Cycles int64
	StackRecord
}

// BlockProfile returns n, the number of records in the current blocking profile.
// If len(p) >= n, BlockProfile copies the profile into p and returns n, true.
// If len(p) < n, BlockProfile does not change p and returns n, false.
//
// Most clients should use the [runtime/pprof] package or
// the [testing] package's -test.blockprofile flag instead
// of calling BlockProfile directly.

			os.Exit(2)
		}
		f.Close()
	}
	if *blockProfile != "" && *blockProfileRate >= 0 {
		f, err := os.Create(toOutputDir(*blockProfile))
		if err != nil {
			fmt.Fprintf(os.Stderr, "testing: %s\n", err)
			os.Exit(2)
		}
		if err = m.deps.WriteProfileTo("block", f, 0); err != nil {
			fmt.Fprintf(os.Stderr, "testing: can't write %s: %s\n", *blockProfile, err)
			os.Exit(2)
		}
		f.Close()
	}

	name:  "heap",
	count: countHeap,
	write: writeHeap,
}

var allocsProfile = &Profile{
	name:  "allocs",
	count: countHeap, // identical to heap profile
	write: writeAlloc,
}

var blockProfile = &Profile{
	name:  "block",
	count: countBlock,
	write: writeBlock,
}

var mutexProfile = &Profile{
	name:  "mutex",
	count: countMutex,
	write: writeMutex,
}

func lockProfiles() {

profile the tests during execution:

	-benchmem
	    Print memory allocation statistics for benchmarks.
	    Allocations made in C or using C.malloc are not counted.

	-blockprofile block.out
	    Write a goroutine blocking profile to the specified file
	    when all tests are complete.
	    Writes test binary as -c would.

	-blockprofilerate n

// profile the tests during execution:
//
//	-benchmem
//	    Print memory allocation statistics for benchmarks.
//	    Allocations made in C or using C.malloc are not counted.
//
//	-blockprofile block.out
//	    Write a goroutine blocking profile to the specified file
//	    when all tests are complete.
//	    Writes test binary as -c would.
//
//	-blockprofilerate n

	v := atomic.Xchg(key32(&l.key), mutex_unlocked)
	if v == mutex_unlocked {
		throw("unlock of unlocked lock")
	}
	if v == mutex_sleeping {
		futexwakeup(key32(&l.key), 1)
	}

	gp := getg()
	gp.m.mLockProfile.recordUnlock(l)
	gp.m.locks--
	if gp.m.locks < 0 {
		throw("runtime·unlock: lock count")
	}
	if gp.m.locks == 0 && gp.preempt { // restore the preemption request in case we've cleared it in newstack

			// Dequeue an M.
			mp = muintptr(v &^ locked).ptr()
			if atomic.Casuintptr(&l.key, v, uintptr(mp.nextwaitm)) {
				// Dequeued an M.  Wake it.
				semawakeup(mp)
				break
			}
		}
	}
	gp.m.mLockProfile.recordUnlock(l)
	gp.m.locks--
	if gp.m.locks < 0 {
		throw("runtime·unlock: lock count")
	}
	if gp.m.locks == 0 && gp.preempt { // restore the preemption request in case we've cleared it in newstack

	lockedExt     uint32      // tracking for external LockOSThread
	lockedInt     uint32      // tracking for internal lockOSThread
	nextwaitm     muintptr    // next m waiting for lock

	mLockProfile mLockProfile // fields relating to runtime.lock contention
	profStack    []uintptr    // used for memory/block/mutex stack traces

	// wait* are used to carry arguments from gopark into park_m, because

// malloc and runtime locks for mLockProfile.
// TODO(mknyszek): Implement lazy allocation if this becomes a problem.
func mProfStackInit(mp *m) {
	if debug.profstackdepth == 0 {
		// debug.profstack is set to 0 by the user, or we're being called from
		// schedinit before parsedebugvars.
		return
	}
	mp.profStack = makeProfStackFP()
	mp.mLockProfile.stack = makeProfStackFP()
}