go_libinit.go RawHistoryFolder

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
3
4//go:build !cgo && (darwin || freebsd || linux)
5
6package fakecgo
7
8import (
9	"syscall"
10	"unsafe"
11)
12
13var (
14	pthread_g pthread_key_t
15
16	runtime_init_cond = PTHREAD_COND_INITIALIZER
17	runtime_init_mu   = PTHREAD_MUTEX_INITIALIZER
18	runtime_init_done int
19)
20
21//go:nosplit
22func x_cgo_notify_runtime_init_done() {
23	pthread_mutex_lock(&runtime_init_mu)
24	runtime_init_done = 1
25	pthread_cond_broadcast(&runtime_init_cond)
26	pthread_mutex_unlock(&runtime_init_mu)
27}
28
29// Store the g into a thread-specific value associated with the pthread key pthread_g.
30// And pthread_key_destructor will dropm when the thread is exiting.
31func x_cgo_bindm(g unsafe.Pointer) {
32	// We assume this will always succeed, otherwise, there might be extra M leaking,
33	// when a C thread exits after a cgo call.
34	// We only invoke this function once per thread in runtime.needAndBindM,
35	// and the next calls just reuse the bound m.
36	pthread_setspecific(pthread_g, g)
37}
38
39// _cgo_try_pthread_create retries pthread_create if it fails with
40// EAGAIN.
41//
42//go:nosplit
43//go:norace
44func _cgo_try_pthread_create(thread *pthread_t, attr *pthread_attr_t, pfn unsafe.Pointer, arg *ThreadStart) int {
45	var ts syscall.Timespec
46	// tries needs to be the same type as syscall.Timespec.Nsec
47	// but the fields are int32 on 32bit and int64 on 64bit.
48	// tries is assigned to syscall.Timespec.Nsec in order to match its type.
49	tries := ts.Nsec
50	var err int
51
52	for tries = 0; tries < 20; tries++ {
53		err = int(pthread_create(thread, attr, pfn, unsafe.Pointer(arg)))
54		if err == 0 {
55			pthread_detach(*thread)
56			return 0
57		}
58		if err != int(syscall.EAGAIN) {
59			return err
60		}
61		ts.Sec = 0
62		ts.Nsec = (tries + 1) * 1000 * 1000 // Milliseconds.
63		nanosleep(&ts, nil)
64	}
65	return int(syscall.EAGAIN)
66}