1 // Copyright 2012 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 sync 6 7 import "unsafe" 8 9 // defined in package runtime 10 11 // Semacquire waits until *s > 0 and then atomically decrements it. 12 // It is intended as a simple sleep primitive for use by the synchronization 13 // library and should not be used directly. 14 func runtime_Semacquire(s *uint32) 15 16 // Semrelease atomically increments *s and notifies a waiting goroutine 17 // if one is blocked in Semacquire. 18 // It is intended as a simple wakeup primitive for use by the synchronization 19 // library and should not be used directly. 20 func runtime_Semrelease(s *uint32) 21 22 // Approximation of syncSema in runtime/sema.go. 23 type syncSema struct { 24 lock uintptr 25 head unsafe.Pointer 26 tail unsafe.Pointer 27 } 28 29 // Syncsemacquire waits for a pairing Syncsemrelease on the same semaphore s. 30 func runtime_Syncsemacquire(s *syncSema) 31 32 // Syncsemrelease waits for n pairing Syncsemacquire on the same semaphore s. 33 func runtime_Syncsemrelease(s *syncSema, n uint32) 34 35 // Ensure that sync and runtime agree on size of syncSema. 36 func runtime_Syncsemcheck(size uintptr) 37 func init() { 38 var s syncSema 39 runtime_Syncsemcheck(unsafe.Sizeof(s)) 40 } 41 42 // Active spinning runtime support. 43 // runtime_canSpin returns true is spinning makes sense at the moment. 44 func runtime_canSpin(i int) bool 45 46 // runtime_doSpin does active spinning. 47 func runtime_doSpin() 48
