| Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/C/Linux/include/linux/ (Open Source Betriebssystem Version 6.17.9©) Datei vom 24.10.2025 mit Größe 2 kB |
|
Quelle rolling_buffer.h Sprache: C |
|||||||||
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Rolling buffer of folios * * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #ifndef _ROLLING_BUFFER_H #define _ROLLING_BUFFER_H #include <linux/folio_queue.h> #include <linux/uio.h> /* * Rolling buffer. Whilst the buffer is live and in use, folios and folio * queue segments can be added to one end by one thread and removed from the * other end by another thread. The buffer isn't allowed to be empty; it must * always have at least one folio_queue in it so that neither side has to * modify both queue pointers. * * The iterator in the buffer is extended as buffers are inserted. It can be * snapshotted to use a segment of the buffer. */ struct rolling_buffer { struct folio_queue *head; /* Producer's insertion point */ struct folio_queue *tail; /* Consumer's removal point */ struct iov_iter iter; /* Iterator tracking what's left in the buffer */ u8 next_head_slot; /* Next slot in ->head */ u8 first_tail_slot; /* First slot in ->tail */ }; /* * Snapshot of a rolling buffer. */ struct rolling_buffer_snapshot { struct folio_queue *curr_folioq; /* Queue segment in which current folio resides */ unsigned char curr_slot; /* Folio currently being read */ unsigned char curr_order; /* Order of folio */ }; /* Marks to store per-folio in the internal folio_queue structs. */ #define ROLLBUF_MARK_1 BIT(0) #define ROLLBUF_MARK_2 BIT(1) int rolling_buffer_init(struct rolling_buffer *roll, unsigned int rreq_id, unsigned int direction); int rolling_buffer_make_space(struct rolling_buffer *roll); ssize_t rolling_buffer_load_from_ra(struct rolling_buffer *roll, struct readahead_control *ractl, struct folio_batch *put_batch); ssize_t rolling_buffer_append(struct rolling_buffer *roll, struct folio *folio, unsigned int flags); struct folio_queue *rolling_buffer_delete_spent(struct rolling_buffer *roll); void rolling_buffer_clear(struct rolling_buffer *roll); static inline void rolling_buffer_advance(struct rolling_buffer *roll, size_t amount) { iov_iter_advance(&roll->iter, amount); } #endif /* _ROLLING_BUFFER_H */ ¤ Dauer der Verarbeitung: 0.10 Sekunden (vorverarbeitet) ¤*© Formatika GbR, Deutschland |
|
2026-03-28