//
// This function is idempotent.
//
// The heap lock must not be held over this operation, since it will briefly acquire
// the heap lock.
//
// Must be called on the system stack because it acquires the heap lock.
//
//go:systemstack
func (h *mheap) enableMetadataHugePages() {
	// Enable huge pages for page structure.
	h.pages.enableChunkHugePages()

		// can't record a stack trace.
		return
	}
	if skip > maxSkip {
		print("requested skip=", skip)
		throw("invalid skip value")
	}
	gp := getg()
	mp := acquirem() // we must not be preempted while accessing profstack

	nstk := 1
	if tracefpunwindoff() || gp.m.hasCgoOnStack() {
		mp.profStack[0] = logicalStackSentinel
		if gp.m.curg == nil || gp.m.curg == gp {

	// has marked as idle with no timers, in which case the timer could
	// go unnoticed until long after t.when.
	// Calling acquirem instead of using getg().m makes sure that
	// we end up locking and inserting into the current P's timers.
	mp := acquirem()
	ts := &mp.p.ptr().timers
	ts.lock()
	ts.cleanHead()
	t.lock()
	t.trace("maybeAdd")
	when := int64(0)
	wake := false
	if t.needsAdd() {

//
//go:nosplit
func traceAcquireEnabled() traceLocker {
	// Any time we acquire a traceLocker, we may flush a trace buffer. But
	// buffer flushes are rare. Record the lock edge even if it doesn't happen
	// this time.
	lockRankMayTraceFlush()

	// Prevent preemption.
	mp := acquirem()

	// Acquire the trace seqlock. This prevents traceAdvance from moving forward

	restore = false
}

func unwindm(restore *bool) {
	if *restore {
		// Restore sp saved by cgocallback during
		// unwind of g's stack (see comment at top of file).
		mp := acquirem()
		sched := &mp.g0.sched
		sched.sp = *(*uintptr)(unsafe.Pointer(sched.sp + alignUp(sys.MinFrameSize, sys.StackAlign)))

		// Do the accounting that cgocall will not have a chance to do
		// during an unwind.
		//

	noPLock mutex
}

// acquire returns a heapStatsDelta to be updated. In effect,
// it acquires the shard for writing. release must be called
// as soon as the relevant deltas are updated.
//
// The returned heapStatsDelta must be updated atomically.
//
// The caller's P must not change between acquire and
// release. This also means that the caller should not
// acquire a P or release its P in between. A P also must

type Weighted struct {
	size    int64
	cur     int64
	mu      sync.Mutex
	waiters list.List
}

// Acquire acquires the semaphore with a weight of n, blocking until resources
// are available or ctx is done. On success, returns nil. On failure, returns
// ctx.Err() and leaves the semaphore unchanged.
func (s *Weighted) Acquire(ctx context.Context, n int64) error {
	done := ctx.Done()

	s.mu.Lock()
	select {
	case <-done:

   */
  @CanIgnoreReturnValue
  public double acquire() {
    return acquire(1);
  }

  /**
   * Acquires the given number of permits from this {@code RateLimiter}, blocking until the request
   * can be granted. Tells the amount of time slept, if any.
   *
   * @param permits the number of permits to acquire
   * @return time spent sleeping to enforce rate, in seconds; 0.0 if not rate-limited

   */
  @CanIgnoreReturnValue
  public double acquire() {
    return acquire(1);
  }

  /**
   * Acquires the given number of permits from this {@code RateLimiter}, blocking until the request
   * can be granted. Tells the amount of time slept, if any.
   *
   * @param permits the number of permits to acquire
   * @return time spent sleeping to enforce rate, in seconds; 0.0 if not rate-limited

	}
	r.c <- initial
	return r
}

// _Acquire acquires the exclusive value for private use.
// It must be released using the Release method.
func (e *_Exclusive[Val]) Acquire() Val {
	return <-e.c
}

// TryAcquire attempts to acquire the value. The ok result reports whether
// the value was acquired. If the value is acquired, it must be released
// using the Release method.