Boost event logger - events

http://boost-log.sourceforge.net/libs/log/doc/html/log/detailed/sink_backends.html
In this page there is sample code to initialize boost windows event backends,
but when I run it it gives memory error at first line.
void init_logging()
{
// Create an event log sink
boost::shared_ptr< sink_t > sink(new sink_t());
sink->set_formatter
(
expr::format("%1%: [%2%] - %3%")
% expr::attr< unsigned int >("LineID")
% expr::attr< boost::posix_time::ptime >("TimeStamp")
% expr::smessage
);
// We'll have to map our custom levels to the event log event types
sinks::event_log::custom_event_type_mapping< severity_level > mapping("Severity");
mapping[normal] = sinks::event_log::info;
mapping[warning] = sinks::event_log::warning;
mapping[error] = sinks::event_log::error;
sink->locked_backend()->set_event_type_mapper(mapping);
// Add the sink to the core
logging::core::get()->add_sink(sink);
}
Here it fails to create sink_t object.
boost::shared_ptr< sink_t > sink(new sink_t());
Any idea what is the problem and how can I solve this?
Also If you know any other source that I can learn using boost event logging please write.

No answer yet...
But I have found a solution in a blog by Timo Geusch.
http://www.lonecpluspluscoder.com/2011/01/boost-log-preventing-the-unhandled-exception-in-windows-7-when-attempting-to-log-to-the-event-log/
The reason for this problem was that the registry key in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\EventLog\ that the application needs access to both has to be present (if you’re not administrator, you don’t have the privileges to create it) and the user who runs the application also needs to be able to both read and write to it.

Related

Jdbi transaction - multiple methods - Resources should be closed

Suppose I want to run two sql queries in a transaction I have code like the below:
jdbi.useHandle(handle -> handle.useTransaction(h -> {
var id = handle.createUpdate("some query")
.executeAndReturnGeneratedKeys()
.mapTo(Long.class).findOne().orElseThrow(() -> new IllegalStateException("No id"));
handle.createUpdate("INSERT INTO SOMETABLE (id) " +
"VALUES (:id , xxx);")
.bind("id")
.execute();
}
));
Now as the complexity grows I want to extract each update in into it's own method:
jdbi.useHandle(handle -> handle.useTransaction(h -> {
var id = someQuery1(h);
someQuery2(id, h);
}
));
...with someQuery1 looking like:
private Long someQuery1(Handle handle) {
return handle.createUpdate("some query")
.executeAndReturnGeneratedKeys()
.mapTo(Long.class).findOne().orElseThrow(() -> new IllegalStateException("No id"));
}
Now when I refactor to the latter I get a SonarQube blocker bug on the someQuery1 handle.createUpdate stating:
Resources should be closed
Connections, streams, files, and other
classes that implement the Closeable interface or its super-interface,
AutoCloseable, needs to be closed after use....*
I was under the impression, that because I'm using jdbi.useHandle (and passing the same handle to the called methods) that a callback would be used and immediately release the handle upon return. As per the jdbi docs:
Both withHandle and useHandle open a temporary handle, call your
callback, and immediately release the handle when your callback
returns.
Any help / suggestions appreciated.
TIA
SonarQube doesn't know any specifics regarding JDBI implementation and just triggers by AutoCloseable/Closable not being closed. Just suppress sonar issue and/or file a feature-request to SonarQube team to improve this behavior.

Enabling Closed-Display Mode w/o Meeting Apple's Requirements

EDIT:
I have heavily edited this question after making some significant new discoveries and the question not having any answers yet.
Historically/AFAIK, keeping your Mac awake while in closed-display mode and not meeting Apple's requirements, has only been possible with a kernel extension (kext), or a command run as root. Recently however, I have discovered that there must be another way. I could really use some help figuring out how to get this working for use in a (100% free, no IAP) sandboxed Mac App Store (MAS) compatible app.
I have confirmed that some other MAS apps are able to do this, and it looks like they might be writing YES to a key named clamshellSleepDisabled. Or perhaps there's some other trickery involved that causes the key value to be set to YES? I found the function in IOPMrootDomain.cpp:
void IOPMrootDomain::setDisableClamShellSleep( bool val )
{
if (gIOPMWorkLoop->inGate() == false) {
gIOPMWorkLoop->runAction(
OSMemberFunctionCast(IOWorkLoop::Action, this, &IOPMrootDomain::setDisableClamShellSleep),
(OSObject *)this,
(void *)val);
return;
}
else {
DLOG("setDisableClamShellSleep(%x)\n", (uint32_t) val);
if ( clamshellSleepDisabled != val )
{
clamshellSleepDisabled = val;
// If clamshellSleepDisabled is reset to 0, reevaluate if
// system need to go to sleep due to clamshell state
if ( !clamshellSleepDisabled && clamshellClosed)
handlePowerNotification(kLocalEvalClamshellCommand);
}
}
}
I'd like to give this a try and see if that's all it takes, but I don't really have any idea about how to go about calling this function. It's certainly not a part of the IOPMrootDomain documentation, and I can't seem to find any helpful example code for functions that are in the IOPMrootDomain documentation, such as setAggressiveness or setPMAssertionLevel. Here's some evidence of what's going on behind the scenes according to Console:
I've had a tiny bit of experience working with IOMProotDomain via adapting some of ControlPlane's source for another project, but I'm at a loss for how to get started on this. Any help would be greatly appreciated. Thank you!
EDIT:
With #pmdj's contribution/answer, this has been solved!
Full example project:
https://github.com/x74353/CDMManager
This ended up being surprisingly simple/straightforward:
1. Import header:
#import <IOKit/pwr_mgt/IOPMLib.h>
2. Add this function in your implementation file:
IOReturn RootDomain_SetDisableClamShellSleep (io_connect_t root_domain_connection, bool disable)
{
uint32_t num_outputs = 0;
uint32_t input_count = 1;
uint64_t input[input_count];
input[0] = (uint64_t) { disable ? 1 : 0 };
return IOConnectCallScalarMethod(root_domain_connection, kPMSetClamshellSleepState, input, input_count, NULL, &num_outputs);
}
3. Use the following to call the above function from somewhere else in your implementation:
io_connect_t connection = IO_OBJECT_NULL;
io_service_t pmRootDomain = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("IOPMrootDomain"));
IOServiceOpen (pmRootDomain, current_task(), 0, &connection);
// 'enable' is a bool you should assign a YES or NO value to prior to making this call
RootDomain_SetDisableClamShellSleep(connection, enable);
IOServiceClose(connection);
I have no personal experience with the PM root domain, but I do have extensive experience with IOKit, so here goes:
You want IOPMrootDomain::setDisableClamShellSleep() to be called.
A code search for sites calling setDisableClamShellSleep() quickly reveals a location in RootDomainUserClient::externalMethod(), in the file iokit/Kernel/RootDomainUserClient.cpp. This is certainly promising, as externalMethod() is what gets called in response to user space programs calling the IOConnectCall*() family of functions.
Let's dig in:
IOReturn RootDomainUserClient::externalMethod(
uint32_t selector,
IOExternalMethodArguments * arguments,
IOExternalMethodDispatch * dispatch __unused,
OSObject * target __unused,
void * reference __unused )
{
IOReturn ret = kIOReturnBadArgument;
switch (selector)
{
…
…
…
case kPMSetClamshellSleepState:
fOwner->setDisableClamShellSleep(arguments->scalarInput[0] ? true : false);
ret = kIOReturnSuccess;
break;
…
So, to invoke setDisableClamShellSleep() you'll need to:
Open a user client connection to IOPMrootDomain. This looks straightforward, because:
Upon inspection, IOPMrootDomain has an IOUserClientClass property of RootDomainUserClient, so IOServiceOpen() from user space will by default create an RootDomainUserClient instance.
IOPMrootDomain does not override the newUserClient member function, so there are no access controls there.
RootDomainUserClient::initWithTask() does not appear to place any restrictions (e.g. root user, code signing) on the connecting user space process.
So it should simply be a case of running this code in your program:
io_connect_t connection = IO_OBJECT_NULL;
IOReturn ret = IOServiceOpen(
root_domain_service,
current_task(),
0, // user client type, ignored
&connection);
Call the appropriate external method.
From the code excerpt earlier on, we know that the selector must be kPMSetClamshellSleepState.
arguments->scalarInput[0] being zero will call setDisableClamShellSleep(false), while a nonzero value will call setDisableClamShellSleep(true).
This amounts to:
IOReturn RootDomain_SetDisableClamShellSleep(io_connect_t root_domain_connection, bool disable)
{
uint32_t num_outputs = 0;
uint64_t inputs[] = { disable ? 1 : 0 };
return IOConnectCallScalarMethod(
root_domain_connection, kPMSetClamshellSleepState,
&inputs, 1, // 1 = length of array 'inputs'
NULL, &num_outputs);
}
When you're done with your io_connect_t handle, don't forget to IOServiceClose() it.
This should let you toggle clamshell sleep on or off. Note that there does not appear to be any provision for automatically resetting the value to its original state, so if your program crashes or exits without cleaning up after itself, whatever state was last set will remain. This might not be great from a user experience perspective, so perhaps try to defend against it somehow, for example in a crash handler.

Workaround for a certain IOServiceOpen() call requiring root privileges

Background
It is possible to perform a software-controlled disconnection of the power adapter of a Mac laptop by creating an DisableInflow power management assertion.
Code from this answer to an SO question can be used to create said assertion. The following is a working example that creates this assertion until the process is killed:
#include <IOKit/pwr_mgt/IOPMLib.h>
#include <unistd.h>
int main()
{
IOPMAssertionID neverSleep = 0;
IOPMAssertionCreateWithName(kIOPMAssertionTypeDisableInflow,
kIOPMAssertionLevelOn,
CFSTR("disable inflow"),
&neverSleep);
while (1)
{
sleep(1);
}
}
This runs successfully and the power adapter is disconnected by software while the process is running.
What's interesting, though, is that I was able to run this code as a regular user, without root privileges, which wasn't supposed to happen. For instance, note the comment in this file from Apple's open source repositories:
// Disables AC Power Inflow (requires root to initiate)
#define kIOPMAssertionTypeDisableInflow CFSTR("DisableInflow")
#define kIOPMInflowDisableAssertion kIOPMAssertionTypeDisableInflow
I found some code which apparently performs the actual communication with the charger; it can be found here. The following functions, from this file, appears to be of particular interest:
IOReturn
AppleSmartBatteryManagerUserClient::externalMethod(
uint32_t selector,
IOExternalMethodArguments * arguments,
IOExternalMethodDispatch * dispatch __unused,
OSObject * target __unused,
void * reference __unused )
{
if (selector >= kNumBattMethods) {
// Invalid selector
return kIOReturnBadArgument;
}
switch (selector)
{
case kSBInflowDisable:
// 1 scalar in, 1 scalar out
return this->secureInflowDisable((int)arguments->scalarInput[0],
(int *)&arguments->scalarOutput[0]);
break;
// ...
}
// ...
}
IOReturn AppleSmartBatteryManagerUserClient::secureInflowDisable(
int level,
int *return_code)
{
int admin_priv = 0;
IOReturn ret = kIOReturnNotPrivileged;
if( !(level == 0 || level == 1))
{
*return_code = kIOReturnBadArgument;
return kIOReturnSuccess;
}
ret = clientHasPrivilege(fOwningTask, kIOClientPrivilegeAdministrator);
admin_priv = (kIOReturnSuccess == ret);
if(admin_priv && fOwner) {
*return_code = fOwner->disableInflow( level );
return kIOReturnSuccess;
} else {
*return_code = kIOReturnNotPrivileged;
return kIOReturnSuccess;
}
}
Note how, in secureInflowDisable(), root privileges are checked for prior to running the code. Note also this initialization code in the same file, again requiring root privileges, as explicitly pointed out in the comments:
bool AppleSmartBatteryManagerUserClient::initWithTask(task_t owningTask,
void *security_id, UInt32 type, OSDictionary * properties)
{
uint32_t _pid;
/* 1. Only root processes may open a SmartBatteryManagerUserClient.
* 2. Attempts to create exclusive UserClients will fail if an
* exclusive user client is attached.
* 3. Non-exclusive clients will not be able to perform transactions
* while an exclusive client is attached.
* 3a. Only battery firmware updaters should bother being exclusive.
*/
if ( kIOReturnSuccess !=
clientHasPrivilege(owningTask, kIOClientPrivilegeAdministrator))
{
return false;
}
// ...
}
Starting from the code from the same SO question above (the question itself, not the answer), for the sendSmartBatteryCommand() function, I wrote some code that calls the function passing kSBInflowDisable as the selector (the variable which in the code).
Unlike the code using assertions, this one only works as root. If running as a regular user, IOServiceOpen() returns, weirdly enough, kIOReturnBadArgument (not kIOReturnNotPrivileged, as I would have expected). Perhaps this has to do with the initWithTask() method above.
The question
I need to perform a call with a different selector to this same Smart Battery Manager kext. Even so, I can't even get to the IOConnectCallMethod() since IOServiceOpen() fails, presumably because the initWithTask() method prevents any non-root users from opening the service.
The question, therefore, is this: how is IOPMAssertionCreateWithName() capable of creating a DisableInflow assertion without root privileges?
The only possibility I can think of is if there's a root-owned process to which requests are forwarded, and which performs the actual work of calling IOServiceOpen() and later IOConnectCallMethod() as root.
However, I'm hoping there's a different way of calling the Smart Battery Manager kext which doesn't require root (one that doesn't involve the IOServiceOpen() call.) Using IOPMAssertionCreateWithName() itself is not possible in my application, since I need to call a different selector within that kext, not the one that disables inflow.
It's also possible this is in fact a security vulnerability, which Apple will now fix in a future release as soon as it is alerted to this question. That would be too bad, but understandable.
Although running as root is a possibility in macOS, it's obviously desirable to avoid privilege elevation unless absolutely necessary. Also, in the future I'd like to run the same code under iOS, where it's impossible to run anything as root, in my understanding (note this is an app I'm developing for my own personal use; I understand linking to IOKit wipes out any chance of getting the app published in the App Store).

http_listener cpprestsdk how to handle multiple POST requests

I have developed a client server application with casablanca cpprestskd.
Every 5 minutes a client send informations from his task manager (processes,cpu usage etc) to server via POST method.
The project should be able to manage about 100 clients.
Every time that server receives a POST request he opens an output file stream ("uploaded.txt") ,extract some initial infos from client (login,password),manage this infos, save all infos in a file with the same name of client (for example: client1.txt, client2.txt) in append mode and finally reply to client with a status code.
This is basically my POST handle code from server side:
void Server::handle_post(http_request request)
{
auto fileBuffer =
std::make_shared<Concurrency::streams::basic_ostream<uint8_t>>();
try
{
auto stream = concurrency::streams::fstream::open_ostream(
U("uploaded.txt"),
std::ios_base::out | std::ios_base::binary).then([request, fileBuffer](pplx::task<Concurrency::streams::basic_ostream<unsigned char>> Previous_task)
{
*fileBuffer = Previous_task.get();
try
{
request.body().read_to_end(fileBuffer->streambuf()).get();
}
catch (const exception&)
{
wcout << L"<exception>" << std::endl;
//return pplx::task_from_result();
}
//Previous_task.get().close();
}).then([=](pplx::task<void> Previous_task)
{
fileBuffer->close();
//Previous_task.get();
}).then([](task<void> previousTask)
{
// This continuation is run because it is value-based.
try
{
// The call to task::get rethrows the exception.
previousTask.get();
}
catch (const exception& e)
{
wcout << e.what() << endl;
}
});
//stream.get().close();
}
catch (const exception& e)
{
wcout << e.what() << endl;
}
ManageClient();
request.reply(status_codes::OK, U("Hello, World!")).then([](pplx::task<void> t) { handle_error(t); });
return;
}
Basically it works but if i try to send info from due clients at the same time sometimes it works sometimes it doen't work.
Obviously the problem if when i open "uploaded.txt" stream file.
Questions:
1)Is CASABLANCA http_listener real multitasking?how many task it's able to handle?
2)I didn't found in documentation ax example similar to mine,the only one who is approaching to mine is "Casalence120" Project but he uses Concurrency::Reader_writer_lock class (it seems a mutex method).
What can i do in order to manage multiple POST?
3)Is it possible to read some client infos before starting to open uploaded.txt?
I could open an output file stream directly with the name of the client.
4)If i lock access via mutex on uploaded.txt file, Server become sequential and i think this is not a good way to use cpprestsdk.
I'm still approaching cpprestskd so any suggestions would be helpful.
Yes, the REST sdk processes every request on a different thread
I confirm there are not many examples using the listener.
The official sample using the listener can be found here:
https://github.com/Microsoft/cpprestsdk/blob/master/Release/samples/CasaLens/casalens.cpp
I see you are working with VS. I would strongly suggest to move to VC++2015 or better VC++2017 because the most recent compiler supports co-routines.
Using co_await dramatically simplify the readability of the code.
Substantially every time you 'co_await' a function, the compiler will refactor the code in a "continuation" avoiding the penalty to freeze the threads executing the function itself. This way, you get rid of the ".then" statements.
The file problem is a different story than the REST sdk. Accessing the file system concurrently is something that you should test in a separate project. You can probably cache the first read and share the content with the other threads instead of accessing the disk every time.

ContainerLaunchContext.setResource() missing of hadoop yarn

http://hadoop.apache.org/docs/r2.1.0-beta/hadoop-yarn/hadoop-yarn-site/WritingYarnApplications.html
I am try to make the example work well from the above link.but I can't compile the code below
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(512);
amContainer.setResource(capability);
// Set the container launch content into the
// ApplicationSubmissionContext
appContext.setAMContainerSpec(amContainer);
amContainer is ContainerLaunchContext and my hadoop version is 2.1.0-beta.
I did some investigation. I found there's no method "setResource" in ContainerLaunchContext
I have 3 question about this
1) the method has been removed or something?
2) if the method has been removed, how can I do now?
3) is there any doc about yarn, because I found the doc in website is very easy, I hope I can get a manual or something. for example,
capability.setMemory(512);
I don't know it's 512k or 512M according comments in code.
This is actually proper solution to the question. Previous answer might cause incorrect execution !!!
#Dyin I couldn't fit it in the comment ;) Validated for 2.2.0 and 2.3.0
Driver setting up resources for AppMaster:
ApplicationSubmissionContext appContext = app.getApplicationSubmissionContext();
ApplicationId appId = appContext.getApplicationId();
appContext.setApplicationName(this.appName);
// Set up the container launch context for the application master
ContainerLaunchContext amContainer = Records.newRecord(ContainerLaunchContext.class);
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(amMemory);
appContext.setResource(capability);
appContext.setAMContainerSpec(amContainer);
Priority pri = Records.newRecord(Priority.class);
pri.setPriority(amPriority);
appContext.setPriority(pri);
appContext.setQueue(amQueue);
// Submit the application to the applications manager
yarnClient.submitApplication(appContext); // this.yarnClient = YarnClient.createYarnClient();
In ApplicationMaster this is how you should specify resources for containers (workers).
private AMRMClient.ContainerRequest setupContainerAskForRM() {
// setup requirements for hosts
// using * as any host will do for the distributed shell app
// set the priority for the request
Priority pri = Records.newRecord(Priority.class);
pri.setPriority(requestPriority);
// Set up resource type requirements
// For now, only memory is supported so we set memory requirements
Resource capability = Records.newRecord(Resource.class);
capability.setMemory(containerMemory);
AMRMClient.ContainerRequest request = new AMRMClient.ContainerRequest(capability, null, null,
pri);
return request;
}
Some run() or main() method in your AppMaster
AMRMClientAsync.CallbackHandler allocListener = new RMCallbackHandler();
resourceManager = AMRMClientAsync.createAMRMClientAsync(1000, allocListener);
resourceManager.init(conf);
resourceManager.start();
for (int i = 0; i < numTotalContainers; ++i) {
AMRMClient.ContainerRequest containerAsk = setupContainerAskForRM();
resourceManager.addContainerRequest(containerAsk); //
}
Launching containers
You can use the original answer solution (java cmd), but it's just a cherry on top. It should work anyway.
You can set memory available to ApplicationMaster via commend. As such:
// Set the necessary command to execute the application master
Vector<CharSequence> vargs = new Vector<CharSequence>(30);
...
vargs.add("-Xmx" + amMemory + "m"); // notice "m" indicating megabytes, you can use also -Xms combined with -Xmx
... // transform vargs to String commands
amContainer.setCommands(commands);
This should solve your problem. As for the 3 questions. Yarn is rapidly evolving software. My advice forget documentation, get source code and read it. This will answer a lot of your questions.

Resources