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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 
     31 egl_tls_t::egl_tls_t()
     32     : error(EGL_SUCCESS), ctx(nullptr), logCallWithNoContext(true) {
     33 }
     34 
     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 
     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 
     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 
     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 
    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 
    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 
    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 
    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 
    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 
    157 void egl_tls_t::setContext(EGLContext ctx) {
    158     validateTLSKey();
    159     getTLS()->ctx = ctx;
    160 }
    161 
    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