1#ifndef JEMALLOC_INTERNAL_LOG_H
2#define JEMALLOC_INTERNAL_LOG_H
3
4#include "jemalloc/internal/atomic.h"
5#include "jemalloc/internal/malloc_io.h"
6#include "jemalloc/internal/mutex.h"
7
8#ifdef JEMALLOC_LOG
9# define JEMALLOC_LOG_VAR_BUFSIZE 1000
10#else
11# define JEMALLOC_LOG_VAR_BUFSIZE 1
12#endif
13
14#define JEMALLOC_LOG_BUFSIZE 4096
15
16/*
17 * The log malloc_conf option is a '|'-delimited list of log_var name segments
18 * which should be logged. The names are themselves hierarchical, with '.' as
19 * the delimiter (a "segment" is just a prefix in the log namespace). So, if
20 * you have:
21 *
22 * log("arena", "log msg for arena"); // 1
23 * log("arena.a", "log msg for arena.a"); // 2
24 * log("arena.b", "log msg for arena.b"); // 3
25 * log("arena.a.a", "log msg for arena.a.a"); // 4
26 * log("extent.a", "log msg for extent.a"); // 5
27 * log("extent.b", "log msg for extent.b"); // 6
28 *
29 * And your malloc_conf option is "log=arena.a|extent", then lines 2, 4, 5, and
30 * 6 will print at runtime. You can enable logging from all log vars by
31 * writing "log=.".
32 *
33 * None of this should be regarded as a stable API for right now. It's intended
34 * as a debugging interface, to let us keep around some of our printf-debugging
35 * statements.
36 */
37
38extern char log_var_names[JEMALLOC_LOG_VAR_BUFSIZE];
39extern atomic_b_t log_init_done;
40
41typedef struct log_var_s log_var_t;
42struct log_var_s {
43 /*
44 * Lowest bit is "inited", second lowest is "enabled". Putting them in
45 * a single word lets us avoid any fences on weak architectures.
46 */
47 atomic_u_t state;
48 const char *name;
49};
50
51#define LOG_NOT_INITIALIZED 0U
52#define LOG_INITIALIZED_NOT_ENABLED 1U
53#define LOG_ENABLED 2U
54
55#define LOG_VAR_INIT(name_str) {ATOMIC_INIT(LOG_NOT_INITIALIZED), name_str}
56
57/*
58 * Returns the value we should assume for state (which is not necessarily
59 * accurate; if logging is done before logging has finished initializing, then
60 * we default to doing the safe thing by logging everything).
61 */
62unsigned log_var_update_state(log_var_t *log_var);
63
64/* We factor out the metadata management to allow us to test more easily. */
65#define log_do_begin(log_var) \
66if (config_log) { \
67 unsigned log_state = atomic_load_u(&(log_var).state, \
68 ATOMIC_RELAXED); \
69 if (unlikely(log_state == LOG_NOT_INITIALIZED)) { \
70 log_state = log_var_update_state(&(log_var)); \
71 assert(log_state != LOG_NOT_INITIALIZED); \
72 } \
73 if (log_state == LOG_ENABLED) { \
74 {
75 /* User code executes here. */
76#define log_do_end(log_var) \
77 } \
78 } \
79}
80
81/*
82 * MSVC has some preprocessor bugs in its expansion of __VA_ARGS__ during
83 * preprocessing. To work around this, we take all potential extra arguments in
84 * a var-args functions. Since a varargs macro needs at least one argument in
85 * the "...", we accept the format string there, and require that the first
86 * argument in this "..." is a const char *.
87 */
88static inline void
89log_impl_varargs(const char *name, ...) {
90 char buf[JEMALLOC_LOG_BUFSIZE];
91 va_list ap;
92
93 va_start(ap, name);
94 const char *format = va_arg(ap, const char *);
95 size_t dst_offset = 0;
96 dst_offset += malloc_snprintf(buf, JEMALLOC_LOG_BUFSIZE, "%s: ", name);
97 dst_offset += malloc_vsnprintf(buf + dst_offset,
98 JEMALLOC_LOG_BUFSIZE - dst_offset, format, ap);
99 dst_offset += malloc_snprintf(buf + dst_offset,
100 JEMALLOC_LOG_BUFSIZE - dst_offset, "\n");
101 va_end(ap);
102
103 malloc_write(buf);
104}
105
106/* Call as log("log.var.str", "format_string %d", arg_for_format_string); */
107#define LOG(log_var_str, ...) \
108do { \
109 static log_var_t log_var = LOG_VAR_INIT(log_var_str); \
110 log_do_begin(log_var) \
111 log_impl_varargs((log_var).name, __VA_ARGS__); \
112 log_do_end(log_var) \
113} while (0)
114
115#endif /* JEMALLOC_INTERNAL_LOG_H */
116