Loader.cpp revision ada798b7ca7cabc255aa159964b64975e7fdb2df 
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#include <ctype.h>
18#include <stdlib.h>
19#include <stdio.h>
20#include <string.h>
21#include <errno.h>
22#include <dlfcn.h>
23#include <limits.h>
24
25#include <cutils/log.h>
26#include <cutils/properties.h>
27
28#include <EGL/egl.h>
29
30#include "egldefs.h"
31#include "glestrace.h"
32#include "hooks.h"
33#include "Loader.h"
34
35// ----------------------------------------------------------------------------
36namespace android {
37// ----------------------------------------------------------------------------
38
39
40/*
41 * EGL drivers are called
42 *
43 * /system/lib/egl/lib{[EGL|GLESv1_CM|GLESv2] | GLES}_$TAG.so
44 *
45 */
46
47ANDROID_SINGLETON_STATIC_INSTANCE( Loader )
48
49/* This function is called to check whether we run inside the emulator,
50 * and if this is the case whether GLES GPU emulation is supported.
51 *
52 * Returned values are:
53 *  -1   -> not running inside the emulator
54 *   0   -> running inside the emulator, but GPU emulation not supported
55 *   1   -> running inside the emulator, GPU emulation is supported
56 *          through the "emulation" config.
57 */
58static int
59checkGlesEmulationStatus(void)
60{
61    /* We're going to check for the following kernel parameters:
62     *
63     *    qemu=1                      -> tells us that we run inside the emulator
64     *    android.qemu.gles=<number>  -> tells us the GLES GPU emulation status
65     *
66     * Note that we will return <number> if we find it. This let us support
67     * more additionnal emulation modes in the future.
68     */
69    char  prop[PROPERTY_VALUE_MAX];
70    int   result = -1;
71
72    /* First, check for qemu=1 */
73    property_get("ro.kernel.qemu",prop,"0");
74    if (atoi(prop) != 1)
75        return -1;
76
77    /* We are in the emulator, get GPU status value */
78    property_get("ro.kernel.qemu.gles",prop,"0");
79    return atoi(prop);
80}
81
82// ----------------------------------------------------------------------------
83
84Loader::driver_t::driver_t(void* gles)
85{
86    dso[0] = gles;
87    for (size_t i=1 ; i<NELEM(dso) ; i++)
88        dso[i] = 0;
89}
90
91Loader::driver_t::~driver_t()
92{
93    for (size_t i=0 ; i<NELEM(dso) ; i++) {
94        if (dso[i]) {
95            dlclose(dso[i]);
96            dso[i] = 0;
97        }
98    }
99}
100
101status_t Loader::driver_t::set(void* hnd, int32_t api)
102{
103    switch (api) {
104        case EGL:
105            dso[0] = hnd;
106            break;
107        case GLESv1_CM:
108            dso[1] = hnd;
109            break;
110        case GLESv2:
111            dso[2] = hnd;
112            break;
113        default:
114            return BAD_INDEX;
115    }
116    return NO_ERROR;
117}
118
119// ----------------------------------------------------------------------------
120
121Loader::Loader()
122{
123    char line[256];
124    char tag[256];
125
126    /* Special case for GLES emulation */
127    if (checkGlesEmulationStatus() == 0) {
128        ALOGD("Emulator without GPU support detected. "
129              "Fallback to software renderer.");
130        mDriverTag.setTo("android");
131        return;
132    }
133
134    /* Otherwise, use egl.cfg */
135    FILE* cfg = fopen("/system/lib/egl/egl.cfg", "r");
136    if (cfg == NULL) {
137        // default config
138        ALOGD("egl.cfg not found, using default config");
139        mDriverTag.setTo("android");
140    } else {
141        while (fgets(line, 256, cfg)) {
142            int dpy, impl;
143            if (sscanf(line, "%u %u %s", &dpy, &impl, tag) == 3) {
144                //ALOGD(">>> %u %u %s", dpy, impl, tag);
145                // We only load the h/w accelerated implementation
146                if (tag != String8("android")) {
147                    mDriverTag = tag;
148                }
149            }
150        }
151        fclose(cfg);
152    }
153}
154
155Loader::~Loader()
156{
157    GLTrace_stop();
158}
159
160void* Loader::open(egl_connection_t* cnx)
161{
162    void* dso;
163    driver_t* hnd = 0;
164
165    char const* tag = mDriverTag.string();
166    if (tag) {
167        dso = load_driver("GLES", tag, cnx, EGL | GLESv1_CM | GLESv2);
168        if (dso) {
169            hnd = new driver_t(dso);
170        } else {
171            // Always load EGL first
172            dso = load_driver("EGL", tag, cnx, EGL);
173            if (dso) {
174                hnd = new driver_t(dso);
175                // TODO: make this more automated
176                hnd->set( load_driver("GLESv1_CM", tag, cnx, GLESv1_CM), GLESv1_CM );
177                hnd->set( load_driver("GLESv2",    tag, cnx, GLESv2),    GLESv2 );
178            }
179        }
180    }
181
182    LOG_FATAL_IF(!index && !hnd,
183            "couldn't find the default OpenGL ES implementation "
184            "for default display");
185
186    return (void*)hnd;
187}
188
189status_t Loader::close(void* driver)
190{
191    driver_t* hnd = (driver_t*)driver;
192    delete hnd;
193    return NO_ERROR;
194}
195
196void Loader::init_api(void* dso,
197        char const * const * api,
198        __eglMustCastToProperFunctionPointerType* curr,
199        getProcAddressType getProcAddress)
200{
201    const size_t SIZE = 256;
202    char scrap[SIZE];
203    while (*api) {
204        char const * name = *api;
205        __eglMustCastToProperFunctionPointerType f =
206            (__eglMustCastToProperFunctionPointerType)dlsym(dso, name);
207        if (f == NULL) {
208            // couldn't find the entry-point, use eglGetProcAddress()
209            f = getProcAddress(name);
210        }
211        if (f == NULL) {
212            // Try without the OES postfix
213            ssize_t index = ssize_t(strlen(name)) - 3;
214            if ((index>0 && (index<SIZE-1)) && (!strcmp(name+index, "OES"))) {
215                strncpy(scrap, name, index);
216                scrap[index] = 0;
217                f = (__eglMustCastToProperFunctionPointerType)dlsym(dso, scrap);
218                //ALOGD_IF(f, "found <%s> instead", scrap);
219            }
220        }
221        if (f == NULL) {
222            // Try with the OES postfix
223            ssize_t index = ssize_t(strlen(name)) - 3;
224            if (index>0 && strcmp(name+index, "OES")) {
225                snprintf(scrap, SIZE, "%sOES", name);
226                f = (__eglMustCastToProperFunctionPointerType)dlsym(dso, scrap);
227                //ALOGD_IF(f, "found <%s> instead", scrap);
228            }
229        }
230        if (f == NULL) {
231            //ALOGD("%s", name);
232            f = (__eglMustCastToProperFunctionPointerType)gl_unimplemented;
233
234            /*
235             * GL_EXT_debug_label is special, we always report it as
236             * supported, it's handled by GLES_trace. If GLES_trace is not
237             * enabled, then these are no-ops.
238             */
239            if (!strcmp(name, "glInsertEventMarkerEXT")) {
240                f = (__eglMustCastToProperFunctionPointerType)gl_noop;
241            } else if (!strcmp(name, "glPushGroupMarkerEXT")) {
242                f = (__eglMustCastToProperFunctionPointerType)gl_noop;
243            } else if (!strcmp(name, "glPopGroupMarkerEXT")) {
244                f = (__eglMustCastToProperFunctionPointerType)gl_noop;
245            }
246        }
247        *curr++ = f;
248        api++;
249    }
250}
251
252void *Loader::load_driver(const char* kind, const char *tag,
253        egl_connection_t* cnx, uint32_t mask)
254{
255    char driver_absolute_path[PATH_MAX];
256    const char* const search1 = "/vendor/lib/egl/lib%s_%s.so";
257    const char* const search2 = "/system/lib/egl/lib%s_%s.so";
258
259    snprintf(driver_absolute_path, PATH_MAX, search1, kind, tag);
260    if (access(driver_absolute_path, R_OK)) {
261        snprintf(driver_absolute_path, PATH_MAX, search2, kind, tag);
262        if (access(driver_absolute_path, R_OK)) {
263            // this happens often, we don't want to log an error
264            return 0;
265        }
266    }
267
268    void* dso = dlopen(driver_absolute_path, RTLD_NOW | RTLD_LOCAL);
269    if (dso == 0) {
270        const char* err = dlerror();
271        ALOGE("load_driver(%s): %s", driver_absolute_path, err?err:"unknown");
272        return 0;
273    }
274
275    ALOGD("loaded %s", driver_absolute_path);
276
277    if (mask & EGL) {
278        getProcAddress = (getProcAddressType)dlsym(dso, "eglGetProcAddress");
279
280        ALOGE_IF(!getProcAddress,
281                "can't find eglGetProcAddress() in %s", driver_absolute_path);
282
283        egl_t* egl = &cnx->egl;
284        __eglMustCastToProperFunctionPointerType* curr =
285            (__eglMustCastToProperFunctionPointerType*)egl;
286        char const * const * api = egl_names;
287        while (*api) {
288            char const * name = *api;
289            __eglMustCastToProperFunctionPointerType f =
290                (__eglMustCastToProperFunctionPointerType)dlsym(dso, name);
291            if (f == NULL) {
292                // couldn't find the entry-point, use eglGetProcAddress()
293                f = getProcAddress(name);
294                if (f == NULL) {
295                    f = (__eglMustCastToProperFunctionPointerType)0;
296                }
297            }
298            *curr++ = f;
299            api++;
300        }
301    }
302
303    if (mask & GLESv1_CM) {
304        init_api(dso, gl_names,
305            (__eglMustCastToProperFunctionPointerType*)
306                &cnx->hooks[GLESv1_INDEX]->gl,
307            getProcAddress);
308    }
309
310    if (mask & GLESv2) {
311      init_api(dso, gl_names,
312            (__eglMustCastToProperFunctionPointerType*)
313                &cnx->hooks[GLESv2_INDEX]->gl,
314            getProcAddress);
315    }
316
317    return dso;
318}
319
320// ----------------------------------------------------------------------------
321}; // namespace android
322// ----------------------------------------------------------------------------
323