lib ring buffer initial import

[lttng-ust.git] / libringbuffer / backend_types.h

diff --git a/libringbuffer/backend_types.h b/libringbuffer/backend_types.h
new file mode 100644 (file)
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+++ b/libringbuffer/backend_types.h
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+#ifndef _LINUX_RING_BUFFER_BACKEND_TYPES_H
+#define _LINUX_RING_BUFFER_BACKEND_TYPES_H
+
+/*
+ * linux/ringbuffer/backend_types.h
+ *
+ * Copyright (C) 2008-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Ring buffer backend (types).
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/cpumask.h>
+#include <linux/types.h>
+
+struct lib_ring_buffer_backend_page {
+       void *virt;                     /* page virtual address (cached) */
+       struct page *page;              /* pointer to page structure */
+};
+
+struct lib_ring_buffer_backend_pages {
+       unsigned long mmap_offset;      /* offset of the subbuffer in mmap */
+       union v_atomic records_commit;  /* current records committed count */
+       union v_atomic records_unread;  /* records to read */
+       unsigned long data_size;        /* Amount of data to read from subbuf */
+       struct lib_ring_buffer_backend_page p[];
+};
+
+struct lib_ring_buffer_backend_subbuffer {
+       /* Identifier for subbuf backend pages. Exchanged atomically. */
+       unsigned long id;               /* backend subbuffer identifier */
+};
+
+/*
+ * Forward declaration of frontend-specific channel and ring_buffer.
+ */
+struct channel;
+struct lib_ring_buffer;
+
+struct lib_ring_buffer_backend {
+       /* Array of ring_buffer_backend_subbuffer for writer */
+       struct lib_ring_buffer_backend_subbuffer *buf_wsb;
+       /* ring_buffer_backend_subbuffer for reader */
+       struct lib_ring_buffer_backend_subbuffer buf_rsb;
+       /*
+        * Pointer array of backend pages, for whole buffer.
+        * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
+        */
+       struct lib_ring_buffer_backend_pages **array;
+       unsigned int num_pages_per_subbuf;
+
+       struct channel *chan;           /* Associated channel */
+       int cpu;                        /* This buffer's cpu. -1 if global. */
+       union v_atomic records_read;    /* Number of records read */
+       unsigned int allocated:1;       /* Bool: is buffer allocated ? */
+};
+
+struct channel_backend {
+       unsigned long buf_size;         /* Size of the buffer */
+       unsigned long subbuf_size;      /* Sub-buffer size */
+       unsigned int subbuf_size_order; /* Order of sub-buffer size */
+       unsigned int num_subbuf_order;  /*
+                                        * Order of number of sub-buffers/buffer
+                                        * for writer.
+                                        */
+       unsigned int buf_size_order;    /* Order of buffer size */
+       int extra_reader_sb:1;          /* Bool: has extra reader subbuffer */
+       struct lib_ring_buffer *buf;    /* Channel per-cpu buffers */
+
+       unsigned long num_subbuf;       /* Number of sub-buffers for writer */
+       u64 start_tsc;                  /* Channel creation TSC value */
+       void *priv;                     /* Client-specific information */
+       struct notifier_block cpu_hp_notifier;   /* CPU hotplug notifier */
+       const struct lib_ring_buffer_config *config; /* Ring buffer configuration */
+       cpumask_var_t cpumask;          /* Allocated per-cpu buffers cpumask */
+       char name[NAME_MAX];            /* Channel name */
+};
+
+#endif /* _LINUX_RING_BUFFER_BACKEND_TYPES_H */