// "Effective" offsets means the total number of reads or writes, mod 2^length.
// The offset in the buffer is the effective offset mod the length of the buffer.
// To make wraparound mod 2^length match wraparound mod length of the buffer,
// the length of the buffer must be a power of two.
//
// If the reader catches up to the writer, a flag passed to read controls

	alloc := memstats.Alloc

	// second time shouldn't increase footprint by much
	go sender(c, 100000)
	receiver(c, dummy, 100000)
	runtime.GC()
	runtime.ReadMemStats(memstats)

	// Be careful to avoid wraparound.
	if memstats.Alloc > alloc && memstats.Alloc-alloc > 1.1e5 {
		println("BUG: too much memory for 100,000 selects:", memstats.Alloc-alloc)
	}

	w.Close()

	for ; offset <= 256; offset *= 2 {
		w, err := NewWriter(io.Discard, level)
		if err != nil {
			t.Fatalf("NewWriter: level %d: %v", level, err)
		}

		// Reset until we are right before the wraparound.
		// Each reset adds maxMatchOffset to the offset.
		for i := 0; i < (bufferReset-len(in)-offset-maxMatchOffset)/maxMatchOffset; i++ {
			// skip ahead to where we are close to wrap around...
			w.d.reset(nil)
		}

func (e *deflateFast) reset() {
	e.prev = e.prev[:0]
	// Bump the offset, so all matches will fail distance check.
	// Nothing should be >= e.cur in the table.
	e.cur += maxMatchOffset

	// Protect against e.cur wraparound.
	if e.cur >= bufferReset {
		e.shiftOffsets()
	}
}

// shiftOffsets will shift down all match offset.
// This is only called in rare situations to prevent integer overflow.
//

								break
							}
							if port = nextPortCounter.Load(); port >= 0 && port < 1<<16 {
								break
							}
						}
						if portWrapped {
							// This is the second wraparound, so we've scanned the whole port space
							// at least once already and it's time to give up.
							return 0, false
						}
						portWrapped = true
						prevPort = 0
						continue
					}

	wantSecondTokens := len(enc.encode(nil, testData))

	if wantFirstTokens <= wantSecondTokens {
		t.Fatalf("test needs matches between inputs to be generated")
	}
	// Forward the current indicator to before wraparound.
	enc.cur = bufferReset - int32(len(testData))

	// Part 1 before wrap, should match clean state.
	got := len(enc.encode(nil, testData))
	if wantFirstTokens != got {

			p = appendp(p, AI32Const, constAddr(framesize-abi.StackSmall))
			p = appendp(p, AI32Add)
			p = appendp(p, AI32LeU)
		}
		// TODO(neelance): handle wraparound case

		p = appendp(p, AIf)
		// This CALL does *not* have a resume point after it
		// (we already inserted all of the resume points). As
		// a result, morestack will resume at the *previous*

		if hc.seq[i] != 0 {
			return
		}
	}

	// Not allowed to let sequence number wrap.
	// Instead, must renegotiate before it does.
	// Not likely enough to bother.
	panic("TLS: sequence number wraparound")
}

// explicitNonceLen returns the number of bytes of explicit nonce or IV included
// in each record. Explicit nonces are present only in CBC modes after TLS 1.0
// and in certain AEAD modes in TLS 1.2.

			return false
		}
		lastgc := int64(atomic.Load64(&memstats.last_gc_nanotime))
		return lastgc != 0 && t.now-lastgc > forcegcperiod
	case gcTriggerCycle:
		// t.n > work.cycles, but accounting for wraparound.
		return int32(t.n-work.cycles.Load()) > 0
	}
	return true
}

// gcStart starts the GC. It transitions from _GCoff to _GCmark (if
// debug.gcstoptheworld == 0) or performs all of GC (if

// increment increases the cycle count by one, wrapping the value at
// mProfCycleWrap. It clears the flushed flag.
func (c *mProfCycleHolder) increment() {
	// We explicitly wrap mProfCycle rather than depending on
	// uint wraparound because the memRecord.future ring does not
	// itself wrap at a power of two.
	for {
		prev := c.value.Load()
		cycle := prev >> 1
		cycle = (cycle + 1) % mProfCycleWrap
		next := cycle << 1