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1 /*
2  ** Copyright 2011, 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 #include "egl_tls.h"
18 
19 #include <stdlib.h>
20 
21 #include <cutils/properties.h>
22 #include <log/log.h>
23 #include "CallStack.h"
24 #include "egl_platform_entries.h"
25 
26 namespace android {
27 
28 pthread_key_t egl_tls_t::sKey = TLS_KEY_NOT_INITIALIZED;
29 pthread_once_t egl_tls_t::sOnceKey = PTHREAD_ONCE_INIT;
30 
egl_tls_t()31 egl_tls_t::egl_tls_t()
32     : error(EGL_SUCCESS), ctx(nullptr), logCallWithNoContext(true) {
33 }
34 
egl_strerror(EGLint err)35 const char *egl_tls_t::egl_strerror(EGLint err) {
36     switch (err) {
37         case EGL_SUCCESS:               return "EGL_SUCCESS";
38         case EGL_NOT_INITIALIZED:       return "EGL_NOT_INITIALIZED";
39         case EGL_BAD_ACCESS:            return "EGL_BAD_ACCESS";
40         case EGL_BAD_ALLOC:             return "EGL_BAD_ALLOC";
41         case EGL_BAD_ATTRIBUTE:         return "EGL_BAD_ATTRIBUTE";
42         case EGL_BAD_CONFIG:            return "EGL_BAD_CONFIG";
43         case EGL_BAD_CONTEXT:           return "EGL_BAD_CONTEXT";
44         case EGL_BAD_CURRENT_SURFACE:   return "EGL_BAD_CURRENT_SURFACE";
45         case EGL_BAD_DISPLAY:           return "EGL_BAD_DISPLAY";
46         case EGL_BAD_MATCH:             return "EGL_BAD_MATCH";
47         case EGL_BAD_NATIVE_PIXMAP:     return "EGL_BAD_NATIVE_PIXMAP";
48         case EGL_BAD_NATIVE_WINDOW:     return "EGL_BAD_NATIVE_WINDOW";
49         case EGL_BAD_PARAMETER:         return "EGL_BAD_PARAMETER";
50         case EGL_BAD_SURFACE:           return "EGL_BAD_SURFACE";
51         case EGL_CONTEXT_LOST:          return "EGL_CONTEXT_LOST";
52         default: return "UNKNOWN";
53     }
54 }
55 
validateTLSKey()56 void egl_tls_t::validateTLSKey()
57 {
58     struct TlsKeyInitializer {
59         static void create() { pthread_key_create(&sKey, destructTLSData); }
60     };
61     pthread_once(&sOnceKey, TlsKeyInitializer::create);
62 }
63 
destructTLSData(void * data)64 void egl_tls_t::destructTLSData(void* data) {
65     egl_tls_t* tls = static_cast<egl_tls_t*>(data);
66     if (!tls) return;
67 
68     // Several things in the call tree of eglReleaseThread expect to be able to get the current
69     // thread state directly from TLS. That's a problem because Bionic has already cleared our
70     // TLS pointer before calling this function (pthread_getspecific(sKey) will return nullptr).
71     // Instead the data is passed as our parameter.
72     //
73     // Ideally we'd refactor this so we have thin wrappers that retrieve thread state from TLS and
74     // then pass it as a parameter (or 'this' pointer) to functions that do the real work without
75     // touching TLS. Then from here we could just call those implementation functions with the the
76     // TLS data we just received as a parameter.
77     //
78     // But that's a fairly invasive refactoring, so to do this robustly in the short term we just
79     // put the data *back* in TLS and call the top-level eglReleaseThread. It and it's call tree
80     // will retrieve the value from TLS, and then finally clear the TLS data. Bionic explicitly
81     // tolerates re-setting the value that it's currently trying to destruct (see
82     // pthread_key_clean_all()). Even if we forgot to clear the restored TLS data, bionic would
83     // call the destructor again, but eventually gives up and just leaks the data rather than
84     // enter an infinite loop.
85     pthread_setspecific(sKey, tls);
86     eglReleaseThread();
87     ALOGE_IF(pthread_getspecific(sKey) != nullptr,
88              "EGL TLS data still exists after eglReleaseThread");
89 }
90 
setErrorEtcImpl(const char * caller,int line,EGLint error,bool quiet)91 void egl_tls_t::setErrorEtcImpl(
92         const char* caller, int line, EGLint error, bool quiet) {
93     validateTLSKey();
94     egl_tls_t* tls = getTLS();
95     if (tls->error != error) {
96         if (!quiet) {
97             ALOGE("%s:%d error %x (%s)",
98                     caller, line, error, egl_strerror(error));
99             char value[PROPERTY_VALUE_MAX];
100             property_get("debug.egl.callstack", value, "0");
101             if (atoi(value)) {
102                 CallStack::log(LOG_TAG);
103             }
104         }
105         tls->error = error;
106     }
107 }
108 
logNoContextCall()109 bool egl_tls_t::logNoContextCall() {
110     egl_tls_t* tls = getTLS();
111     if (tls->logCallWithNoContext) {
112         tls->logCallWithNoContext = false;
113         return true;
114     }
115     return false;
116 
117 }
118 
getTLS()119 egl_tls_t* egl_tls_t::getTLS() {
120     egl_tls_t* tls = (egl_tls_t*)pthread_getspecific(sKey);
121     if (tls == nullptr) {
122         tls = new egl_tls_t;
123         pthread_setspecific(sKey, tls);
124     }
125     return tls;
126 }
127 
clearTLS()128 void egl_tls_t::clearTLS() {
129     if (sKey != TLS_KEY_NOT_INITIALIZED) {
130         egl_tls_t* tls = (egl_tls_t*)pthread_getspecific(sKey);
131         if (tls) {
132             pthread_setspecific(sKey, nullptr);
133             delete tls;
134         }
135     }
136 }
137 
clearError()138 void egl_tls_t::clearError() {
139     // This must clear the error from all the underlying EGL implementations as
140     // well as the EGL wrapper layer.
141     android::eglGetErrorImpl();
142 }
143 
getError()144 EGLint egl_tls_t::getError() {
145     if (sKey == TLS_KEY_NOT_INITIALIZED) {
146         return EGL_SUCCESS;
147     }
148     egl_tls_t* tls = (egl_tls_t*)pthread_getspecific(sKey);
149     if (!tls) {
150         return EGL_SUCCESS;
151     }
152     EGLint error = tls->error;
153     tls->error = EGL_SUCCESS;
154     return error;
155 }
156 
setContext(EGLContext ctx)157 void egl_tls_t::setContext(EGLContext ctx) {
158     validateTLSKey();
159     getTLS()->ctx = ctx;
160 }
161 
getContext()162 EGLContext egl_tls_t::getContext() {
163     if (sKey == TLS_KEY_NOT_INITIALIZED) {
164         return EGL_NO_CONTEXT;
165     }
166     egl_tls_t* tls = (egl_tls_t *)pthread_getspecific(sKey);
167     if (!tls) return EGL_NO_CONTEXT;
168     return tls->ctx;
169 }
170 
171 
172 } // namespace android
173