os_openbsd_libc.go

Documentation: runtime

		 1  // Copyright 2020 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 openbsd
		 6  // +build openbsd
		 7  
		 8  package runtime
		 9  
		10  import (
		11  	"unsafe"
		12  )
		13  
		14  var failThreadCreate = []byte("runtime: failed to create new OS thread\n")
		15  
		16  // mstart_stub provides glue code to call mstart from pthread_create.
		17  func mstart_stub()
		18  
		19  // May run with m.p==nil, so write barriers are not allowed.
		20  //go:nowritebarrierrec
		21  func newosproc(mp *m) {
		22  	if false {
		23  		print("newosproc m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
		24  	}
		25  
		26  	// Initialize an attribute object.
		27  	var attr pthreadattr
		28  	if err := pthread_attr_init(&attr); err != 0 {
		29  		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
		30  		exit(1)
		31  	}
		32  
		33  	// Find out OS stack size for our own stack guard.
		34  	var stacksize uintptr
		35  	if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
		36  		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
		37  		exit(1)
		38  	}
		39  	mp.g0.stack.hi = stacksize // for mstart
		40  
		41  	// Tell the pthread library we won't join with this thread.
		42  	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
		43  		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
		44  		exit(1)
		45  	}
		46  
		47  	// Finally, create the thread. It starts at mstart_stub, which does some low-level
		48  	// setup and then calls mstart.
		49  	var oset sigset
		50  	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
		51  	err := pthread_create(&attr, funcPC(mstart_stub), unsafe.Pointer(mp))
		52  	sigprocmask(_SIG_SETMASK, &oset, nil)
		53  	if err != 0 {
		54  		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
		55  		exit(1)
		56  	}
		57  
		58  	pthread_attr_destroy(&attr)
		59  }
		60
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