I'm using shaderc that comes VulkanSDK-1.3.224.1. Attempting to compile the following when added to any of my shaders:
#extension GL_EXT_scalar_block_layout: enable
#extension GL_EXT_buffer_reference2 : enable
#extension GL_EXT_shader_explicit_arithmetic_types_int64 : enable
layout(buffer_reference, buffer_reference_align=4, scalar) buffer test_ref_type{
uint32_t data[];
};
struct RefTest{
test_ref_type test;
};
RefTest extract_RefTest(){
return RefTest(test_ref_type(uint64_t(0)));
}
void main(){
RefTest ref_test = extract_RefTest();
}
results in
shaderc: internal error: compilation succeeded but failed to optimize: ID 108[%108] has not been defined
%109 = OpConstantComposite %RefTest %108
However, if I first convert to a uint64_t it works fine:
#extension GL_EXT_scalar_block_layout: enable
#extension GL_EXT_buffer_reference2 : enable
#extension GL_EXT_shader_explicit_arithmetic_types_int64 : enable
layout(buffer_reference, buffer_reference_align=4, scalar) buffer test_ref_type{
uint32_t data[];
};
struct RefTest{
uint64_t test;
};
RefTest extract_RefTest(){
return RefTest(uint64_t(test_ref_type(uint64_t(0))));
}
void main(){
RefTest ref_test = extract_RefTest();
}
How do I have composite structs with buffer_reference types with out explicit uint64_t conversion?
Related
Suppose some kernel (a __global__ function named foo) is running on a CUDA device. And suppose that kernel calls a __device__ function bar which is sometimes called from other kernels, i.e. the code of bar does not know at compile-time whether the kernel is foo or something else.
Can a thread running foo, within bar, obtain either the name "foo", the signature, or some other identifier of the kernel, preferable a human-readable one?
If necessary, assume the code has been compiled with any of --debug, --device-debug and/or --lineinfo.
The kernel can read the special register %gridid. %gridid is unique per launch. If performance then a simple kernel prolog can have one thread from each kernel launch output the gridid global function map using func and %gridid. Alternatively, the CUPTI SDK Activity API can be used to collect this information. The CUpti_ActivityKernel2 event contains per launch meta-data including the gridId and CUfunction name.
Here is an example reading %gridid.
#include "cuda_runtime.h"
#include "device_launch_parameters.h"
#include <stdio.h>
#include <stdint.h>
cudaError_t addWithCuda(int *c, const int *a, const int *b, unsigned int size);
static __device__ __inline__ uint64_t __gridid()
{
uint64_t gridid;
asm volatile("mov.u64 %0, %%gridid;" : "=l"(gridid));
return gridid;
}
__device__ void devPrintName()
{
static const char* name = __func__;
printf("%llu %s\n", __gridid(), name);
}
__global__ void globPrintName()
{
static const char* name = __func__;
printf("%llu %s\n", __gridid(), name);
devPrintName();
}
int main()
{
for (int i = 0; i < 4; ++i)
{
globPrintName<<<1,1,0>>>();
cudaDeviceReset();
}
return 0;
}
This sample outputs
1 globPrintName
1 devPrintName
2 globPrintName
2 devPrintName
3 globPrintName
3 devPrintName
4 globPrintName
4 devPrintName
I have created a shared memory segment with the help of a binary in C and written some data into it. Now I want read that data from Qt. How to attach to existing shared memory from Qt?
QSharedMemory isn't really meant to interoperate with anything else. On Unix, it is implemented via SYSV shared memory, but it passes Qt-specific arguments to ftok:
::ftok(filename.constData(), qHash(filename, proj_id));
You could emulate this behavior in your C code, but I don't think it's necessary.
Instead of opening a shared memory segment, simply map a file to memory, and access it from multiple processes. On Qt, QFile::map does what you need.
The example below shows both techniques: using SYSV shared memory and using memory-mapped files:
// https://github.com/KubaO/stackoverflown/tree/master/questions/sharedmem-interop-39573295
#include <QtCore>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <cerrno>
#include <stdexcept>
#include <string>
First, let's have a shared data structure.
struct Data {
int a = 1;
bool b = true;
char c = 'S';
bool operator==(const Data & o) const { return o.a == a && o.b == b && o.c == c; }
static void compare(const void * a, const void * b) {
auto data1 = reinterpret_cast<const Data*>(a);
auto data2 = reinterpret_cast<const Data*>(b);
Q_ASSERT(*data1 == *data2);
}
};
We definitely want error checking, so let's add some helpers that make that easier:
void check(bool ok, const char * msg, const char * detail) {
if (ok) return;
std::string str{msg};
str.append(": ");
str.append(detail);
throw std::runtime_error{str};
}
void check(int f, const char * msg) { check(f != -1, msg, strerror(errno)); }
void check(void * f, const char * msg) { check(f != MAP_FAILED, msg, strerror(errno)); }
void check(bool rc, const QSharedMemory & shm, const char * msg) { check(rc, msg, shm.errorString().toLocal8Bit()); }
void check(bool rc, const QFile & file, const char * msg) { check(rc, msg, file.errorString().toLocal8Bit()); }
And we need RAII wrappers for C APIs:
struct noncopyable { Q_DISABLE_COPY(noncopyable) noncopyable() {} };
struct ShmId : noncopyable {
int id;
ShmId(int id) : id{id} {}
~ShmId() { if (id != -1) shmctl(id, IPC_RMID, NULL); }
};
struct ShmPtr : noncopyable {
void * ptr;
ShmPtr(void * ptr) : ptr{ptr} {}
~ShmPtr() { if (ptr != (void*)-1) shmdt(ptr); }
};
struct Handle : noncopyable {
int fd;
Handle(int fd) : fd{fd} {}
~Handle() { if (fd != -1) close(fd); }
};
Here's how to interoperates SYSV shared memory sections between C and Qt. Unfortunately, unless you reimplement qHash in C, it's not possible:
void ipc_shm_test() {
QTemporaryFile shmFile;
check(shmFile.open(), shmFile, "shmFile.open");
// SYSV SHM
auto nativeKey = QFile::encodeName(shmFile.fileName());
auto key = ftok(nativeKey.constData(), qHash(nativeKey, 'Q'));
check(key, "ftok");
ShmId id{shmget(key, sizeof(Data), IPC_CREAT | 0600)};
check(id.id, "shmget");
ShmPtr ptr1{shmat(id.id, NULL, 0)};
check(ptr1.ptr, "shmat");
new (ptr1.ptr) Data;
// Qt
QSharedMemory shm;
shm.setNativeKey(shmFile.fileName());
check(shm.attach(QSharedMemory::ReadOnly), shm, "shm.attach");
auto ptr2 = shm.constData();
Data::compare(ptr1.ptr, ptr2);
}
Here's how to interoperate memory-mapped files:
void mmap_test() {
QTemporaryFile shmFile;
check(shmFile.open(), "shmFile.open");
shmFile.write({sizeof(Data), 0});
check(true, shmFile, "shmFile.write");
check(shmFile.flush(), shmFile, "shmFile.flush");
// SYSV MMAP
Handle fd{open(QFile::encodeName(shmFile.fileName()), O_RDWR)};
check(fd.fd, "open");
auto ptr1 = mmap(NULL, sizeof(Data), PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd.fd, 0);
check(ptr1, "mmap");
new (ptr1) Data;
// Qt
auto ptr2 = shmFile.map(0, sizeof(Data));
Data::compare(ptr1, ptr2);
}
And finally, the test harness:
int main() {
try {
ipc_shm_test();
mmap_test();
}
catch (const std::runtime_error & e) {
qWarning() << e.what();
return 1;
}
return 0;
}
ALL,
I'm using Anjuta to do my development.
I created a project for my main application, and then made 2 more: 1 for the static library (libdbinterface.a) and 1 for the dynamic library (libsqlite_lib.so).
Both those libraries contains one exported class each: libdbinterface.a - class Database, libsqlite_lib.so - public SQLiteDatabase : public Database.
Now I'm trying to link libdbinterface.a to libsqlite_lib.so.
So in Anjuta I added following to the "Linker Option" for the target libsqlite_lib.so:
-L/home/igor/dbhandler/Debug/dbinterface -ldbinterface
However, trying to compile I received following error from linker:
/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.4/../../../../x86_64-pc-linux-gnu/bin/ld: /home/igor/dbhandler/Debug/dbinterface/libdbinterface.a(database.o): relocation R_X86_64_32S against `_ZTV8Database' can not be used when making a shared object; recompile with -fPIC
I tried to recompile libsqlite_lib.so with -fPIC explicitely added to "C++ Options" of that project but that didn't solve it - I still receive the same error.
Unfortunately trying to Google on how to link .a and .so is not helpful.
Can someone sched some light on how to fix this error?
TIA.
[EDIT]
libsqlite_lib.so Makefile - https://bpaste.net/show/1495231e58cc
libdbinterface.a Makefile - https://bpaste.net/show/3a71c119d0fc
libdbinterface.a contains 2 files databse.h:
#ifndef DBMANAGER_DATABASE
#define DBMANAGER_DATABASE
class Field
{
public:
Field(const std::string &columnName, const std::string &columnType, const std::string &columnDefaultValue = "", const bool columnIsNull = false, const bool columnPK = false)
{
column_name = columnName;
column_type = columnType;
column_defaultValue = columnDefaultValue;
column_isNull = columnIsNull;
column_pk = columnPK;
}
private:
std::string column_name, column_type, column_defaultValue;
bool column_isNull, column_pk;
};
struct FKField
{
FKField(const std::string &table_name, const std::string &original_field, const std::string &referenced_field)
{
tableName = table_name;
originalField = original_field;
referencedField = referenced_field;
}
std::string tableName, originalField, referencedField;
};
class Table
{
public:
Table(const std::string &tableName, const std::vector<Field> &tableFields, const std::map<int,std::vector<FKField> > &foreignKeys)
{
table_name = tableName;
table_fields = tableFields;
foreign_keys = foreignKeys;
}
const std::string &GetTableName() { return table_name; }
std::map<int,std::vector<FKField> > &GetForeignKeyVector() { return foreign_keys; }
private:
std::string table_name;
std::vector<Field> table_fields;
std::map<int,std::vector<FKField> > foreign_keys;
};
#ifdef WIN32
class __declspec(dllexport) Database
#else
class Database
#endif
{
private:
struct Impl;
Impl *pimpl;
public:
Database();
virtual ~Database();
Impl &GetTableVector();
static void *operator new(std::size_t size);
static void operator delete(void *ptr, std::size_t size);
virtual int Connect(const char *selectedDSN, std::vector<std::wstring> &errorMsg);
virtual int GetTableListFromDb(std::string &) { return 0; }
};
#endif
and database.cpp:
#ifdef WIN32
#include <windows.h>
#endif
#include <map>
#include <vector>
#include <string>
#include <sqlext.h>
#include "database.h"
struct Database::Impl
{
std::vector<Table> m_tables;
};
Database::Database() : pimpl( new Impl )
{
}
Database::~Database()
{
delete pimpl;
}
void *Database::operator new(std::size_t size)
{
return ::operator new( size );
}
void Database::operator delete(void *ptr, std::size_t size)
{
return ::operator delete( ptr );
}
Database::Impl &Database::GetTableVector()
{
return *pimpl;
}
int Database::Connect(const char *selectedDSN, std::vector<std::wstring> &errorMsg)
{
selectedDSN = selectedDSN;
errorMsg = errorMsg;
return 0;
}
libsqlite_lib.so has also 2 files: database_sqlite.h
#ifndef DBMANAGER_SQLITE
#define DBMANAGER_SQLITE
#ifdef WIN32
class __declspec(dllexport) SQLiteDatabase : public Database
#else
class SQLiteDatabase : public Database
#endif
{
public:
SQLiteDatabase();
~SQLiteDatabase();
virtual int Connect(const char *selectedDSN, std::vector<std::wstring> &errorMsg);
virtual int GetTableListFromDb(std::vector<std::wstring> &errorMsg);
protected:
void GetErrorMessage(int code, std::wstring &errorMsg);
private:
sqlite3 *m_db;
};
#endif
and database_sqlite.cpp with the actual implementation.
[/EDIT]
Well, apparently the solution is to rebuild static library with "-fPIC", not the dynamic one.
Thank you for reading.
At the bottom of the documentation on PROGMEM, it shows what looks like a wonderfully simple way to compile strings into the program .text segment:
The F() macro
When an instruction like:
Serial.print("Write something");
is used, the string to be printed is normally saved in RAM. If your sketch prints a lot of stuff on the Serial Monitor, you can easily fill the RAM. If you have free FLASH memory space, you can easily indicate that the string must be saved in FLASH using the syntax:
Serial.print(F("Write something that is stored in FLASH"));
However, I have had only bad luck getting this to compile.
#include <avr/pgmspace.h>
static const struct {short cmd; const char *txt;} cmds[] = {
{2, F("Hi")},
};
It complains with
t.c:3: error: initializer element is not constant
{2, F("hi")},
^
t.c:3: error: (near initialization for 'cmds[0].txt')
exit status 1
initializer element is not constant
Without the F macro, it compiles just fine.
{2, "Hi"},
Does anyone have experience getting this to work? I have like 10K of strings I'd like to get into the program space.
The F macro can only be used in executable parts of the code, not variable definitions. And because struct member can't have the PROGMEM attribute, you have to do it in two steps: declare each text string in PROGMEM, then use the PROGMEM address in the struct.
An array of structs can be in PROGMEM, too.
static const char cmd_0_txt[] PROGMEM = "Hello";
static const char cmd_1_txt[] PROGMEM = "World";
struct cmd_t {short cmd; const char *txt; }; // the struct type
// An array of structs in PROGMEM
static const cmd_t cmds[] PROGMEM = {
{2, cmd_0_txt},
{2, cmd_1_txt},
};
void setup()
{
Serial.begin( 9600 );
Serial.println( F("Test") );
for (uint8_t i=0; i < sizeof(cmds)/sizeof(cmds[0]); i++) {
// First, read the PROGMEM txt member (a pointer to the text)
const char *ptr = (const char *) pgm_read_word( &cmds[i].txt ); // cast required
// Next, read each text character from that PROGMEM location
for (;;) {
char c = pgm_read_byte( ptr++ );
if (!c)
break;
Serial.print( c );
}
Serial.println();
}
}
void loop()
{}
When I want to code about lets say zigbee library so how I will come to know that which functions are supported by zigbee object?Please help.
Let's say you want to know what SoftwareSerial.h provides. Search for it in Arduino directory, e.g.: C:\Program Files (x86)\Arduino. All public methods are at your disposal.
This applies to already installed libraries into Arduino IDE:
SoftwareSerial.h:
#include <inttypes.h>
#include <Stream.h>
.........
.........
class SoftwareSerial : public Stream
{
private:
// per object data
uint8_t _receivePin;
uint8_t _receiveBitMask;
volatile uint8_t *_receivePortRegister;
uint8_t _transmitBitMask;
volatile uint8_t *_transmitPortRegister;
.........
.........
public:
// public methods
SoftwareSerial(uint8_t receivePin, uint8_t transmitPin, bool inverse_logic = false);
~SoftwareSerial();
void begin(long speed);
bool listen();
void end();
bool isListening() { return this == active_object; }
bool overflow() { bool ret = _buffer_overflow; _buffer_overflow = false; return ret; }
int peek();
virtual size_t write(uint8_t byte);
virtual int read();
virtual int available();
virtual void flush();
using Print::write;
// public only for easy access by interrupt handlers
static inline void handle_interrupt();
};
Generally open a library header file and all public methods and properties are at your disposal.