xref: /freebsd/contrib/jemalloc/src/log.c (revision 73577bf01de5c4677dc54d97f93310286c254780)
1 #include "jemalloc/internal/jemalloc_preamble.h"
2 #include "jemalloc/internal/jemalloc_internal_includes.h"
3 
4 #include "jemalloc/internal/log.h"
5 
6 char log_var_names[JEMALLOC_LOG_VAR_BUFSIZE];
7 atomic_b_t log_init_done = ATOMIC_INIT(false);
8 
9 /*
10  * Returns true if we were able to pick out a segment.  Fills in r_segment_end
11  * with a pointer to the first character after the end of the string.
12  */
13 static const char *
14 log_var_extract_segment(const char* segment_begin) {
15 	const char *end;
16 	for (end = segment_begin; *end != '\0' && *end != '|'; end++) {
17 	}
18 	return end;
19 }
20 
21 static bool
22 log_var_matches_segment(const char *segment_begin, const char *segment_end,
23     const char *log_var_begin, const char *log_var_end) {
24 	assert(segment_begin <= segment_end);
25 	assert(log_var_begin < log_var_end);
26 
27 	ptrdiff_t segment_len = segment_end - segment_begin;
28 	ptrdiff_t log_var_len = log_var_end - log_var_begin;
29 	/* The special '.' segment matches everything. */
30 	if (segment_len == 1 && *segment_begin == '.') {
31 		return true;
32 	}
33         if (segment_len == log_var_len) {
34 		return strncmp(segment_begin, log_var_begin, segment_len) == 0;
35 	} else if (segment_len < log_var_len) {
36 		return strncmp(segment_begin, log_var_begin, segment_len) == 0
37 		    && log_var_begin[segment_len] == '.';
38         } else {
39 		return false;
40 	}
41 }
42 
43 unsigned
44 log_var_update_state(log_var_t *log_var) {
45 	const char *log_var_begin = log_var->name;
46 	const char *log_var_end = log_var->name + strlen(log_var->name);
47 
48 	/* Pointer to one before the beginning of the current segment. */
49 	const char *segment_begin = log_var_names;
50 
51 	/*
52 	 * If log_init done is false, we haven't parsed the malloc conf yet.  To
53 	 * avoid log-spew, we default to not displaying anything.
54 	 */
55 	if (!atomic_load_b(&log_init_done, ATOMIC_ACQUIRE)) {
56 		return LOG_INITIALIZED_NOT_ENABLED;
57 	}
58 
59 	while (true) {
60 		const char *segment_end = log_var_extract_segment(
61 		    segment_begin);
62 		assert(segment_end < log_var_names + JEMALLOC_LOG_VAR_BUFSIZE);
63 		if (log_var_matches_segment(segment_begin, segment_end,
64 		    log_var_begin, log_var_end)) {
65 			atomic_store_u(&log_var->state, LOG_ENABLED,
66 			    ATOMIC_RELAXED);
67 			return LOG_ENABLED;
68 		}
69 		if (*segment_end == '\0') {
70 			/* Hit the end of the segment string with no match. */
71 			atomic_store_u(&log_var->state,
72 			    LOG_INITIALIZED_NOT_ENABLED, ATOMIC_RELAXED);
73 			return LOG_INITIALIZED_NOT_ENABLED;
74 		}
75 		/* Otherwise, skip the delimiter and continue. */
76 		segment_begin = segment_end + 1;
77 	}
78 }
79