trace/simple.h

   1 /*
   2  * Simple trace backend
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2.  See
   7  * the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #ifndef TRACE_SIMPLE_H
  12 #define TRACE_SIMPLE_H
  13
  14 #include <stdint.h>
  15 #include <stdbool.h>
  16 #include <stdio.h>
  17
  18 typedef uint64_t TraceEventID;
  19
  20 typedef struct {
  21     const char *tp_name;
  22     bool state;
  23 } TraceEvent;
  24
  25 void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
  26 void st_set_trace_file_enabled(bool enable);
  27 bool st_set_trace_file(const char *file);
  28 void st_flush_trace_buffer(void);
  29
  30 typedef struct {
  31     unsigned int tbuf_idx;
  32     unsigned int next_tbuf_idx;
  33     unsigned int rec_off;
  34 } TraceBufferRecord;
  35
  36 /* Note for hackers: Make sure MAX_TRACE_LEN < sizeof(uint32_t) */
  37 #define MAX_TRACE_STRLEN 512
  38 /**
  39  * Initialize a trace record and claim space for it in the buffer
  40  *
  41  * @arglen  number of bytes required for arguments
  42  */
  43 int trace_record_start(TraceBufferRecord *rec, TraceEventID id, size_t arglen);
  44
  45 /**
  46  * Append a 64-bit argument to a trace record
  47  */
  48 void trace_record_write_u64(TraceBufferRecord *rec, uint64_t val);
  49
  50 /**
  51  * Append a string argument to a trace record
  52  */
  53 void trace_record_write_str(TraceBufferRecord *rec, const char *s, uint32_t slen);
  54
  55 /**
  56  * Mark a trace record completed
  57  *
  58  * Don't append any more arguments to the trace record after calling this.
  59  */
  60 void trace_record_finish(TraceBufferRecord *rec);
  61
  62 #endif /* TRACE_SIMPLE_H */