github.com/FenixAra/go@v0.0.0-20170127160404-96ea0918e670/src/runtime/cgo/callbacks.go (about)

     1  // Copyright 2011 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 cgo
     6  
     7  import "unsafe"
     8  
     9  // These utility functions are available to be called from code
    10  // compiled with gcc via crosscall2.
    11  
    12  // cgocallback is defined in runtime
    13  //go:linkname _runtime_cgocallback runtime.cgocallback
    14  func _runtime_cgocallback(unsafe.Pointer, unsafe.Pointer, uintptr, uintptr)
    15  
    16  // The declaration of crosscall2 is:
    17  //   void crosscall2(void (*fn)(void *, int), void *, int);
    18  //
    19  // We need to export the symbol crosscall2 in order to support
    20  // callbacks from shared libraries. This applies regardless of
    21  // linking mode.
    22  //
    23  // Compatibility note: crosscall2 actually takes four arguments, but
    24  // it works to call it with three arguments when calling _cgo_panic.
    25  // That is supported for backward compatibility.
    26  //go:cgo_export_static crosscall2
    27  //go:cgo_export_dynamic crosscall2
    28  
    29  // Panic. The argument is converted into a Go string.
    30  
    31  // Call like this in code compiled with gcc:
    32  //   struct { const char *p; } a;
    33  //   a.p = /* string to pass to panic */;
    34  //   crosscall2(_cgo_panic, &a, sizeof a);
    35  //   /* The function call will not return.  */
    36  
    37  //go:linkname _runtime_cgo_panic_internal runtime._cgo_panic_internal
    38  var _runtime_cgo_panic_internal byte
    39  
    40  //go:linkname _cgo_panic _cgo_panic
    41  //go:cgo_export_static _cgo_panic
    42  //go:cgo_export_dynamic _cgo_panic
    43  //go:nosplit
    44  //go:norace
    45  func _cgo_panic(a unsafe.Pointer, n int32) {
    46  	_runtime_cgocallback(unsafe.Pointer(&_runtime_cgo_panic_internal), a, uintptr(n), 0)
    47  }
    48  
    49  //go:cgo_import_static x_cgo_init
    50  //go:linkname x_cgo_init x_cgo_init
    51  //go:linkname _cgo_init _cgo_init
    52  var x_cgo_init byte
    53  var _cgo_init = &x_cgo_init
    54  
    55  //go:cgo_import_static x_cgo_thread_start
    56  //go:linkname x_cgo_thread_start x_cgo_thread_start
    57  //go:linkname _cgo_thread_start _cgo_thread_start
    58  var x_cgo_thread_start byte
    59  var _cgo_thread_start = &x_cgo_thread_start
    60  
    61  // Creates a new system thread without updating any Go state.
    62  //
    63  // This method is invoked during shared library loading to create a new OS
    64  // thread to perform the runtime initialization. This method is similar to
    65  // _cgo_sys_thread_start except that it doesn't update any Go state.
    66  
    67  //go:cgo_import_static x_cgo_sys_thread_create
    68  //go:linkname x_cgo_sys_thread_create x_cgo_sys_thread_create
    69  //go:linkname _cgo_sys_thread_create _cgo_sys_thread_create
    70  var x_cgo_sys_thread_create byte
    71  var _cgo_sys_thread_create = &x_cgo_sys_thread_create
    72  
    73  // Notifies that the runtime has been initialized.
    74  //
    75  // We currently block at every CGO entry point (via _cgo_wait_runtime_init_done)
    76  // to ensure that the runtime has been initialized before the CGO call is
    77  // executed. This is necessary for shared libraries where we kickoff runtime
    78  // initialization in a separate thread and return without waiting for this
    79  // thread to complete the init.
    80  
    81  //go:cgo_import_static x_cgo_notify_runtime_init_done
    82  //go:linkname x_cgo_notify_runtime_init_done x_cgo_notify_runtime_init_done
    83  //go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done
    84  var x_cgo_notify_runtime_init_done byte
    85  var _cgo_notify_runtime_init_done = &x_cgo_notify_runtime_init_done
    86  
    87  // Sets the traceback context function. See runtime.SetCgoTraceback.
    88  
    89  //go:cgo_import_static x_cgo_set_context_function
    90  //go:linkname x_cgo_set_context_function x_cgo_set_context_function
    91  //go:linkname _cgo_set_context_function _cgo_set_context_function
    92  var x_cgo_set_context_function byte
    93  var _cgo_set_context_function = &x_cgo_set_context_function
    94  
    95  //go:cgo_export_static _cgo_topofstack
    96  //go:cgo_export_dynamic _cgo_topofstack