threadprof.go

     1  // Copyright 2015 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  package main
     9  
    10  /*
    11  #include <stdint.h>
    12  #include <stdlib.h>
    13  #include <signal.h>
    14  #include <pthread.h>
    15  
    16  volatile int32_t spinlock;
    17  
    18  // Note that this thread is only started if GO_START_SIGPROF_THREAD
    19  // is set in the environment, which is only done when running the
    20  // CgoExternalThreadSIGPROF test.
    21  static void *thread1(void *p) {
    22  	(void)p;
    23  	while (spinlock == 0)
    24  		;
    25  	pthread_kill(pthread_self(), SIGPROF);
    26  	spinlock = 0;
    27  	return NULL;
    28  }
    29  
    30  // This constructor function is run when the program starts.
    31  // It is used for the CgoExternalThreadSIGPROF test.
    32  __attribute__((constructor)) void issue9456() {
    33  	if (getenv("GO_START_SIGPROF_THREAD") != NULL) {
    34  		pthread_t tid;
    35  		pthread_create(&tid, 0, thread1, NULL);
    36  	}
    37  }
    38  
    39  void **nullptr;
    40  
    41  void *crash(void *p) {
    42  	*nullptr = p;
    43  	return 0;
    44  }
    45  
    46  int start_crashing_thread(void) {
    47  	pthread_t tid;
    48  	return pthread_create(&tid, 0, crash, 0);
    49  }
    50  */
    51  import "C"
    52  
    53  import (
    54  	"fmt"
    55  	"os"
    56  	"os/exec"
    57  	"runtime"
    58  	"sync/atomic"
    59  	"time"
    60  	"unsafe"
    61  )
    62  
    63  func init() {
    64  	register("CgoExternalThreadSIGPROF", CgoExternalThreadSIGPROF)
    65  	register("CgoExternalThreadSignal", CgoExternalThreadSignal)
    66  }
    67  
    68  func CgoExternalThreadSIGPROF() {
    69  	// This test intends to test that sending SIGPROF to foreign threads
    70  	// before we make any cgo call will not abort the whole process, so
    71  	// we cannot make any cgo call here. See https://golang.org/issue/9456.
    72  	atomic.StoreInt32((*int32)(unsafe.Pointer(&C.spinlock)), 1)
    73  	for atomic.LoadInt32((*int32)(unsafe.Pointer(&C.spinlock))) == 1 {
    74  		runtime.Gosched()
    75  	}
    76  	println("OK")
    77  }
    78  
    79  func CgoExternalThreadSignal() {
    80  	if len(os.Args) > 2 && os.Args[2] == "crash" {
    81  		i := C.start_crashing_thread()
    82  		if i != 0 {
    83  			fmt.Println("pthread_create failed:", i)
    84  			// Exit with 0 because parent expects us to crash.
    85  			return
    86  		}
    87  
    88  		// We should crash immediately, but give it plenty of
    89  		// time before failing (by exiting 0) in case we are
    90  		// running on a slow system.
    91  		time.Sleep(5 * time.Second)
    92  		return
    93  	}
    94  
    95  	cmd := exec.Command(os.Args[0], "CgoExternalThreadSignal", "crash")
    96  	cmd.Dir = os.TempDir() // put any core file in tempdir
    97  	out, err := cmd.CombinedOutput()
    98  	if err == nil {
    99  		fmt.Println("C signal did not crash as expected")
   100  		fmt.Printf("\n%s\n", out)
   101  		os.Exit(1)
   102  	}
   103  
   104  	fmt.Println("OK")
   105  }
   106
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