1 /*
2  ** Copyright 2007, 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 #ifndef ANDROID_EGL_DISPLAY_H
18 #define ANDROID_EGL_DISPLAY_H
19 
20 
21 #include <ctype.h>
22 #include <stdint.h>
23 #include <stdlib.h>
24 
25 #include <EGL/egl.h>
26 #include <EGL/eglext.h>
27 
28 #include <cutils/compiler.h>
29 #include <utils/SortedVector.h>
30 #include <utils/threads.h>
31 #include <utils/String8.h>
32 
33 #include "egldefs.h"
34 #include "../hooks.h"
35 
36 // ----------------------------------------------------------------------------
37 namespace android {
38 // ----------------------------------------------------------------------------
39 
40 class egl_object_t;
41 class egl_context_t;
42 struct egl_connection_t;
43 
44 // ----------------------------------------------------------------------------
45 
46 class EGLAPI egl_display_t { // marked as EGLAPI for testing purposes
47     static egl_display_t sDisplay[NUM_DISPLAYS];
48     EGLDisplay getDisplay(EGLNativeDisplayType display);
49     void loseCurrentImpl(egl_context_t * cur_c);
50 
51 public:
52     enum {
53         NOT_INITIALIZED = 0,
54         INITIALIZED     = 1,
55         TERMINATED      = 2
56     };
57 
58     egl_display_t();
59     ~egl_display_t();
60 
61     EGLBoolean initialize(EGLint *major, EGLint *minor);
62     EGLBoolean terminate();
63 
64     // add object to this display's list
65     void addObject(egl_object_t* object);
66     // remove object from this display's list
67     void removeObject(egl_object_t* object);
68     // add reference to this object. returns true if this is a valid object.
69     bool getObject(egl_object_t* object) const;
70 
71     // These notifications allow the display to keep track of how many window
72     // surfaces exist, which it uses to decide whether to hibernate the
73     // underlying EGL implementation. They can be called by any thread without
74     // holding a lock, but must be called via egl_display_ptr to ensure
75     // proper hibernate/wakeup sequencing. If a surface destruction triggers
76     // hibernation, hibernation will be delayed at least until the calling
77     // thread's egl_display_ptr is destroyed.
onWindowSurfaceCreated()78     void onWindowSurfaceCreated() {
79         mHibernation.incWakeCount(HibernationMachine::STRONG);
80     }
onWindowSurfaceDestroyed()81     void onWindowSurfaceDestroyed() {
82         mHibernation.decWakeCount(HibernationMachine::STRONG);
83     }
84 
85     static egl_display_t* get(EGLDisplay dpy);
86     static EGLDisplay getFromNativeDisplay(EGLNativeDisplayType disp);
87 
88     EGLBoolean makeCurrent(egl_context_t* c, egl_context_t* cur_c,
89             EGLSurface draw, EGLSurface read, EGLContext ctx,
90             EGLSurface impl_draw, EGLSurface impl_read, EGLContext impl_ctx);
91     static void loseCurrent(egl_context_t * cur_c);
92 
isReady()93     inline bool isReady() const { return (refs > 0); }
isValid()94     inline bool isValid() const { return magic == '_dpy'; }
isAlive()95     inline bool isAlive() const { return isValid(); }
96 
getVendorString()97     char const * getVendorString() const { return mVendorString.string(); }
getVersionString()98     char const * getVersionString() const { return mVersionString.string(); }
getClientApiString()99     char const * getClientApiString() const { return mClientApiString.string(); }
getExtensionString()100     char const * getExtensionString() const { return mExtensionString.string(); }
101 
102     bool haveExtension(const char* name, size_t nameLen = 0) const;
103 
getRefsCount()104     inline uint32_t getRefsCount() const { return refs; }
105 
106     struct strings_t {
107         char const * vendor;
108         char const * version;
109         char const * clientApi;
110         char const * extensions;
111     };
112 
113     struct DisplayImpl {
DisplayImplDisplayImpl114         DisplayImpl() : dpy(EGL_NO_DISPLAY), state(NOT_INITIALIZED) { }
115         EGLDisplay  dpy;
116         EGLint      state;
117         strings_t   queryString;
118     };
119 
120 private:
121     uint32_t        magic;
122 
123 public:
124     DisplayImpl     disp;
125     bool    finishOnSwap;       // property: debug.egl.finish
126     bool    traceGpuCompletion; // property: debug.egl.traceGpuCompletion
127 
128 private:
129     friend class egl_display_ptr;
enter()130     bool enter() { return mHibernation.incWakeCount(HibernationMachine::WEAK); }
leave()131     void leave() { return mHibernation.decWakeCount(HibernationMachine::WEAK); }
132 
133             uint32_t                    refs;
134             bool                        eglIsInitialized;
135     mutable Mutex                       lock, refLock;
136     mutable Condition                   refCond;
137             SortedVector<egl_object_t*> objects;
138             String8 mVendorString;
139             String8 mVersionString;
140             String8 mClientApiString;
141             String8 mExtensionString;
142 
143     // HibernationMachine uses its own internal mutex to protect its own data.
144     // The owning egl_display_t's lock may be but is not required to be held
145     // when calling HibernationMachine methods. As a result, nothing in this
146     // class may call back up to egl_display_t directly or indirectly.
147     class HibernationMachine {
148     public:
149         // STRONG refs cancel (inc) or initiate (dec) a hibernation attempt
150         // the next time the wakecount reaches zero. WEAK refs don't affect
151         // whether a hibernation attempt will be made. Use STRONG refs only
152         // for infrequent/heavy changes that are likely to indicate the
153         // EGLDisplay is entering or leaving a long-term idle state.
154         enum WakeRefStrength {
155             WEAK   = 0,
156             STRONG = 1,
157         };
158 
HibernationMachine()159         HibernationMachine(): mWakeCount(0), mHibernating(false),
160                 mAttemptHibernation(false), mDpyValid(false),
161 #if BOARD_ALLOW_EGL_HIBERNATION
162                 mAllowHibernation(true)
163 #else
164                 mAllowHibernation(false)
165 #endif
166         {}
~HibernationMachine()167         ~HibernationMachine() {}
168 
169         bool incWakeCount(WakeRefStrength strenth);
170         void decWakeCount(WakeRefStrength strenth);
171 
172         void setDisplayValid(bool valid);
173 
174     private:
175         Mutex      mLock;
176         int32_t    mWakeCount;
177         bool       mHibernating;
178         bool       mAttemptHibernation;
179         bool       mDpyValid;
180         const bool mAllowHibernation;
181     };
182     HibernationMachine mHibernation;
183 };
184 
185 // ----------------------------------------------------------------------------
186 
187 // An egl_display_ptr is a kind of smart pointer for egl_display_t objects.
188 // It doesn't refcount the egl_display_t, but does ensure that the underlying
189 // EGL implementation is "awake" (not hibernating) and ready for use as long
190 // as the egl_display_ptr exists.
191 class egl_display_ptr {
192 public:
egl_display_ptr(egl_display_t * dpy)193     explicit egl_display_ptr(egl_display_t* dpy): mDpy(dpy) {
194         if (mDpy) {
195             if (CC_UNLIKELY(!mDpy->enter())) {
196                 mDpy = NULL;
197             }
198         }
199     }
200 
201     // We only really need a C++11 move constructor, not a copy constructor.
202     // A move constructor would save an enter()/leave() pair on every EGL API
203     // call. But enabling -std=c++0x causes lots of errors elsewhere, so I
204     // can't use a move constructor until those are cleaned up.
205     //
206     // egl_display_ptr(egl_display_ptr&& other) {
207     //     mDpy = other.mDpy;
208     //     other.mDpy = NULL;
209     // }
210     //
egl_display_ptr(const egl_display_ptr & other)211     egl_display_ptr(const egl_display_ptr& other): mDpy(other.mDpy) {
212         if (mDpy) {
213             mDpy->enter();
214         }
215     }
216 
~egl_display_ptr()217     ~egl_display_ptr() {
218         if (mDpy) {
219             mDpy->leave();
220         }
221     }
222 
223     const egl_display_t* operator->() const { return mDpy; }
224           egl_display_t* operator->()       { return mDpy; }
225 
get()226     const egl_display_t* get() const { return mDpy; }
get()227           egl_display_t* get()       { return mDpy; }
228 
229     operator bool() const { return mDpy != NULL; }
230 
231 private:
232     egl_display_t* mDpy;
233 
234     // non-assignable
235     egl_display_ptr& operator=(const egl_display_ptr&);
236 };
237 
238 // ----------------------------------------------------------------------------
239 
get_display(EGLDisplay dpy)240 inline egl_display_ptr get_display(EGLDisplay dpy) {
241     return egl_display_ptr(egl_display_t::get(dpy));
242 }
243 
244 // Does not ensure EGL is unhibernated. Use with caution: calls into the
245 // underlying EGL implementation are not safe.
get_display_nowake(EGLDisplay dpy)246 inline egl_display_t* get_display_nowake(EGLDisplay dpy) {
247     return egl_display_t::get(dpy);
248 }
249 
250 // ----------------------------------------------------------------------------
251 
252 egl_display_ptr validate_display(EGLDisplay dpy);
253 egl_display_ptr validate_display_connection(EGLDisplay dpy,
254         egl_connection_t*& cnx);
255 EGLBoolean validate_display_context(EGLDisplay dpy, EGLContext ctx);
256 EGLBoolean validate_display_surface(EGLDisplay dpy, EGLSurface surface);
257 
258 // ----------------------------------------------------------------------------
259 }; // namespace android
260 // ----------------------------------------------------------------------------
261 
262 #endif // ANDROID_EGL_DISPLAY_H
263