golang callbacks 代码
文件路径：/src/runtime/cgo/callbacks.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 cgo
import "unsafe"
/ These utility functions are available to be called from code
/ compiled with gcc via crosscall2.
/ The declaration of crosscall2 is:
/ void crosscall2(void (*fn)(void *), void *, int);
/
/ We need to export the symbol crosscall2 in order to support
/ callbacks from shared libraries. This applies regardless of
/ linking mode.
/
/ Compatibility note: SWIG uses crosscall2 in exactly one situation:
/ to call _cgo_panic using the pattern shown below. We need to keep
/ that pattern working. In particular, crosscall2 actually takes four
/ arguments, but it works to call it with three arguments when
/ calling _cgo_panic.
/
/go:cgo_export_static crosscall2
/go:cgo_export_dynamic crosscall2
/ Panic. The argument is converted into a Go string.
/ Call like this in code compiled with gcc:
/ struct { const char *p; } a;
/ a.p = /* string to pass to panic */;
/ crosscall2(_cgo_panic, &a, sizeof a);
/ /* The function call will not return. */
/ TODO: We should export a regular C function to panic, change SWIG
/ to use that instead of the above pattern, and then we can drop
/ backwards-compatibility from crosscall2 and stop exporting it.
/go:linkname _runtime_cgo_panic_internal runtime._cgo_panic_internal
func _runtime_cgo_panic_internal(p *byte)
/go:linkname _cgo_panic _cgo_panic
/go:cgo_export_static _cgo_panic
/go:cgo_export_dynamic _cgo_panic
func _cgo_panic(a *struct{ cstr *byte }) {
_runtime_cgo_panic_internal(a.cstr)
}
/go:cgo_import_static x_cgo_init
/go:linkname x_cgo_init x_cgo_init
/go:linkname _cgo_init _cgo_init
var x_cgo_init byte
var _cgo_init = &x_cgo_init
/go:cgo_import_static x_cgo_thread_start
/go:linkname x_cgo_thread_start x_cgo_thread_start
/go:linkname _cgo_thread_start _cgo_thread_start
var x_cgo_thread_start byte
var _cgo_thread_start = &x_cgo_thread_start
/ Creates a new system thread without updating any Go state.
/
/ This method is invoked during shared library loading to create a new OS
/ thread to perform the runtime initialization. This method is similar to
/ _cgo_sys_thread_start except that it doesn't update any Go state.
/go:cgo_import_static x_cgo_sys_thread_create
/go:linkname x_cgo_sys_thread_create x_cgo_sys_thread_create
/go:linkname _cgo_sys_thread_create _cgo_sys_thread_create
var x_cgo_sys_thread_create byte
var _cgo_sys_thread_create = &x_cgo_sys_thread_create
/ Notifies that the runtime has been initialized.
/
/ We currently block at every CGO entry point (via _cgo_wait_runtime_init_done)
/ to ensure that the runtime has been initialized before the CGO call is
/ executed. This is necessary for shared libraries where we kickoff runtime
/ initialization in a separate thread and return without waiting for this
/ thread to complete the init.
/go:cgo_import_static x_cgo_notify_runtime_init_done
/go:linkname x_cgo_notify_runtime_init_done x_cgo_notify_runtime_init_done
/go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done
var x_cgo_notify_runtime_init_done byte
var _cgo_notify_runtime_init_done = &x_cgo_notify_runtime_init_done
/ Sets the traceback context function. See runtime.SetCgoTraceback.
/go:cgo_import_static x_cgo_set_context_function
/go:linkname x_cgo_set_context_function x_cgo_set_context_function
/go:linkname _cgo_set_context_function _cgo_set_context_function
var x_cgo_set_context_function byte
var _cgo_set_context_function = &x_cgo_set_context_function
/ Calls a libc function to execute background work injected via libc
/ interceptors, such as processing pending signals under the thread
/ sanitizer.
/
/ Left as a nil pointer if no libc interceptors are expected.
/go:cgo_import_static _cgo_yield
/go:linkname _cgo_yield _cgo_yield
var _cgo_yield unsafe.Pointer
/go:cgo_export_static _cgo_topofstack
/go:cgo_export_dynamic _cgo_topofstack