U.become(lltype.GcStruct('U', ('next', lltype.Ptr(U)),
                                 ('x', lltype.Signed)))
        S = lltype.GcStruct('S', ('u', lltype.Ptr(U)))
        A = lltype.GcArray(lltype.Ptr(S))
        filename = self.filename_dump_typeids_z
        open_flags = os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0)

        def fn():
            s = lltype.malloc(S)
            s.u = lltype.malloc(U)
            s.u.next = lltype.malloc(U)
            s.u.next.next = lltype.malloc(U)
            a = lltype.malloc(A, 1000)
            s2 = lltype.malloc(S)
            #
            p = rgc.get_typeids_z()
            s = ''.join([p[i] for i in range(len(p))])
            fd = os.open(filename, open_flags, 0666)
            os.write(fd, s)
            os.close(fd)
            #
            a = rgc.get_typeids_list()
            assert len(a) > 1
            assert 0 < rffi.cast(lltype.Signed, a[1]) < 10000
            return 0

        return fn

    def test_write_typeids_z(self):
        self.run("write_typeids_z")
        f = open(self.filename_dump_typeids_z, 'rb')
        data_z = f.read()
        f.close()
        import zlib
        data = zlib.decompress(data_z)
        assert data.startswith('member0')
        assert 'GcArray of * GcStruct S {' in data

    def define_gcflag_extra(self):
        class A:
            pass
        a1 = A()
        def fn():
            a2 = A()
            if not rgc.has_gcflag_extra():
                return 0     # cannot test it then
            assert rgc.get_gcflag_extra(a1) == False
            assert rgc.get_gcflag_extra(a2) == False
            rgc.toggle_gcflag_extra(a1)
            assert rgc.get_gcflag_extra(a1) == True
            assert rgc.get_gcflag_extra(a2) == False
            rgc.toggle_gcflag_extra(a2)
            assert rgc.get_gcflag_extra(a1) == True
            assert rgc.get_gcflag_extra(a2) == True
            rgc.toggle_gcflag_extra(a1)
            assert rgc.get_gcflag_extra(a1) == False
            assert rgc.get_gcflag_extra(a2) == True
            rgc.toggle_gcflag_extra(a2)
            assert rgc.get_gcflag_extra(a1) == False
            assert rgc.get_gcflag_extra(a2) == False
            return 0
        return fn

    def test_gcflag_extra(self):
        self.run("gcflag_extra")

    def define_check_zero_works(self):
        S = lltype.GcStruct("s", ('x', lltype.Signed))
        S2 = lltype.GcStruct("s2", ('parent',
                                    lltype.Struct("s1", ("x", lltype.Signed))),
                                    ('y', lltype.Signed))
        A = lltype.GcArray(lltype.Signed)
        B = lltype.GcStruct("b", ('x', lltype.Signed),
                                 ('y', lltype.Array(lltype.Signed)))

        def fn():
            s = lltype.malloc(S, zero=True)
            assert s.x == 0
            s2 = lltype.malloc(S2, zero=True)
            assert s2.parent.x == 0
            a = lltype.malloc(A, 3, zero=True)
            assert a[2] == 0
            # XXX not supported right now in gctransform/framework.py:
            #b = lltype.malloc(B, 3, zero=True)
            #assert len(b.y) == 3
            #assert b.x == 0
            #assert b.y[0] == b.y[1] == b.y[2] == 0
            return 0
        return fn

    def test_check_zero_works(self):
        self.run("check_zero_works")

    def define_long_chain_of_instances(self):
        class A(object):
            def __init__(self, next):
                self.next = next
        a = None
        for i in range(1500):
            a = A(a)

        def fn():
            i = 0
            x = a
            while x is not None:
                i += 1
                x = x.next
            return i
        return fn

    def test_long_chain_of_instances(self):
        res = self.run("long_chain_of_instances")
        assert res == 1500
        

class TestSemiSpaceGC(UsingFrameworkTest, snippet.SemiSpaceGCTestDefines):
    gcpolicy = "semispace"
    should_be_moving = True
    GC_CAN_MOVE = True
    GC_CAN_SHRINK_ARRAY = True

    # for snippets
    large_tests_ok = True

    def define_many_ids(cls):
        from rpython.rlib.objectmodel import compute_unique_id
        class A(object):
            pass
        def f():
            from rpython.rtyper.lltypesystem import lltype, rffi
            alist = [A() for i in range(50000)]
            idarray = lltype.malloc(rffi.SIGNEDP.TO, len(alist), flavor='raw')
            # Compute the id of all elements of the list.  The goal is
            # to not allocate memory, so that if the GC needs memory to
            # remember the ids, it will trigger some collections itself
            i = 0
            while i < len(alist):
                idarray[i] = compute_unique_id(alist[i])
                i += 1
            j = 0
            while j < 2:
                if j == 1:     # allocate some stuff between the two iterations
                    [A() for i in range(20000)]
                i = 0
                while i < len(alist):
                    if idarray[i] != compute_unique_id(alist[i]):
                        return j * 1000000 + i
                    i += 1
                j += 1
            lltype.free(idarray, flavor='raw')
            return -2
        return f

    def test_many_ids(self):
        res = self.run('many_ids')
        assert res == -2

    def define_gc_set_max_heap_size(cls):
        def g(n):
            return 'x' * n
        def fn():
            # the semispace size starts at 8MB for now, so setting a
            # smaller limit has no effect
            # set to more than 32MB -- which should be rounded down to 32MB
            rgc.set_max_heap_size(32 * 1024 * 1024 + 20000)
            s1 = s2 = s3 = None
            try:
                s1 = g(400000)      # ~ 400 KB
                s2 = g(4000000)     # ~ 4 MB
                s3 = g(40000000)    # ~ 40 MB
            except MemoryError:
                pass
            return (s1 is not None) + (s2 is not None) + (s3 is not None)
        return fn

    def test_gc_set_max_heap_size(self):
        res = self.run('gc_set_max_heap_size')
        assert res == 2

    def define_gc_heap_stats(cls):
        S = lltype.GcStruct('S', ('x', lltype.Signed))
        l1 = []
        l2 = []
        l3 = []

        def f():
            for i in range(10):
                s = lltype.malloc(S)
                l1.append(s)
                l2.append(s)
                l3.append(s)
            tb = rgc._heap_stats()
            a = 0
            nr = 0
            b = 0
            c = 0
            for i in range(len(tb)):
                if tb[i].count == 10:      # the type of S
                    a += 1
                    nr = i
            for i in range(len(tb)):
                if tb[i].count == 3:       # the type GcArray(Ptr(S))
                    b += 1
                    c += tb[i].links[nr]
            # b can be 1 or 2 here since _heap_stats() is free to return or
            # ignore the three GcStructs that point to the GcArray(Ptr(S)).
            # important one is c, a is for check
            return c * 100 + b * 10 + a
        return f

    def test_gc_heap_stats(self):
        res = self.run("gc_heap_stats")
        assert res == 3011 or res == 3021

    def definestr_string_builder(cls):
        def fn(_):
            s = StringBuilder()
            s.append("a")
            s.append("abc")
            s.append_slice("abc", 1, 2)
            s.append_multiple_char('d', 4)
            return s.build()
        return fn

    def test_string_builder(self):
        res = self.run('string_builder')
        assert res == "aabcbdddd"

    def definestr_string_builder_over_allocation(cls):
        def fn(_):
            s = StringBuilder(4)
            s.append("abcd")
            s.append("defg")
            s.append("rty")
            s.append_multiple_char('y', 1000)
            gc.collect()
            s.append_multiple_char('y', 1000)
            res = s.build()
            gc.collect()
            return res
        return fn

    def test_string_builder_over_allocation(self):
        res = self.run('string_builder_over_allocation')
        assert res[1000] == 'y'

    def definestr_string_builder_multiple_builds(cls):
        def fn(_):
            s = StringBuilder(4)
            got = []
            for i in range(50):
                s.append(chr(33+i))
                got.append(s.build())
                gc.collect()
            return ' '.join(got)
        return fn

    def test_string_builder_multiple_builds(self):
        res = self.run('string_builder_multiple_builds')
        assert res == ' '.join([''.join(map(chr, range(33, 33+length)))
                                for length in range(1, 51)])

    def definestr_string_builder_multiple_builds_2(cls):
        def fn(_):
            got = []
            for j in range(3, 76, 5):
                s = StringBuilder()
                for i in range(j):
                    s.append(chr(33+i))
                    gc.collect()
                got.append(s.build())
            return ' '.join(got)
        return fn

    def test_string_builder_multiple_builds_2(self):
        res = self.run('string_builder_multiple_builds_2')
        assert res == ' '.join([''.join(map(chr, range(33, 33+length)))
                                for length in range(3, 76, 5)])

    def define_nursery_hash_base(cls):
        from rpython.rlib.debug import debug_print
        
        class A:
            pass
        def fn():
            objects = []
            hashes = []
            for i in range(200):
                debug_print("starting nursery collection", i)
                rgc.collect(0)     # nursery-only collection, if possible
                debug_print("finishing nursery collection", i)
                obj = A()
                objects.append(obj)
                hashes.append(compute_identity_hash(obj))
            unique = {}
            debug_print("objects", len(objects))
            for i in range(len(objects)):
                debug_print(i)
                assert compute_identity_hash(objects[i]) == hashes[i]
                debug_print("storing in dict")
                unique[hashes[i]] = None
                debug_print("done")
            debug_print("finished")
            return len(unique)
        return fn

    def test_nursery_hash_base(self):
        res = self.run('nursery_hash_base')
        assert res >= 195

    def define_extra_item_after_alloc(cls):
        from rpython.rtyper.lltypesystem import rstr
        # all STR objects should be allocated with enough space for
        # one extra char.  Check this with our GCs.  Use strings of 8,
        # 16 and 24 chars because if the extra char is missing,
        # writing to it is likely to cause corruption in nearby
        # structures.
        sizes = [random.choice([8, 16, 24]) for i in range(100)]
        A = lltype.Struct('A', ('x', lltype.Signed))
        prebuilt = [(rstr.mallocstr(sz),
                     lltype.malloc(A, flavor='raw', immortal=True))
                        for sz in sizes]
        k = 0
        for i, (s, a) in enumerate(prebuilt):
            a.x = i
            for i in range(len(s.chars)):
                k += 1
                if k == 256:
                    k = 1
                s.chars[i] = chr(k)

        def check(lst):
            hashes = []
            for i, (s, a) in enumerate(lst):
                assert a.x == i
                rgc.ll_write_final_null_char(s)
            for i, (s, a) in enumerate(lst):
                assert a.x == i     # check it was not overwritten
        def fn():
            check(prebuilt)
            lst1 = []
            for i, sz in enumerate(sizes):
                s = rstr.mallocstr(sz)
                a = lltype.malloc(A, flavor='raw')
                a.x = i
                lst1.append((s, a))
            check(lst1)
            for _, a in lst1:
                lltype.free(a, flavor='raw')
            return 42
        return fn

    def test_extra_item_after_alloc(self):
        res = self.run('extra_item_after_alloc')
        assert res == 42


class TestGenerationalGC(TestSemiSpaceGC):
    gcpolicy = "generation"
    should_be_moving = True


class TestHybridGC(TestGenerationalGC):
    gcpolicy = "hybrid"
    should_be_moving = True

    def test_gc_set_max_heap_size(self):
        py.test.skip("not implemented")


class TestHybridGCRemoveTypePtr(TestHybridGC):
    removetypeptr = True


class TestMiniMarkGC(TestSemiSpaceGC):
    gcpolicy = "minimark"
    should_be_moving = True
    GC_CAN_SHRINK_ARRAY = True

    def test_gc_heap_stats(self):
        py.test.skip("not implemented")

    def define_nongc_attached_to_gc(cls):
        from rpython.rtyper.lltypesystem import rffi
        ARRAY = rffi.CArray(rffi.INT)
        class A:
            def __init__(self, n):
                self.buf = lltype.malloc(ARRAY, n, flavor='raw',
                                         add_memory_pressure=True)
            def __del__(self):
                lltype.free(self.buf, flavor='raw')
        A(6)
        def f():
            # allocate a total of ~77GB, but if the automatic gc'ing works,
            # it should never need more than a few MBs at once
            am1 = am2 = am3 = None
            res = 0
            for i in range(1, 100001):
                if am3 is not None:
                    res += rffi.cast(lltype.Signed, am3.buf[0])
                am3 = am2
                am2 = am1
                am1 = A(i * 4)
                am1.buf[0] = rffi.cast(rffi.INT, i - 50000)
            return res
        return f

    def test_nongc_attached_to_gc(self):
        res = self.run("nongc_attached_to_gc")
        assert res == -99997

    def define_nongc_opaque_attached_to_gc(cls):
        from rpython.rlib import rgc, ropenssl

        class A:
            def __init__(self):
                self.ctx = lltype.malloc(ropenssl.EVP_MD_CTX.TO,
                    flavor='raw')
                digest = ropenssl.EVP_get_digestbyname('sha1')
                ropenssl.EVP_DigestInit(self.ctx, digest)
                rgc.add_memory_pressure(ropenssl.HASH_MALLOC_SIZE + 64)

            def __del__(self):
                ropenssl.EVP_MD_CTX_cleanup(self.ctx)
                lltype.free(self.ctx, flavor='raw')
        #A() --- can't call it here?? get glibc crashes on tannit64
        def f():
            am1 = am2 = am3 = None
            for i in range(100000):
                am3 = am2
                am2 = am1
                am1 = A()
            # what can we use for the res?
            return 0
        return f

    def test_nongc_opaque_attached_to_gc(self):
        res = self.run("nongc_opaque_attached_to_gc")
        assert res == 0

    def define_limited_memory(self):
        class A(object):
            def __init__(self, next):
                self.next = next
        def g(i):
            a = None
            while i != 0:
                a = A(a)
                i -= 1
            return 0
        def f(i):
            try:
                return g(i)
            except MemoryError:
                g(20)       # allocate some more stuff, but exit
                return 42
        return f

    def test_limited_memory(self):
        import random
        #
        def myrunner(args):
            env = os.environ.copy()
            env['PYPY_GC_MAX'] = '%dKB' % gcmax
            return subprocess.check_output(args, env=env)
        #
        for i in range(10):
            gcmax = random.randrange(50000, 100000)
            print gcmax
            res = self.run("limited_memory", -1, runner=myrunner)
            assert res == 42


class TestIncrementalMiniMarkGC(TestMiniMarkGC):
    gcpolicy = "incminimark"

    def define_random_pin(self):
        class A:
            foo = None
            bar = '..'
        def f():
            alist = [A()]
            slist = ['..']
            i = 0
            j = 0
            k = 0
            while i < 400000:
                k = (k * 1291 + i) % 4603
                a = A()
                if k < 1000:
                    alist.append(a)
                elif k < 2000:
                    j = (i * k)
                    alist[j % len(alist)].foo = alist[(j+i) % len(alist)]
                elif k < 3000:
                    alist[i % len(alist)].bar = slist[(j+i) % len(slist)]
                elif k < 4000:
                    slist.append(chr(i & 255) + chr(k & 255))
                elif k < 4100 and len(alist) > 1:
                    drop = alist.pop()
                    alist[i % len(alist)] = drop
                elif k < 4200 and len(slist) > 1:
                    drop = slist.pop()
                    slist[i % len(slist)] = drop
                elif k < 4300:
                    rgc.pin(slist[i % len(slist)])      # <------ pin!
                keepalive_until_here(a)
                i += 1
            n = 0
            m = 0
            for i in range(len(alist)):
                a = alist[i]
                if a.foo is None:
                    n -= 1
                else:
                    n += ord(a.foo.bar[0])
                    m += ord(a.foo.bar[1])
            return m - n
        assert f() == 28495
        return f

    def test_random_pin(self):
        res = self.run("random_pin")
        assert res == 28495

    define_limited_memory_linux = TestMiniMarkGC.define_limited_memory.im_func

    def test_limited_memory_linux(self):
        if not sys.platform.startswith('linux'):
            py.test.skip("linux only")
        #
        import random
        #
        def myrunner(args):
            args1 = ['/bin/bash', '-c', 'ulimit -v %d && %s' %
                     (ulimitv, ' '.join(args),)]
            popen = subprocess.Popen(args1, stderr=subprocess.PIPE)
            _, child_stderr = popen.communicate()
            assert popen.wait() == 134     # aborted
            assert 'out of memory:' in child_stderr
            return '42'
        #
        for i in range(10):
            ulimitv = random.randrange(50000, 100000)
            print ulimitv
            res = self.run("limited_memory_linux", -1, runner=myrunner)
            assert res == 42


# ____________________________________________________________________

class TaggedPointersTest(object):
    taggedpointers = True

    def define_tagged(cls):
        class Unrelated(object):
            pass

        u = Unrelated()
        u.x = UnboxedObject(47)
        def fn(n):
            rgc.collect() # check that a prebuilt tagged pointer doesn't explode
            if n > 0:
                x = BoxedObject(n)
            else:
                x = UnboxedObject(n)
            u.x = x # invoke write barrier
            rgc.collect()
            return x.meth(100)
        def func():
            return fn(1000) + fn(-1000)
        return func

    def test_tagged(self):
        expected = self.run_orig("tagged")
        res = self.run("tagged")
        assert res == expected

    def define_erased(cls):
        from rpython.rlib import rerased
        erase, unerase = rerased.new_erasing_pair("test")
        class Unrelated(object):
            pass

        u = Unrelated()
        u.tagged = True
        u.x = rerased.erase_int(41)
        class A(object):
            pass
        def fn():
            n = 1
            while n >= 0:
                if u.tagged:
                    n = rerased.unerase_int(u.x)
                    a = A()
                    a.n = n - 1
                    u.x = erase(a)
                    u.tagged = False
                else:
                    n = unerase(u.x).n
                    u.x = rerased.erase_int(n - 1)
                    u.tagged = True
        def func():
            rgc.collect() # check that a prebuilt erased integer doesn't explode
            u.x = rerased.erase_int(1000)
            u.tagged = True
            fn()
            return 1
        return func

    def test_erased(self):
        expected = self.run_orig("erased")
        res = self.run("erased")
        assert res == expected

from rpython.rlib.objectmodel import UnboxedValue

class TaggedBase(object):
    __slots__ = ()
    def meth(self, x):
        raise NotImplementedError

class BoxedObject(TaggedBase):
    attrvalue = 66
    def __init__(self, normalint):
        self.normalint = normalint
    def meth(self, x):
        return self.normalint + x + 2

class UnboxedObject(TaggedBase, UnboxedValue):
    __slots__ = 'smallint'
    def meth(self, x):
        return self.smallint + x + 3


class TestHybridTaggedPointers(TaggedPointersTest, TestHybridGC):
    pass


class TestMiniMarkGCMostCompact(TaggedPointersTest, TestMiniMarkGC):
    removetypeptr = True

class TestIncrementalMiniMarkGCMostCompact(TaggedPointersTest, TestIncrementalMiniMarkGC):
    removetypeptr = True