quorum: Avoid bdrv_aio_writev() for rewrites
[qemu.git] / 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 void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
15 void st_set_trace_file_enabled(bool enable);
16 void st_set_trace_file(const char *file);
17 bool st_init(void);
18 void st_flush_trace_buffer(void);
19
20 typedef struct {
21 unsigned int tbuf_idx;
22 unsigned int rec_off;
23 } TraceBufferRecord;
24
25 /* Note for hackers: Make sure MAX_TRACE_LEN < sizeof(uint32_t) */
26 #define MAX_TRACE_STRLEN 512
27 /**
28 * Initialize a trace record and claim space for it in the buffer
29 *
30 * @arglen number of bytes required for arguments
31 */
32 int trace_record_start(TraceBufferRecord *rec, uint32_t id, size_t arglen);
33
34 /**
35 * Append a 64-bit argument to a trace record
36 */
37 void trace_record_write_u64(TraceBufferRecord *rec, uint64_t val);
38
39 /**
40 * Append a string argument to a trace record
41 */
42 void trace_record_write_str(TraceBufferRecord *rec, const char *s, uint32_t slen);
43
44 /**
45 * Mark a trace record completed
46 *
47 * Don't append any more arguments to the trace record after calling this.
48 */
49 void trace_record_finish(TraceBufferRecord *rec);
50
51 #endif /* TRACE_SIMPLE_H */