diff options
| -rw-r--r-- | Lib/test/test_gdb.py | 101 | ||||
| -rw-r--r-- | Misc/NEWS | 9 | ||||
| -rw-r--r-- | Tools/gdb/libpython.py | 101 |
3 files changed, 200 insertions, 11 deletions
diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py index fd1275c..27fccd6 100644 --- a/Lib/test/test_gdb.py +++ b/Lib/test/test_gdb.py @@ -11,6 +11,12 @@ import sysconfig import unittest import locale +# Is this Python configured to support threads? +try: + import _thread +except ImportError: + _thread = None + from test.support import run_unittest, findfile, python_is_optimized try: @@ -151,7 +157,6 @@ class DebuggerTests(unittest.TestCase): # Ensure no unexpected error messages: self.assertEqual(err, '') - return out def get_gdb_repr(self, source, @@ -172,7 +177,7 @@ class DebuggerTests(unittest.TestCase): # gdb can insert additional '\n' and space characters in various places # in its output, depending on the width of the terminal it's connected # to (using its "wrap_here" function) - m = re.match('.*#0\s+builtin_id\s+\(self\=.*,\s+v=\s*(.*?)\)\s+at\s+Python/bltinmodule.c.*', + m = re.match('.*#0\s+builtin_id\s+\(self\=.*,\s+v=\s*(.*?)\)\s+at\s+\S*Python/bltinmodule.c.*', gdb_output, re.DOTALL) if not m: self.fail('Unexpected gdb output: %r\n%s' % (gdb_output, gdb_output)) @@ -671,6 +676,98 @@ Traceback \(most recent call first\): foo\(1, 2, 3\) ''') + @unittest.skipUnless(_thread, + "Python was compiled without thread support") + def test_threads(self): + 'Verify that "py-bt" indicates threads that are waiting for the GIL' + cmd = ''' +from threading import Thread + +class TestThread(Thread): + # These threads would run forever, but we'll interrupt things with the + # debugger + def run(self): + i = 0 + while 1: + i += 1 + +t = {} +for i in range(4): + t[i] = TestThread() + t[i].start() + +# Trigger a breakpoint on the main thread +id(42) + +''' + # Verify with "py-bt": + gdb_output = self.get_stack_trace(cmd, + cmds_after_breakpoint=['thread apply all py-bt']) + self.assertIn('Waiting for the GIL', gdb_output) + + # Verify with "py-bt-full": + gdb_output = self.get_stack_trace(cmd, + cmds_after_breakpoint=['thread apply all py-bt-full']) + self.assertIn('Waiting for the GIL', gdb_output) + + @unittest.skipIf(python_is_optimized(), + "Python was compiled with optimizations") + # Some older versions of gdb will fail with + # "Cannot find new threads: generic error" + # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround + @unittest.skipUnless(_thread, + "Python was compiled without thread support") + def test_gc(self): + 'Verify that "py-bt" indicates if a thread is garbage-collecting' + cmd = ('from gc import collect\n' + 'id(42)\n' + 'def foo():\n' + ' collect()\n' + 'def bar():\n' + ' foo()\n' + 'bar()\n') + # Verify with "py-bt": + gdb_output = self.get_stack_trace(cmd, + cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt'], + ) + self.assertIn('Garbage-collecting', gdb_output) + + # Verify with "py-bt-full": + gdb_output = self.get_stack_trace(cmd, + cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt-full'], + ) + self.assertIn('Garbage-collecting', gdb_output) + + @unittest.skipIf(python_is_optimized(), + "Python was compiled with optimizations") + # Some older versions of gdb will fail with + # "Cannot find new threads: generic error" + # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround + @unittest.skipUnless(_thread, + "Python was compiled without thread support") + def test_pycfunction(self): + 'Verify that "py-bt" displays invocations of PyCFunction instances' + cmd = ('from time import sleep\n' + 'def foo():\n' + ' sleep(1)\n' + 'def bar():\n' + ' foo()\n' + 'bar()\n') + # Verify with "py-bt": + gdb_output = self.get_stack_trace(cmd, + breakpoint='time_sleep', + cmds_after_breakpoint=['bt', 'py-bt'], + ) + self.assertIn('<built-in method sleep', gdb_output) + + # Verify with "py-bt-full": + gdb_output = self.get_stack_trace(cmd, + breakpoint='time_sleep', + cmds_after_breakpoint=['py-bt-full'], + ) + self.assertIn('#0 <built-in method sleep', gdb_output) + + class PyPrintTests(DebuggerTests): @unittest.skipIf(python_is_optimized(), "Python was compiled with optimizations") @@ -22,6 +22,15 @@ Extension Modules - Issue #15194: Update libffi to the 3.0.11 release. +Tools/Demos +----------- + +- Issue #12605: The gdb hooks for debugging CPython (within Tools/gdb) have + been enhanced to show information on more C frames relevant to CPython within + the "py-bt" and "py-bt-full" commands: + * C frames that are waiting on the GIL + * C frames that are garbage-collecting + * C frames that are due to the invocation of a PyCFunction What's New in Python 3.3.0 Beta 1? ================================== diff --git a/Tools/gdb/libpython.py b/Tools/gdb/libpython.py index cf67cf8..2cdc3da 100644 --- a/Tools/gdb/libpython.py +++ b/Tools/gdb/libpython.py @@ -1390,6 +1390,23 @@ class Frame(object): iter_frame = iter_frame.newer() return index + # We divide frames into: + # - "python frames": + # - "bytecode frames" i.e. PyEval_EvalFrameEx + # - "other python frames": things that are of interest from a python + # POV, but aren't bytecode (e.g. GC, GIL) + # - everything else + + def is_python_frame(self): + '''Is this a PyEval_EvalFrameEx frame, or some other important + frame? (see is_other_python_frame for what "important" means in this + context)''' + if self.is_evalframeex(): + return True + if self.is_other_python_frame(): + return True + return False + def is_evalframeex(self): '''Is this a PyEval_EvalFrameEx frame?''' if self._gdbframe.name() == 'PyEval_EvalFrameEx': @@ -1406,6 +1423,49 @@ class Frame(object): return False + def is_other_python_frame(self): + '''Is this frame worth displaying in python backtraces? + Examples: + - waiting on the GIL + - garbage-collecting + - within a CFunction + If it is, return a descriptive string + For other frames, return False + ''' + if self.is_waiting_for_gil(): + return 'Waiting for the GIL' + elif self.is_gc_collect(): + return 'Garbage-collecting' + else: + # Detect invocations of PyCFunction instances: + older = self.older() + if older and older._gdbframe.name() == 'PyCFunction_Call': + # Within that frame: + # "func" is the local containing the PyObject* of the + # PyCFunctionObject instance + # "f" is the same value, but cast to (PyCFunctionObject*) + # "self" is the (PyObject*) of the 'self' + try: + # Use the prettyprinter for the func: + func = older._gdbframe.read_var('func') + return str(func) + except RuntimeError: + return 'PyCFunction invocation (unable to read "func")' + + # This frame isn't worth reporting: + return False + + def is_waiting_for_gil(self): + '''Is this frame waiting on the GIL?''' + # This assumes the _POSIX_THREADS version of Python/ceval_gil.h: + name = self._gdbframe.name() + if name: + return name.startswith('pthread_cond_timedwait') + + def is_gc_collect(self): + '''Is this frame "collect" within the the garbage-collector?''' + return self._gdbframe.name() == 'collect' + def get_pyop(self): try: f = self._gdbframe.read_var('f') @@ -1435,8 +1495,22 @@ class Frame(object): @classmethod def get_selected_python_frame(cls): - '''Try to obtain the Frame for the python code in the selected frame, - or None''' + '''Try to obtain the Frame for the python-related code in the selected + frame, or None''' + frame = cls.get_selected_frame() + + while frame: + if frame.is_python_frame(): + return frame + frame = frame.older() + + # Not found: + return None + + @classmethod + def get_selected_bytecode_frame(cls): + '''Try to obtain the Frame for the python bytecode interpreter in the + selected GDB frame, or None''' frame = cls.get_selected_frame() while frame: @@ -1460,7 +1534,11 @@ class Frame(object): else: sys.stdout.write('#%i (unable to read python frame information)\n' % self.get_index()) else: - sys.stdout.write('#%i\n' % self.get_index()) + info = self.is_other_python_frame() + if info: + sys.stdout.write('#%i %s\n' % (self.get_index(), info)) + else: + sys.stdout.write('#%i\n' % self.get_index()) def print_traceback(self): if self.is_evalframeex(): @@ -1474,7 +1552,11 @@ class Frame(object): else: sys.stdout.write(' (unable to read python frame information)\n') else: - sys.stdout.write(' (not a python frame)\n') + info = self.is_other_python_frame() + if info: + sys.stdout.write(' %s\n' % info) + else: + sys.stdout.write(' (not a python frame)\n') class PyList(gdb.Command): '''List the current Python source code, if any @@ -1510,9 +1592,10 @@ class PyList(gdb.Command): if m: start, end = map(int, m.groups()) - frame = Frame.get_selected_python_frame() + # py-list requires an actual PyEval_EvalFrameEx frame: + frame = Frame.get_selected_bytecode_frame() if not frame: - print 'Unable to locate python frame' + print 'Unable to locate gdb frame for python bytecode interpreter' return pyop = frame.get_pyop() @@ -1564,7 +1647,7 @@ def move_in_stack(move_up): if not iter_frame: break - if iter_frame.is_evalframeex(): + if iter_frame.is_python_frame(): # Result: if iter_frame.select(): iter_frame.print_summary() @@ -1618,7 +1701,7 @@ class PyBacktraceFull(gdb.Command): def invoke(self, args, from_tty): frame = Frame.get_selected_python_frame() while frame: - if frame.is_evalframeex(): + if frame.is_python_frame(): frame.print_summary() frame = frame.older() @@ -1637,7 +1720,7 @@ class PyBacktrace(gdb.Command): sys.stdout.write('Traceback (most recent call first):\n') frame = Frame.get_selected_python_frame() while frame: - if frame.is_evalframeex(): + if frame.is_python_frame(): frame.print_traceback() frame = frame.older() |