t4038: Remove non-portable '-a' option passed to test_cmp
[git/git.git] / trace2 / tr2_tls.c
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1#include "cache.h"
2#include "thread-utils.h"
3#include "trace2/tr2_tls.h"
4
5/*
6 * Initialize size of the thread stack for nested regions.
7 * This is used to store nested region start times. Note that
8 * this stack is per-thread and not per-trace-key.
9 */
10#define TR2_REGION_NESTING_INITIAL_SIZE (100)
11
12static struct tr2tls_thread_ctx *tr2tls_thread_main;
a0897249 13static uint64_t tr2tls_us_start_process;
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14
15static pthread_mutex_t tr2tls_mutex;
16static pthread_key_t tr2tls_key;
17
18static int tr2_next_thread_id; /* modify under lock */
19
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20void tr2tls_start_process_clock(void)
21{
22 if (tr2tls_us_start_process)
23 return;
24
25 /*
26 * Keep the absolute start time of the process (i.e. the main
27 * process) in a fixed variable since other threads need to
28 * access it. This allows them to do that without a lock on
29 * main thread's array data (because of reallocs).
30 */
31 tr2tls_us_start_process = getnanotime() / 1000;
32}
33
34struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
35 uint64_t us_thread_start)
ee4512ed 36{
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37 struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
38
39 /*
40 * Implicitly "tr2tls_push_self()" to capture the thread's start
41 * time in array_us_start[0]. For the main thread this gives us the
42 * application run time.
43 */
44 ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
45 ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
a0897249 46 ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
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47
48 ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
49
50 strbuf_init(&ctx->thread_name, 0);
51 if (ctx->thread_id)
52 strbuf_addf(&ctx->thread_name, "th%02d:", ctx->thread_id);
53 strbuf_addstr(&ctx->thread_name, thread_name);
54 if (ctx->thread_name.len > TR2_MAX_THREAD_NAME)
55 strbuf_setlen(&ctx->thread_name, TR2_MAX_THREAD_NAME);
56
57 pthread_setspecific(tr2tls_key, ctx);
58
59 return ctx;
60}
61
62struct tr2tls_thread_ctx *tr2tls_get_self(void)
63{
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64 struct tr2tls_thread_ctx *ctx;
65
66 if (!HAVE_THREADS)
67 return tr2tls_thread_main;
68
69 ctx = pthread_getspecific(tr2tls_key);
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70
71 /*
72 * If the thread-proc did not call trace2_thread_start(), we won't
73 * have any TLS data associated with the current thread. Fix it
74 * here and silently continue.
75 */
76 if (!ctx)
a0897249 77 ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
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78
79 return ctx;
80}
81
82int tr2tls_is_main_thread(void)
83{
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84 if (!HAVE_THREADS)
85 return 1;
ee4512ed 86
5fdae9d3 87 return pthread_getspecific(tr2tls_key) == tr2tls_thread_main;
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88}
89
90void tr2tls_unset_self(void)
91{
92 struct tr2tls_thread_ctx *ctx;
93
94 ctx = tr2tls_get_self();
95
96 pthread_setspecific(tr2tls_key, NULL);
97
98 free(ctx->array_us_start);
99 free(ctx);
100}
101
102void tr2tls_push_self(uint64_t us_now)
103{
104 struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
105
106 ALLOC_GROW(ctx->array_us_start, ctx->nr_open_regions + 1, ctx->alloc);
107 ctx->array_us_start[ctx->nr_open_regions++] = us_now;
108}
109
110void tr2tls_pop_self(void)
111{
112 struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
113
114 if (!ctx->nr_open_regions)
115 BUG("no open regions in thread '%s'", ctx->thread_name.buf);
116
117 ctx->nr_open_regions--;
118}
119
120void tr2tls_pop_unwind_self(void)
121{
122 struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
123
124 while (ctx->nr_open_regions > 1)
125 tr2tls_pop_self();
126}
127
128uint64_t tr2tls_region_elasped_self(uint64_t us)
129{
130 struct tr2tls_thread_ctx *ctx;
131 uint64_t us_start;
132
133 ctx = tr2tls_get_self();
134 if (!ctx->nr_open_regions)
135 return 0;
136
137 us_start = ctx->array_us_start[ctx->nr_open_regions - 1];
138
139 return us - us_start;
140}
141
142uint64_t tr2tls_absolute_elapsed(uint64_t us)
143{
144 if (!tr2tls_thread_main)
145 return 0;
146
a0897249 147 return us - tr2tls_us_start_process;
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148}
149
150void tr2tls_init(void)
151{
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152 tr2tls_start_process_clock();
153
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154 pthread_key_create(&tr2tls_key, NULL);
155 init_recursive_mutex(&tr2tls_mutex);
156
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157 tr2tls_thread_main =
158 tr2tls_create_self("main", tr2tls_us_start_process);
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159}
160
161void tr2tls_release(void)
162{
163 tr2tls_unset_self();
164 tr2tls_thread_main = NULL;
165
166 pthread_mutex_destroy(&tr2tls_mutex);
167 pthread_key_delete(tr2tls_key);
168}
169
170int tr2tls_locked_increment(int *p)
171{
172 int current_value;
173
174 pthread_mutex_lock(&tr2tls_mutex);
175 current_value = *p;
176 *p = current_value + 1;
177 pthread_mutex_unlock(&tr2tls_mutex);
178
179 return current_value;
180}