HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2
can do so by setting [Transport.TLSNextProto] (for clients) or
[Server.TLSNextProto] (for servers) to a non-nil, empty
map. Alternatively, the following GODEBUG settings are
currently supported:

	GODEBUG=http2client=0  # disable HTTP/2 client support
	GODEBUG=http2server=0  # disable HTTP/2 server support
	GODEBUG=http2debug=1   # enable verbose HTTP/2 debug logs

		writeErrStr(failthreadcreate)
		exit(1)
	}

	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
		writeErrStr(failthreadcreate)
		exit(1)
	}

	// Disable signals during create, so that the new thread starts
	// with signals disabled. It will enable them in minit.
	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
	var ret int32
	for tries := 0; tries < 20; tries++ {

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package sym

// Happens-before relationships are indicated to the race detector via:
// - Unlock  -> Lock:  readerSem
// - Unlock  -> RLock: readerSem
// - RUnlock -> Lock:  writerSem
//
// The methods below temporarily disable handling of race synchronization
// events in order to provide the more precise model above to the race
// detector.
//
// For example, atomic.AddInt32 in RLock should not appear to provide

//
//go:linkname signal_enable os/signal.signal_enable
func signal_enable(s uint32) {
	if !sig.inuse {
		// This is the first call to signal_enable. Initialize.
		sig.inuse = true // enable reception of signals; cannot disable
		if GOOS == "darwin" || GOOS == "ios" {
			sigNoteSetup(&sig.note)
		} else {
			noteclear(&sig.note)
		}
	}

	if s >= uint32(len(sig.wanted)*32) {
		return
	}

	w := sig.wanted[s/32]

	if !isSecureMode() {
		return
	}

	// When secure mode is enabled, we do one thing: enforce specific
	// environment variable values (currently we only force GOTRACEBACK=none)
	//
	// Other packages may also disable specific functionality when secure mode
	// is enabled (determined by using linkname to call isSecureMode).

	secureEnv()
}

func secureEnv() {
	var hasTraceback bool
	for i := 0; i < len(envs); i++ {

	}
	return Compare(Lang(v), Lang(release)) >= 0
}

// Before reports whether the file version v is strictly before a Go release.
//
// Use this predicate to disable a behavior once a certain Go release
// has happened (and stays enabled in the future).
func Before(v, release string) bool {
	if v == Future {
		return false // an unknown future version happens after y.
	}

	ARM64.HasSHA512 = isSet(HWCap, hwcap_SHA512)

	// The Samsung S9+ kernel reports support for atomics, but not all cores
	// actually support them, resulting in SIGILL. See issue #28431.
	// TODO(elias.naur): Only disable the optimization on bad chipsets on android.
	ARM64.HasATOMICS = isSet(HWCap, hwcap_ATOMICS) && os != "android"

	// Check to see if executing on a Neoverse core and in order to do that,

	err = os.WriteFile(mod, []byte("module lldbtest"), 0644)
	if err != nil {
		t.Fatalf("failed to create mod file: %v", err)
	}

	// As of 2018-07-17, lldb doesn't support compressed DWARF, so
	// disable it for this test.
	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-ldflags=-compressdwarf=false", "-o", "a.exe")
	cmd.Dir = dir
	cmd.Env = append(os.Environ(), "GOPATH=") // issue 31100

//	OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
//	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
//	ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE
//	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
//	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR