ds: add a ringbuffer data structure

2026-06-06 17:50:23 +01:00
parent 44bcc8c805
commit 249ac7a8cf
2 changed files with 368 additions and 0 deletions
@@ -0,0 +1,45 @@
+#ifndef KERNEL_RINGBUF_H_
+#define KERNEL_RINGBUF_H_
+
+#include <kernel/wait.h>
+#include <magenta/types.h>
+
+struct ringbuf {
+	unsigned int buf_read;
+	unsigned int buf_write;
+	unsigned int buf_capacity;
+
+	unsigned int buf_flags;
+	unsigned char *buf_ptr;
+	struct waitqueue buf_read_queue;
+	struct waitqueue buf_write_queue;
+	spin_lock_t buf_lock;
+
+	unsigned char *buf_opened_ptr;
+	unsigned int buf_opened_capacity;
+};
+
+#define RINGBUF_DECLARE(name, size)                                            \
+	static unsigned char __buf_##name[size] = {0};                         \
+	static struct ringbuf name = {                                         \
+		.buf_ptr = __buf_##name,                                       \
+		.buf_capacity = size,                                          \
+	}
+
+extern kern_status_t ringbuf_lock(struct ringbuf *buf, unsigned long *flags);
+extern kern_status_t ringbuf_unlock(struct ringbuf *buf, unsigned long flags);
+
+extern kern_status_t ringbuf_read(
+	struct ringbuf *buf,
+	void *out,
+	size_t count,
+	size_t *nr_read,
+	unsigned long *irq_flags);
+extern kern_status_t ringbuf_write(
+	struct ringbuf *buf,
+	const void *out,
+	size_t count,
+	size_t *nr_written,
+	unsigned long *irq_flags);
+
+#endif