I have a pyclips / clips program for which I wrote some unit tests using pytest.
Each test case involes an initial clips.Clear() followed by the execution of real clips COOL code via clips.Load(rule_file.clp). Running each test individually works fine.
Yet, when telling pytest to run all tests, some fail with ClipsError: S03: environment could not be cleared. In fact, it depends on the order of the tests in the .py file. There seem to be test cases, that cause the subsequent test case to throw the exception.
Maybe some clips code is still "in use" so that the clearing fails?
I read here that (clear)
Clears CLIPS. Removes all constructs and all associated data structures (such as facts and instances) from the CLIPS environment. A clear may be performed safely at any time, however, certain constructs will not allow themselves to be deleted while they are in use.
Could this be the case here? What is causing the (clear) command to fail?
EDIT:
I was able to narrow down the problem. It occurs under the following circumstances:
test_case_A comes right before test_case_B.
In test_case_A there is a test such as
(test (eq (type ?f_bio_puts) clips_FUNCTION))
but f_bio_puts has been set to
(slot f_bio_puts (default [nil]))
So testing the type of a slot variable, which has been set to [nil] initially, seems to cause the (clear) command to fail. Any ideas?
EDIT 2
I think I know what is causing the problem. It is the test line. I adapted my code to make it run in the clips Dialog Windows. And I got this error when loading via (batch ...)
[INSFUN2] No such instance nil in function type.
[DRIVE1] This error occurred in the join network
Problem resided in associated join
Of pattern #1 in rule part_1
I guess it is a bug of pyclips that this is masked.
Change the EnvClear function in the CLIPS source code construct.c file adding the following lines of code to reset the error flags:
globle void EnvClear(
void *theEnv)
{
struct callFunctionItem *theFunction;
/*==============================*/
/* Clear error flags if issued */
/* from an embedded controller. */
/*==============================*/
if ((EvaluationData(theEnv)->CurrentEvaluationDepth == 0) &&
(! CommandLineData(theEnv)->EvaluatingTopLevelCommand) &&
(EvaluationData(theEnv)->CurrentExpression == NULL))
{
SetEvaluationError(theEnv,FALSE);
SetHaltExecution(theEnv,FALSE);
}
Related
I am trying to use the implementation of std::iostream provided by boost::asio on top of boost::asio::ip::tcp::socket. My code replicate almost line to line the example that is published in Boost Asio's documentation:
#include <iostream>
#include <stdexcept>
#include <boost/asio.hpp>
int main()
{
using boost::asio::ip::tcp;
try
{
boost::asio::io_service io_service;
tcp::endpoint endpoint(tcp::v4(), 8000);
tcp::acceptor acceptor(io_service, endpoint);
for (;;)
{
tcp::iostream stream; // <-- The exception is triggered on this line, on the second loop iteration.
boost::system::error_code error_code;
acceptor.accept(*stream.rdbuf(), error_code);
std::cout << stream.rdbuf() << std::flush;
}
}
catch (std::exception& exception)
{
std::cerr << exception.what() << std::endl;
}
return 0;
}
The only difference is the use I make of the resulting tcp::iostream: I forward everything I receive to the standard output.
When I compile this code with VisualStudio2019/toolset v142 and Boost from the NuGet boost-vc142, I get an Access Violation Exception only in the second iteration in the for loop, in the function
template <typename Service>
Service& service_registry::use_service(io_context& owner)
{
execution_context::service::key key;
init_key<Service>(key, 0);
factory_type factory = &service_registry::create<Service, io_context>;
return *static_cast<Service*>(do_use_service(key, factory, &owner));
} // <-- The debugger show the exception was raised on this line
in asio/detail/impl/service_registry.hpp. So the first iteration everything goes as planned, the connection is accepted, the data shows up on the standard output, and as soon as the stream is instanciated on the stack for the second time, the exception pops.
I don't have a high confidence in the accuracy of this location of the exception reported by the debugger. For some reason, the stack seams to be messed up and show only one frame.
If the declaration of stream is moved out of the loop, no exception is raised any more but then I need to stream.close() at the end of the loop, or nothing shows up on the standard output except the data from the first client's connection.
Basically, as soon as I try to instanciate more than one boost::asio::tcp::iostream (not necessarily at the same time), the exception is raised.
I tried the exact same code under linux (Arch linux, latest version of g++, same version of Boost) and everything works perfectly.
I could work around this issue by not using iostreams, but my idea is to feed the data received on the tcp socket to a parser which only accept implementations of std::iostream, hence I would still need to wrap asio's tcp socket in an homebrewed (and mediocre) implementation of std::iostream.
Does anybody have an idea on what's wrong with this setup, if I missed a crucial #define somewhere or anything?
Update:
Subsequent investigation show that the only situation where the access violation happens is when the executable is run from within Visual Studio (typ. from the menu Debug -> Start Debugging).
The build process seems to have no effect (calling directly cl.exe, using MSBuild, using devenv.exe).
Moreover, if the executable is run from a command prompt, and only then the debugger is attached, no access violation happens.
At this point, the issue is most likely not linked to the code itself.
Okay, it was exceedingly painful to test this on windows.
Of course I first tried on Linux (clang/gcc) and MingW 8.1 on windows.
Then I bit the bullet and jumped the hoops to get MSVC in command line with boost packages¹.
I cheated by manually copying the .lib/.dll for boost_{system,date_time,regex} into the working directory so the command line stayed "wieldy":
C:\work>C:\Users\sghee\Downloads\nuget.exe install boost_system-vc142
C:\work>C:\Users\sghee\Downloads\nuget.exe install boost_date_time-vc142
C:\work>C:\Users\sghee\Downloads\nuget.exe install boost_regex-vc142
(Be sure to get some coffee during those)
C:\work\> cl /EHsc test.cpp /I .\boost.1.72.0.0\lib\native\include /link
Now I can run test.exe
C:\work\> test.exe
And it listens fine, accepts connections (sequentially, not simultaneously). If you connect a second client while the first is still connected, it will be queued and be accepted only after the first disconnects. That's fine, because it's what you expect with the synchronous accept and loop.
I used Ncat.exe (from Nmap) to connect:
C:\Program Files (x86)\Nmap>.\ncat.exe localhost 8000
Quirk: The buffering was fine with the MSVC cl.exe build (linewise) as opposed to MingW behaviour, even though MingW also uses ws2_32.dll. #trivia
I know this doesn't "help", but maybe you can compare notes and see what is different with your system.
Video Of Test
¹ (that's a tough job without VS and also I - obviously - ran out of space, because 50GiB for a VM can't be enough right)
I have tested two cases:
I use STEPCAFControl_Reader then STEPControl_Reader to read my step file but both methods crash when I call STEPCAFControl_Reader::Transfer, repsectively STEPControl_Reader:: TransferRoots.
By using STEPControl_Reader, I displayed a log on my console, then there is a message like this:
1 F:(BOUNDED_SURFACE,B_SPLINE_SURFACE,B_SPLINE_SURFACE_WITH_KNOTS,GEOMETRIC_REPRESENTATION_ITEM,RATIONAL_B_SPLINE_SURFACE,REPRESENTATION_ITEM,SURFACE): Count of Parameters is not 1 for representation_item
EDIT:
There is a null reference inside TransferRoots() method.
const Handle(Transfer_TransientProcess) &proc = thesession->TransferReader()->TransientProcess();
if (proc->GetProgress().IsNull())
{
//This condition does not exist from the source code
std::cout << "GetProgress is null" << std::endl;
return 0;
}
Message_ProgressSentry PS ( proc->GetProgress(), "Root", 0, nb, 1 );
My app and FreeCAD crash but if I use CAD Assitant which OCC official viewer, it loads.
It looks like comments already provide an answer to the question - or more precisely answers:
STEPCAFControl_Reader::ReadFile() returns reading status, which should be checked before calling STEPCAFControl_Reader::Transfer().
Normally, it is a good practice to put OCCT algorithm into try/catch block and check for OCCT exceptions (Standard_Failure).
Add OCC_CATCH_SIGNALS at the beginning of try statements (required only on Linux) and OSD::SetSignal(false) within working thread creation to redirect abnormal cases (access violation, NULL dereference and others) to C++ exceptions (OSD_Signal which is subclass of Standard_Failure). This may conflict other signal handlers in mixed environment - so check also documentation of other frameworks used by application.
If you catch failures like NULL dereference on calling OCCT algorithm with valid arguments - this is a bug in OCCT which is desirable to be fixed in one or another way, even if input STEP file contains syntax/logical errors triggering such kind of issues. Report the issue on OCCT Bugtracker with sufficient information for reproducing bug, including sample files - it is not helpful to developers just saying that OCCT crashes somewhere. Consider also contributing into this open source project by debugging OCCT code and suggesting patches.
Check STEP file reading log for possible errors in the file itself. Consider reporting an issue to system producing a broken file, even if main file content can be loaded by STEP readers.
It is a common practice to use OSD::SetSignal() within OCCT-based applications (like CAD Assistant) to improve their robustness on non-fatal errors in application/OCCT code. It is more user friendly reporting an internal error message instead of silently crashing.
But it should be noted, that OSD::SetSignal() doesn't guarantee application not being crashed nor that application can work properly after catching such failure - due to asynchronous nature of some signals, the memory can be already corrupted at the moment, when C++ exception has been raised leading to all kinds of undesired behavior. For that reason, it is better not ignoring such kind of exceptions, even if it looks like application works fine with them.
OSD::SetSignal(false); // should be called ones at application startup
STEPCAFControl_Reader aReader;
try
{
OCC_CATCH_SIGNALS // necessary for redirecting signals on Linux
if (aReader.ReadFile (theFilePath) != IFSelect_RetDone) { return false; }
if (!aReader.Transfer (myXdeDoc)) { return false; }
}
catch (Standard_Failure const& theFailure)
{
std::cerr << "STEP import failed: " << theFailure.GetMessageString() << "\n";
return false;
}
return true;
I am trying to get familiar with gem5 simulator.
To start, I wrote a simple program with
int main()
{
m5_reset_stats(0, 0);
m5_dump_stats(0, 0);
return 0;
}
I compiled it with util/m5/m5op_x86.S and ran it using...
./build/X86/gem5.opt configs/example/se.py --caches -c ~/tmp/hello
The m5out/stats.txt shows (among other things)...
system.cpu.dcache.ReadReq_hits::total 881
system.cpu.dcache.WriteReq_hits::total 917
system.cpu.dcache.ReadReq_misses::total 54
system.cpu.dcache.WriteReq_misses::total 42
Why is an empty function showing so much hits and misses? Are the hits and misses caused by libc? If so, then what is the purpose of m5_reset_stats() and m5_dump_stats()?
I would check in the stats.txt file if there are two chunks of
---Begin---
---End-----
because as you explained it, the simulator is supposed to dump the stats at dump_stats(0,0) and at the end of the run. So, it seems like you either are looking at one of those intervals (and I would expect the other interval to have 0 for all stats); or there was a bug in the simulation and the dump_stats() (or reset_stats())didn't actually do anything. That actually happened to me plenty of times, but I am not really sure as to the source of this bug.
If you want to troubleshoot further, you could do the following:
Look at the disassembly of your code and find the reset_stats.w and dump_stats.w
Dump a trace from gem5 and see if it ends up executing the dump and reset instructions and also what instructions (and how many) are executed before/after.
Hope this helps!
I have an All Exceptions breakpoint configured in Xcode:
Sometimes Xcode will stop on a line like:
[managedObjectContext save:&error];
with the following backtrace:
but the program continues on as if nothing happened if you click Continue.
How can I ignore these "normal" exceptions, but still have the debugger stop on exceptions in my own code?
(I understand that this happens because Core Data internally throws and catches exceptions, and that Xcode is simply honoring my request to pause the program whenever an exception is thrown. However, I want to ignore these so I can get back to debugging my own code!)
Moderators: this is similar to "Xcode 4 exception breakpoint filtering", but I think that question takes too long to get around to the point and doesn't have any useful answers. Can they be linked?
For Core Data exceptions, what I typically do is remove the "All Exceptions" breakpoint from Xcode and instead:
Add a Symbolic Breakpoint on objc_exception_throw
Set a Condition on the Breakpoint to (BOOL)(! (BOOL)[[(NSException *)$x0 className] hasPrefix:#"_NSCoreData"])
The configured breakpoint should look something like this:
This will ignore any private Core Data exceptions (as determined by the class name being prefixed by _NSCoreData) that are used for control flow. Note that the appropriate register is going to be dependent on the target device / simulator that you are running in. Take a look at this table for reference.
Note that this technique can be adapted easily to other conditionals. The tricky part was in crafting the BOOL and NSException casts to get lldb happy with the condition.
I wrote an lldb script that lets you selectively ignore Objective-C exceptions with a much simpler syntax, and it handles both OS X, iOS Simulator, and both 32bit and 64bit ARM.
Installation
Put this script in ~/Library/lldb/ignore_specified_objc_exceptions.py or somewhere useful.
import lldb
import re
import shlex
# This script allows Xcode to selectively ignore Obj-C exceptions
# based on any selector on the NSException instance
def getRegister(target):
if target.triple.startswith('x86_64'):
return "rdi"
elif target.triple.startswith('i386'):
return "eax"
elif target.triple.startswith('arm64'):
return "x0"
else:
return "r0"
def callMethodOnException(frame, register, method):
return frame.EvaluateExpression("(NSString *)[(NSException *)${0} {1}]".format(register, method)).GetObjectDescription()
def filterException(debugger, user_input, result, unused):
target = debugger.GetSelectedTarget()
frame = target.GetProcess().GetSelectedThread().GetFrameAtIndex(0)
if frame.symbol.name != 'objc_exception_throw':
# We can't handle anything except objc_exception_throw
return None
filters = shlex.split(user_input)
register = getRegister(target)
for filter in filters:
method, regexp_str = filter.split(":", 1)
value = callMethodOnException(frame, register, method)
if value is None:
output = "Unable to grab exception from register {0} with method {1}; skipping...".format(register, method)
result.PutCString(output)
result.flush()
continue
regexp = re.compile(regexp_str)
if regexp.match(value):
output = "Skipping exception because exception's {0} ({1}) matches {2}".format(method, value, regexp_str)
result.PutCString(output)
result.flush()
# If we tell the debugger to continue before this script finishes,
# Xcode gets into a weird state where it won't refuse to quit LLDB,
# so we set async so the script terminates and hands control back to Xcode
debugger.SetAsync(True)
debugger.HandleCommand("continue")
return None
return None
def __lldb_init_module(debugger, unused):
debugger.HandleCommand('command script add --function ignore_specified_objc_exceptions.filterException ignore_specified_objc_exceptions')
Add the following to ~/.lldbinit:
command script import ~/Library/lldb/ignore_specified_objc_exceptions.py
replacing ~/Library/lldb/ignore_specified_objc_exceptions.py with the correct path if you saved it somewhere else.
Usage
In Xcode, add a breakpoint to catch all Objective-C exceptions
Edit the breakpoint and add a Debugger Command with the following command:
ignore_specified_objc_exceptions name:NSAccessibilityException className:NSSomeException
This will ignore exceptions where NSException -name matches NSAccessibilityException OR -className matches NSSomeException
It should look something like this:
In your case, you would use ignore_specified_objc_exceptions className:_NSCoreData
See http://chen.do/blog/2013/09/30/selectively-ignoring-objective-c-exceptions-in-xcode/ for the script and more details.
Here is an alternative quick answer for when you have a block of code e.g. a 3rd part library that throws multiple exceptions that you want to ignore:
Set two breakpoints, one before and one after the exception throwing block of code you want to ignore.
Run the program, until it stops at an exception, and type 'breakpoint list' into the debugger console, and find the number of the 'all exceptions' break point, it should look like this:
2: names = {'objc_exception_throw', '__cxa_throw'}, locations = 2
Options: disabled
2.1: where = libobjc.A.dylibobjc_exception_throw, address = 0x00007fff8f8da6b3, unresolved, hit count = 0
2.2: where = libc++abi.dylib__cxa_throw, address = 0x00007fff8d19fab7, unresolved, hit count = 0
This means it is breakpoint 2. Now in xcode, edit the first breakpoint (before the exception throwing code) and change the action to 'debugger command' and type in 'breakpoint disable 2' (and set 'automatically continue...' checkbox ).
Do the same for the break point after the offending line and have the command 'breakpoint enable 2'.
The all breakpoints exception will now turn on and off so it's only active when you need it.
I am trying to use Invoke process to invoke an executable from my windows workflow in my TFS 2010 build.
But when I am looking at the log file it is not logging any error.
I did use WriteBuildMessage and WriteBuildwarning inside my invoke process activity.
I also set the filename,workingdirectory etc in activity.
Can someone please point out why it is not logging?
You can do something like this:
In this case you have to ensure that Message are set as follows:
With those parameters set as depicted, I catch what you seem to be after.
Furthermore, you can check in the Properties of your InvokeProcess: Set the Result into a string-variable and then set in a subsequent WriteBuildMessage this string-variable to be the Message. This way, you 'll additionally catch the return of your invoked process.
EDIT
Another common thing that you 've possibly overlooked is the BuildMessageImportance: if it is not set as High, messages do NOT appear under default Logging Verbosity (= Normal). See here for some background.
In your Invoke Process, you want to set the Result property to update a variable (returns an Int, so lets call it ExitCode), under your Invoke Process (but still in the Agent Scope) you can drop in an If, so you can set the condition of this to ExitCode <> 0 and do whatever you like on a failure (such as failing the build).
Also, as a note, if your WriteBuildMessage is not showing anything in your log, you need to set the Importance to Microsoft.TeamFoundation.Build.Client.BuildMessageImportance.High, anything lower and it wont show in the Normal logging level.