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Diffstat (limited to 'src/runtime/stubs.go')
| -rw-r--r-- | src/runtime/stubs.go | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go new file mode 100644 index 000000000..fe8f9c922 --- /dev/null +++ b/src/runtime/stubs.go @@ -0,0 +1,316 @@ +// 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 "unsafe" + +// Declarations for runtime services implemented in C or assembly. + +const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const +const regSize = 4 << (^uintreg(0) >> 63) // unsafe.Sizeof(uintreg(0)) but an ideal const + +// 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) +} + +// n must be a power of 2 +func roundup(p unsafe.Pointer, n uintptr) unsafe.Pointer { + delta := -uintptr(p) & (n - 1) + return unsafe.Pointer(uintptr(p) + delta) +} + +// in runtime.c +func getg() *g +func acquirem() *m +func releasem(mp *m) +func gomcache() *mcache +func readgstatus(*g) uint32 // proc.c + +// 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). +//go:noescape +func mcall(fn func(*g)) + +// onM switches from the g to the g0 stack and invokes fn(). +// When fn returns, onM switches back to the g and returns, +// continuing execution on the g stack. +// If arguments must be passed to fn, they can be written to +// g->m->ptrarg (pointers) and g->m->scalararg (non-pointers) +// before the call and then consulted during fn. +// Similarly, fn can pass return values back in those locations. +// If fn is written in Go, it can be a closure, which avoids the need for +// ptrarg and scalararg entirely. +// After reading values out of ptrarg and scalararg it is conventional +// to zero them to avoid (memory or information) leaks. +// +// If onM is called from a g0 stack, it invokes fn and returns, +// without any stack switches. +// +// If onM is called from a gsignal stack, it crashes the program. +// The implication is that functions used in signal handlers must +// not use onM. +// +// NOTE(rsc): We could introduce a separate onMsignal that is +// like onM but if called from a gsignal stack would just run fn on +// that stack. The caller of onMsignal would be required to save the +// old values of ptrarg/scalararg and restore them when the call +// was finished, in case the signal interrupted an onM sequence +// in progress on the g or g0 stacks. Until there is a clear need for this, +// we just reject onM in signal handling contexts entirely. +// +//go:noescape +func onM(fn func()) + +// onMsignal is like onM but is allowed to be used in code that +// might run on the gsignal stack. Code running on a signal stack +// may be interrupting an onM sequence on the main stack, so +// if the onMsignal calling sequence writes to ptrarg/scalararg, +// it must first save the old values and then restore them when +// finished. As an exception to the rule, it is fine not to save and +// restore the values if the program is trying to crash rather than +// return from the signal handler. +// Once all the runtime is written in Go, there will be no ptrarg/scalararg +// and the distinction between onM and onMsignal (and perhaps mcall) +// can go away. +// +// If onMsignal is called from a gsignal stack, it invokes fn directly, +// without a stack switch. Otherwise onMsignal behaves like onM. +// +//go:noescape +func onM_signalok(fn func()) + +func badonm() { + gothrow("onM called from signal goroutine") +} + +// C functions that run on the M stack. +// Call using mcall. +func gosched_m(*g) +func park_m(*g) +func recovery_m(*g) + +// More C functions that run on the M stack. +// Call using onM. +func mcacheRefill_m() +func largeAlloc_m() +func gc_m() +func scavenge_m() +func setFinalizer_m() +func removeFinalizer_m() +func markallocated_m() +func unrollgcprog_m() +func unrollgcproginplace_m() +func setgcpercent_m() +func setmaxthreads_m() +func ready_m() +func deferproc_m() +func goexit_m() +func startpanic_m() +func dopanic_m() +func readmemstats_m() +func writeheapdump_m() + +// memclr clears n bytes starting at ptr. +// in memclr_*.s +//go:noescape +func memclr(ptr unsafe.Pointer, n uintptr) + +// memmove copies n bytes from "from" to "to". +// in memmove_*.s +//go:noescape +func memmove(to unsafe.Pointer, from unsafe.Pointer, n uintptr) + +func starttheworld() +func stoptheworld() +func newextram() +func lockOSThread() +func unlockOSThread() + +// exported value for testing +var hashLoad = loadFactor + +// in asm_*.s +func fastrand1() uint32 + +// in asm_*.s +//go:noescape +func memeq(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 entersyscall() +func reentersyscall(pc uintptr, sp unsafe.Pointer) +func entersyscallblock() +func exitsyscall() + +func cgocallback(fn, frame unsafe.Pointer, framesize uintptr) +func gogo(buf *gobuf) +func gosave(buf *gobuf) +func read(fd int32, p unsafe.Pointer, n int32) int32 +func close(fd int32) int32 +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 exit(code int32) +func breakpoint() +func nanotime() int64 +func usleep(usec uint32) + +// careful: cputicks is not guaranteed to be monotonic! In particular, we have +// noticed drift between cpus on certain os/arch combinations. See issue 8976. +func cputicks() int64 + +func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) unsafe.Pointer +func munmap(addr unsafe.Pointer, n uintptr) +func madvise(addr unsafe.Pointer, n uintptr, flags int32) +func reflectcall(fn, arg unsafe.Pointer, n uint32, retoffset uint32) +func osyield() +func procyield(cycles uint32) +func cgocallback_gofunc(fv *funcval, frame unsafe.Pointer, framesize uintptr) +func readgogc() int32 +func purgecachedstats(c *mcache) +func gostringnocopy(b *byte) string +func goexit() + +//go:noescape +func write(fd uintptr, p unsafe.Pointer, n int32) int32 + +//go:noescape +func cas(ptr *uint32, old, new uint32) bool + +//go:noescape +func casp(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool + +//go:noescape +func casuintptr(ptr *uintptr, old, new uintptr) bool + +//go:noescape +func atomicstoreuintptr(ptr *uintptr, new uintptr) + +//go:noescape +func atomicloaduintptr(ptr *uintptr) uintptr + +//go:noescape +func atomicloaduint(ptr *uint) uint + +//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 := getcallerpc(unsafe.Pointer(&arg2)) +// } +// +// 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 + +//go:noescape +func asmcgocall(fn, arg unsafe.Pointer) + +//go:noescape +func asmcgocall_errno(fn, arg unsafe.Pointer) int32 + +//go:noescape +func open(name *byte, mode, perm int32) int32 + +//go:noescape +func gotraceback(*bool) int32 + +const _NoArgs = ^uintptr(0) + +func newstack() +func newproc() +func morestack() +func mstart() +func rt0_go() + +// return0 is a stub used to return 0 from deferproc. +// It is called at the very end of deferproc to signal +// the calling Go function that it should not jump +// to deferreturn. +// in asm_*.s +func return0() + +// thunk to call time.now. +func timenow() (sec int64, nsec int32) + +// in asm_*.s +// not called directly; definitions here supply type information for traceback. +func call16(fn, arg unsafe.Pointer, n, retoffset uint32) +func call32(fn, arg unsafe.Pointer, n, retoffset uint32) +func call64(fn, arg unsafe.Pointer, n, retoffset uint32) +func call128(fn, arg unsafe.Pointer, n, retoffset uint32) +func call256(fn, arg unsafe.Pointer, n, retoffset uint32) +func call512(fn, arg unsafe.Pointer, n, retoffset uint32) +func call1024(fn, arg unsafe.Pointer, n, retoffset uint32) +func call2048(fn, arg unsafe.Pointer, n, retoffset uint32) +func call4096(fn, arg unsafe.Pointer, n, retoffset uint32) +func call8192(fn, arg unsafe.Pointer, n, retoffset uint32) +func call16384(fn, arg unsafe.Pointer, n, retoffset uint32) +func call32768(fn, arg unsafe.Pointer, n, retoffset uint32) +func call65536(fn, arg unsafe.Pointer, n, retoffset uint32) +func call131072(fn, arg unsafe.Pointer, n, retoffset uint32) +func call262144(fn, arg unsafe.Pointer, n, retoffset uint32) +func call524288(fn, arg unsafe.Pointer, n, retoffset uint32) +func call1048576(fn, arg unsafe.Pointer, n, retoffset uint32) +func call2097152(fn, arg unsafe.Pointer, n, retoffset uint32) +func call4194304(fn, arg unsafe.Pointer, n, retoffset uint32) +func call8388608(fn, arg unsafe.Pointer, n, retoffset uint32) +func call16777216(fn, arg unsafe.Pointer, n, retoffset uint32) +func call33554432(fn, arg unsafe.Pointer, n, retoffset uint32) +func call67108864(fn, arg unsafe.Pointer, n, retoffset uint32) +func call134217728(fn, arg unsafe.Pointer, n, retoffset uint32) +func call268435456(fn, arg unsafe.Pointer, n, retoffset uint32) +func call536870912(fn, arg unsafe.Pointer, n, retoffset uint32) +func call1073741824(fn, arg unsafe.Pointer, n, retoffset uint32) |