bpo-5001: More-informative multiprocessing error messages (#3079)
* Make error message more informative
Replace assertions in error-reporting code with more-informative version that doesn't cause confusion over where and what the error is.
* Additional clarification + get travis to check
* Change from SystemError to TypeError
As suggested in PR comment by @pitrou, changing from SystemError; TypeError appears appropriate.
* NEWS file installation; ACKS addition (will do my best to justify it by additional work)
* Making current AssertionErrors in multiprocessing more informative
* Blurb added re multiprocessing managers.py, queues.py cleanup
* Further multiprocessing cleanup - went through pool.py
* Fix two asserts in multiprocessing/util.py
* Most asserts in multiprocessing more informative
* Didn't save right version
* Further work on multiprocessing error messages
* Correct typo
* Correct typo v2
* Blasted colon... serves me right for trying to work on two things at once
* Simplify NEWS entry
* Update 2017-08-18-17-16-38.bpo-5001.gwnthq.rst
* Update 2017-08-18-17-16-38.bpo-5001.gwnthq.rst
OK, never mind.
* Corrected (thanks to pitrou) error messages for notify
* Remove extraneous backslash in docstring.
diff --git a/Lib/multiprocessing/heap.py b/Lib/multiprocessing/heap.py
index ee3ed55..566173a 100644
--- a/Lib/multiprocessing/heap.py
+++ b/Lib/multiprocessing/heap.py
@@ -211,7 +211,10 @@
# synchronously sometimes later from malloc() or free(), by calling
# _free_pending_blocks() (appending and retrieving from a list is not
# strictly thread-safe but under cPython it's atomic thanks to the GIL).
- assert os.getpid() == self._lastpid
+ if os.getpid() != self._lastpid:
+ raise ValueError(
+ "My pid ({0:n}) is not last pid {1:n}".format(
+ os.getpid(),self._lastpid))
if not self._lock.acquire(False):
# can't acquire the lock right now, add the block to the list of
# pending blocks to free
@@ -227,7 +230,10 @@
def malloc(self, size):
# return a block of right size (possibly rounded up)
- assert 0 <= size < sys.maxsize
+ if size < 0:
+ raise ValueError("Size {0:n} out of range".format(size))
+ if sys.maxsize <= size:
+ raise OverflowError("Size {0:n} too large".format(size))
if os.getpid() != self._lastpid:
self.__init__() # reinitialize after fork
with self._lock:
@@ -250,7 +256,10 @@
_heap = Heap()
def __init__(self, size):
- assert 0 <= size < sys.maxsize
+ if size < 0:
+ raise ValueError("Size {0:n} out of range".format(size))
+ if sys.maxsize <= size:
+ raise OverflowError("Size {0:n} too large".format(size))
block = BufferWrapper._heap.malloc(size)
self._state = (block, size)
util.Finalize(self, BufferWrapper._heap.free, args=(block,))