Implement file-backed ring buffer
[lttng-ust.git] / include / lttng / ringbuffer-config.h
index b377b9b3521289b0f9fe7fda15ef5eace1279447..87344c94c8285f94b296f318ae58880dedcc7a39 100644 (file)
@@ -1,28 +1,47 @@
-#ifndef _LINUX_RING_BUFFER_CONFIG_H
-#define _LINUX_RING_BUFFER_CONFIG_H
+#ifndef _LTTNG_RING_BUFFER_CONFIG_H
+#define _LTTNG_RING_BUFFER_CONFIG_H
 
 /*
- * linux/ringbuffer/config.h
+ * lttng/ringbuffer-config.h
  *
  * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * Ring buffer configuration header. Note: after declaring the standard inline
  * functions, clients should also include linux/ringbuffer/api.h.
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
  */
 
 #include <errno.h>
 #include "lttng/ust-tracer.h"
-#include "lttng/usterr-signal-safe.h"
-#include "lttng/kcompat/kcompat.h"
+#include <stdint.h>
+#include <stddef.h>
+#include <urcu/arch.h>
+#include <string.h>
 #include "lttng/align.h"
+#include <lttng/ust-compiler.h>
 
 struct lttng_ust_lib_ring_buffer;
 struct channel;
 struct lttng_ust_lib_ring_buffer_config;
 struct lttng_ust_lib_ring_buffer_ctx;
-struct lttng_ust_shm_handle *handle;
+struct lttng_ust_shm_handle;
 
 /*
  * Ring buffer client callbacks. Only used by slow path, never on fast path.
@@ -34,7 +53,7 @@ struct lttng_ust_lib_ring_buffer_client_cb {
        /* Mandatory callbacks */
 
        /* A static inline version is also required for fast path */
-       u64 (*ring_buffer_clock_read) (struct channel *chan);
+       uint64_t (*ring_buffer_clock_read) (struct channel *chan);
        size_t (*record_header_size) (const struct lttng_ust_lib_ring_buffer_config *config,
                                      struct channel *chan, size_t offset,
                                      size_t *pre_header_padding,
@@ -42,10 +61,10 @@ struct lttng_ust_lib_ring_buffer_client_cb {
 
        /* Slow path only, at subbuffer switch */
        size_t (*subbuffer_header_size) (void);
-       void (*buffer_begin) (struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
+       void (*buffer_begin) (struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
                              unsigned int subbuf_idx,
                              struct lttng_ust_shm_handle *handle);
-       void (*buffer_end) (struct lttng_ust_lib_ring_buffer *buf, u64 tsc,
+       void (*buffer_end) (struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc,
                            unsigned int subbuf_idx, unsigned long data_size,
                            struct lttng_ust_shm_handle *handle);
 
@@ -71,8 +90,15 @@ struct lttng_ust_lib_ring_buffer_client_cb {
        void (*record_get) (const struct lttng_ust_lib_ring_buffer_config *config,
                            struct channel *chan, struct lttng_ust_lib_ring_buffer *buf,
                            size_t offset, size_t *header_len,
-                           size_t *payload_len, u64 *timestamp,
+                           size_t *payload_len, uint64_t *timestamp,
                            struct lttng_ust_shm_handle *handle);
+       /*
+        * Offset and size of content size field in client.
+        */
+       void (*content_size_field) (const struct lttng_ust_lib_ring_buffer_config *config,
+                               size_t *offset, size_t *length);
+       void (*packet_size_field) (const struct lttng_ust_lib_ring_buffer_config *config,
+                               size_t *offset, size_t *length);
 };
 
 /*
@@ -114,47 +140,65 @@ struct lttng_ust_lib_ring_buffer_client_cb {
  * RING_BUFFER_WAKEUP_NONE does not perform any wakeup whatsoever. The client
  * has the responsibility to perform wakeups.
  */
+#define LTTNG_UST_RING_BUFFER_CONFIG_PADDING   20
+
+enum lttng_ust_lib_ring_buffer_alloc_types {
+       RING_BUFFER_ALLOC_PER_CPU,
+       RING_BUFFER_ALLOC_GLOBAL,
+};
+
+enum lttng_ust_lib_ring_buffer_sync_types {
+       RING_BUFFER_SYNC_PER_CPU,       /* Wait-free */
+       RING_BUFFER_SYNC_GLOBAL,        /* Lock-free */
+};
+
+enum lttng_ust_lib_ring_buffer_mode_types {
+       RING_BUFFER_OVERWRITE = 0,      /* Overwrite when buffer full */
+       RING_BUFFER_DISCARD = 1,        /* Discard when buffer full */
+};
+
+enum lttng_ust_lib_ring_buffer_output_types {
+       RING_BUFFER_SPLICE,
+       RING_BUFFER_MMAP,
+       RING_BUFFER_READ,               /* TODO */
+       RING_BUFFER_ITERATOR,
+       RING_BUFFER_NONE,
+};
+
+enum lttng_ust_lib_ring_buffer_backend_types {
+       RING_BUFFER_PAGE,
+       RING_BUFFER_VMAP,               /* TODO */
+       RING_BUFFER_STATIC,             /* TODO */
+};
+
+enum lttng_ust_lib_ring_buffer_oops_types {
+       RING_BUFFER_NO_OOPS_CONSISTENCY,
+       RING_BUFFER_OOPS_CONSISTENCY,
+};
+
+enum lttng_ust_lib_ring_buffer_ipi_types {
+       RING_BUFFER_IPI_BARRIER,
+       RING_BUFFER_NO_IPI_BARRIER,
+};
+
+enum lttng_ust_lib_ring_buffer_wakeup_types {
+       RING_BUFFER_WAKEUP_BY_TIMER,    /* wake up performed by timer */
+       RING_BUFFER_WAKEUP_BY_WRITER,   /*
+                                        * writer wakes up reader,
+                                        * not lock-free
+                                        * (takes spinlock).
+                                        */
+};
+
 struct lttng_ust_lib_ring_buffer_config {
-       enum {
-               RING_BUFFER_ALLOC_PER_CPU,
-               RING_BUFFER_ALLOC_GLOBAL,
-       } alloc;
-       enum {
-               RING_BUFFER_SYNC_PER_CPU,       /* Wait-free */
-               RING_BUFFER_SYNC_GLOBAL,        /* Lock-free */
-       } sync;
-       enum {
-               RING_BUFFER_OVERWRITE,          /* Overwrite when buffer full */
-               RING_BUFFER_DISCARD,            /* Discard when buffer full */
-       } mode;
-       enum {
-               RING_BUFFER_SPLICE,
-               RING_BUFFER_MMAP,
-               RING_BUFFER_READ,               /* TODO */
-               RING_BUFFER_ITERATOR,
-               RING_BUFFER_NONE,
-       } output;
-       enum {
-               RING_BUFFER_PAGE,
-               RING_BUFFER_VMAP,               /* TODO */
-               RING_BUFFER_STATIC,             /* TODO */
-       } backend;
-       enum {
-               RING_BUFFER_NO_OOPS_CONSISTENCY,
-               RING_BUFFER_OOPS_CONSISTENCY,
-       } oops;
-       enum {
-               RING_BUFFER_IPI_BARRIER,
-               RING_BUFFER_NO_IPI_BARRIER,
-       } ipi;
-       enum {
-               RING_BUFFER_WAKEUP_BY_TIMER,    /* wake up performed by timer */
-               RING_BUFFER_WAKEUP_BY_WRITER,   /*
-                                                * writer wakes up reader,
-                                                * not lock-free
-                                                * (takes spinlock).
-                                                */
-       } wakeup;
+       enum lttng_ust_lib_ring_buffer_alloc_types alloc;
+       enum lttng_ust_lib_ring_buffer_sync_types sync;
+       enum lttng_ust_lib_ring_buffer_mode_types mode;
+       enum lttng_ust_lib_ring_buffer_output_types output;
+       enum lttng_ust_lib_ring_buffer_backend_types backend;
+       enum lttng_ust_lib_ring_buffer_oops_types oops;
+       enum lttng_ust_lib_ring_buffer_ipi_types ipi;
+       enum lttng_ust_lib_ring_buffer_wakeup_types wakeup;
        /*
         * tsc_bits: timestamp bits saved at each record.
         *   0 and 64 disable the timestamp compression scheme.
@@ -167,6 +211,9 @@ struct lttng_ust_lib_ring_buffer_config {
         * callbacks and update the cb pointers.
         */
        int client_type;
+       int _unused1;
+       const struct lttng_ust_lib_ring_buffer_client_cb *cb_ptr;
+       char padding[LTTNG_UST_RING_BUFFER_CONFIG_PADDING];
 };
 
 /*
@@ -175,7 +222,13 @@ struct lttng_ust_lib_ring_buffer_config {
  * Context passed to lib_ring_buffer_reserve(), lib_ring_buffer_commit(),
  * lib_ring_buffer_try_discard_reserve(), lib_ring_buffer_align_ctx() and
  * lib_ring_buffer_write().
+ *
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Fields need to be only added at the end, never reordered, never
+ * removed.
  */
+#define LTTNG_UST_RING_BUFFER_CTX_PADDING      \
+               (24 - sizeof(int) - sizeof(void *))
 struct lttng_ust_lib_ring_buffer_ctx {
        /* input received by lib_ring_buffer_reserve(), saved here. */
        struct channel *chan;           /* channel */
@@ -201,8 +254,11 @@ struct lttng_ust_lib_ring_buffer_ctx {
                                         * prior to record header alignment
                                         * padding.
                                         */
-       u64 tsc;                        /* time-stamp counter value */
+       uint64_t tsc;                   /* time-stamp counter value */
        unsigned int rflags;            /* reservation flags */
+       unsigned int padding1;          /* padding to realign on pointer */
+       void *ip;                       /* caller ip address */
+       char padding2[LTTNG_UST_RING_BUFFER_CTX_PADDING];
 };
 
 /**
@@ -214,6 +270,11 @@ struct lttng_ust_lib_ring_buffer_ctx {
  * @largest_align: largest alignment within data payload types
  * @cpu: processor id
  */
+static inline lttng_ust_notrace
+void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                             struct channel *chan, void *priv,
+                             size_t data_size, int largest_align,
+                             int cpu, struct lttng_ust_shm_handle *handle);
 static inline
 void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
                              struct channel *chan, void *priv,
@@ -227,6 +288,9 @@ void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
        ctx->cpu = cpu;
        ctx->rflags = 0;
        ctx->handle = handle;
+       ctx->padding1 = 0;
+       ctx->ip = 0;
+       memset(ctx->padding2, 0, LTTNG_UST_RING_BUFFER_CTX_PADDING);
 }
 
 /*
@@ -260,6 +324,8 @@ void lib_ring_buffer_ctx_init(struct lttng_ust_lib_ring_buffer_ctx *ctx,
  * Calculate the offset needed to align the type.
  * size_of_type must be non-zero.
  */
+static inline lttng_ust_notrace
+unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type);
 static inline
 unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
 {
@@ -274,6 +340,8 @@ unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
  * Calculate the offset needed to align the type.
  * size_of_type must be non-zero.
  */
+static inline lttng_ust_notrace
+unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type);
 static inline
 unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
 {
@@ -286,6 +354,9 @@ unsigned int lib_ring_buffer_align(size_t align_drift, size_t size_of_type)
  * lib_ring_buffer_align_ctx - Align context offset on "alignment"
  * @ctx: ring buffer context.
  */
+static inline lttng_ust_notrace
+void lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                          size_t alignment);
 static inline
 void lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
                           size_t alignment)
@@ -298,6 +369,10 @@ void lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
  * lib_ring_buffer_check_config() returns 0 on success.
  * Used internally to check for valid configurations at channel creation.
  */
+static inline lttng_ust_notrace
+int lib_ring_buffer_check_config(const struct lttng_ust_lib_ring_buffer_config *config,
+                            unsigned int switch_timer_interval,
+                            unsigned int read_timer_interval);
 static inline
 int lib_ring_buffer_check_config(const struct lttng_ust_lib_ring_buffer_config *config,
                             unsigned int switch_timer_interval,
@@ -310,6 +385,4 @@ int lib_ring_buffer_check_config(const struct lttng_ust_lib_ring_buffer_config *
        return 0;
 }
 
-#include <lttng/vatomic.h>
-
-#endif /* _LINUX_RING_BUFFER_CONFIG_H */
+#endif /* _LTTNG_RING_BUFFER_CONFIG_H */
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