dropm.go

     1  // Copyright 2016 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 !plan9 && !windows
     6  // +build !plan9,!windows
     7  
     8  // Test that a sequence of callbacks from C to Go get the same m.
     9  // This failed to be true on arm and arm64, which was the root cause
    10  // of issue 13881.
    11  
    12  package main
    13  
    14  /*
    15  #include <stddef.h>
    16  #include <pthread.h>
    17  
    18  extern void GoCheckM();
    19  
    20  static void* thread(void* arg __attribute__ ((unused))) {
    21  	GoCheckM();
    22  	return NULL;
    23  }
    24  
    25  static void CheckM() {
    26  	pthread_t tid;
    27  	pthread_create(&tid, NULL, thread, NULL);
    28  	pthread_join(tid, NULL);
    29  	pthread_create(&tid, NULL, thread, NULL);
    30  	pthread_join(tid, NULL);
    31  }
    32  */
    33  import "C"
    34  
    35  import (
    36  	"fmt"
    37  	"os"
    38  )
    39  
    40  func init() {
    41  	register("EnsureDropM", EnsureDropM)
    42  }
    43  
    44  var savedM uintptr
    45  
    46  //export GoCheckM
    47  func GoCheckM() {
    48  	m := runtime_getm_for_test()
    49  	if savedM == 0 {
    50  		savedM = m
    51  	} else if savedM != m {
    52  		fmt.Printf("m == %x want %x\n", m, savedM)
    53  		os.Exit(1)
    54  	}
    55  }
    56  
    57  func EnsureDropM() {
    58  	C.CheckM()
    59  	fmt.Println("OK")
    60  }
    61
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