| 47 | } |
| 48 | |
| 49 | static bool openShmSegment(const char* name, int& fd, DaxShmBlock*& block) |
| 50 | { |
| 51 | // Try to open existing segment first (HAL plugin may already have it mapped). |
| 52 | fd = shm_open(name, O_RDWR, 0666); |
| 53 | if (fd < 0) { |
| 54 | // Does not exist yet — create it. |
| 55 | fd = shm_open(name, O_CREAT | O_RDWR, 0666); |
| 56 | if (fd < 0) { |
| 57 | qCWarning(lcDax) << "VirtualAudioBridge: shm_open failed for" << name; |
| 58 | return false; |
| 59 | } |
| 60 | if (ftruncate(fd, sizeof(DaxShmBlock)) != 0) { |
| 61 | qCWarning(lcDax) << "VirtualAudioBridge: ftruncate failed for" << name; |
| 62 | ::close(fd); |
| 63 | fd = -1; |
| 64 | return false; |
| 65 | } |
| 66 | } |
| 67 | // else: segment already exists at the right size — reuse it so the |
| 68 | // HAL plugin's existing mmap stays valid. |
| 69 | |
| 70 | void* ptr = mmap(nullptr, sizeof(DaxShmBlock), PROT_READ | PROT_WRITE, |
| 71 | MAP_SHARED, fd, 0); |
| 72 | if (ptr == MAP_FAILED) { |
| 73 | qCWarning(lcDax) << "VirtualAudioBridge: mmap failed for" << name; |
| 74 | ::close(fd); |
| 75 | fd = -1; |
| 76 | return false; |
| 77 | } |
| 78 | |
| 79 | // Re-initialize the header fields (resets write/read positions). |
| 80 | auto* b = static_cast<DaxShmBlock*>(ptr); |
| 81 | b->writePos.store(0, std::memory_order_relaxed); |
| 82 | b->readPos.store(0, std::memory_order_relaxed); |
| 83 | b->sampleRate = 24000; |
| 84 | b->channels = 2; |
| 85 | block = b; |
| 86 | return true; |
| 87 | } |
| 88 | |
| 89 | bool VirtualAudioBridge::open() |
| 90 | { |