callbacks.go raw

   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  //go:build !cgo && (darwin || freebsd || linux || netbsd)
   6  
   7  package fakecgo
   8  
   9  import (
  10  	_ "unsafe"
  11  )
  12  
  13  // TODO: decide if we need _runtime_cgo_panic_internal
  14  
  15  //go:linkname x_cgo_init_trampoline x_cgo_init_trampoline
  16  //go:linkname _cgo_init _cgo_init
  17  var x_cgo_init_trampoline byte
  18  var _cgo_init = &x_cgo_init_trampoline
  19  
  20  // Creates a new system thread without updating any Go state.
  21  //
  22  // This method is invoked during shared library loading to create a new OS
  23  // thread to perform the runtime initialization. This method is similar to
  24  // _cgo_sys_thread_start except that it doesn't update any Go state.
  25  
  26  //go:linkname x_cgo_thread_start_trampoline x_cgo_thread_start_trampoline
  27  //go:linkname _cgo_thread_start _cgo_thread_start
  28  var x_cgo_thread_start_trampoline byte
  29  var _cgo_thread_start = &x_cgo_thread_start_trampoline
  30  
  31  // Notifies that the runtime has been initialized.
  32  //
  33  // We currently block at every CGO entry point (via _cgo_wait_runtime_init_done)
  34  // to ensure that the runtime has been initialized before the CGO call is
  35  // executed. This is necessary for shared libraries where we kickoff runtime
  36  // initialization in a separate thread and return without waiting for this
  37  // thread to complete the init.
  38  
  39  //go:linkname x_cgo_notify_runtime_init_done_trampoline x_cgo_notify_runtime_init_done_trampoline
  40  //go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done
  41  var x_cgo_notify_runtime_init_done_trampoline byte
  42  var _cgo_notify_runtime_init_done = &x_cgo_notify_runtime_init_done_trampoline
  43  
  44  // Indicates whether a dummy thread key has been created or not.
  45  //
  46  // When calling go exported function from C, we register a destructor
  47  // callback, for a dummy thread key, by using pthread_key_create.
  48  
  49  //go:linkname _cgo_pthread_key_created _cgo_pthread_key_created
  50  var x_cgo_pthread_key_created uintptr
  51  var _cgo_pthread_key_created = &x_cgo_pthread_key_created
  52  
  53  // Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
  54  // It's for the runtime package to call at init time.
  55  func set_crosscall2() {
  56  	// nothing needs to be done here for fakecgo
  57  	// because it's possible to just call cgocallback directly
  58  }
  59  
  60  //go:linkname _set_crosscall2 runtime.set_crosscall2
  61  var _set_crosscall2 = set_crosscall2
  62  
  63  // Store the g into the thread-specific value.
  64  // So that pthread_key_destructor will dropm when the thread is exiting.
  65  
  66  //go:linkname x_cgo_bindm_trampoline x_cgo_bindm_trampoline
  67  //go:linkname _cgo_bindm _cgo_bindm
  68  var x_cgo_bindm_trampoline byte
  69  var _cgo_bindm = &x_cgo_bindm_trampoline
  70  
  71  // TODO: decide if we need x_cgo_set_context_function
  72  // TODO: decide if we need _cgo_yield
  73  
  74  var (
  75  	// In Go 1.20 the race detector was rewritten to pure Go
  76  	// on darwin. This means that when CGO_ENABLED=0 is set
  77  	// fakecgo is built with race detector code. This is not
  78  	// good since this code is pretending to be C. The go:norace
  79  	// pragma is not enough, since it only applies to the native
  80  	// ABIInternal function. The ABIO wrapper (which is necessary,
  81  	// since all references to text symbols from assembly will use it)
  82  	// does not inherit the go:norace pragma, so it will still be
  83  	// instrumented by the race detector.
  84  	//
  85  	// To circumvent this issue, using closure calls in the
  86  	// assembly, which forces the compiler to use the ABIInternal
  87  	// native implementation (which has go:norace) instead.
  88  	threadentry_call        = threadentry
  89  	x_cgo_init_call         = x_cgo_init
  90  	x_cgo_setenv_call       = x_cgo_setenv
  91  	x_cgo_unsetenv_call     = x_cgo_unsetenv
  92  	x_cgo_thread_start_call = x_cgo_thread_start
  93  )
  94