usertrace-fast/ltt-usertrace-fast.h

   1
   2 /* LTTng user-space "fast" tracing header
   3  *
   4  * Copyright 2006 Mathieu Desnoyers
   5  *
   6  */
   7
   8 #ifndef _LTT_USERTRACE_FAST_H
   9 #define _LTT_USERTRACE_FAST_H
  10
  11 #include <errno.h>
  12 #include <asm/atomic.h>
  13 #include <pthread.h>
  14
  15
  16 #ifndef LTT_N_SUBBUFS
  17 #define LTT_N_SUBBUFS 2
  18 #endif //LTT_N_SUBBUFS
  19
  20 #ifndef LTT_SUBBUF_SIZE_CPU
  21 #define LTT_SUBBUF_SIZE_CPU 1048576
  22 #endif //LTT_BUF_SIZE_CPU
  23
  24 #define LTT_BUF_SIZE_CPU (LTT_SUBBUF_SIZE_CPU * LTT_N_SUBBUFS)
  25
  26 #ifndef LTT_SUBBUF_SIZE_FACILITIES
  27 #define LTT_SUBBUF_SIZE_FACILITIES 4096
  28 #endif //LTT_BUF_SIZE_FACILITIES
  29
  30 #define LTT_BUF_SIZE_FACILITIES  (LTT_SUBBUF_SIZE_FACILITIES * LTT_N_SUBBUFS)
  31
  32 #ifndef LTT_USERTRACE_ROOT
  33 #define LTT_USERTRACE_ROOT "/tmp/ltt-usertrace"
  34 #endif //LTT_USERTRACE_ROOT
  35
  36
  37 /* Buffer offset macros */
  38
  39 #define BUFFER_OFFSET(offset, buf) (offset & (buf->alloc_size-1))
  40 #define SUBBUF_OFFSET(offset, buf) (offset & (buf->subbuf_size-1))
  41 #define SUBBUF_ALIGN(offset, buf) \
  42   (((offset) + buf->subbuf_size) & (~(buf->subbuf_size-1)))
  43 #define SUBBUF_TRUNC(offset, buf) \
  44   ((offset) & (~(buf->subbuf_size-1)))
  45 #define SUBBUF_INDEX(offset, buf) \
  46   (BUFFER_OFFSET(offset,buf)/buf->subbuf_size)
  47
  48
  49 struct ltt_buf {
  50         atomic_t        offset;
  51         atomic_t        consumed;
  52         atomic_t        reserve_count[LTT_N_SUBBUFS];
  53         atomic_t        commit_count[LTT_N_SUBBUFS];
  54
  55         atomic_t        events_lost;
  56         atomic_t        full;   /* futex on which the writer waits : 1 : full */
  57         unsigned int    alloc_size;
  58         unsigned int    subbuf_size;
  59 };
  60
  61 struct ltt_trace_info {
  62         int init;
  63         int filter;
  64         pid_t daemon_id;
  65         atomic_t nesting;
  66         struct {
  67                 struct ltt_buf facilities;
  68                 struct ltt_buf cpu;
  69                 char facilities_buf[LTT_BUF_SIZE_FACILITIES] __attribute__ ((aligned (8)));
  70                 char cpu_buf[LTT_BUF_SIZE_CPU] __attribute__ ((aligned (8)));
  71         } channel;
  72 };
  73
  74 extern __thread struct ltt_trace_info *thread_trace_info;
  75
  76 void ltt_thread_init(void);
  77
  78 void ltt_usertrace_fast_buffer_switch(void);
  79
  80 #endif //_LTT_USERTRACE_FAST_H