github.com/miolini/go@v0.0.0-20160405192216-fca68c8cb408/src/runtime/cgo/gcc_libinit_windows.c (about)

     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  // +build cgo
     6  #define WIN64_LEAN_AND_MEAN
     7  #include <windows.h>
     8  #include <process.h>
     9  
    10  #include <stdio.h>
    11  #include <stdlib.h>
    12  
    13  static volatile long runtime_init_once_gate = 0;
    14  static volatile long runtime_init_once_done = 0;
    15  
    16  static CRITICAL_SECTION runtime_init_cs;
    17  
    18  static HANDLE runtime_init_wait;
    19  static int runtime_init_done;
    20  
    21  // Pre-initialize the runtime synchronization objects
    22  void
    23  _cgo_preinit_init() {
    24  	 runtime_init_wait = CreateEvent(NULL, TRUE, FALSE, NULL);
    25  	 if (runtime_init_wait == NULL) {
    26  		fprintf(stderr, "runtime: failed to create runtime initialization wait event.\n");
    27  		abort();
    28  	 }
    29  
    30  	 InitializeCriticalSection(&runtime_init_cs);
    31  }
    32  
    33  // Make sure that the preinit sequence has run.
    34  void
    35  _cgo_maybe_run_preinit() {
    36  	 if (!InterlockedExchangeAdd(&runtime_init_once_done, 0)) {
    37  			if (InterlockedIncrement(&runtime_init_once_gate) == 1) {
    38  				 _cgo_preinit_init();
    39  				 InterlockedIncrement(&runtime_init_once_done);
    40  			} else {
    41  				 // Decrement to avoid overflow.
    42  				 InterlockedDecrement(&runtime_init_once_gate);
    43  				 while(!InterlockedExchangeAdd(&runtime_init_once_done, 0)) {
    44  						Sleep(0);
    45  				 }
    46  			}
    47  	 }
    48  }
    49  
    50  void
    51  x_cgo_sys_thread_create(void (*func)(void*), void* arg) {
    52  	uintptr_t thandle;
    53  
    54  	thandle = _beginthread(func, 0, arg);
    55  	if(thandle == -1) {
    56  		fprintf(stderr, "runtime: failed to create new OS thread (%d)\n", errno);
    57  		abort();
    58  	}
    59  }
    60  
    61  int
    62  _cgo_is_runtime_initialized() {
    63  	 EnterCriticalSection(&runtime_init_cs);
    64  	 int status = runtime_init_done;
    65  	 LeaveCriticalSection(&runtime_init_cs);
    66  	 return status;
    67  }
    68  
    69  void
    70  _cgo_wait_runtime_init_done() {
    71  	 _cgo_maybe_run_preinit();
    72  	while (!_cgo_is_runtime_initialized()) {
    73  			WaitForSingleObject(runtime_init_wait, INFINITE);
    74  	}
    75  }
    76  
    77  void
    78  x_cgo_notify_runtime_init_done(void* dummy) {
    79  	 _cgo_maybe_run_preinit();
    80  
    81  	 EnterCriticalSection(&runtime_init_cs);
    82  	runtime_init_done = 1;
    83  	 LeaveCriticalSection(&runtime_init_cs);
    84  
    85  	 if (!SetEvent(runtime_init_wait)) {
    86  		fprintf(stderr, "runtime: failed to signal runtime initialization complete.\n");
    87  		abort();
    88  	}
    89  }
    90