Merge branch 'jh/trace2'

* jh/trace2:
trace2: fix tracing when NO_PTHREADS is defined

diff --combined trace2/tr2_tls.c
index e76d8c5d92aec764280506bb78cd7e4a3e48eeb2,e0c4529f73c3577e58a4f2c70e289b732720e649..067c23755fb557895bf8cd12d497130dd55041fe
--- 1/trace2/tr2_tls.c
--- 2/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@@ -10,30 -10,16 +10,30 @@@
  #define TR2_REGION_NESTING_INITIAL_SIZE (100)
  
  static struct tr2tls_thread_ctx *tr2tls_thread_main;
 -static uint64_t tr2tls_us_start_main;
 +static uint64_t tr2tls_us_start_process;
  
  static pthread_mutex_t tr2tls_mutex;
  static pthread_key_t tr2tls_key;
  
  static int tr2_next_thread_id; /* modify under lock */
  
 -struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 +void tr2tls_start_process_clock(void)
 +{
 +      if (tr2tls_us_start_process)
 +              return;
 +
 +      /*
 +       * Keep the absolute start time of the process (i.e. the main
 +       * process) in a fixed variable since other threads need to
 +       * access it.  This allows them to do that without a lock on
 +       * main thread's array data (because of reallocs).
 +       */
 +      tr2tls_us_start_process = getnanotime() / 1000;
 +}
 +
 +struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
 +                                           uint64_t us_thread_start)
  {
 -      uint64_t us_now = getnanotime() / 1000;
        struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
  
        /*
@@@ -43,7 -29,7 +43,7 @@@
         */
        ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
        ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
 -      ctx->array_us_start[ctx->nr_open_regions++] = us_now;
 +      ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
  
        ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
  
@@@ -61,7 -47,12 +61,12 @@@
  
  struct tr2tls_thread_ctx *tr2tls_get_self(void)
  {
-       struct tr2tls_thread_ctx *ctx = pthread_getspecific(tr2tls_key);
+       struct tr2tls_thread_ctx *ctx;
+ 
+       if (!HAVE_THREADS)
+               return tr2tls_thread_main;
+ 
+       ctx = pthread_getspecific(tr2tls_key);
  
        /*
         * If the thread-proc did not call trace2_thread_start(), we won't
@@@ -69,16 -60,17 +74,17 @@@
         * here and silently continue.
         */
        if (!ctx)
 -              ctx = tr2tls_create_self("unknown");
 +              ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
  
        return ctx;
  }
  
  int tr2tls_is_main_thread(void)
  {
-       struct tr2tls_thread_ctx *ctx = pthread_getspecific(tr2tls_key);
+       if (!HAVE_THREADS)
+               return 1;
  
-       return ctx == tr2tls_thread_main;
+       return pthread_getspecific(tr2tls_key) == tr2tls_thread_main;
  }
  
  void tr2tls_unset_self(void)
@@@ -138,18 -130,22 +144,18 @@@ uint64_t tr2tls_absolute_elapsed(uint64
        if (!tr2tls_thread_main)
                return 0;
  
 -      return us - tr2tls_us_start_main;
 +      return us - tr2tls_us_start_process;
  }
  
  void tr2tls_init(void)
  {
 +      tr2tls_start_process_clock();
 +
        pthread_key_create(&tr2tls_key, NULL);
        init_recursive_mutex(&tr2tls_mutex);
  
 -      tr2tls_thread_main = tr2tls_create_self("main");
 -      /*
 -       * Keep a copy of the absolute start time of the main thread
 -       * in a fixed variable since other threads need to access it.
 -       * This also eliminates the need to lock accesses to the main
 -       * thread's array (because of reallocs).
 -       */
 -      tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
 +      tr2tls_thread_main =
 +              tr2tls_create_self("main", tr2tls_us_start_process);
  }
  
  void tr2tls_release(void)