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// Copyright 2014 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 (
"runtime/internal/atomic"
"runtime/internal/sys"
"unsafe"
)
// Should be a built-in for unsafe.Pointer?
//go:nosplit
func add(p unsafe.Pointer, x uintptr) unsafe.Pointer {
return unsafe.Pointer(uintptr(p) + x)
}
// getg returns the pointer to the current g.
// The compiler rewrites calls to this function into instructions
// that fetch the g directly (from TLS or from the dedicated register).
func getg() *g
// mcall switches from the g to the g0 stack and invokes fn(g),
// where g is the goroutine that made the call.
// mcall saves g's current PC/SP in g->sched so that it can be restored later.
// It is up to fn to arrange for that later execution, typically by recording
// g in a data structure, causing something to call ready(g) later.
// mcall returns to the original goroutine g later, when g has been rescheduled.
// fn must not return at all; typically it ends by calling schedule, to let the m
// run other goroutines.
//
// mcall can only be called from g stacks (not g0, not gsignal).
//
// This must NOT be go:noescape: if fn is a stack-allocated closure,
// fn puts g on a run queue, and g executes before fn returns, the
// closure will be invalidated while it is still executing.
func mcall(fn func(*g))
// systemstack runs fn on a system stack.
//
// It is common to use a func literal as the argument, in order
// to share inputs and outputs with the code around the call
// to system stack:
//
// ... set up y ...
// systemstack(func() {
// x = bigcall(y)
// })
// ... use x ...
//
// For the gc toolchain this permits running a function that requires
// additional stack space in a context where the stack can not be
// split. For gccgo, however, stack splitting is not managed by the
// Go runtime. In effect, all stacks are system stacks. So this gccgo
// version just runs the function.
func systemstack(fn func()) {
fn()
}
func badsystemstack() {
throw("systemstack called from unexpected goroutine")
}
// memclr clears n bytes starting at ptr.
// in memclr_*.s
//go:noescape
func memclr(ptr unsafe.Pointer, n uintptr)
//go:linkname reflect_memclr reflect.memclr
func reflect_memclr(ptr unsafe.Pointer, n uintptr) {
memclr(ptr, n)
}
// memmove copies n bytes from "from" to "to".
// in memmove_*.s
//go:noescape
func memmove(to, from unsafe.Pointer, n uintptr)
//go:linkname reflect_memmove reflect.memmove
func reflect_memmove(to, from unsafe.Pointer, n uintptr) {
memmove(to, from, n)
}
// exported value for testing
var hashLoad = loadFactor
// in asm_*.s
func fastrand1() uint32
// in asm_*.s
//go:noescape
func memequal(a, b unsafe.Pointer, size uintptr) bool
// noescape hides a pointer from escape analysis. noescape is
// the identity function but escape analysis doesn't think the
// output depends on the input. noescape is inlined and currently
// compiles down to a single xor instruction.
// USE CAREFULLY!
//go:nosplit
func noescape(p unsafe.Pointer) unsafe.Pointer {
x := uintptr(p)
return unsafe.Pointer(x ^ 0)
}
func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32
//go:noescape
func jmpdefer(fv *funcval, argp uintptr)
func exit1(code int32)
func asminit()
func setg(gg *g)
func breakpoint()
// reflectcall calls fn with a copy of the n argument bytes pointed at by arg.
// After fn returns, reflectcall copies n-retoffset result bytes
// back into arg+retoffset before returning. If copying result bytes back,
// the caller should pass the argument frame type as argtype, so that
// call can execute appropriate write barriers during the copy.
// Package reflect passes a frame type. In package runtime, there is only
// one call that copies results back, in cgocallbackg1, and it does NOT pass a
// frame type, meaning there are no write barriers invoked. See that call
// site for justification.
func reflectcall(argtype *_type, fn, arg unsafe.Pointer, argsize uint32, retoffset uint32)
func procyield(cycles uint32)
type neverCallThisFunction struct{}
// goexit is the return stub at the top of every goroutine call stack.
// Each goroutine stack is constructed as if goexit called the
// goroutine's entry point function, so that when the entry point
// function returns, it will return to goexit, which will call goexit1
// to perform the actual exit.
//
// This function must never be called directly. Call goexit1 instead.
// gentraceback assumes that goexit terminates the stack. A direct
// call on the stack will cause gentraceback to stop walking the stack
// prematurely and if there are leftover stack barriers it may panic.
func goexit(neverCallThisFunction)
// publicationBarrier performs a store/store barrier (a "publication"
// or "export" barrier). Some form of synchronization is required
// between initializing an object and making that object accessible to
// another processor. Without synchronization, the initialization
// writes and the "publication" write may be reordered, allowing the
// other processor to follow the pointer and observe an uninitialized
// object. In general, higher-level synchronization should be used,
// such as locking or an atomic pointer write. publicationBarrier is
// for when those aren't an option, such as in the implementation of
// the memory manager.
//
// There's no corresponding barrier for the read side because the read
// side naturally has a data dependency order. All architectures that
// Go supports or seems likely to ever support automatically enforce
// data dependency ordering.
func publicationBarrier()
//go:noescape
func setcallerpc(argp unsafe.Pointer, pc uintptr)
// getcallerpc returns the program counter (PC) of its caller's caller.
// getcallersp returns the stack pointer (SP) of its caller's caller.
// For both, the argp must be a pointer to the caller's first function argument.
// The implementation may or may not use argp, depending on
// the architecture.
//
// For example:
//
// func f(arg1, arg2, arg3 int) {
// pc := getcallerpc(unsafe.Pointer(&arg1))
// sp := getcallersp(unsafe.Pointer(&arg1))
// }
//
// These two lines find the PC and SP immediately following
// the call to f (where f will return).
//
// The call to getcallerpc and getcallersp must be done in the
// frame being asked about. It would not be correct for f to pass &arg1
// to another function g and let g call getcallerpc/getcallersp.
// The call inside g might return information about g's caller or
// information about f's caller or complete garbage.
//
// The result of getcallersp is correct at the time of the return,
// but it may be invalidated by any subsequent call to a function
// that might relocate the stack in order to grow or shrink it.
// A general rule is that the result of getcallersp should be used
// immediately and can only be passed to nosplit functions.
//go:noescape
func getcallerpc(argp unsafe.Pointer) uintptr
//go:noescape
func getcallersp(argp unsafe.Pointer) uintptr
// argp used in Defer structs when there is no argp.
const _NoArgs = ^uintptr(0)
//go:linkname time_now time.now
func time_now() (sec int64, nsec int32)
// For gccgo, expose this for C callers.
//go:linkname unixnanotime runtime.unixnanotime
func unixnanotime() int64 {
sec, nsec := time_now()
return sec*1e9 + int64(nsec)
}
// round n up to a multiple of a. a must be a power of 2.
func round(n, a uintptr) uintptr {
return (n + a - 1) &^ (a - 1)
}
// checkASM returns whether assembly runtime checks have passed.
func checkASM() bool {
return true
}
// For gccgo this is in the C code.
func osyield()
// For gccgo this can be called directly.
//extern syscall
func syscall(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) uintptr
// throw crashes the program.
// For gccgo unless and until we port panic.go.
func throw(string)
// newobject allocates a new object.
// For gccgo unless and until we port malloc.go.
func newobject(*_type) unsafe.Pointer
// newarray allocates a new array of objects.
// For gccgo unless and until we port malloc.go.
func newarray(*_type, int) unsafe.Pointer
// funcPC returns the entry PC of the function f.
// It assumes that f is a func value. Otherwise the behavior is undefined.
// For gccgo here unless and until we port proc.go.
//go:nosplit
func funcPC(f interface{}) uintptr {
return **(**uintptr)(add(unsafe.Pointer(&f), sys.PtrSize))
}
// typedmemmove copies a typed value.
// For gccgo for now.
//go:nosplit
func typedmemmove(typ *_type, dst, src unsafe.Pointer) {
memmove(dst, src, typ.size)
}
// Here for gccgo unless and until we port slice.go.
type slice struct {
array unsafe.Pointer
len int
cap int
}
// Here for gccgo until we port malloc.go.
const (
_64bit = 1 << (^uintptr(0) >> 63) / 2
_MHeapMap_TotalBits = (_64bit*sys.GoosWindows)*35 + (_64bit*(1-sys.GoosWindows)*(1-sys.GoosDarwin*sys.GoarchArm64))*39 + sys.GoosDarwin*sys.GoarchArm64*31 + (1-_64bit)*32
_MaxMem = uintptr(1<<_MHeapMap_TotalBits - 1)
)
// Here for gccgo until we port malloc.go.
//extern runtime_mallocgc
func c_mallocgc(size uintptr, typ uintptr, flag uint32) unsafe.Pointer
func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
flag := uint32(0)
if !needzero {
flag = 1 << 3
}
return c_mallocgc(size, uintptr(unsafe.Pointer(typ)), flag)
}
// Here for gccgo until we port mgc.go.
var writeBarrier struct {
enabled bool // compiler emits a check of this before calling write barrier
needed bool // whether we need a write barrier for current GC phase
cgo bool // whether we need a write barrier for a cgo check
alignme uint64 // guarantee alignment so that compiler can use a 32 or 64-bit load
}
// Here for gccgo until we port atomic_pointer.go and mgc.go.
//go:nosplit
func casp(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool {
if !atomic.Casp1((*unsafe.Pointer)(noescape(unsafe.Pointer(ptr))), noescape(old), new) {
return false
}
return true
}
// Here for gccgo until we port lock_*.go.
func lock(l *mutex)
func unlock(l *mutex)
// Here for gccgo for Solaris.
func errno() int
// Temporary for gccgo until we port proc.go.
func entersyscall(int32)
func entersyscallblock(int32)
func exitsyscall(int32)
func gopark(func(*g, unsafe.Pointer) bool, unsafe.Pointer, string, byte, int)
func goparkunlock(*mutex, string, byte, int)
func goready(*g, int)
// Temporary hack for gccgo until we port proc.go.
//go:nosplit
func acquireSudog() *sudog {
mp := acquirem()
pp := mp.p.ptr()
if len(pp.sudogcache) == 0 {
pp.sudogcache = append(pp.sudogcache, new(sudog))
}
n := len(pp.sudogcache)
s := pp.sudogcache[n-1]
pp.sudogcache[n-1] = nil
pp.sudogcache = pp.sudogcache[:n-1]
if s.elem != nil {
throw("acquireSudog: found s.elem != nil in cache")
}
releasem(mp)
return s
}
// Temporary hack for gccgo until we port proc.go.
//go:nosplit
func releaseSudog(s *sudog) {
if s.elem != nil {
throw("runtime: sudog with non-nil elem")
}
if s.selectdone != nil {
throw("runtime: sudog with non-nil selectdone")
}
if s.next != nil {
throw("runtime: sudog with non-nil next")
}
if s.prev != nil {
throw("runtime: sudog with non-nil prev")
}
if s.waitlink != nil {
throw("runtime: sudog with non-nil waitlink")
}
if s.c != nil {
throw("runtime: sudog with non-nil c")
}
gp := getg()
if gp.param != nil {
throw("runtime: releaseSudog with non-nil gp.param")
}
mp := acquirem() // avoid rescheduling to another P
pp := mp.p.ptr()
pp.sudogcache = append(pp.sudogcache, s)
releasem(mp)
}
// Temporary hack for gccgo until we port the garbage collector.
func typeBitsBulkBarrier(typ *_type, p, size uintptr) {}
// Here for gccgo until we port msize.go.
func roundupsize(uintptr) uintptr
// Here for gccgo until we port mgc.go.
func GC()
// Here for gccgo until we port proc.go.
var worldsema uint32 = 1
func stopTheWorldWithSema()
func startTheWorldWithSema()
// For gccgo to call from C code.
//go:linkname acquireWorldsema runtime.acquireWorldsema
func acquireWorldsema() {
semacquire(&worldsema, false)
}
// For gccgo to call from C code.
//go:linkname releaseWorldsema runtime.releaseWorldsema
func releaseWorldsema() {
semrelease(&worldsema)
}
// Here for gccgo until we port proc.go.
func stopTheWorld(reason string) {
semacquire(&worldsema, false)
getg().m.preemptoff = reason
getg().m.gcing = 1
systemstack(stopTheWorldWithSema)
}
// Here for gccgo until we port proc.go.
func startTheWorld() {
getg().m.gcing = 0
getg().m.locks++
systemstack(startTheWorldWithSema)
// worldsema must be held over startTheWorldWithSema to ensure
// gomaxprocs cannot change while worldsema is held.
semrelease(&worldsema)
getg().m.preemptoff = ""
getg().m.locks--
}
// For gccgo to call from C code, so that the C code and the Go code
// can share the memstats variable for now.
//go:linkname getMstats runtime.getMstats
func getMstats() *mstats {
return &memstats
}
// Temporary for gccgo until we port proc.go.
func setcpuprofilerate_m(hz int32)
// Temporary for gccgo until we port mem_GOOS.go.
func sysAlloc(n uintptr, sysStat *uint64) unsafe.Pointer
// Temporary for gccgo until we port proc.go, so that the C signal
// handler can call into cpuprof.
//go:linkname cpuprofAdd runtime.cpuprofAdd
func cpuprofAdd(stk []uintptr) {
cpuprof.add(stk)
}
// For gccgo until we port proc.go.
func Breakpoint()
func LockOSThread()
func UnlockOSThread()
func allm() *m
func allgs() []*g
//go:nosplit
func readgstatus(gp *g) uint32 {
return atomic.Load(&gp.atomicstatus)
}
// Temporary for gccgo until we port malloc.go
func persistentalloc(size, align uintptr, sysStat *uint64) unsafe.Pointer
// Temporary for gccgo until we port mheap.go
func setprofilebucket(p unsafe.Pointer, b *bucket)
// Currently in proc.c.
func tracebackothers(*g)
// Temporary for gccgo until we port mgc.go.
func setgcpercent(int32) int32
//go:linkname setGCPercent runtime_debug.setGCPercent
func setGCPercent(in int32) (out int32) {
return setgcpercent(in)
}
// Temporary for gccgo until we port proc.go.
func setmaxthreads(int) int
//go:linkname setMaxThreads runtime_debug.setMaxThreads
func setMaxThreads(in int) (out int) {
return setmaxthreads(in)
}
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