xyosc/vendor/github.com/ebitengine/purego/internal/fakecgo/go_util.go
2024-12-21 17:38:26 +01:00

38 lines
1.3 KiB
Go

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
//go:build !cgo && (darwin || freebsd || linux)
package fakecgo
import "unsafe"
// _cgo_thread_start is split into three parts in cgo since only one part is system dependent (keep it here for easier handling)
// _cgo_thread_start(ThreadStart *arg) (runtime/cgo/gcc_util.c)
// This get's called instead of the go code for creating new threads
// -> pthread_* stuff is used, so threads are setup correctly for C
// If this is missing, TLS is only setup correctly on thread 1!
// This function should be go:systemstack instead of go:nosplit (but that requires runtime)
//
//go:nosplit
//go:norace
func x_cgo_thread_start(arg *ThreadStart) {
var ts *ThreadStart
// Make our own copy that can persist after we return.
// _cgo_tsan_acquire();
ts = (*ThreadStart)(malloc(unsafe.Sizeof(*ts)))
// _cgo_tsan_release();
if ts == nil {
println("fakecgo: out of memory in thread_start")
abort()
}
// *ts = *arg would cause a writebarrier so copy using slices
s1 := unsafe.Slice((*uintptr)(unsafe.Pointer(ts)), unsafe.Sizeof(*ts)/8)
s2 := unsafe.Slice((*uintptr)(unsafe.Pointer(arg)), unsafe.Sizeof(*arg)/8)
for i := range s2 {
s1[i] = s2[i]
}
_cgo_sys_thread_start(ts) // OS-dependent half
}