// meaning to start a new counter file with a different date in the name.
// rotate is also used to open the file initially, meaning f.current can be nil.
// In general rotate should be called just once for each file.
// rotate will arrange a timer to call itself again when necessary.
func (f *file) rotate() {
	expire, cleanup := f.rotate1()
	cleanup()
	if !expire.IsZero() {
		// TODO(rsc): Does this do the right thing for laptops closing?

	// and consumes a hash from an adjacent subtree.
	m := int(bits.TrailingZeros64(uint64(n + 1)))
	indexes := make([]int64, m)
	for i := 0; i < m; i++ {
		// We arrange indexes in sorted order.
		// Note that n>>i is always odd.
		indexes[m-1-i] = StoredHashIndex(i, n>>uint(i)-1)
	}

	// Fetch hashes.
	old, err := r.ReadHashes(indexes)
	if err != nil {
		return nil, err

	// still shade that pointer, which would preserve it for the
	// in-progress GC, so all is well. Any future GC will see the
	// value we copied when scanning b.tags (heap-allocated).
	// We arrange that the store here is always overwriting a nil,
	// so there is no need for a deletion barrier on b.tags[wt].
	wt := int(bw.tagCount() % uint32(len(b.tags)))
	if tagPtr != nil {

// deferprocat using that head will throw.
// (The atomic head is ordinary garbage collected memory so that
// it's not a problem if user code holds onto it beyond
// the lifetime of drangefunc.)
//
// TODO: We could arrange for the compiler to call into the
// runtime after the loop finishes normally, to do an eager
// deferconvert, which would catch calling the loop body
// and having it defer after the loop is done. If we have a

	// It is the caller's responsibility to arrange for it to be
	// freed, such as by calling C.free (be sure to include stdlib.h
	// if C.free is needed).
	func C.CString(string) *C.char

	// Go []byte slice to C array
	// The C array is allocated in the C heap using malloc.
	// It is the caller's responsibility to arrange for it to be
	// freed, such as by calling C.free (be sure to include stdlib.h

// by reference, so make sure all map keys are addressable
// by copying them to temporaries as needed.
// The same is true for channel operations.
//
// Arrange that map index expressions only appear in direct
// assignments x = m[k] or m[k] = x, never in larger expressions.
//
// Arrange that receive expressions only appear in direct assignments
// x = <-c or as standalone statements <-c, never in larger expressions.

 * well as a simple framework for helping to make sure that assertions failing in generated threads
 * cause the associated test that generated them to itself fail (which JUnit does not otherwise
 * arrange). The rules for creating such tests are:
 *
 * <ol>
 *   <li>All assertions in code running in generated threads must use the forms {@link #threadFail},

// that if multiple go commands call raceSafeCopy(old, new) at the same time,
// they don't interfere with each other: both will succeed and return and
// later observe the correct content in new. Like in the build cache, we arrange
// this by opening new without truncation and then writing the content.
// Both go commands can do this simultaneously and will write the same thing
// (old never changes content).
func raceSafeCopy(old, new string) error {

 * well as a simple framework for helping to make sure that assertions failing in generated threads
 * cause the associated test that generated them to itself fail (which JUnit does not otherwise
 * arrange). The rules for creating such tests are:
 *
 * <ol>
 *   <li>All assertions in code running in generated threads must use the forms {@link #threadFail},

				PGOProfile:     p.Internal.PGOProfile,
			},
		}
		if pxtestNeedsPtest {
			pxtest.Internal.Imports = append(pxtest.Internal.Imports, ptest)
		}
	}

	// Arrange for testing.Testing to report true.
	ldflags := append(p.Internal.Ldflags, "-X", "testing.testBinary=1")
	gccgoflags := append(p.Internal.Gccgoflags, "-Wl,--defsym,testing.gccgoTestBinary=1")

	// Build main package.