...
Run Format

Source file src/runtime/os_openbsd.go

Documentation: runtime

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package runtime
     6  
     7  import (
     8  	"runtime/internal/atomic"
     9  	"unsafe"
    10  )
    11  
    12  type mOS struct {
    13  	waitsemacount uint32
    14  }
    15  
    16  //go:noescape
    17  func setitimer(mode int32, new, old *itimerval)
    18  
    19  //go:noescape
    20  func sigaction(sig uint32, new, old *sigactiont)
    21  
    22  //go:noescape
    23  func sigaltstack(new, old *stackt)
    24  
    25  //go:noescape
    26  func obsdsigprocmask(how int32, new sigset) sigset
    27  
    28  //go:nosplit
    29  //go:nowritebarrierrec
    30  func sigprocmask(how int32, new, old *sigset) {
    31  	n := sigset(0)
    32  	if new != nil {
    33  		n = *new
    34  	}
    35  	r := obsdsigprocmask(how, n)
    36  	if old != nil {
    37  		*old = r
    38  	}
    39  }
    40  
    41  //go:noescape
    42  func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
    43  
    44  func raise(sig uint32)
    45  func raiseproc(sig uint32)
    46  
    47  //go:noescape
    48  func tfork(param *tforkt, psize uintptr, mm *m, gg *g, fn uintptr) int32
    49  
    50  //go:noescape
    51  func thrsleep(ident uintptr, clock_id int32, tsp *timespec, lock uintptr, abort *uint32) int32
    52  
    53  //go:noescape
    54  func thrwakeup(ident uintptr, n int32) int32
    55  
    56  func osyield()
    57  
    58  const (
    59  	_ESRCH       = 3
    60  	_EAGAIN      = 35
    61  	_EWOULDBLOCK = _EAGAIN
    62  	_ENOTSUP     = 91
    63  
    64  	// From OpenBSD's sys/time.h
    65  	_CLOCK_REALTIME  = 0
    66  	_CLOCK_VIRTUAL   = 1
    67  	_CLOCK_PROF      = 2
    68  	_CLOCK_MONOTONIC = 3
    69  )
    70  
    71  type sigset uint32
    72  
    73  var sigset_all = ^sigset(0)
    74  
    75  // From OpenBSD's <sys/sysctl.h>
    76  const (
    77  	_CTL_HW      = 6
    78  	_HW_NCPU     = 3
    79  	_HW_PAGESIZE = 7
    80  )
    81  
    82  func getncpu() int32 {
    83  	mib := [2]uint32{_CTL_HW, _HW_NCPU}
    84  	out := uint32(0)
    85  	nout := unsafe.Sizeof(out)
    86  
    87  	// Fetch hw.ncpu via sysctl.
    88  	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
    89  	if ret >= 0 {
    90  		return int32(out)
    91  	}
    92  	return 1
    93  }
    94  
    95  func getPageSize() uintptr {
    96  	mib := [2]uint32{_CTL_HW, _HW_PAGESIZE}
    97  	out := uint32(0)
    98  	nout := unsafe.Sizeof(out)
    99  	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
   100  	if ret >= 0 {
   101  		return uintptr(out)
   102  	}
   103  	return 0
   104  }
   105  
   106  //go:nosplit
   107  func semacreate(mp *m) {
   108  }
   109  
   110  //go:nosplit
   111  func semasleep(ns int64) int32 {
   112  	_g_ := getg()
   113  
   114  	// Compute sleep deadline.
   115  	var tsp *timespec
   116  	if ns >= 0 {
   117  		var ts timespec
   118  		var nsec int32
   119  		ns += nanotime()
   120  		ts.set_sec(int64(timediv(ns, 1000000000, &nsec)))
   121  		ts.set_nsec(nsec)
   122  		tsp = &ts
   123  	}
   124  
   125  	for {
   126  		v := atomic.Load(&_g_.m.waitsemacount)
   127  		if v > 0 {
   128  			if atomic.Cas(&_g_.m.waitsemacount, v, v-1) {
   129  				return 0 // semaphore acquired
   130  			}
   131  			continue
   132  		}
   133  
   134  		// Sleep until woken by semawakeup or timeout; or abort if waitsemacount != 0.
   135  		//
   136  		// From OpenBSD's __thrsleep(2) manual:
   137  		// "The abort argument, if not NULL, points to an int that will
   138  		// be examined [...] immediately before blocking. If that int
   139  		// is non-zero then __thrsleep() will immediately return EINTR
   140  		// without blocking."
   141  		ret := thrsleep(uintptr(unsafe.Pointer(&_g_.m.waitsemacount)), _CLOCK_MONOTONIC, tsp, 0, &_g_.m.waitsemacount)
   142  		if ret == _EWOULDBLOCK {
   143  			return -1
   144  		}
   145  	}
   146  }
   147  
   148  //go:nosplit
   149  func semawakeup(mp *m) {
   150  	atomic.Xadd(&mp.waitsemacount, 1)
   151  	ret := thrwakeup(uintptr(unsafe.Pointer(&mp.waitsemacount)), 1)
   152  	if ret != 0 && ret != _ESRCH {
   153  		// semawakeup can be called on signal stack.
   154  		systemstack(func() {
   155  			print("thrwakeup addr=", &mp.waitsemacount, " sem=", mp.waitsemacount, " ret=", ret, "\n")
   156  		})
   157  	}
   158  }
   159  
   160  // May run with m.p==nil, so write barriers are not allowed.
   161  //go:nowritebarrier
   162  func newosproc(mp *m, stk unsafe.Pointer) {
   163  	if false {
   164  		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
   165  	}
   166  
   167  	param := tforkt{
   168  		tf_tcb:   unsafe.Pointer(&mp.tls[0]),
   169  		tf_tid:   (*int32)(unsafe.Pointer(&mp.procid)),
   170  		tf_stack: uintptr(stk),
   171  	}
   172  
   173  	var oset sigset
   174  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
   175  	ret := tfork(&param, unsafe.Sizeof(param), mp, mp.g0, funcPC(mstart))
   176  	sigprocmask(_SIG_SETMASK, &oset, nil)
   177  
   178  	if ret < 0 {
   179  		print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", -ret, ")\n")
   180  		if ret == -_EAGAIN {
   181  			println("runtime: may need to increase max user processes (ulimit -p)")
   182  		}
   183  		throw("runtime.newosproc")
   184  	}
   185  }
   186  
   187  func osinit() {
   188  	ncpu = getncpu()
   189  	physPageSize = getPageSize()
   190  }
   191  
   192  var urandom_dev = []byte("/dev/urandom\x00")
   193  
   194  //go:nosplit
   195  func getRandomData(r []byte) {
   196  	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
   197  	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
   198  	closefd(fd)
   199  	extendRandom(r, int(n))
   200  }
   201  
   202  func goenvs() {
   203  	goenvs_unix()
   204  }
   205  
   206  // Called to initialize a new m (including the bootstrap m).
   207  // Called on the parent thread (main thread in case of bootstrap), can allocate memory.
   208  func mpreinit(mp *m) {
   209  	mp.gsignal = malg(32 * 1024)
   210  	mp.gsignal.m = mp
   211  }
   212  
   213  // Called to initialize a new m (including the bootstrap m).
   214  // Called on the new thread, can not allocate memory.
   215  func minit() {
   216  	// m.procid is a uint64, but tfork writes an int32. Fix it up.
   217  	_g_ := getg()
   218  	_g_.m.procid = uint64(*(*int32)(unsafe.Pointer(&_g_.m.procid)))
   219  
   220  	minitSignals()
   221  }
   222  
   223  // Called from dropm to undo the effect of an minit.
   224  //go:nosplit
   225  func unminit() {
   226  	unminitSignals()
   227  }
   228  
   229  func memlimit() uintptr {
   230  	return 0
   231  }
   232  
   233  func sigtramp()
   234  
   235  type sigactiont struct {
   236  	sa_sigaction uintptr
   237  	sa_mask      uint32
   238  	sa_flags     int32
   239  }
   240  
   241  //go:nosplit
   242  //go:nowritebarrierrec
   243  func setsig(i uint32, fn uintptr) {
   244  	var sa sigactiont
   245  	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
   246  	sa.sa_mask = uint32(sigset_all)
   247  	if fn == funcPC(sighandler) {
   248  		fn = funcPC(sigtramp)
   249  	}
   250  	sa.sa_sigaction = fn
   251  	sigaction(i, &sa, nil)
   252  }
   253  
   254  //go:nosplit
   255  //go:nowritebarrierrec
   256  func setsigstack(i uint32) {
   257  	throw("setsigstack")
   258  }
   259  
   260  //go:nosplit
   261  //go:nowritebarrierrec
   262  func getsig(i uint32) uintptr {
   263  	var sa sigactiont
   264  	sigaction(i, nil, &sa)
   265  	return sa.sa_sigaction
   266  }
   267  
   268  // setSignaltstackSP sets the ss_sp field of a stackt.
   269  //go:nosplit
   270  func setSignalstackSP(s *stackt, sp uintptr) {
   271  	s.ss_sp = sp
   272  }
   273  
   274  //go:nosplit
   275  //go:nowritebarrierrec
   276  func sigaddset(mask *sigset, i int) {
   277  	*mask |= 1 << (uint32(i) - 1)
   278  }
   279  
   280  func sigdelset(mask *sigset, i int) {
   281  	*mask &^= 1 << (uint32(i) - 1)
   282  }
   283  
   284  func (c *sigctxt) fixsigcode(sig uint32) {
   285  }
   286  

View as plain text