// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package runtime
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import (
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"internal/cpu"
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"runtime/internal/atomic"
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"runtime/internal/sys"
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"unsafe"
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)
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// defined constants
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const (
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// G status
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//
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// Beyond indicating the general state of a G, the G status
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// acts like a lock on the goroutine's stack (and hence its
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// ability to execute user code).
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//
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// If you add to this list, add to the list
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// of "okay during garbage collection" status
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// in mgcmark.go too.
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// _Gidle means this goroutine was just allocated and has not
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// yet been initialized.
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_Gidle = iota // 0
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// _Grunnable means this goroutine is on a run queue. It is
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// not currently executing user code. The stack is not owned.
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_Grunnable // 1
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// _Grunning means this goroutine may execute user code. The
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// stack is owned by this goroutine. It is not on a run queue.
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// It is assigned an M and a P.
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_Grunning // 2
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// _Gsyscall means this goroutine is executing a system call.
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// It is not executing user code. The stack is owned by this
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// goroutine. It is not on a run queue. It is assigned an M.
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_Gsyscall // 3
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// _Gwaiting means this goroutine is blocked in the runtime.
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// It is not executing user code. It is not on a run queue,
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// but should be recorded somewhere (e.g., a channel wait
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// queue) so it can be ready()d when necessary. The stack is
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// not owned *except* that a channel operation may read or
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// write parts of the stack under the appropriate channel
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// lock. Otherwise, it is not safe to access the stack after a
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// goroutine enters _Gwaiting (e.g., it may get moved).
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_Gwaiting // 4
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// _Gmoribund_unused is currently unused, but hardcoded in gdb
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// scripts.
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_Gmoribund_unused // 5
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// _Gdead means this goroutine is currently unused. It may be
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// just exited, on a free list, or just being initialized. It
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// is not executing user code. It may or may not have a stack
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// allocated. The G and its stack (if any) are owned by the M
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// that is exiting the G or that obtained the G from the free
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// list.
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_Gdead // 6
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// _Genqueue_unused is currently unused.
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_Genqueue_unused // 7
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// _Gcopystack means this goroutine's stack is being moved. It
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// is not executing user code and is not on a run queue. The
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// stack is owned by the goroutine that put it in _Gcopystack.
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_Gcopystack // 8
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// _Gscan combined with one of the above states other than
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// _Grunning indicates that GC is scanning the stack. The
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// goroutine is not executing user code and the stack is owned
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// by the goroutine that set the _Gscan bit.
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//
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// _Gscanrunning is different: it is used to briefly block
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// state transitions while GC signals the G to scan its own
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// stack. This is otherwise like _Grunning.
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//
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// atomicstatus&~Gscan gives the state the goroutine will
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// return to when the scan completes.
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_Gscan = 0x1000
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_Gscanrunnable = _Gscan + _Grunnable // 0x1001
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_Gscanrunning = _Gscan + _Grunning // 0x1002
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_Gscansyscall = _Gscan + _Gsyscall // 0x1003
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_Gscanwaiting = _Gscan + _Gwaiting // 0x1004
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)
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const (
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// P status
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_Pidle = iota
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_Prunning // Only this P is allowed to change from _Prunning.
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_Psyscall
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_Pgcstop
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_Pdead
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)
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// Mutual exclusion locks. In the uncontended case,
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// as fast as spin locks (just a few user-level instructions),
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// but on the contention path they sleep in the kernel.
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// A zeroed Mutex is unlocked (no need to initialize each lock).
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type mutex struct {
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// Futex-based impl treats it as uint32 key,
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// while sema-based impl as M* waitm.
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// Used to be a union, but unions break precise GC.
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key uintptr
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}
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// sleep and wakeup on one-time events.
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// before any calls to notesleep or notewakeup,
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// must call noteclear to initialize the Note.
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// then, exactly one thread can call notesleep
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// and exactly one thread can call notewakeup (once).
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// once notewakeup has been called, the notesleep
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// will return. future notesleep will return immediately.
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// subsequent noteclear must be called only after
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// previous notesleep has returned, e.g. it's disallowed
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// to call noteclear straight after notewakeup.
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//
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// notetsleep is like notesleep but wakes up after
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// a given number of nanoseconds even if the event
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// has not yet happened. if a goroutine uses notetsleep to
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// wake up early, it must wait to call noteclear until it
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// can be sure that no other goroutine is calling
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// notewakeup.
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//
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// notesleep/notetsleep are generally called on g0,
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// notetsleepg is similar to notetsleep but is called on user g.
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type note struct {
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// Futex-based impl treats it as uint32 key,
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// while sema-based impl as M* waitm.
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// Used to be a union, but unions break precise GC.
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key uintptr
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}
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type funcval struct {
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fn uintptr
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// variable-size, fn-specific data here
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}
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type iface struct {
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tab *itab
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data unsafe.Pointer
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}
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type eface struct {
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_type *_type
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data unsafe.Pointer
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}
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func efaceOf(ep *interface{}) *eface {
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return (*eface)(unsafe.Pointer(ep))
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}
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// The guintptr, muintptr, and puintptr are all used to bypass write barriers.
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// It is particularly important to avoid write barriers when the current P has
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// been released, because the GC thinks the world is stopped, and an
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// unexpected write barrier would not be synchronized with the GC,
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// which can lead to a half-executed write barrier that has marked the object
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// but not queued it. If the GC skips the object and completes before the
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// queuing can occur, it will incorrectly free the object.
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//
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// We tried using special assignment functions invoked only when not
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// holding a running P, but then some updates to a particular memory
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// word went through write barriers and some did not. This breaks the
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// write barrier shadow checking mode, and it is also scary: better to have
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// a word that is completely ignored by the GC than to have one for which
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// only a few updates are ignored.
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//
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// Gs and Ps are always reachable via true pointers in the
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// allgs and allp lists or (during allocation before they reach those lists)
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// from stack variables.
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//
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// Ms are always reachable via true pointers either from allm or
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// freem. Unlike Gs and Ps we do free Ms, so it's important that
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// nothing ever hold an muintptr across a safe point.
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// A guintptr holds a goroutine pointer, but typed as a uintptr
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// to bypass write barriers. It is used in the Gobuf goroutine state
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// and in scheduling lists that are manipulated without a P.
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//
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// The Gobuf.g goroutine pointer is almost always updated by assembly code.
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// In one of the few places it is updated by Go code - func save - it must be
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// treated as a uintptr to avoid a write barrier being emitted at a bad time.
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// Instead of figuring out how to emit the write barriers missing in the
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// assembly manipulation, we change the type of the field to uintptr,
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// so that it does not require write barriers at all.
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//
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// Goroutine structs are published in the allg list and never freed.
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// That will keep the goroutine structs from being collected.
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// There is never a time that Gobuf.g's contain the only references
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// to a goroutine: the publishing of the goroutine in allg comes first.
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// Goroutine pointers are also kept in non-GC-visible places like TLS,
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// so I can't see them ever moving. If we did want to start moving data
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// in the GC, we'd need to allocate the goroutine structs from an
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// alternate arena. Using guintptr doesn't make that problem any worse.
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type guintptr uintptr
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//go:nosplit
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func (gp guintptr) ptr() *g { return (*g)(unsafe.Pointer(gp)) }
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//go:nosplit
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func (gp *guintptr) set(g *g) { *gp = guintptr(unsafe.Pointer(g)) }
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//go:nosplit
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func (gp *guintptr) cas(old, new guintptr) bool {
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return atomic.Casuintptr((*uintptr)(unsafe.Pointer(gp)), uintptr(old), uintptr(new))
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}
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// setGNoWB performs *gp = new without a write barrier.
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// For times when it's impractical to use a guintptr.
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//go:nosplit
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//go:nowritebarrier
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func setGNoWB(gp **g, new *g) {
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(*guintptr)(unsafe.Pointer(gp)).set(new)
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}
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type puintptr uintptr
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//go:nosplit
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func (pp puintptr) ptr() *p { return (*p)(unsafe.Pointer(pp)) }
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//go:nosplit
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func (pp *puintptr) set(p *p) { *pp = puintptr(unsafe.Pointer(p)) }
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// muintptr is a *m that is not tracked by the garbage collector.
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//
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// Because we do free Ms, there are some additional constrains on
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// muintptrs:
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//
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// 1. Never hold an muintptr locally across a safe point.
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//
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// 2. Any muintptr in the heap must be owned by the M itself so it can
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// ensure it is not in use when the last true *m is released.
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type muintptr uintptr
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//go:nosplit
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func (mp muintptr) ptr() *m { return (*m)(unsafe.Pointer(mp)) }
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//go:nosplit
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func (mp *muintptr) set(m *m) { *mp = muintptr(unsafe.Pointer(m)) }
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// setMNoWB performs *mp = new without a write barrier.
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// For times when it's impractical to use an muintptr.
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//go:nosplit
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//go:nowritebarrier
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func setMNoWB(mp **m, new *m) {
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(*muintptr)(unsafe.Pointer(mp)).set(new)
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}
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type gobuf struct {
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// The offsets of sp, pc, and g are known to (hard-coded in) libmach.
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//
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// ctxt is unusual with respect to GC: it may be a
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// heap-allocated funcval, so GC needs to track it, but it
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// needs to be set and cleared from assembly, where it's
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// difficult to have write barriers. However, ctxt is really a
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// saved, live register, and we only ever exchange it between
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// the real register and the gobuf. Hence, we treat it as a
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// root during stack scanning, which means assembly that saves
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// and restores it doesn't need write barriers. It's still
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// typed as a pointer so that any other writes from Go get
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// write barriers.
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sp uintptr
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pc uintptr
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g guintptr
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ctxt unsafe.Pointer
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ret sys.Uintreg
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lr uintptr
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bp uintptr // for GOEXPERIMENT=framepointer
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}
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// sudog represents a g in a wait list, such as for sending/receiving
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// on a channel.
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//
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// sudog is necessary because the g ↔ synchronization object relation
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// is many-to-many. A g can be on many wait lists, so there may be
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// many sudogs for one g; and many gs may be waiting on the same
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// synchronization object, so there may be many sudogs for one object.
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//
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// sudogs are allocated from a special pool. Use acquireSudog and
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// releaseSudog to allocate and free them.
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type sudog struct {
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// The following fields are protected by the hchan.lock of the
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// channel this sudog is blocking on. shrinkstack depends on
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// this for sudogs involved in channel ops.
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g *g
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// isSelect indicates g is participating in a select, so
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// g.selectDone must be CAS'd to win the wake-up race.
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isSelect bool
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next *sudog
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prev *sudog
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elem unsafe.Pointer // data element (may point to stack)
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// The following fields are never accessed concurrently.
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// For channels, waitlink is only accessed by g.
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// For semaphores, all fields (including the ones above)
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// are only accessed when holding a semaRoot lock.
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acquiretime int64
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releasetime int64
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ticket uint32
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parent *sudog // semaRoot binary tree
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waitlink *sudog // g.waiting list or semaRoot
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waittail *sudog // semaRoot
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c *hchan // channel
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}
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type libcall struct {
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fn uintptr
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n uintptr // number of parameters
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args uintptr // parameters
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r1 uintptr // return values
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r2 uintptr
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err uintptr // error number
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}
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// describes how to handle callback
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type wincallbackcontext struct {
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gobody unsafe.Pointer // go function to call
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argsize uintptr // callback arguments size (in bytes)
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restorestack uintptr // adjust stack on return by (in bytes) (386 only)
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cleanstack bool
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}
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// Stack describes a Go execution stack.
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// The bounds of the stack are exactly [lo, hi),
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// with no implicit data structures on either side.
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type stack struct {
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lo uintptr
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hi uintptr
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}
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type g struct {
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// Stack parameters.
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// stack describes the actual stack memory: [stack.lo, stack.hi).
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// stackguard0 is the stack pointer compared in the Go stack growth prologue.
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// It is stack.lo+StackGuard normally, but can be StackPreempt to trigger a preemption.
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// stackguard1 is the stack pointer compared in the C stack growth prologue.
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// It is stack.lo+StackGuard on g0 and gsignal stacks.
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// It is ~0 on other goroutine stacks, to trigger a call to morestackc (and crash).
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stack stack // offset known to runtime/cgo
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stackguard0 uintptr // offset known to liblink
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stackguard1 uintptr // offset known to liblink
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_panic *_panic // innermost panic - offset known to liblink
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_defer *_defer // innermost defer
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m *m // current m; offset known to arm liblink
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sched gobuf
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syscallsp uintptr // if status==Gsyscall, syscallsp = sched.sp to use during gc
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syscallpc uintptr // if status==Gsyscall, syscallpc = sched.pc to use during gc
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stktopsp uintptr // expected sp at top of stack, to check in traceback
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param unsafe.Pointer // passed parameter on wakeup
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atomicstatus uint32
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stackLock uint32 // sigprof/scang lock; TODO: fold in to atomicstatus
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goid int64
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schedlink guintptr
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waitsince int64 // approx time when the g become blocked
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waitreason waitReason // if status==Gwaiting
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preempt bool // preemption signal, duplicates stackguard0 = stackpreempt
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paniconfault bool // panic (instead of crash) on unexpected fault address
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preemptscan bool // preempted g does scan for gc
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gcscandone bool // g has scanned stack; protected by _Gscan bit in status
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gcscanvalid bool // false at start of gc cycle, true if G has not run since last scan; TODO: remove?
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throwsplit bool // must not split stack
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raceignore int8 // ignore race detection events
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sysblocktraced bool // StartTrace has emitted EvGoInSyscall about this goroutine
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sysexitticks int64 // cputicks when syscall has returned (for tracing)
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traceseq uint64 // trace event sequencer
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tracelastp puintptr // last P emitted an event for this goroutine
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lockedm muintptr
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sig uint32
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writebuf []byte
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sigcode0 uintptr
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sigcode1 uintptr
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sigpc uintptr
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gopc uintptr // pc of go statement that created this goroutine
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ancestors *[]ancestorInfo // ancestor information goroutine(s) that created this goroutine (only used if debug.tracebackancestors)
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startpc uintptr // pc of goroutine function
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racectx uintptr
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waiting *sudog // sudog structures this g is waiting on (that have a valid elem ptr); in lock order
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cgoCtxt []uintptr // cgo traceback context
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labels unsafe.Pointer // profiler labels
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timer *timer // cached timer for time.Sleep
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selectDone uint32 // are we participating in a select and did someone win the race?
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// Per-G GC state
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// gcAssistBytes is this G's GC assist credit in terms of
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// bytes allocated. If this is positive, then the G has credit
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// to allocate gcAssistBytes bytes without assisting. If this
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// is negative, then the G must correct this by performing
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// scan work. We track this in bytes to make it fast to update
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// and check for debt in the malloc hot path. The assist ratio
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// determines how this corresponds to scan work debt.
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gcAssistBytes int64
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}
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type m struct {
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g0 *g // goroutine with scheduling stack
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morebuf gobuf // gobuf arg to morestack
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divmod uint32 // div/mod denominator for arm - known to liblink
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// Fields not known to debuggers.
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procid uint64 // for debuggers, but offset not hard-coded
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gsignal *g // signal-handling g
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goSigStack gsignalStack // Go-allocated signal handling stack
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sigmask sigset // storage for saved signal mask
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tls [6]uintptr // thread-local storage (for x86 extern register)
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mstartfn func()
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curg *g // current running goroutine
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caughtsig guintptr // goroutine running during fatal signal
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p puintptr // attached p for executing go code (nil if not executing go code)
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nextp puintptr
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oldp puintptr // the p that was attached before executing a syscall
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id int64
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mallocing int32
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throwing int32
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preemptoff string // if != "", keep curg running on this m
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locks int32
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dying int32
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profilehz int32
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spinning bool // m is out of work and is actively looking for work
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blocked bool // m is blocked on a note
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inwb bool // m is executing a write barrier
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newSigstack bool // minit on C thread called sigaltstack
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printlock int8
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incgo bool // m is executing a cgo call
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freeWait uint32 // if == 0, safe to free g0 and delete m (atomic)
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fastrand [2]uint32
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needextram bool
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traceback uint8
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ncgocall uint64 // number of cgo calls in total
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ncgo int32 // number of cgo calls currently in progress
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cgoCallersUse uint32 // if non-zero, cgoCallers in use temporarily
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cgoCallers *cgoCallers // cgo traceback if crashing in cgo call
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park note
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alllink *m // on allm
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schedlink muintptr
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mcache *mcache
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lockedg guintptr
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createstack [32]uintptr // stack that created this thread.
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lockedExt uint32 // tracking for external LockOSThread
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lockedInt uint32 // tracking for internal lockOSThread
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nextwaitm muintptr // next m waiting for lock
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waitunlockf unsafe.Pointer // todo go func(*g, unsafe.pointer) bool
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waitlock unsafe.Pointer
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waittraceev byte
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waittraceskip int
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startingtrace bool
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syscalltick uint32
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thread uintptr // thread handle
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freelink *m // on sched.freem
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// these are here because they are too large to be on the stack
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// of low-level NOSPLIT functions.
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libcall libcall
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libcallpc uintptr // for cpu profiler
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libcallsp uintptr
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libcallg guintptr
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syscall libcall // stores syscall parameters on windows
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vdsoSP uintptr // SP for traceback while in VDSO call (0 if not in call)
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vdsoPC uintptr // PC for traceback while in VDSO call
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mOS
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}
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type p struct {
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lock mutex
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id int32
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status uint32 // one of pidle/prunning/...
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link puintptr
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schedtick uint32 // incremented on every scheduler call
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syscalltick uint32 // incremented on every system call
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sysmontick sysmontick // last tick observed by sysmon
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m muintptr // back-link to associated m (nil if idle)
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mcache *mcache
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racectx uintptr
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deferpool [5][]*_defer // pool of available defer structs of different sizes (see panic.go)
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deferpoolbuf [5][32]*_defer
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// Cache of goroutine ids, amortizes accesses to runtime·sched.goidgen.
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goidcache uint64
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goidcacheend uint64
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// Queue of runnable goroutines. Accessed without lock.
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runqhead uint32
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runqtail uint32
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runq [256]guintptr
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// runnext, if non-nil, is a runnable G that was ready'd by
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// the current G and should be run next instead of what's in
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// runq if there's time remaining in the running G's time
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// slice. It will inherit the time left in the current time
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// slice. If a set of goroutines is locked in a
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// communicate-and-wait pattern, this schedules that set as a
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// unit and eliminates the (potentially large) scheduling
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// latency that otherwise arises from adding the ready'd
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// goroutines to the end of the run queue.
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runnext guintptr
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// Available G's (status == Gdead)
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gFree struct {
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gList
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n int32
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}
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sudogcache []*sudog
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sudogbuf [128]*sudog
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tracebuf traceBufPtr
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// traceSweep indicates the sweep events should be traced.
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// This is used to defer the sweep start event until a span
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// has actually been swept.
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traceSweep bool
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// traceSwept and traceReclaimed track the number of bytes
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// swept and reclaimed by sweeping in the current sweep loop.
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traceSwept, traceReclaimed uintptr
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palloc persistentAlloc // per-P to avoid mutex
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// Per-P GC state
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gcAssistTime int64 // Nanoseconds in assistAlloc
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gcFractionalMarkTime int64 // Nanoseconds in fractional mark worker
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gcBgMarkWorker guintptr
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gcMarkWorkerMode gcMarkWorkerMode
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// gcMarkWorkerStartTime is the nanotime() at which this mark
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// worker started.
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gcMarkWorkerStartTime int64
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// gcw is this P's GC work buffer cache. The work buffer is
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// filled by write barriers, drained by mutator assists, and
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// disposed on certain GC state transitions.
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gcw gcWork
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// wbBuf is this P's GC write barrier buffer.
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//
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// TODO: Consider caching this in the running G.
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wbBuf wbBuf
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runSafePointFn uint32 // if 1, run sched.safePointFn at next safe point
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pad cpu.CacheLinePad
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}
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type schedt struct {
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// accessed atomically. keep at top to ensure alignment on 32-bit systems.
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goidgen uint64
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lastpoll uint64
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lock mutex
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// When increasing nmidle, nmidlelocked, nmsys, or nmfreed, be
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// sure to call checkdead().
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midle muintptr // idle m's waiting for work
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nmidle int32 // number of idle m's waiting for work
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nmidlelocked int32 // number of locked m's waiting for work
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mnext int64 // number of m's that have been created and next M ID
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maxmcount int32 // maximum number of m's allowed (or die)
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nmsys int32 // number of system m's not counted for deadlock
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nmfreed int64 // cumulative number of freed m's
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ngsys uint32 // number of system goroutines; updated atomically
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pidle puintptr // idle p's
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npidle uint32
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nmspinning uint32 // See "Worker thread parking/unparking" comment in proc.go.
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// Global runnable queue.
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runq gQueue
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runqsize int32
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// disable controls selective disabling of the scheduler.
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//
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// Use schedEnableUser to control this.
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//
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// disable is protected by sched.lock.
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disable struct {
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// user disables scheduling of user goroutines.
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user bool
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runnable gQueue // pending runnable Gs
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n int32 // length of runnable
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}
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// Global cache of dead G's.
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gFree struct {
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lock mutex
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stack gList // Gs with stacks
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noStack gList // Gs without stacks
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n int32
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}
|
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// Central cache of sudog structs.
|
sudoglock mutex
|
sudogcache *sudog
|
|
// Central pool of available defer structs of different sizes.
|
deferlock mutex
|
deferpool [5]*_defer
|
|
// freem is the list of m's waiting to be freed when their
|
// m.exited is set. Linked through m.freelink.
|
freem *m
|
|
gcwaiting uint32 // gc is waiting to run
|
stopwait int32
|
stopnote note
|
sysmonwait uint32
|
sysmonnote note
|
|
// safepointFn should be called on each P at the next GC
|
// safepoint if p.runSafePointFn is set.
|
safePointFn func(*p)
|
safePointWait int32
|
safePointNote note
|
|
profilehz int32 // cpu profiling rate
|
|
procresizetime int64 // nanotime() of last change to gomaxprocs
|
totaltime int64 // ∫gomaxprocs dt up to procresizetime
|
}
|
|
// Values for the flags field of a sigTabT.
|
const (
|
_SigNotify = 1 << iota // let signal.Notify have signal, even if from kernel
|
_SigKill // if signal.Notify doesn't take it, exit quietly
|
_SigThrow // if signal.Notify doesn't take it, exit loudly
|
_SigPanic // if the signal is from the kernel, panic
|
_SigDefault // if the signal isn't explicitly requested, don't monitor it
|
_SigGoExit // cause all runtime procs to exit (only used on Plan 9).
|
_SigSetStack // add SA_ONSTACK to libc handler
|
_SigUnblock // always unblock; see blockableSig
|
_SigIgn // _SIG_DFL action is to ignore the signal
|
)
|
|
// Layout of in-memory per-function information prepared by linker
|
// See https://golang.org/s/go12symtab.
|
// Keep in sync with linker (../cmd/link/internal/ld/pcln.go:/pclntab)
|
// and with package debug/gosym and with symtab.go in package runtime.
|
type _func struct {
|
entry uintptr // start pc
|
nameoff int32 // function name
|
|
args int32 // in/out args size
|
deferreturn uint32 // offset of a deferreturn block from entry, if any.
|
|
pcsp int32
|
pcfile int32
|
pcln int32
|
npcdata int32
|
funcID funcID // set for certain special runtime functions
|
_ [2]int8 // unused
|
nfuncdata uint8 // must be last
|
}
|
|
// Pseudo-Func that is returned for PCs that occur in inlined code.
|
// A *Func can be either a *_func or a *funcinl, and they are distinguished
|
// by the first uintptr.
|
type funcinl struct {
|
zero uintptr // set to 0 to distinguish from _func
|
entry uintptr // entry of the real (the "outermost") frame.
|
name string
|
file string
|
line int
|
}
|
|
// layout of Itab known to compilers
|
// allocated in non-garbage-collected memory
|
// Needs to be in sync with
|
// ../cmd/compile/internal/gc/reflect.go:/^func.dumptypestructs.
|
type itab struct {
|
inter *interfacetype
|
_type *_type
|
hash uint32 // copy of _type.hash. Used for type switches.
|
_ [4]byte
|
fun [1]uintptr // variable sized. fun[0]==0 means _type does not implement inter.
|
}
|
|
// Lock-free stack node.
|
// // Also known to export_test.go.
|
type lfnode struct {
|
next uint64
|
pushcnt uintptr
|
}
|
|
type forcegcstate struct {
|
lock mutex
|
g *g
|
idle uint32
|
}
|
|
// startup_random_data holds random bytes initialized at startup. These come from
|
// the ELF AT_RANDOM auxiliary vector (vdso_linux_amd64.go or os_linux_386.go).
|
var startupRandomData []byte
|
|
// extendRandom extends the random numbers in r[:n] to the whole slice r.
|
// Treats n<0 as n==0.
|
func extendRandom(r []byte, n int) {
|
if n < 0 {
|
n = 0
|
}
|
for n < len(r) {
|
// Extend random bits using hash function & time seed
|
w := n
|
if w > 16 {
|
w = 16
|
}
|
h := memhash(unsafe.Pointer(&r[n-w]), uintptr(nanotime()), uintptr(w))
|
for i := 0; i < sys.PtrSize && n < len(r); i++ {
|
r[n] = byte(h)
|
n++
|
h >>= 8
|
}
|
}
|
}
|
|
// A _defer holds an entry on the list of deferred calls.
|
// If you add a field here, add code to clear it in freedefer.
|
type _defer struct {
|
siz int32
|
started bool
|
sp uintptr // sp at time of defer
|
pc uintptr
|
fn *funcval
|
_panic *_panic // panic that is running defer
|
link *_defer
|
}
|
|
// A _panic holds information about an active panic.
|
//
|
// This is marked go:notinheap because _panic values must only ever
|
// live on the stack.
|
//
|
// The argp and link fields are stack pointers, but don't need special
|
// handling during stack growth: because they are pointer-typed and
|
// _panic values only live on the stack, regular stack pointer
|
// adjustment takes care of them.
|
//
|
//go:notinheap
|
type _panic struct {
|
argp unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
|
arg interface{} // argument to panic
|
link *_panic // link to earlier panic
|
recovered bool // whether this panic is over
|
aborted bool // the panic was aborted
|
}
|
|
// stack traces
|
type stkframe struct {
|
fn funcInfo // function being run
|
pc uintptr // program counter within fn
|
continpc uintptr // program counter where execution can continue, or 0 if not
|
lr uintptr // program counter at caller aka link register
|
sp uintptr // stack pointer at pc
|
fp uintptr // stack pointer at caller aka frame pointer
|
varp uintptr // top of local variables
|
argp uintptr // pointer to function arguments
|
arglen uintptr // number of bytes at argp
|
argmap *bitvector // force use of this argmap
|
}
|
|
// ancestorInfo records details of where a goroutine was started.
|
type ancestorInfo struct {
|
pcs []uintptr // pcs from the stack of this goroutine
|
goid int64 // goroutine id of this goroutine; original goroutine possibly dead
|
gopc uintptr // pc of go statement that created this goroutine
|
}
|
|
const (
|
_TraceRuntimeFrames = 1 << iota // include frames for internal runtime functions.
|
_TraceTrap // the initial PC, SP are from a trap, not a return PC from a call
|
_TraceJumpStack // if traceback is on a systemstack, resume trace at g that called into it
|
)
|
|
// The maximum number of frames we print for a traceback
|
const _TracebackMaxFrames = 100
|
|
// A waitReason explains why a goroutine has been stopped.
|
// See gopark. Do not re-use waitReasons, add new ones.
|
type waitReason uint8
|
|
const (
|
waitReasonZero waitReason = iota // ""
|
waitReasonGCAssistMarking // "GC assist marking"
|
waitReasonIOWait // "IO wait"
|
waitReasonChanReceiveNilChan // "chan receive (nil chan)"
|
waitReasonChanSendNilChan // "chan send (nil chan)"
|
waitReasonDumpingHeap // "dumping heap"
|
waitReasonGarbageCollection // "garbage collection"
|
waitReasonGarbageCollectionScan // "garbage collection scan"
|
waitReasonPanicWait // "panicwait"
|
waitReasonSelect // "select"
|
waitReasonSelectNoCases // "select (no cases)"
|
waitReasonGCAssistWait // "GC assist wait"
|
waitReasonGCSweepWait // "GC sweep wait"
|
waitReasonChanReceive // "chan receive"
|
waitReasonChanSend // "chan send"
|
waitReasonFinalizerWait // "finalizer wait"
|
waitReasonForceGGIdle // "force gc (idle)"
|
waitReasonSemacquire // "semacquire"
|
waitReasonSleep // "sleep"
|
waitReasonSyncCondWait // "sync.Cond.Wait"
|
waitReasonTimerGoroutineIdle // "timer goroutine (idle)"
|
waitReasonTraceReaderBlocked // "trace reader (blocked)"
|
waitReasonWaitForGCCycle // "wait for GC cycle"
|
waitReasonGCWorkerIdle // "GC worker (idle)"
|
)
|
|
var waitReasonStrings = [...]string{
|
waitReasonZero: "",
|
waitReasonGCAssistMarking: "GC assist marking",
|
waitReasonIOWait: "IO wait",
|
waitReasonChanReceiveNilChan: "chan receive (nil chan)",
|
waitReasonChanSendNilChan: "chan send (nil chan)",
|
waitReasonDumpingHeap: "dumping heap",
|
waitReasonGarbageCollection: "garbage collection",
|
waitReasonGarbageCollectionScan: "garbage collection scan",
|
waitReasonPanicWait: "panicwait",
|
waitReasonSelect: "select",
|
waitReasonSelectNoCases: "select (no cases)",
|
waitReasonGCAssistWait: "GC assist wait",
|
waitReasonGCSweepWait: "GC sweep wait",
|
waitReasonChanReceive: "chan receive",
|
waitReasonChanSend: "chan send",
|
waitReasonFinalizerWait: "finalizer wait",
|
waitReasonForceGGIdle: "force gc (idle)",
|
waitReasonSemacquire: "semacquire",
|
waitReasonSleep: "sleep",
|
waitReasonSyncCondWait: "sync.Cond.Wait",
|
waitReasonTimerGoroutineIdle: "timer goroutine (idle)",
|
waitReasonTraceReaderBlocked: "trace reader (blocked)",
|
waitReasonWaitForGCCycle: "wait for GC cycle",
|
waitReasonGCWorkerIdle: "GC worker (idle)",
|
}
|
|
func (w waitReason) String() string {
|
if w < 0 || w >= waitReason(len(waitReasonStrings)) {
|
return "unknown wait reason"
|
}
|
return waitReasonStrings[w]
|
}
|
|
var (
|
allglen uintptr
|
allm *m
|
allp []*p // len(allp) == gomaxprocs; may change at safe points, otherwise immutable
|
allpLock mutex // Protects P-less reads of allp and all writes
|
gomaxprocs int32
|
ncpu int32
|
forcegc forcegcstate
|
sched schedt
|
newprocs int32
|
|
// Information about what cpu features are available.
|
// Packages outside the runtime should not use these
|
// as they are not an external api.
|
// Set on startup in asm_{386,amd64,amd64p32}.s
|
processorVersionInfo uint32
|
isIntel bool
|
lfenceBeforeRdtsc bool
|
|
goarm uint8 // set by cmd/link on arm systems
|
framepointer_enabled bool // set by cmd/link
|
)
|
|
// Set by the linker so the runtime can determine the buildmode.
|
var (
|
islibrary bool // -buildmode=c-shared
|
isarchive bool // -buildmode=c-archive
|
)
|
