1/*
2 ** Copyright 2013, The Android Open Source Project
3 **
4 ** Licensed under the Apache License, Version 2.0 (the "License");
5 ** you may not use this file except in compliance with the License.
6 ** You may obtain a copy of the License at
7 **
8 **     http://www.apache.org/licenses/LICENSE-2.0
9 **
10 ** Unless required by applicable law or agreed to in writing, software
11 ** distributed under the License is distributed on an "AS IS" BASIS,
12 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 ** See the License for the specific language governing permissions and
14 ** limitations under the License.
15 */
16
17#define LOG_TAG "GLConsumer"
18
19#define EGL_EGLEXT_PROTOTYPES
20
21#include <EGL/egl.h>
22#include <EGL/eglext.h>
23
24#include <utils/Log.h>
25#include <utils/Singleton.h>
26#include <utils/String8.h>
27
28#include <private/gui/SyncFeatures.h>
29
30EGLAPI const char* eglQueryStringImplementationANDROID(EGLDisplay dpy, EGLint name);
31
32namespace android {
33
34ANDROID_SINGLETON_STATIC_INSTANCE(SyncFeatures);
35
36SyncFeatures::SyncFeatures() : Singleton<SyncFeatures>(),
37        mHasNativeFenceSync(false),
38        mHasFenceSync(false),
39        mHasWaitSync(false) {
40    EGLDisplay dpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
41    // This can only be called after EGL has been initialized; otherwise the
42    // check below will abort.
43    const char* exts = eglQueryStringImplementationANDROID(dpy, EGL_EXTENSIONS);
44    LOG_ALWAYS_FATAL_IF(exts == NULL, "eglQueryStringImplementationANDROID failed");
45    if (strstr(exts, "EGL_ANDROID_native_fence_sync")) {
46        // This makes GLConsumer use the EGL_ANDROID_native_fence_sync
47        // extension to create Android native fences to signal when all
48        // GLES reads for a given buffer have completed.
49        mHasNativeFenceSync = true;
50    }
51    if (strstr(exts, "EGL_KHR_fence_sync")) {
52        mHasFenceSync = true;
53    }
54    if (strstr(exts, "EGL_KHR_wait_sync")) {
55        mHasWaitSync = true;
56    }
57    mString.append("[using:");
58    if (useNativeFenceSync()) {
59        mString.append(" EGL_ANDROID_native_fence_sync");
60    }
61    if (useFenceSync()) {
62        mString.append(" EGL_KHR_fence_sync");
63    }
64    if (useWaitSync()) {
65        mString.append(" EGL_KHR_wait_sync");
66    }
67    mString.append("]");
68}
69
70bool SyncFeatures::useNativeFenceSync() const {
71    // EGL_ANDROID_native_fence_sync is not compatible with using the
72    // EGL_KHR_fence_sync extension for the same purpose.
73    return mHasNativeFenceSync;
74}
75bool SyncFeatures::useFenceSync() const {
76#ifdef DONT_USE_FENCE_SYNC
77    // on some devices it's better to not use EGL_KHR_fence_sync
78    // even if they have it
79    return false;
80#else
81    // currently we shall only attempt to use EGL_KHR_fence_sync if
82    // USE_FENCE_SYNC is set in our makefile
83    return !mHasNativeFenceSync && mHasFenceSync;
84#endif
85}
86bool SyncFeatures::useWaitSync() const {
87    return (useNativeFenceSync() || useFenceSync()) && mHasWaitSync;
88}
89
90String8 SyncFeatures::toString() const {
91    return mString;
92}
93
94} // namespace android
95