[pypy-commit] pypy stm-gc: Started work on the STM GC.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: stm-gc
Changeset: r52023:beaddf970c53
Date: 2012-02-01 16:53 +0100
http://bitbucket.org/pypy/pypy/changeset/beaddf970c53/

Log:	Started work on the STM GC.

diff --git a/pypy/rpython/memory/gc/stmgc.py b/pypy/rpython/memory/gc/stmgc.py
new file mode 100644
--- /dev/null
+++ b/pypy/rpython/memory/gc/stmgc.py
@@ -0,0 +1,92 @@
+from pypy.rpython.lltypesystem import lltype, llmemory, llarena
+from pypy.rpython.memory.gc.base import GCBase
+from pypy.rlib.rarithmetic import LONG_BIT
+
+
+WORD = LONG_BIT // 8
+NULL = llmemory.NULL
+
+first_gcflag = 1 << (LONG_BIT//2)
+
+GCFLAG_GLOBAL     = first_gcflag << 0
+GCFLAG_WAS_COPIED = first_gcflag << 1
+
+
+def always_inline(fn):
+    fn._always_inline_ = True
+    return fn
+def dont_inline(fn):
+    fn._dont_inline_ = True
+    return fn
+
+
+class StmOperations(object):
+    def _freeze_(self):
+        return True
+
+
+class StmGC(GCBase):
+    _alloc_flavor_ = "raw"
+    inline_simple_malloc = True
+    inline_simple_malloc_varsize = True
+    needs_write_barrier = "stm"
+    prebuilt_gc_objects_are_static_roots = False
+    malloc_zero_filled = True    # xxx?
+
+    HDR = lltype.Struct('header', ('tid', lltype.Signed),
+                                  ('version', lltype.Signed))
+    typeid_is_in_field = 'tid'
+    withhash_flag_is_in_field = 'tid', 'XXX'
+
+    GCTLS = lltype.Struct('GCTLS', ('nursery_free', llmemory.Address),
+                                   ('nursery_top', llmemory.Address),
+                                   ('nursery_start', llmemory.Address),
+                                   ('nursery_size', lltype.Signed))
+
+
+    def __init__(self, config, stm_operations,
+                 max_nursery_size=1024,
+                 **kwds):
+        GCBase.__init__(self, config, **kwds)
+        self.stm_operations = stm_operations
+        self.max_nursery_size = max_nursery_size
+
+
+    def setup(self):
+        """Called at run-time to initialize the GC."""
+        GCBase.setup(self)
+        self.setup_thread()
+
+    def _alloc_nursery(self):
+        nursery = llarena.arena_malloc(self.max_nursery_size, 1)
+        if not nursery:
+            raise MemoryError("cannot allocate nursery")
+        return nursery
+
+    def setup_thread(self):
+        tls = lltype.malloc(self.GCTLS, flavor='raw')
+        self.stm_operations.set_tls(llmemory.cast_ptr_to_adr(tls))
+        tls.nursery_start = self._alloc_nursery()
+        tls.nursery_size  = self.max_nursery_size
+        tls.nursery_free  = tls.nursery_start
+        tls.nursery_top   = tls.nursery_start + tls.nursery_size
+
+    @always_inline
+    def get_tls(self):
+        tls = self.stm_operations.get_tls()
+        return llmemory.cast_adr_to_ptr(tls, lltype.Ptr(self.GCTLS))
+
+    @always_inline
+    def allocate_bump_pointer(self, size):
+        tls = self.get_tls()
+        free = tls.nursery_free
+        top  = tls.nursery_top
+        new  = free + size
+        tls.nursery_free = new
+        if new > top:
+            free = self.local_collection(free)
+        return free
+
+    @dont_inline
+    def local_collection(self, oldfree):
+        raise MemoryError("nursery exhausted")   # XXX for now
diff --git a/pypy/rpython/memory/gc/test/test_stmgc.py b/pypy/rpython/memory/gc/test/test_stmgc.py
new file mode 100644
--- /dev/null
+++ b/pypy/rpython/memory/gc/test/test_stmgc.py
@@ -0,0 +1,35 @@
+from pypy.rpython.lltypesystem import lltype, llmemory
+from pypy.rpython.memory.gc.stmgc import StmGC
+
+
+class FakeStmOperations:
+    def set_tls(self, tls):
+        assert lltype.typeOf(tls) == llmemory.Address
+        self._tls = tls
+
+    def get_tls(self):
+        return self._tls
+
+
+class TestBasic:
+    GCClass = StmGC
+
+    def setup_method(self, meth):
+        from pypy.config.pypyoption import get_pypy_config
+        config = get_pypy_config(translating=True).translation
+        self.gc = self.GCClass(config, FakeStmOperations(),
+                               translated_to_c=False)
+        self.gc.DEBUG = True
+        self.gc.setup()
+
+    def test_gc_creation_works(self):
+        pass
+
+    def test_allocate_bump_pointer(self):
+        a3 = self.gc.allocate_bump_pointer(3)
+        a4 = self.gc.allocate_bump_pointer(4)
+        a5 = self.gc.allocate_bump_pointer(5)
+        a6 = self.gc.allocate_bump_pointer(6)
+        assert a4 - a3 == 3
+        assert a5 - a4 == 4
+        assert a6 - a5 == 5