| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package runtime |
| |
| import ( |
| "internal/abi" |
| "internal/stringslite" |
| "unsafe" |
| ) |
| |
| type mOS struct { |
| initialized bool |
| mutex pthreadmutex |
| cond pthreadcond |
| count int |
| } |
| |
| func unimplemented(name string) { |
| println(name, "not implemented") |
| *(*int)(unsafe.Pointer(uintptr(1231))) = 1231 |
| } |
| |
| //go:nosplit |
| func semacreate(mp *m) { |
| if mp.initialized { |
| return |
| } |
| mp.initialized = true |
| if err := pthread_mutex_init(&mp.mutex, nil); err != 0 { |
| throw("pthread_mutex_init") |
| } |
| if err := pthread_cond_init(&mp.cond, nil); err != 0 { |
| throw("pthread_cond_init") |
| } |
| } |
| |
| //go:nosplit |
| func semasleep(ns int64) int32 { |
| var start int64 |
| if ns >= 0 { |
| start = nanotime() |
| } |
| g := getg() |
| mp := g.m |
| if g == mp.gsignal { |
| // sema sleep/wakeup are implemented with pthreads, which are not async-signal-safe on Darwin. |
| throw("semasleep on Darwin signal stack") |
| } |
| pthread_mutex_lock(&mp.mutex) |
| for { |
| if mp.count > 0 { |
| mp.count-- |
| pthread_mutex_unlock(&mp.mutex) |
| return 0 |
| } |
| if ns >= 0 { |
| spent := nanotime() - start |
| if spent >= ns { |
| pthread_mutex_unlock(&mp.mutex) |
| return -1 |
| } |
| var t timespec |
| t.setNsec(ns - spent) |
| err := pthread_cond_timedwait_relative_np(&mp.cond, &mp.mutex, &t) |
| if err == _ETIMEDOUT { |
| pthread_mutex_unlock(&mp.mutex) |
| return -1 |
| } |
| } else { |
| pthread_cond_wait(&mp.cond, &mp.mutex) |
| } |
| } |
| } |
| |
| //go:nosplit |
| func semawakeup(mp *m) { |
| if g := getg(); g == g.m.gsignal { |
| throw("semawakeup on Darwin signal stack") |
| } |
| pthread_mutex_lock(&mp.mutex) |
| mp.count++ |
| if mp.count > 0 { |
| pthread_cond_signal(&mp.cond) |
| } |
| pthread_mutex_unlock(&mp.mutex) |
| } |
| |
| // The read and write file descriptors used by the sigNote functions. |
| var sigNoteRead, sigNoteWrite int32 |
| |
| // sigNoteSetup initializes a single, there-can-only-be-one, async-signal-safe note. |
| // |
| // The current implementation of notes on Darwin is not async-signal-safe, |
| // because the functions pthread_mutex_lock, pthread_cond_signal, and |
| // pthread_mutex_unlock, called by semawakeup, are not async-signal-safe. |
| // There is only one case where we need to wake up a note from a signal |
| // handler: the sigsend function. The signal handler code does not require |
| // all the features of notes: it does not need to do a timed wait. |
| // This is a separate implementation of notes, based on a pipe, that does |
| // not support timed waits but is async-signal-safe. |
| func sigNoteSetup(*note) { |
| if sigNoteRead != 0 || sigNoteWrite != 0 { |
| // Generalizing this would require avoiding the pipe-fork-closeonexec race, which entangles syscall. |
| throw("duplicate sigNoteSetup") |
| } |
| var errno int32 |
| sigNoteRead, sigNoteWrite, errno = pipe() |
| if errno != 0 { |
| throw("pipe failed") |
| } |
| closeonexec(sigNoteRead) |
| closeonexec(sigNoteWrite) |
| |
| // Make the write end of the pipe non-blocking, so that if the pipe |
| // buffer is somehow full we will not block in the signal handler. |
| // Leave the read end of the pipe blocking so that we will block |
| // in sigNoteSleep. |
| setNonblock(sigNoteWrite) |
| } |
| |
| // sigNoteWakeup wakes up a thread sleeping on a note created by sigNoteSetup. |
| func sigNoteWakeup(*note) { |
| var b byte |
| write(uintptr(sigNoteWrite), unsafe.Pointer(&b), 1) |
| } |
| |
| // sigNoteSleep waits for a note created by sigNoteSetup to be woken. |
| func sigNoteSleep(*note) { |
| for { |
| var b byte |
| entersyscallblock() |
| n := read(sigNoteRead, unsafe.Pointer(&b), 1) |
| exitsyscall() |
| if n != -_EINTR { |
| return |
| } |
| } |
| } |
| |
| // BSD interface for threading. |
| func osinit() { |
| // pthread_create delayed until end of goenvs so that we |
| // can look at the environment first. |
| |
| ncpu = getncpu() |
| physPageSize = getPageSize() |
| |
| osinit_hack() |
| } |
| |
| func sysctlbynameInt32(name []byte) (int32, int32) { |
| out := int32(0) |
| nout := unsafe.Sizeof(out) |
| ret := sysctlbyname(&name[0], (*byte)(unsafe.Pointer(&out)), &nout, nil, 0) |
| return ret, out |
| } |
| |
| //go:linkname internal_cpu_getsysctlbyname internal/cpu.getsysctlbyname |
| func internal_cpu_getsysctlbyname(name []byte) (int32, int32) { |
| return sysctlbynameInt32(name) |
| } |
| |
| const ( |
| _CTL_HW = 6 |
| _HW_NCPU = 3 |
| _HW_PAGESIZE = 7 |
| ) |
| |
| func getncpu() int32 { |
| // Use sysctl to fetch hw.ncpu. |
| mib := [2]uint32{_CTL_HW, _HW_NCPU} |
| out := uint32(0) |
| nout := unsafe.Sizeof(out) |
| ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0) |
| if ret >= 0 && int32(out) > 0 { |
| return int32(out) |
| } |
| return 1 |
| } |
| |
| func getPageSize() uintptr { |
| // Use sysctl to fetch hw.pagesize. |
| mib := [2]uint32{_CTL_HW, _HW_PAGESIZE} |
| out := uint32(0) |
| nout := unsafe.Sizeof(out) |
| ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0) |
| if ret >= 0 && int32(out) > 0 { |
| return uintptr(out) |
| } |
| return 0 |
| } |
| |
| var urandom_dev = []byte("/dev/urandom\x00") |
| |
| //go:nosplit |
| func readRandom(r []byte) int { |
| fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0) |
| n := read(fd, unsafe.Pointer(&r[0]), int32(len(r))) |
| closefd(fd) |
| return int(n) |
| } |
| |
| func goenvs() { |
| goenvs_unix() |
| } |
| |
| // May run with m.p==nil, so write barriers are not allowed. |
| // |
| //go:nowritebarrierrec |
| func newosproc(mp *m) { |
| stk := unsafe.Pointer(mp.g0.stack.hi) |
| if false { |
| print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n") |
| } |
| |
| // Initialize an attribute object. |
| var attr pthreadattr |
| var err int32 |
| err = pthread_attr_init(&attr) |
| if err != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| |
| // Find out OS stack size for our own stack guard. |
| var stacksize uintptr |
| if pthread_attr_getstacksize(&attr, &stacksize) != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| mp.g0.stack.hi = stacksize // for mstart |
| |
| // Tell the pthread library we won't join with this thread. |
| if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| |
| // Finally, create the thread. It starts at mstart_stub, which does some low-level |
| // setup and then calls mstart. |
| var oset sigset |
| sigprocmask(_SIG_SETMASK, &sigset_all, &oset) |
| err = retryOnEAGAIN(func() int32 { |
| return pthread_create(&attr, abi.FuncPCABI0(mstart_stub), unsafe.Pointer(mp)) |
| }) |
| sigprocmask(_SIG_SETMASK, &oset, nil) |
| if err != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| } |
| |
| // glue code to call mstart from pthread_create. |
| func mstart_stub() |
| |
| // newosproc0 is a version of newosproc that can be called before the runtime |
| // is initialized. |
| // |
| // This function is not safe to use after initialization as it does not pass an M as fnarg. |
| // |
| //go:nosplit |
| func newosproc0(stacksize uintptr, fn uintptr) { |
| // Initialize an attribute object. |
| var attr pthreadattr |
| var err int32 |
| err = pthread_attr_init(&attr) |
| if err != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| |
| // The caller passes in a suggested stack size, |
| // from when we allocated the stack and thread ourselves, |
| // without libpthread. Now that we're using libpthread, |
| // we use the OS default stack size instead of the suggestion. |
| // Find out that stack size for our own stack guard. |
| if pthread_attr_getstacksize(&attr, &stacksize) != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| g0.stack.hi = stacksize // for mstart |
| memstats.stacks_sys.add(int64(stacksize)) |
| |
| // Tell the pthread library we won't join with this thread. |
| if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| |
| // Finally, create the thread. It starts at mstart_stub, which does some low-level |
| // setup and then calls mstart. |
| var oset sigset |
| sigprocmask(_SIG_SETMASK, &sigset_all, &oset) |
| err = pthread_create(&attr, fn, nil) |
| sigprocmask(_SIG_SETMASK, &oset, nil) |
| if err != 0 { |
| writeErrStr(failthreadcreate) |
| exit(1) |
| } |
| } |
| |
| // Called to do synchronous initialization of Go code built with |
| // -buildmode=c-archive or -buildmode=c-shared. |
| // None of the Go runtime is initialized. |
| // |
| //go:nosplit |
| //go:nowritebarrierrec |
| func libpreinit() { |
| initsig(true) |
| } |
| |
| // Called to initialize a new m (including the bootstrap m). |
| // Called on the parent thread (main thread in case of bootstrap), can allocate memory. |
| func mpreinit(mp *m) { |
| mp.gsignal = malg(32 * 1024) // OS X wants >= 8K |
| mp.gsignal.m = mp |
| if GOOS == "darwin" && GOARCH == "arm64" { |
| // mlock the signal stack to work around a kernel bug where it may |
| // SIGILL when the signal stack is not faulted in while a signal |
| // arrives. See issue 42774. |
| mlock(unsafe.Pointer(mp.gsignal.stack.hi-physPageSize), physPageSize) |
| } |
| } |
| |
| // Called to initialize a new m (including the bootstrap m). |
| // Called on the new thread, cannot allocate memory. |
| func minit() { |
| // iOS does not support alternate signal stack. |
| // The signal handler handles it directly. |
| if !(GOOS == "ios" && GOARCH == "arm64") { |
| minitSignalStack() |
| } |
| minitSignalMask() |
| getg().m.procid = uint64(pthread_self()) |
| } |
| |
| // Called from dropm to undo the effect of an minit. |
| // |
| //go:nosplit |
| func unminit() { |
| // iOS does not support alternate signal stack. |
| // See minit. |
| if !(GOOS == "ios" && GOARCH == "arm64") { |
| unminitSignals() |
| } |
| getg().m.procid = 0 |
| } |
| |
| // Called from exitm, but not from drop, to undo the effect of thread-owned |
| // resources in minit, semacreate, or elsewhere. Do not take locks after calling this. |
| func mdestroy(mp *m) { |
| } |
| |
| //go:nosplit |
| func osyield_no_g() { |
| usleep_no_g(1) |
| } |
| |
| //go:nosplit |
| func osyield() { |
| usleep(1) |
| } |
| |
| const ( |
| _NSIG = 32 |
| _SI_USER = 0 /* empirically true, but not what headers say */ |
| _SIG_BLOCK = 1 |
| _SIG_UNBLOCK = 2 |
| _SIG_SETMASK = 3 |
| _SS_DISABLE = 4 |
| ) |
| |
| //extern SigTabTT runtimeĀ·sigtab[]; |
| |
| type sigset uint32 |
| |
| var sigset_all = ^sigset(0) |
| |
| //go:nosplit |
| //go:nowritebarrierrec |
| func setsig(i uint32, fn uintptr) { |
| var sa usigactiont |
| sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART |
| sa.sa_mask = ^uint32(0) |
| if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go |
| if iscgo { |
| fn = abi.FuncPCABI0(cgoSigtramp) |
| } else { |
| fn = abi.FuncPCABI0(sigtramp) |
| } |
| } |
| *(*uintptr)(unsafe.Pointer(&sa.__sigaction_u)) = fn |
| sigaction(i, &sa, nil) |
| } |
| |
| // sigtramp is the callback from libc when a signal is received. |
| // It is called with the C calling convention. |
| func sigtramp() |
| func cgoSigtramp() |
| |
| //go:nosplit |
| //go:nowritebarrierrec |
| func setsigstack(i uint32) { |
| var osa usigactiont |
| sigaction(i, nil, &osa) |
| handler := *(*uintptr)(unsafe.Pointer(&osa.__sigaction_u)) |
| if osa.sa_flags&_SA_ONSTACK != 0 { |
| return |
| } |
| var sa usigactiont |
| *(*uintptr)(unsafe.Pointer(&sa.__sigaction_u)) = handler |
| sa.sa_mask = osa.sa_mask |
| sa.sa_flags = osa.sa_flags | _SA_ONSTACK |
| sigaction(i, &sa, nil) |
| } |
| |
| //go:nosplit |
| //go:nowritebarrierrec |
| func getsig(i uint32) uintptr { |
| var sa usigactiont |
| sigaction(i, nil, &sa) |
| return *(*uintptr)(unsafe.Pointer(&sa.__sigaction_u)) |
| } |
| |
| // setSignalstackSP sets the ss_sp field of a stackt. |
| // |
| //go:nosplit |
| func setSignalstackSP(s *stackt, sp uintptr) { |
| *(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp |
| } |
| |
| //go:nosplit |
| //go:nowritebarrierrec |
| func sigaddset(mask *sigset, i int) { |
| *mask |= 1 << (uint32(i) - 1) |
| } |
| |
| func sigdelset(mask *sigset, i int) { |
| *mask &^= 1 << (uint32(i) - 1) |
| } |
| |
| func setProcessCPUProfiler(hz int32) { |
| setProcessCPUProfilerTimer(hz) |
| } |
| |
| func setThreadCPUProfiler(hz int32) { |
| setThreadCPUProfilerHz(hz) |
| } |
| |
| //go:nosplit |
| func validSIGPROF(mp *m, c *sigctxt) bool { |
| return true |
| } |
| |
| //go:linkname executablePath os.executablePath |
| var executablePath string |
| |
| func sysargs(argc int32, argv **byte) { |
| // skip over argv, envv and the first string will be the path |
| n := argc + 1 |
| for argv_index(argv, n) != nil { |
| n++ |
| } |
| executablePath = gostringnocopy(argv_index(argv, n+1)) |
| |
| // strip "executable_path=" prefix if available, it's added after OS X 10.11. |
| executablePath = stringslite.TrimPrefix(executablePath, "executable_path=") |
| } |
| |
| func signalM(mp *m, sig int) { |
| pthread_kill(pthread(mp.procid), uint32(sig)) |
| } |
| |
| // sigPerThreadSyscall is only used on linux, so we assign a bogus signal |
| // number. |
| const sigPerThreadSyscall = 1 << 31 |
| |
| //go:nosplit |
| func runPerThreadSyscall() { |
| throw("runPerThreadSyscall only valid on linux") |
| } |