A DESCRIPTION OF THE PROBLEM :
The documentation of the new JVMTI method SetHeapSamplingInterval method explicitly describes what happens when the interval is 0, which makes me think that 0 is a special value, a corner case.

However, the JDK source code seems to actually treat 1 as a special value instead of 0.

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from jvmtiEnv.cpp:
--------------------
        jvmtiError
        JvmtiEnv::SetHeapSamplingInterval(jint sampling_interval) {
          if (sampling_interval < 0) {
            return JVMTI_ERROR_ILLEGAL_ARGUMENT;
          }
          ThreadHeapSampler::set_sampling_interval(sampling_interval);
          return JVMTI_ERROR_NONE;
        }

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from threadHeapSampler.cpp:
--------------------
      void ThreadHeapSampler::pick_next_sample(size_t overflowed_bytes) {
        if (get_sampling_interval() == 1) {
          _bytes_until_sample = 1;
          return;
        }

        pick_next_geometric_sample();
        ...
      }

Please note that special processing (the short path, presumably the fastest) is performed when the interval is exactly 1. The interval equal to 0 goes the long, common path.

Shouldn't "if (get_sampling_interval() == 1)" be replaced with "if (get_sampling_interval() == 0)" or "if (get_sampling_interval() <= 1)"?