I try to read out the ActiveState property of a systemd unit with gdbus/glib-2.0. For sd-bus there exists the convenient function sd_bus_get_property_string. What would the equivalent call if gdbus is used. I am ware of the gdbus introspect command, but I need to implement that in C/C++.
I managed to start and stop units already. Now I need to verify that a unit has been successful started/stopped. I am new to dbus and have been searching the internet for some hours for an example, without finding something helpful.
I also implemented some systemd stuff in C++. Here was my solution:
std::string Unit::GetPropertyString(const std::string& property) const
{
sd_bus_error err = SD_BUS_ERROR_NULL;
char* msg = nullptr;
int r;
r = sd_bus_get_property_string(m_bus,
"org.freedesktop.systemd1",
("/org/freedesktop/systemd1/unit/" + m_unit).c_str(),
"org.freedesktop.systemd1.Unit",
property.c_str(),
&err,
&msg);
if (r < 0)
{
std::string err_msg(err.message);
sd_bus_error_free(&err);
std::string err_str("Failed to get " + property + " for service "
+ m_name + ". Error: " + err_msg);
throw slib_exception(err_str);
}
sd_bus_error_free(&err);
// Free memory (avoid leaking)
std::string ret(msg);
free (msg);
return ret;
}
From this, you can call
activestate = GetPropertyString("ActiveState");
substate = GetPropertyString("SubState");
I found that a lot of the <systemd/sd-bus.h> wasn't well documented. There is a fantastic explanation by the author here:
http://0pointer.net/blog/the-new-sd-bus-api-of-systemd.html
But outside of the few examples he gives, I found it was easier to inspect the source code. Specifically, I found it nice looking into the source-code of the systemctl and journalctl applications to see how sd-bus was used in those contexts.
Related
Recently I've updated my system and tried to recompile my Vulkan app (which uses Vulkan cpp binding) and got almost no output from vk::DebugUtilsMessengerEXT (except the string "Added messenger"). I set it up to std::cout every kind of callback, and it printed lots of information strings (before update). Does anyone know, what to do to bring back debug output?
Here is my debug messenger code:
// ...
vk::DebugUtilsMessengerCreateInfoEXT messengerInfo;
messengerInfo.setMessageSeverity(
vk::DebugUtilsMessageSeverityFlagBitsEXT::eError |
vk::DebugUtilsMessageSeverityFlagBitsEXT::eWarning |
vk::DebugUtilsMessageSeverityFlagBitsEXT::eInfo |
vk::DebugUtilsMessageSeverityFlagBitsEXT::eVerbose);
messengerInfo.setMessageType(
vk::DebugUtilsMessageTypeFlagBitsEXT::eGeneral |
vk::DebugUtilsMessageTypeFlagBitsEXT::eValidation |
vk::DebugUtilsMessageTypeFlagBitsEXT::ePerformance);
messengerInfo.setPfnUserCallback(callback);
messengerInfo.setPUserData(nullptr);
if(instance.createDebugUtilsMessengerEXT(&messengerInfo, nullptr, &debugMessenger, loader) != vk::Result::eSuccess) throw std::runtime_error("Failed to create debug messenger!\n");
}
VKAPI_ATTR VkBool32 VKAPI_CALL System::callback(VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity, VkDebugUtilsMessageTypeFlagsEXT messageType, const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData, void* pUserData)
{
std::cout << pCallbackData->pMessage << '\n';
return false;
}
"loader" is vk::DispatchLoaderDynamic
Seems like the trouble is not only with Vulkan-Hpp, but also with C Vulkan.
Did some testing and the callbacks seem to be working correctly. I'm thinking the issue here might be the removal of some old INFO messages for performance reasons -- see Vulkan-ValidationLayers commits 18BF5C637 and 523D9C775. If INFORMATION_BIT messages were enabled in SDK releases previous to 1.1.108, you'd have seen a ton of spew. If expected validation errors are not making it to your callback, please create a github issue in the VVL repo and we'll address it immediately.
How I'm doing it and it works, albeit not the latest SDK:
void VulkanContext::createInstance()
{
// create the list of required extensions
uint32_t glfwExtensionCount = 0;
const char **glfwExtensions;
glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);
std::vector<const char *> extensions(glfwExtensions, glfwExtensions + glfwExtensionCount);
extensions.push_back(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME);
auto layers = std::vector<const char *>();
if ( enableValidationLayers )
{
extensions.push_back(VK_EXT_DEBUG_REPORT_EXTENSION_NAME);
extensions.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
layers.push_back("VK_LAYER_LUNARG_standard_validation");
}
vk::ApplicationInfo appInfo("Vulkan test", 1, "test", 1, VK_API_VERSION_1_1);
auto createInfo = vk::InstanceCreateInfo(
vk::InstanceCreateFlags(),
&appInfo,
static_cast<uint32_t>(layers.size()),
layers.empty() ? nullptr : layers.data(),
static_cast<uint32_t>(extensions.size()),
extensions.empty() ? nullptr : extensions.data()
);
instance = vk::createInstanceUnique(createInfo);
dispatcher = vk::DispatchLoaderDynamic(instance.get(), vkGetInstanceProcAddr);
if ( enableValidationLayers )
{
auto severityFlags = vk::DebugUtilsMessageSeverityFlagBitsEXT::eError
| vk::DebugUtilsMessageSeverityFlagBitsEXT::eWarning
| vk::DebugUtilsMessageSeverityFlagBitsEXT::eVerbose
| vk::DebugUtilsMessageSeverityFlagBitsEXT::eInfo;
auto typeFlags = vk::DebugUtilsMessageTypeFlagBitsEXT::eGeneral
| vk::DebugUtilsMessageTypeFlagBitsEXT::eValidation
| vk::DebugUtilsMessageTypeFlagBitsEXT::ePerformance;
messenger = instance->createDebugUtilsMessengerEXTUnique(
{{}, severityFlags, typeFlags, debugCallback},
nullptr,
dispatcher
);
}
}
Make sure you're enabling the debug extensions and validation layers.
Check that your loader/dispatcher is initialized correctly.
Try some of the other commands for creating the messenger, not sure but maybe the API changed and the severity flags are passed in the wrong place.
Make sure the validation layers are installed correctly, don't recall dealing with that myself but saw mentions that it can be an issue.
I'm starter of RTOS and I'm using Xenomai v2.6.3.
I'm trying to get some data using Serial communication.
I did my best on the task following the xenomai's guide and open sources, but it doesn't work well.
the link of the guide --> (https://xenomai.org//serial-16550a-driver/)
I just followed the sequence to use the module xeno_16550A. (with port io = 0x2f8 and irq=3)
I followed open source http://www.acadis.org/pages/captain.at/serial-port-example
It works well in write task, but read task doesn't work well.
It gave me the error sentence with error while RTSER_RTIOC_WAIT_EVENT, code -110 (it means connection timed out)
Moreover I checked the irq number3 by typing command 'cat /proc/xenomai/irq', but the interrupt number doesn't increase.
In my case, I don't need to write data, so I erase the write task code.
The read task proc is follow
void read_task_proc(void *arg) {
int ret;
ssize_t red = 0;
struct rtser_event rx_event;
while (1) {
/* waiting for event */
ret = rt_dev_ioctl(my_fd, RTSER_RTIOC_WAIT_EVENT, &rx_event );
if (ret) {
printf(RTASK_PREFIX "error while RTSER_RTIOC_WAIT_EVENT, code %d\n",ret);
if (ret == -ETIMEDOUT)
continue;
break;
}
unsigned char buf[1];
red = rt_dev_read(my_fd, &buf, 1);
if (red < 0 ) {
printf(RTASK_PREFIX "error while rt_dev_read, code %d\n",red);
} else {
printf(RTASK_PREFIX "only %d byte received , char : %c\n",red,buf[0]);
}
}
exit_read_task:
if (my_state & STATE_FILE_OPENED) {
if (!close_file( my_fd, READ_FILE " (rtser)")) {
my_state &= ~STATE_FILE_OPENED;
}
}
printf(RTASK_PREFIX "exit\n");
}
I could guess the causes of the problem.
buffer size or buffer is already full when new data is received.
rx_interrupt doesn't work....
I want to check whether the two things are wrong or not, but How can I check?
Furthermore, does anybody know the cause of the problem? Please give me comments.
I am trying to write a procedure to put each Strongly Connected Component of the given circuit into a distinct sub-module.
So, I tried to add a function to SCC pass in Yosys to add each SCC into a submod. The function is:
void putSelectionIntoParition (RTLIL::Design *design,
std::vector<pair<std::string,RTLIL::Selection>>& SelectionVector)
{
int p_count = 0;
for (std::vector<pair<std::string,RTLIL::Selection>>::iterator it = SelectionVector.begin();
it != SelectionVector.end(); ++it)
{
design->selection_stack[0] = it->second;
design->selection_stack[0].optimize(design);
std::string command = "submod -name ";
command.append(it->first);
Pass::call_on_selection(design, it->second, command);
++p_count;
}
}
However, my code does not work properly.
I guess the problem is with "selection" process that I use. I was wondering if there is any utility/API inside the yosys source that accept vector of cells (as well and a name submodule) and put them into a sub-module.
The following should work just fine:
void putSelectionIntoParition(RTLIL::Design *design,
std::vector<pair<std::string, RTLIL::Selection>> &SelectionVector)
{
for (auto it : SelectionVector) {
std::string command = "submod -name " + it.first;
Pass::call_on_selection(design, it.second, command);
}
}
You definitely don't need (nor should) modify selection_stack.
I was wondering if there is any utility/API inside the yosys source that accept vector of cells (as well and a name submodule) and put them into a sub-module.
You would do this by setting the submod="<name>" attribute on the cells. Then simply run the submod command.
You might have seen that the scc documentation mentions a -set_attr option that is yet unimplemented. I have now implemented this option in commit ef603c6 (commit 914aa8a contains a bugfix for scc).
With this feature you can now accomplished what you have described using something like the following yosys script.
read_verilog test.v
prep
scc -set_attr submod scc{}
submod
show test
I have tested this with the folling test.v file:
module test(input A, B, output X, Y);
assign X = (A & B) ^ X, Y = A | (B ^ Y);
endmodule
3. Executing SCC pass (detecting logic loops).
Found an SCC: $xor$test.v:2$2
Found an SCC: $or$test.v:2$4 $xor$test.v:2$3
Found 2 SCCs in module test.
Found 2 SCCs.
I am getting into Vulkan and stumbled on my first problem. When trying to create a debug report callback (validation layers and debug extensions are available on my intel hd vulkan driver, at least it says so), it fails telling me vkCreateDebugReportCallbackEXT is an unresolved symbol. When trying to get the function pointer it fails telling me vkCreateDebugReportCallbackEXT is already defined.
Which it is, in the Vulkan header. I could set VK_NO_PROTOTYPES but then I would have to load everything by hand. Is there a way around this? Just using a different name for the function pointer won't work, since I am using Vulkan-Hpp and it uses vkCreateDebugReportCallbackEXT as it is.
Is this a driver bug, telling me debug extensions are available, but there are not?
Btw, I am using VS2015.
Thanks for any help
That's normal. vulkan.h defines them as a global functions. But the loader commands obviously return function pointer.
Normally you would just use a different name you like. But I like to have the canonical names too...
I solve it by defining the function myself (using the declaration from vulkan.h) which in turn calls the loaded pointer:
VKAPI_ATTR VkResult VKAPI_CALL vkCommandEXT( /*...*/ ){
return fpCommandEXT( /*...*/ );
}
(Shameless self-promotion) Like so:
https://github.com/krOoze/Hello_Triangle/blob/8227220/ErrorHandling.h#L181
I make the command to self-load on its first use — if you don't like that, in older commit I had more conventional loader:
https://github.com/krOoze/Hello_Triangle/blob/699ab57/HelloTriangle.cpp#L731
PS:
Khronos themselves just added loader code that illustrates that nicely:
https://github.com/KhronosGroup/Vulkan-Docs/blob/1.0/src/ext_loader/vulkan_ext.c
If you handle multiple VkInstances or VkDevices the loaded functions have to be dispatched to the correct instance or device. For example, I do that (likely inefficiently) here:
https://github.com/krOoze/Hello_Triangle/blob/a691de5/ExtensionLoader.h
I had same issue, couldn't find solution so i solved it this way
(might be wrong, but i just want to share in case it will help somebody):
struct DebugDispatch {
//KHRONOS
PFN_vkCreateDebugReportCallbackEXT vkCreateDebugReportCallbackEXT = 0;
PFN_vkDestroyDebugReportCallbackEXT vkDestroyDebugReportCallbackEXT = 0;
//LUNARG
PFN_vkCreateDebugUtilsMessengerEXT vkCreateDebugUtilsMessengerEXT = 0;
PFN_vkDestroyDebugUtilsMessengerEXT vkDestroyDebugUtilsMessengerEXT = 0;
}
VKAPI_ATTR vk::Bool32 VKAPI_CALL debugReportCallback(...){...}
VKAPI_ATTR vk::Bool32 VKAPI_CALL debugUtilsMessengerCallback(...){...}
enum class ValidationFlagsBits : unsigned int {
NONE = 0,
KHRONOS = 1,
LUNARG = 1 << 1
};
typedef vk::Flags<ValidationFlagsBits> ValidationFlags;
void Example(){
...
vk::Instance instance;
instance = vk::createInstance(...);
DebugDispatch debug_dispatch;
vk::DebugReportCallbackEXT debug_report_callback;
vk::DebugUtilsMessengerEXT debug_utils_messenger;
if(validation_flags & ValidationFlagsBits::KHRONOS){
debug_dispatch.vkCreateDebugReportCallbackEXT =
(PFN_vkCreateDebugReportCallbackEXT)instance.getProcAddr("vkCreateDebugReportCallbackEXT");
debug_dispatch.vkDestroyDebugReportCallbackEXT =
(PFN_vkDestroyDebugReportCallbackEXT)instance.getProcAddr("vkDestroyDebugReportCallbackEXT");
vk::DebugUtilsMessengerCreateInfoEXT create_info{};
create_info.messageSeverity = ...;
create_info.messageType = ...;
create_info.pfnUserCallback = reinterpret_cast<PFN_vkDebugUtilsMessengerCallbackEXT>(&debugUtilsMessengerCallback);
debug_utils_messenger = instance.createDebugUtilsMessengerEXT(create_info, nullptr, debug_dispatch);
}
if(validation_flags & ValidationFlagsBits::LUNARG){
debug_dispatch.vkCreateDebugUtilsMessengerEXT =
(PFN_vkCreateDebugUtilsMessengerEXT)instance.getProcAddr("vkCreateDebugUtilsMessengerEXT");
debug_dispatch.vkDestroyDebugUtilsMessengerEXT =
(PFN_vkDestroyDebugUtilsMessengerEXT)instance.getProcAddr("vkDestroyDebugUtilsMessengerEXT");
vk::DebugReportCallbackCreateInfoEXT create_info{};
create_info.flags = ...;
create_info.pfnCallback = reinterpret_cast<PFN_vkDebugReportCallbackEXT>(&debugReportCallback);
debug_report_callback = instance.createDebugReportCallbackEXT(create_info, nullptr, debug_dispatch);
}
...
if(validation_flags & ValidationFlagsBits::KHRONOS){
instance.destroyDebugUtilsMessengerEXT(debug_utils_messenger, nullptr, debug_dispatch);
}
if(validation_flags & ValidationFlagsBits::LUNARG){
instance.destroyDebugReportCallbackEXT(debug_report_callback, nullptr, debug_dispatch);
}
instance.destroy();
}
I had read this page , http://llvm.org/docs/WritingAnLLVMPass.html
And i can do the example of the Hello.so completely.
Now i just want to make a .so file that can be called by opt and read my IR file name as input argument. And after i commit it , it will output the name of the file.
I had tried several methods before , but i still don't know how to do it....
I hope i can do it like this.
opt -load ../Debug+Asserts/lib/xxxx.so -flag < llvm.ll > /dev/null
when i press ENTER , it will output the name of the file -> "llvm.ll"
Can anyone help me write this simple program , i am going to optimize the llvm IR as my semester project , and now i stuck here ... help me , thanks ~
Can you tell me the code in detail , this doesn't work for me
using namespace llvm;
namespace {
struct Hello : public ModulePass {
static char ID;
Hello() : ModulePass(ID) {}
virtual bool runOnModule(Module &M) {
dbgs() << M.getModuleIdentifier() << "\n";
return false;
}
};
}
char Hello::ID = 0;
static RegisterPass<Hello> X("hello", "Hello World Pass", false, false);
~
Your question could really be simplified to "how can I access the name of the current .ll file from within an LLVM pass". You don't need to "parse LLVM IR" or anything like that - when an LLVM pass is being ran it is already way past the parsing phase.
In any case, I'm not aware of any surefire way to get the filename from an LLVM module, but you can encode that information when you prepare the .ll file. For example, set the module id to be the filename via ; ModuleID = 'llvm.ll', then retrieve it by writing a module pass and invoking getModuleIdentifier to get the string. Then you could just print it out, e.g.
bool runOnModule(Module& M) {
dbgs() << M.getModuleIdentifier() << "\n";
return false;
}
Alternatively, use metadata.