Add render worker IPC loop

2026-06-04 13:57:36 +08:00
parent 8c1c7658d9
commit b23e01b916
32 changed files with 2346 additions and 5651 deletions
@@ -0,0 +1,123 @@
+/***
+
+  Oak - Non-Linear Video Editor
+  Copyright (C) 2026 Oak Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#ifndef IPC_SHAREDMEMORYREGION_H
+#define IPC_SHAREDMEMORYREGION_H
+
+#include <cstddef>
+#include <QString>
+
+namespace olive
+{
+namespace ipc
+{
+
+/**
+ * @brief A named, fixed-size shared memory segment mapped into the process address space.
+ *
+ * One process Create()s the segment (owner); the peer process Attach()es to it by the same key.
+ * The mapping is a raw contiguous byte range accessible via data() — the IPC ring buffers and frame
+ * slot pools are laid out inside it. Nothing here is locked; synchronization is entirely the
+ * caller's responsibility via the lock-free structures placed in the mapping.
+ *
+ * We deliberately use the raw OS primitives (POSIX shm_open + mmap, Windows CreateFileMapping +
+ * MapViewOfFile) rather than QSharedMemory: QSharedMemory carries an implicit semaphore and a 1-byte
+ * header convention, attaches/detaches with reference counting we don't want, and historically has
+ * cross-platform lifetime quirks. For a render pipeline pushing large frames we want a plain mmap.
+ */
+class SharedMemoryRegion {
+public:
+	enum Mode {
+		/// Create (and own) the segment. Fails if it already exists; unlinks on destruction.
+		kCreate,
+		/// Attach to a segment created by the peer. Does not unlink on destruction.
+		kAttach
+	};
+
+	SharedMemoryRegion();
+	~SharedMemoryRegion();
+
+	SharedMemoryRegion(const SharedMemoryRegion &) = delete;
+	SharedMemoryRegion &operator=(const SharedMemoryRegion &) = delete;
+
+	/**
+   * @brief Open the segment identified by `key` with the given `size` in bytes.
+   *
+   * `key` is a short identifier (no leading slash needed; the platform prefix is added internally).
+   * Returns true on success. On failure, error() carries a human-readable reason.
+   */
+	bool Open(const QString &key, size_t size, Mode mode);
+
+	/**
+   * @brief Unmap and (if owner) unlink the segment. Called automatically by the destructor.
+   */
+	void Close();
+
+	bool IsValid() const
+	{
+		return data_ != nullptr;
+	}
+
+	void *data() const
+	{
+		return data_;
+	}
+
+	size_t size() const
+	{
+		return size_;
+	}
+
+	const QString &key() const
+	{
+		return key_;
+	}
+
+	const QString &error() const
+	{
+		return error_;
+	}
+
+	/**
+   * @brief Build a unique segment key for a worker, e.g. "olive-rw-<pid>-<index>".
+   *
+   * Centralized so the owner and the spawned worker agree on the same name.
+   */
+	static QString MakeKey(qint64 owner_pid, int worker_index);
+
+private:
+	QString key_;
+	size_t size_;
+	void *data_;
+	Mode mode_;
+	QString error_;
+
+#if defined(Q_OS_WIN)
+	void *handle_;  // HANDLE from CreateFileMapping/OpenFileMapping
+#else
+	int fd_;        // file descriptor from shm_open
+	QString shm_name_;  // the platform-prefixed name actually passed to shm_open
+#endif
+};
+
+}  // namespace ipc
+}  // namespace olive
+
+#endif  // IPC_SHAREDMEMORYREGION_H