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
6 7 package fakecgo
8 9 import "unsafe"
10 11 //go:nosplit
12 //go:norace
13 func _cgo_sys_thread_start(ts *ThreadStart) {
14 var attr pthread_attr_t
15 var ign, oset sigset_t
16 var p pthread_t
17 var size size_t
18 var err int
19 20 sigfillset(&ign)
21 pthread_sigmask(SIG_SETMASK, &ign, &oset)
22 23 size = pthread_get_stacksize_np(pthread_self())
24 pthread_attr_init(&attr)
25 pthread_attr_setstacksize(&attr, size)
26 // Leave stacklo=0 and set stackhi=size; mstart will do the rest.
27 ts.g.stackhi = uintptr(size)
28 29 err = _cgo_try_pthread_create(&p, &attr, unsafe.Pointer(threadentry_trampolineABI0), ts)
30 31 pthread_sigmask(SIG_SETMASK, &oset, nil)
32 33 if err != 0 {
34 print("fakecgo: pthread_create failed: ")
35 println(err)
36 abort()
37 }
38 }
39 40 // threadentry_trampolineABI0 maps the C ABI to Go ABI then calls the Go function
41 //
42 //go:linkname x_threadentry_trampoline threadentry_trampoline
43 var x_threadentry_trampoline byte
44 var threadentry_trampolineABI0 = &x_threadentry_trampoline
45 46 //go:nosplit
47 //go:norace
48 func threadentry(v unsafe.Pointer) unsafe.Pointer {
49 ts := *(*ThreadStart)(v)
50 free(v)
51 52 // TODO: support ios
53 //#if TARGET_OS_IPHONE
54 // darwin_arm_init_thread_exception_port();
55 //#endif
56 setg_trampoline(setg_func, uintptr(unsafe.Pointer(ts.g)))
57 58 // faking funcs in go is a bit a... involved - but the following works :)
59 fn := uintptr(unsafe.Pointer(&ts.fn))
60 (*(*func())(unsafe.Pointer(&fn)))()
61 62 return nil
63 }
64 65 // here we will store a pointer to the provided setg func
66 var setg_func uintptr
67 68 // x_cgo_init(G *g, void (*setg)(void*)) (runtime/cgo/gcc_linux_amd64.c)
69 // This get's called during startup, adjusts stacklo, and provides a pointer to setg_gcc for us
70 // Additionally, if we set _cgo_init to non-null, go won't do it's own TLS setup
71 // This function can't be go:systemstack since go is not in a state where the systemcheck would work.
72 //
73 //go:nosplit
74 //go:norace
75 func x_cgo_init(g *G, setg uintptr) {
76 var size size_t
77 78 setg_func = setg
79 size = pthread_get_stacksize_np(pthread_self())
80 g.stacklo = uintptr(unsafe.Add(unsafe.Pointer(&size), -size+4096))
81 82 //TODO: support ios
83 //#if TARGET_OS_IPHONE
84 // darwin_arm_init_mach_exception_handler();
85 // darwin_arm_init_thread_exception_port();
86 // init_working_dir();
87 //#endif
88 }
89