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go/src/runtime/cgocallback.go
Russ Cox fc46931442 runtime: remove untyped allocation of ParFor
Now it's two allocations. I don't see much downside to that,
since the two pieces were in different cache lines anyway.

Rename 'conservative' to 'cgo_conservative_type' and make
clear that _cgo_allocate is the only allowed user.

This depends on CL 141490043, which removes the other
use of conservative (in defer).

LGTM=dvyukov, iant
R=khr, dvyukov, iant
CC=golang-codereviews, rlh
https://golang.org/cl/139610043
2014-09-16 11:03:11 -04:00

38 lines
1.2 KiB
Go

// Copyright 2011 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"
// These functions are called from C code via cgo/callbacks.c.
// Allocate memory. This allocates the requested number of bytes in
// memory controlled by the Go runtime. The allocated memory will be
// zeroed. You are responsible for ensuring that the Go garbage
// collector can see a pointer to the allocated memory for as long as
// it is valid, e.g., by storing a pointer in a local variable in your
// C function, or in memory allocated by the Go runtime. If the only
// pointers are in a C global variable or in memory allocated via
// malloc, then the Go garbage collector may collect the memory.
//
// TODO(rsc,iant): This memory is untyped.
// Either we need to add types or we need to stop using it.
func _cgo_allocate_internal(len uintptr) unsafe.Pointer {
ret := unsafe.Pointer(&make([]unsafe.Pointer, (len+ptrSize-1)/ptrSize)[0])
c := new(cgomal)
c.alloc = ret
gp := getg()
c.next = gp.m.cgomal
gp.m.cgomal = c
return ret
}
// Panic.
func _cgo_panic_internal(p *byte) {
panic(gostringnocopy(p))
}