opensourcemirror
/
mpv
mirror of https://github.com/mpv-player/mpv.git
1
0
Fork 0
Code Issues Releases Wiki Activity

misc: add jni helpers

This commit is contained in:
Aman Gupta 2018-03-09 19:25:51 -08:00
parent f93faf26d8
commit 1a006d6f06
3 changed files with 591 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

429
misc/jni.c Normal file
View File

@ -0,0 +1,429 @@
/*
* JNI utility functions
*
* Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libavcodec/jni.h>
#include <libavutil/mem.h>
#include <libavutil/bprint.h>
#include <pthread.h>
#include <stdlib.h>
#include "jni.h"
static JavaVM *java_vm;
static pthread_key_t current_env;
static pthread_once_t once = PTHREAD_ONCE_INIT;
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
static void jni_detach_env(void *data)
{
if (java_vm) {
(*java_vm)->DetachCurrentThread(java_vm);
}
}
static void jni_create_pthread_key(void)
{
pthread_key_create(&current_env, jni_detach_env);
}
JNIEnv *mp_jni_get_env(struct mp_log *log)
{
int ret = 0;
JNIEnv *env = NULL;
pthread_mutex_lock(&lock);
if (java_vm == NULL) {
java_vm = av_jni_get_java_vm(NULL);
}
if (!java_vm) {
mp_err(log, "No Java virtual machine has been registered\n");
goto done;
}
pthread_once(&once, jni_create_pthread_key);
if ((env = pthread_getspecific(current_env)) != NULL) {
goto done;
}
ret = (*java_vm)->GetEnv(java_vm, (void **)&env, JNI_VERSION_1_6);
switch(ret) {
case JNI_EDETACHED:
if ((*java_vm)->AttachCurrentThread(java_vm, &env, NULL) != 0) {
mp_err(log, "Failed to attach the JNI environment to the current thread\n");
env = NULL;
} else {
pthread_setspecific(current_env, env);
}
break;
case JNI_OK:
break;
case JNI_EVERSION:
mp_err(log, "The specified JNI version is not supported\n");
break;
default:
mp_err(log, "Failed to get the JNI environment attached to this thread\n");
break;
}
done:
pthread_mutex_unlock(&lock);
return env;
}
char *mp_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, struct mp_log *log)
{
char *ret = NULL;
const char *utf_chars = NULL;
jboolean copy = 0;
if (!string) {
return NULL;
}
utf_chars = (*env)->GetStringUTFChars(env, string, &copy);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "String.getStringUTFChars() threw an exception\n");
return NULL;
}
ret = av_strdup(utf_chars);
(*env)->ReleaseStringUTFChars(env, string, utf_chars);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "String.releaseStringUTFChars() threw an exception\n");
return NULL;
}
return ret;
}
jstring mp_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, struct mp_log *log)
{
jstring ret;
ret = (*env)->NewStringUTF(env, utf_chars);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "NewStringUTF() threw an exception\n");
return NULL;
}
return ret;
}
int mp_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, struct mp_log *log)
{
int ret = 0;
AVBPrint bp;
char *name = NULL;
char *message = NULL;
jclass class_class = NULL;
jmethodID get_name_id = NULL;
jclass exception_class = NULL;
jmethodID get_message_id = NULL;
jstring string = NULL;
av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
exception_class = (*env)->GetObjectClass(env, exception);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Could not find Throwable class\n");
ret = -1;
goto done;
}
class_class = (*env)->GetObjectClass(env, exception_class);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Could not find Throwable class's class\n");
ret = -1;
goto done;
}
get_name_id = (*env)->GetMethodID(env, class_class, "getName", "()Ljava/lang/String;");
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Could not find method Class.getName()\n");
ret = -1;
goto done;
}
string = (*env)->CallObjectMethod(env, exception_class, get_name_id);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Class.getName() threw an exception\n");
ret = -1;
goto done;
}
if (string) {
name = mp_jni_jstring_to_utf_chars(env, string, log);
(*env)->DeleteLocalRef(env, string);
string = NULL;
}
get_message_id = (*env)->GetMethodID(env, exception_class, "getMessage", "()Ljava/lang/String;");
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Could not find method java/lang/Throwable.getMessage()\n");
ret = -1;
goto done;
}
string = (*env)->CallObjectMethod(env, exception, get_message_id);
if ((*env)->ExceptionCheck(env)) {
(*env)->ExceptionClear(env);
mp_err(log, "Throwable.getMessage() threw an exception\n");
ret = -1;
goto done;
}
if (string) {
message = mp_jni_jstring_to_utf_chars(env, string, log);
(*env)->DeleteLocalRef(env, string);
string = NULL;
}
if (name && message) {
av_bprintf(&bp, "%s: %s", name, message);
} else if (name && !message) {
av_bprintf(&bp, "%s occurred", name);
} else if (!name && message) {
av_bprintf(&bp, "Exception: %s", message);
} else {
mp_warn(log, "Could not retrieve exception name and message\n");
av_bprintf(&bp, "Exception occurred");
}
ret = av_bprint_finalize(&bp, error);
done:
av_free(name);
av_free(message);
if (class_class) {
(*env)->DeleteLocalRef(env, class_class);
}
if (exception_class) {
(*env)->DeleteLocalRef(env, exception_class);
}
if (string) {
(*env)->DeleteLocalRef(env, string);
}
return ret;
}
int mp_jni_exception_check(JNIEnv *env, int logging, struct mp_log *log)
{
int ret;
jthrowable exception;
char *message = NULL;
if (!(*(env))->ExceptionCheck((env))) {
return 0;
}
if (!logging) {
(*(env))->ExceptionClear((env));
return -1;
}
exception = (*env)->ExceptionOccurred(env);
(*(env))->ExceptionClear((env));
if ((ret = mp_jni_exception_get_summary(env, exception, &message, log)) < 0) {
(*env)->DeleteLocalRef(env, exception);
return ret;
}
(*env)->DeleteLocalRef(env, exception);
mp_err(log, "%s\n", message);
av_free(message);
return -1;
}
int mp_jni_init_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log)
{
int i, ret = 0;
jclass last_clazz = NULL;
for (i = 0; jfields_mapping[i].name; i++) {
int mandatory = jfields_mapping[i].mandatory;
enum MPJniFieldType type = jfields_mapping[i].type;
if (type == MP_JNI_CLASS) {
jclass clazz;
last_clazz = NULL;
clazz = (*env)->FindClass(env, jfields_mapping[i].name);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
last_clazz = *(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset) =
global ? (*env)->NewGlobalRef(env, clazz) : clazz;
if (global) {
(*env)->DeleteLocalRef(env, clazz);
}
} else {
if (!last_clazz) {
ret = -1;
break;
}
switch(type) {
case MP_JNI_FIELD: {
jfieldID field_id = (*env)->GetFieldID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
*(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = field_id;
break;
}
case MP_JNI_STATIC_FIELD_AS_INT:
case MP_JNI_STATIC_FIELD: {
jfieldID field_id = (*env)->GetStaticFieldID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
if (type == MP_JNI_STATIC_FIELD_AS_INT) {
if (field_id) {
jint value = (*env)->GetStaticIntField(env, last_clazz, field_id);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
*(jint*)((uint8_t*)jfields + jfields_mapping[i].offset) = value;
}
} else {
*(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = field_id;
}
break;
}
case MP_JNI_METHOD: {
jmethodID method_id = (*env)->GetMethodID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
*(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = method_id;
break;
}
case MP_JNI_STATIC_METHOD: {
jmethodID method_id = (*env)->GetStaticMethodID(env, last_clazz, jfields_mapping[i].method, jfields_mapping[i].signature);
if ((ret = mp_jni_exception_check(env, mandatory, log)) < 0 && mandatory) {
goto done;
}
*(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = method_id;
break;
}
default:
mp_err(log, "Unknown JNI field type\n");
ret = -1;
goto done;
}
ret = 0;
}
}
done:
if (ret < 0) {
/* reset jfields in case of failure so it does not leak references */
mp_jni_reset_jfields(env, jfields, jfields_mapping, global, log);
}
return ret;
}
int mp_jni_reset_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log)
{
int i;
for (i = 0; jfields_mapping[i].name; i++) {
enum MPJniFieldType type = jfields_mapping[i].type;
switch(type) {
case MP_JNI_CLASS: {
jclass clazz = *(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset);
if (!clazz)
continue;
if (global) {
(*env)->DeleteGlobalRef(env, clazz);
} else {
(*env)->DeleteLocalRef(env, clazz);
}
*(jclass*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
break;
}
case MP_JNI_FIELD: {
*(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
break;
}
case MP_JNI_STATIC_FIELD: {
*(jfieldID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
break;
}
case MP_JNI_STATIC_FIELD_AS_INT: {
*(jint*)((uint8_t*)jfields + jfields_mapping[i].offset) = 0;
break;
}
case MP_JNI_METHOD: {
*(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
break;
}
case MP_JNI_STATIC_METHOD: {
*(jmethodID*)((uint8_t*)jfields + jfields_mapping[i].offset) = NULL;
break;
}
default:
mp_err(log, "Unknown JNI field type\n");
}
}
return 0;
}

161
misc/jni.h Normal file
View File

@ -0,0 +1,161 @@
/*
* JNI utility functions
*
* Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MP_JNI_H
#define MP_JNI_H
#include <jni.h>
#include "common/msg.h"
/* Convenience macros */
#define MP_JNI_GET_ENV(obj) mp_jni_get_env((obj)->log)
#define MP_JNI_EXCEPTION_CHECK() mp_jni_exception_check(env, 0, NULL)
#define MP_JNI_EXCEPTION_LOG(obj) mp_jni_exception_check(env, 1, (obj)->log)
#define MP_JNI_DO(what, obj, method, ...) (*env)->what(env, obj, method, ##__VA_ARGS__)
#define MP_JNI_NEW(clazz, method, ...) MP_JNI_DO(NewObject, clazz, method, ##__VA_ARGS__)
#define MP_JNI_CALL_INT(obj, method, ...) MP_JNI_DO(CallIntMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_BOOL(obj, method, ...) MP_JNI_DO(CallBooleanMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_VOID(obj, method, ...) MP_JNI_DO(CallVoidMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_CALL_STATIC_INT(clazz, method, ...) MP_JNI_DO(CallStaticIntMethod, clazz, method, ##__VA_ARGS__)
#define MP_JNI_CALL_OBJECT(obj, method, ...) MP_JNI_DO(CallObjectMethod, obj, method, ##__VA_ARGS__)
#define MP_JNI_GET_INT(obj, field) MP_JNI_DO(GetIntField, obj, field)
#define MP_JNI_GET_LONG(obj, field) MP_JNI_DO(GetLongField, obj, field)
#define MP_JNI_GET_BOOL(obj, field) MP_JNI_DO(GetBoolField, obj, field)
/*
* Attach permanently a JNI environment to the current thread and retrieve it.
*
* If successfully attached, the JNI environment will automatically be detached
* at thread destruction.
*
* @param attached pointer to an integer that will be set to 1 if the
* environment has been attached to the current thread or 0 if it is
* already attached.
* @param log context used for logging
* @return the JNI environment on success, NULL otherwise
*/
JNIEnv *mp_jni_get_env(struct mp_log *log);
/*
* Convert a jstring to its utf characters equivalent.
*
* @param env JNI environment
* @param string Java string to convert
* @param log context used for logging
* @return a pointer to an array of unicode characters on success, NULL
* otherwise
*/
char *mp_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, struct mp_log *log);
/*
* Convert utf chars to its jstring equivalent.
*
* @param env JNI environment
* @param utf_chars a pointer to an array of unicode characters
* @param log context used for logging
* @return a Java string object on success, NULL otherwise
*/
jstring mp_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, struct mp_log *log);
/*
* Extract the error summary from a jthrowable in the form of "className: errorMessage"
*
* @param env JNI environment
* @param exception exception to get the summary from
* @param error address pointing to the error, the value is updated if a
* summary can be extracted
* @param log context used for logging
* @return 0 on success, < 0 otherwise
*/
int mp_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, struct mp_log *log);
/*
* Check if an exception has occurred,log it using av_log and clear it.
*
* @param env JNI environment
* @param value used to enable logging if an exception has occurred,
* 0 disables logging, != 0 enables logging
* @param log context used for logging
*/
int mp_jni_exception_check(JNIEnv *env, int logging, struct mp_log *log);
/*
* Jni field type.
*/
enum MPJniFieldType {
MP_JNI_CLASS,
MP_JNI_FIELD,
MP_JNI_STATIC_FIELD,
MP_JNI_STATIC_FIELD_AS_INT,
MP_JNI_METHOD,
MP_JNI_STATIC_METHOD
};
/*
* Jni field describing a class, a field or a method to be retrieved using
* the mp_jni_init_jfields method.
*/
struct MPJniField {
const char *name;
const char *method;
const char *signature;
enum MPJniFieldType type;
int offset;
int mandatory;
};
/*
* Retrieve class references, field ids and method ids to an arbitrary structure.
*
* @param env JNI environment
* @param jfields a pointer to an arbitrary structure where the different
* fields are declared and where the MPJNIField mapping table offsets are
* pointing to
* @param jfields_mapping null terminated array of MPJNIFields describing
* the class/field/method to be retrieved
* @param global make the classes references global. It is the caller
* responsibility to properly release global references.
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int mp_jni_init_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log);
/*
* Delete class references, field ids and method ids of an arbitrary structure.
*
* @param env JNI environment
* @param jfields a pointer to an arbitrary structure where the different
* fields are declared and where the MPJNIField mapping table offsets are
* pointing to
* @param jfields_mapping null terminated array of MPJNIFields describing
* the class/field/method to be deleted
* @param global treat the classes references as global and delete them
* accordingly
* @param log_ctx context used for logging, can be NULL
* @return 0 on success, < 0 otherwise
*/
int mp_jni_reset_jfields(JNIEnv *env, void *jfields, const struct MPJniField *jfields_mapping, int global, struct mp_log *log);
#endif

1
wscript_build.py
View File

@ -326,6 +326,7 @@ def build(ctx):
( "misc/bstr.c" ),
( "misc/charset_conv.c" ),
( "misc/dispatch.c" ),
( "misc/jni.c", "android" ),
( "misc/json.c" ),
( "misc/natural_sort.c" ),
( "misc/node.c" ),