github.com/jwijenbergh/purego@v0.0.0-20240126093400-70ff3a61df13/internal/fakecgo/go_darwin_arm64.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 fakecgo
     6  
     7  import "unsafe"
     8  
     9  //go:nosplit
    10  //go:norace
    11  func _cgo_sys_thread_start(ts *ThreadStart) {
    12  	var attr pthread_attr_t
    13  	var ign, oset sigset_t
    14  	var p pthread_t
    15  	var size size_t
    16  	var err int
    17  
    18  	sigfillset(&ign)
    19  	pthread_sigmask(SIG_SETMASK, &ign, &oset)
    20  
    21  	size = pthread_get_stacksize_np(pthread_self())
    22  	pthread_attr_init(&attr)
    23  	pthread_attr_setstacksize(&attr, size)
    24  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    25  	ts.g.stackhi = uintptr(size)
    26  
    27  	err = _cgo_try_pthread_create(&p, &attr, unsafe.Pointer(threadentry_trampolineABI0), ts)
    28  
    29  	pthread_sigmask(SIG_SETMASK, &oset, nil)
    30  
    31  	if err != 0 {
    32  		print("fakecgo: pthread_create failed: ")
    33  		println(err)
    34  		abort()
    35  	}
    36  }
    37  
    38  // threadentry_trampolineABI0 maps the C ABI to Go ABI then calls the Go function
    39  //
    40  //go:linkname x_threadentry_trampoline threadentry_trampoline
    41  var x_threadentry_trampoline byte
    42  var threadentry_trampolineABI0 = &x_threadentry_trampoline
    43  
    44  //go:nosplit
    45  //go:norace
    46  func threadentry(v unsafe.Pointer) unsafe.Pointer {
    47  	ts := *(*ThreadStart)(v)
    48  	free(v)
    49  
    50  	// TODO: support ios
    51  	//#if TARGET_OS_IPHONE
    52  	//	darwin_arm_init_thread_exception_port();
    53  	//#endif
    54  	setg_trampoline(setg_func, uintptr(unsafe.Pointer(ts.g)))
    55  
    56  	// faking funcs in go is a bit a... involved - but the following works :)
    57  	fn := uintptr(unsafe.Pointer(&ts.fn))
    58  	(*(*func())(unsafe.Pointer(&fn)))()
    59  
    60  	return nil
    61  }
    62  
    63  // here we will store a pointer to the provided setg func
    64  var setg_func uintptr
    65  
    66  // x_cgo_init(G *g, void (*setg)(void*)) (runtime/cgo/gcc_linux_amd64.c)
    67  // This get's called during startup, adjusts stacklo, and provides a pointer to setg_gcc for us
    68  // Additionally, if we set _cgo_init to non-null, go won't do it's own TLS setup
    69  // This function can't be go:systemstack since go is not in a state where the systemcheck would work.
    70  //
    71  //go:nosplit
    72  //go:norace
    73  func x_cgo_init(g *G, setg uintptr) {
    74  	var size size_t
    75  
    76  	setg_func = setg
    77  	size = pthread_get_stacksize_np(pthread_self())
    78  	g.stacklo = uintptr(unsafe.Add(unsafe.Pointer(&size), -size+4096))
    79  
    80  	//TODO: support ios
    81  	//#if TARGET_OS_IPHONE
    82  	//	darwin_arm_init_mach_exception_handler();
    83  	//	darwin_arm_init_thread_exception_port();
    84  	//	init_working_dir();
    85  	//#endif
    86  }