Andrew's git - gitweb.git/blob

   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;
  13static uint64_t tr2tls_us_start_process;
  14
  15static pthread_mutex_t tr2tls_mutex;
  16static pthread_key_t tr2tls_key;
  17
  18static int tr2_next_thread_id; /* modify under lock */
  19
  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)
  36{
  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));
  46        ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
  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{
  64        struct tr2tls_thread_ctx *ctx = pthread_getspecific(tr2tls_key);
  65
  66        /*
  67         * If the thread-proc did not call trace2_thread_start(), we won't
  68         * have any TLS data associated with the current thread.  Fix it
  69         * here and silently continue.
  70         */
  71        if (!ctx)
  72                ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
  73
  74        return ctx;
  75}
  76
  77int tr2tls_is_main_thread(void)
  78{
  79        struct tr2tls_thread_ctx *ctx = pthread_getspecific(tr2tls_key);
  80
  81        return ctx == tr2tls_thread_main;
  82}
  83
  84void tr2tls_unset_self(void)
  85{
  86        struct tr2tls_thread_ctx *ctx;
  87
  88        ctx = tr2tls_get_self();
  89
  90        pthread_setspecific(tr2tls_key, NULL);
  91
  92        free(ctx->array_us_start);
  93        free(ctx);
  94}
  95
  96void tr2tls_push_self(uint64_t us_now)
  97{
  98        struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
  99
 100        ALLOC_GROW(ctx->array_us_start, ctx->nr_open_regions + 1, ctx->alloc);
 101        ctx->array_us_start[ctx->nr_open_regions++] = us_now;
 102}
 103
 104void tr2tls_pop_self(void)
 105{
 106        struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 107
 108        if (!ctx->nr_open_regions)
 109                BUG("no open regions in thread '%s'", ctx->thread_name.buf);
 110
 111        ctx->nr_open_regions--;
 112}
 113
 114void tr2tls_pop_unwind_self(void)
 115{
 116        struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 117
 118        while (ctx->nr_open_regions > 1)
 119                tr2tls_pop_self();
 120}
 121
 122uint64_t tr2tls_region_elasped_self(uint64_t us)
 123{
 124        struct tr2tls_thread_ctx *ctx;
 125        uint64_t us_start;
 126
 127        ctx = tr2tls_get_self();
 128        if (!ctx->nr_open_regions)
 129                return 0;
 130
 131        us_start = ctx->array_us_start[ctx->nr_open_regions - 1];
 132
 133        return us - us_start;
 134}
 135
 136uint64_t tr2tls_absolute_elapsed(uint64_t us)
 137{
 138        if (!tr2tls_thread_main)
 139                return 0;
 140
 141        return us - tr2tls_us_start_process;
 142}
 143
 144void tr2tls_init(void)
 145{
 146        tr2tls_start_process_clock();
 147
 148        pthread_key_create(&tr2tls_key, NULL);
 149        init_recursive_mutex(&tr2tls_mutex);
 150
 151        tr2tls_thread_main =
 152                tr2tls_create_self("main", tr2tls_us_start_process);
 153}
 154
 155void tr2tls_release(void)
 156{
 157        tr2tls_unset_self();
 158        tr2tls_thread_main = NULL;
 159
 160        pthread_mutex_destroy(&tr2tls_mutex);
 161        pthread_key_delete(tr2tls_key);
 162}
 163
 164int tr2tls_locked_increment(int *p)
 165{
 166        int current_value;
 167
 168        pthread_mutex_lock(&tr2tls_mutex);
 169        current_value = *p;
 170        *p = current_value + 1;
 171        pthread_mutex_unlock(&tr2tls_mutex);
 172
 173        return current_value;
 174}