1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkTLS.h"
9#include "SkThread.h"
10
11static bool gOnce = false;
12static DWORD gTlsIndex;
13SK_DECLARE_STATIC_MUTEX(gMutex);
14
15void* SkTLS::PlatformGetSpecific(bool forceCreateTheSlot) {
16    if (!forceCreateTheSlot && !gOnce) {
17        return NULL;
18    }
19
20    if (!gOnce) {
21        SkAutoMutexAcquire tmp(gMutex);
22        if (!gOnce) {
23            gTlsIndex = TlsAlloc();
24            gOnce = true;
25        }
26    }
27    return TlsGetValue(gTlsIndex);
28}
29
30void SkTLS::PlatformSetSpecific(void* ptr) {
31    SkASSERT(gOnce);
32    (void)TlsSetValue(gTlsIndex, ptr);
33}
34
35// Call TLS destructors on thread exit. Code based on Chromium's
36// base/threading/thread_local_storage_win.cc
37#ifdef _WIN64
38
39#pragma comment(linker, "/INCLUDE:_tls_used")
40#pragma comment(linker, "/INCLUDE:skia_tls_callback")
41
42#else
43
44#pragma comment(linker, "/INCLUDE:__tls_used")
45#pragma comment(linker, "/INCLUDE:_skia_tls_callback")
46
47#endif
48
49void NTAPI onTLSCallback(PVOID unused, DWORD reason, PVOID unused2) {
50    if ((DLL_THREAD_DETACH == reason || DLL_PROCESS_DETACH == reason) && gOnce) {
51        void* ptr = TlsGetValue(gTlsIndex);
52        if (ptr != NULL) {
53            SkTLS::Destructor(ptr);
54            TlsSetValue(gTlsIndex, NULL);
55        }
56    }
57}
58
59extern "C" {
60
61#ifdef _WIN64
62
63#pragma const_seg(".CRT$XLB")
64extern const PIMAGE_TLS_CALLBACK skia_tls_callback;
65const PIMAGE_TLS_CALLBACK skia_tls_callback = onTLSCallback;
66#pragma const_seg()
67
68#else
69
70#pragma data_seg(".CRT$XLB")
71PIMAGE_TLS_CALLBACK skia_tls_callback = onTLSCallback;
72#pragma data_seg()
73
74#endif
75}
76