UpdatePTUDevCtrl/DCPlugin/src/shared_mem_buffer.cpp

40 lines
1.2 KiB
C++

#include "shared_mem_buffer.h"
#include <QDebug>
#include <atomic>
#ifdef QT_POSIX_IPC
// The POSIX backend can be explicitly selected using the -feature-ipc_posix
// option to the Qt configure script. If it is enabled, the QT_POSIX_IPC
// macro will be defined. -> we use SystemV shared memory
#error "QT_POSIX_IPC defined"
#else
#include <sys/ipc.h> // ftok
#endif
// std::atomic_bool SharedMemBuffer::__sharedMemLocked{false};
QSharedMemory *SharedMemBuffer::getShm(std::size_t size) {
static QSharedMemory shMem;
if (size > 0) {
static const long nativeKey = ftok("/etc/os-release", 'H');
static const QString fkey = std::to_string(nativeKey).c_str();
shMem.setKey(fkey);
if (!shMem.isAttached()) {
if (shMem.create(size)) {
return &shMem;
} else {
if (shMem.error() == QSharedMemory::AlreadyExists) {
if (shMem.attach()) {
return &shMem;
}
}
}
qCritical() << shMem.nativeKey() << shMem.key() << shMem.data()
<< shMem.error() << shMem.errorString();
return nullptr;
}
}
return &shMem;
}