SyncFeatures.cpp revision ca08833d5ea99130797e10ad68a651b50e99da74 
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 GL_GLEXT_PROTOTYPES
20#define EGL_EGLEXT_PROTOTYPES
21
22#include <EGL/egl.h>
23#include <EGL/eglext.h>
24
25#include <utils/Log.h>
26#include <utils/Singleton.h>
27#include <utils/String8.h>
28
29#include <private/gui/SyncFeatures.h>
30
31EGLAPI const char* eglQueryStringImplementationANDROID(EGLDisplay dpy, EGLint name);
32
33namespace android {
34
35ANDROID_SINGLETON_STATIC_INSTANCE(SyncFeatures);
36
37SyncFeatures::SyncFeatures() : Singleton<SyncFeatures>(),
38        mHasNativeFenceSync(false),
39        mHasFenceSync(false),
40        mHasWaitSync(false) {
41    EGLDisplay dpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
42    // This can only be called after EGL has been initialized; otherwise the
43    // check below will abort.
44    const char* exts = eglQueryStringImplementationANDROID(dpy, EGL_EXTENSIONS);
45    LOG_ALWAYS_FATAL_IF(exts == NULL, "eglQueryStringImplementationANDROID failed");
46    if (strstr(exts, "EGL_ANDROID_native_fence_sync")) {
47        // This makes GLConsumer use the EGL_ANDROID_native_fence_sync
48        // extension to create Android native fences to signal when all
49        // GLES reads for a given buffer have completed.
50        mHasNativeFenceSync = true;
51    }
52    if (strstr(exts, "EGL_KHR_fence_sync")) {
53        mHasFenceSync = true;
54    }
55    if (strstr(exts, "EGL_KHR_wait_sync")) {
56        mHasWaitSync = true;
57    }
58    mString.append("[using:");
59    if (useNativeFenceSync()) {
60        mString.append(" EGL_ANDROID_native_fence_sync");
61    }
62    if (useFenceSync()) {
63        mString.append(" EGL_KHR_fence_sync");
64    }
65    if (useWaitSync()) {
66        mString.append(" EGL_KHR_wait_sync");
67    }
68    mString.append("]");
69}
70
71bool SyncFeatures::useNativeFenceSync() const {
72    // EGL_ANDROID_native_fence_sync is not compatible with using the
73    // EGL_KHR_fence_sync extension for the same purpose.
74    return mHasNativeFenceSync;
75}
76bool SyncFeatures::useFenceSync() const {
77#ifdef DONT_USE_FENCE_SYNC
78    // on some devices it's better to not use EGL_KHR_fence_sync
79    // even if they have it
80    return false;
81#endif
82    // currently we shall only attempt to use EGL_KHR_fence_sync if
83    // USE_FENCE_SYNC is set in our makefile
84    return !mHasNativeFenceSync && mHasFenceSync;
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