Author: Armin Rigo <ar...@tunes.org>
Branch: stm
Changeset: r51487:b52f0e138410
Date: 2012-01-19 16:14 +0100
http://bitbucket.org/pypy/pypy/changeset/b52f0e138410/
Log: (bivab, arigo)
Wrote the app-level interface for 'transaction', with careful(?)
messy locking.
diff --git a/pypy/module/transaction/__init__.py
b/pypy/module/transaction/__init__.py
new file mode 100644
--- /dev/null
+++ b/pypy/module/transaction/__init__.py
@@ -0,0 +1,20 @@
+
+from pypy.interpreter.mixedmodule import MixedModule
+
+class Module(MixedModule):
+ """Transaction module. XXX document me
+ """
+
+ interpleveldefs = {
+ 'set_num_threads': 'interp_transaction.set_num_threads',
+ 'add': 'interp_transaction.add',
+ 'run': 'interp_transaction.run',
+ 'TransactionError': 'interp_transaction.state.w_error',
+ }
+
+ appleveldefs = {
+ }
+
+ def startup(self, space):
+ from pypy.module.transaction import interp_transaction
+ interp_transaction.state.startup(space)
diff --git a/pypy/module/transaction/interp_transaction.py
b/pypy/module/transaction/interp_transaction.py
new file mode 100644
--- /dev/null
+++ b/pypy/module/transaction/interp_transaction.py
@@ -0,0 +1,138 @@
+from pypy.interpreter.error import OperationError
+from pypy.interpreter.gateway import unwrap_spec
+from pypy.module.transaction import threadintf
+
+
+NUM_THREADS_DEFAULT = 4 # by default
+
+
+class State(object):
+
+ def _freeze_(self):
+ self.__dict__.clear()
+ self.running = False
+ self.num_threads = NUM_THREADS_DEFAULT
+
+ def startup(self, space):
+ self.space = space
+ self.pending = []
+ self.ll_lock = threadintf.allocate_lock()
+ self.ll_no_tasks_pending_lock = threadintf.allocate_lock()
+ self.ll_unfinished_lock = threadintf.allocate_lock()
+ self.w_error = space.new_exception_class(
+ "transaction.TransactionError")
+ self.lock_no_tasks_pending()
+ self.lock_unfinished()
+
+ def set_num_threads(self, num):
+ if self.running:
+ space = self.space
+ raise OperationError(space.w_ValueError,
+ space.wrap("cannot change the number of "
+ "threads when transaction.run() "
+ "is active"))
+ self.num_threads = num_threads
+
+ def lock(self):
+ # XXX think about the interaction between locks and the GC
+ threadintf.acquire(self.ll_lock, True)
+
+ def unlock(self):
+ threadintf.release(self.ll_lock)
+
+ def lock_no_tasks_pending(self):
+ threadintf.acquire(self.ll_no_tasks_pending_lock, True)
+
+ def unlock_no_tasks_pending(self):
+ threadintf.release(self.ll_no_tasks_pending_lock)
+
+ def assert_locked_no_tasks_pending(self):
+ just_locked = threadintf.acquire(self.ll_no_tasks_pending_lock, False)
+ assert not just_locked
+
+ def lock_unfinished(self):
+ threadintf.acquire(self.ll_unfinished_lock, True)
+
+ def unlock_unfinished(self):
+ threadintf.release(self.ll_unfinished_lock)
+
+
+state = State()
+state._freeze_()
+
+
+@unwrap_spec(num=int)
+def set_num_threads(space, num):
+ if num < 1:
+ num = 1
+ state.set_num_threads(num)
+
+
+class Pending:
+ def __init__(self, w_callback, args):
+ self.w_callback = w_callback
+ self.args = args
+
+ def run(self):
+ space = state.space
+ space.call_args(self.w_callback, self.args)
+ # xxx exceptions?
+
+
+def add(space, w_callback, __args__):
+ state.lock()
+ was_empty = len(state.pending) == 0
+ state.pending.append(Pending(w_callback, __args__))
+ if was_empty:
+ state.unlock_no_tasks_pending()
+ state.unlock()
+
+
+def _run_thread():
+ state.lock()
+ #
+ while True:
+ if len(state.pending) == 0:
+ state.assert_locked_no_tasks_pending()
+ state.num_waiting_threads += 1
+ if state.num_waiting_threads == state.num_threads:
+ state.finished = True
+ state.unlock_unfinished()
+ state.unlock_no_tasks_pending()
+ state.unlock()
+ #
+ state.lock_no_tasks_pending()
+ state.unlock_no_tasks_pending()
+ #
+ state.lock()
+ if state.finished:
+ break
+ state.num_waiting_threads -= 1
+ else:
+ pending = state.pending.pop(0)
+ if len(state.pending) == 0:
+ state.lock_no_tasks_pending()
+ state.unlock()
+ pending.run()
+ state.lock()
+ #
+ state.unlock()
+
+
+def run(space):
+ if state.running:
+ raise OperationError(
+ state.w_error,
+ space.wrap("recursive invocation of transaction.run()"))
+ state.num_waiting_threads = 0
+ state.finished = False
+ state.running = True
+ #
+ for i in range(state.num_threads):
+ threadintf.start_new_thread(_run_thread, ())
+ #
+ state.lock_unfinished()
+ assert state.num_waiting_threads == state.num_threads
+ assert len(state.pending) == 0
+ state.lock_no_tasks_pending()
+ state.running = False
diff --git a/pypy/module/transaction/test/__init__.py
b/pypy/module/transaction/test/__init__.py
new file mode 100644
diff --git a/pypy/module/transaction/test/test_interp_transaction.py
b/pypy/module/transaction/test/test_interp_transaction.py
new file mode 100644
--- /dev/null
+++ b/pypy/module/transaction/test/test_interp_transaction.py
@@ -0,0 +1,24 @@
+from pypy.module.transaction import interp_transaction
+
+
+class FakeSpace:
+ def new_exception_class(self, name):
+ return "some error class"
+ def call_args(self, w_callback, args):
+ w_callback(*args)
+
+
+def test_linear_list():
+ space = FakeSpace()
+ interp_transaction.state.startup(space)
+ seen = []
+ #
+ def do(n):
+ seen.append(n)
+ if n < 200:
+ interp_transaction.add(space, do, (n+1,))
+ #
+ interp_transaction.add(space, do, (0,))
+ assert seen == []
+ interp_transaction.run(space)
+ assert seen == range(201)
diff --git a/pypy/module/transaction/test/test_transaction.py
b/pypy/module/transaction/test/test_transaction.py
new file mode 100644
--- /dev/null
+++ b/pypy/module/transaction/test/test_transaction.py
@@ -0,0 +1,16 @@
+import py
+from pypy.conftest import gettestobjspace
+
+
+class AppTestTransaction:
+ def setup_class(cls):
+ cls.space = gettestobjspace(usemodules=['transaction'])
+
+ def test_simple(self):
+ import transaction
+ lst = []
+ transaction.add(lst.append, 5)
+ transaction.add(lst.append, 6)
+ transaction.add(lst.append, 7)
+ transaction.run()
+ assert sorted(lst) == [5, 6, 7]
diff --git a/pypy/module/transaction/threadintf.py
b/pypy/module/transaction/threadintf.py
new file mode 100644
--- /dev/null
+++ b/pypy/module/transaction/threadintf.py
@@ -0,0 +1,19 @@
+import thread
+
+
+def allocate_lock():
+ "NOT_RPYTHON"
+ return thread.allocate_lock()
+
+def acquire(lock, wait):
+ "NOT_RPYTHON"
+ lock.acquire(wait)
+
+def release(lock):
+ "NOT_RPYTHON"
+ lock.release()
+
+def start_new_thread(callback, args):
+ "NOT_RPYTHON"
+ thread.start_new_thread(callback, args)
+
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