libgo/go/runtime/runtime.go

   1 // Copyright 2009 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" // for go:linkname
  10 )
  11
  12 //go:generate go run wincallback.go
  13 //go:generate go run mkduff.go
  14 //go:generate go run mkfastlog2table.go
  15
  16 // For gccgo, while we still have C runtime code, use go:linkname to
  17 // rename some functions to themselves, so that the compiler will
  18 // export them.
  19 //
  20 //go:linkname tickspersecond runtime.tickspersecond
  21
  22 var ticksLock mutex
  23 var ticksVal uint64
  24
  25 // Note: Called by runtime/pprof in addition to runtime code.
  26 func tickspersecond() int64 {
  27         r := int64(atomic.Load64(&ticksVal))
  28         if r != 0 {
  29                 return r
  30         }
  31         lock(&ticksLock)
  32         r = int64(ticksVal)
  33         if r == 0 {
  34                 t0 := nanotime()
  35                 c0 := cputicks()
  36                 usleep(100 * 1000)
  37                 t1 := nanotime()
  38                 c1 := cputicks()
  39                 if t1 == t0 {
  40                         t1++
  41                 }
  42                 r = (c1 - c0) * 1000 * 1000 * 1000 / (t1 - t0)
  43                 if r == 0 {
  44                         r++
  45                 }
  46                 atomic.Store64(&ticksVal, uint64(r))
  47         }
  48         unlock(&ticksLock)
  49         return r
  50 }
  51
  52 var envs []string
  53 var argslice []string
  54
  55 //go:linkname syscall_runtime_envs syscall.runtime_envs
  56 func syscall_runtime_envs() []string { return append([]string{}, envs...) }
  57
  58 //go:linkname syscall_Getpagesize syscall.Getpagesize
  59 func syscall_Getpagesize() int { return int(physPageSize) }
  60
  61 //go:linkname os_runtime_args os.runtime_args
  62 func os_runtime_args() []string { return append([]string{}, argslice...) }
  63
  64 //go:linkname syscall_Exit syscall.Exit
  65 //go:nosplit
  66 func syscall_Exit(code int) {
  67         exit(int32(code))
  68 }
  69
  70 // Temporary, for the gccgo runtime code written in C.
  71 //go:linkname get_envs runtime_get_envs
  72 func get_envs() []string { return envs }
  73
  74 //go:linkname get_args runtime_get_args
  75 func get_args() []string { return argslice }