M7350/base/core/jni/android_util_EventLog.cpp
2024-09-09 08:52:07 +00:00

304 lines
10 KiB
C++

/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <fcntl.h>
#include "JNIHelp.h"
#include "android_runtime/AndroidRuntime.h"
#include "jni.h"
#include "cutils/logger.h"
// The size of the tag number comes out of the payload size.
#define MAX_EVENT_PAYLOAD (LOGGER_ENTRY_MAX_PAYLOAD - sizeof(int32_t))
namespace android {
static jclass gCollectionClass;
static jmethodID gCollectionAddID;
static jclass gEventClass;
static jmethodID gEventInitID;
static jclass gIntegerClass;
static jfieldID gIntegerValueID;
static jclass gListClass;
static jfieldID gListItemsID;
static jclass gLongClass;
static jfieldID gLongValueID;
static jclass gStringClass;
/*
* In class android.util.EventLog:
* static native int writeEvent(int tag, int value)
*/
static jint android_util_EventLog_writeEvent_Integer(JNIEnv* env, jobject clazz,
jint tag, jint value)
{
return android_btWriteLog(tag, EVENT_TYPE_INT, &value, sizeof(value));
}
/*
* In class android.util.EventLog:
* static native int writeEvent(long tag, long value)
*/
static jint android_util_EventLog_writeEvent_Long(JNIEnv* env, jobject clazz,
jint tag, jlong value)
{
return android_btWriteLog(tag, EVENT_TYPE_LONG, &value, sizeof(value));
}
/*
* In class android.util.EventLog:
* static native int writeEvent(int tag, String value)
*/
static jint android_util_EventLog_writeEvent_String(JNIEnv* env, jobject clazz,
jint tag, jstring value) {
uint8_t buf[MAX_EVENT_PAYLOAD];
// Don't throw NPE -- I feel like it's sort of mean for a logging function
// to be all crashy if you pass in NULL -- but make the NULL value explicit.
const char *str = value != NULL ? env->GetStringUTFChars(value, NULL) : "NULL";
jint len = strlen(str);
const int max = sizeof(buf) - sizeof(len) - 2; // Type byte, final newline
if (len > max) len = max;
buf[0] = EVENT_TYPE_STRING;
memcpy(&buf[1], &len, sizeof(len));
memcpy(&buf[1 + sizeof(len)], str, len);
buf[1 + sizeof(len) + len] = '\n';
if (value != NULL) env->ReleaseStringUTFChars(value, str);
return android_bWriteLog(tag, buf, 2 + sizeof(len) + len);
}
/*
* In class android.util.EventLog:
* static native int writeEvent(long tag, Object... value)
*/
static jint android_util_EventLog_writeEvent_Array(JNIEnv* env, jobject clazz,
jint tag, jobjectArray value) {
if (value == NULL) {
return android_util_EventLog_writeEvent_String(env, clazz, tag, NULL);
}
uint8_t buf[MAX_EVENT_PAYLOAD];
const size_t max = sizeof(buf) - 1; // leave room for final newline
size_t pos = 2; // Save room for type tag & array count
jsize copied = 0, num = env->GetArrayLength(value);
for (; copied < num && copied < 255; ++copied) {
jobject item = env->GetObjectArrayElement(value, copied);
if (item == NULL || env->IsInstanceOf(item, gStringClass)) {
if (pos + 1 + sizeof(jint) > max) break;
const char *str = item != NULL ? env->GetStringUTFChars((jstring) item, NULL) : "NULL";
jint len = strlen(str);
if (pos + 1 + sizeof(len) + len > max) len = max - pos - 1 - sizeof(len);
buf[pos++] = EVENT_TYPE_STRING;
memcpy(&buf[pos], &len, sizeof(len));
memcpy(&buf[pos + sizeof(len)], str, len);
pos += sizeof(len) + len;
if (item != NULL) env->ReleaseStringUTFChars((jstring) item, str);
} else if (env->IsInstanceOf(item, gIntegerClass)) {
jint intVal = env->GetIntField(item, gIntegerValueID);
if (pos + 1 + sizeof(intVal) > max) break;
buf[pos++] = EVENT_TYPE_INT;
memcpy(&buf[pos], &intVal, sizeof(intVal));
pos += sizeof(intVal);
} else if (env->IsInstanceOf(item, gLongClass)) {
jlong longVal = env->GetLongField(item, gLongValueID);
if (pos + 1 + sizeof(longVal) > max) break;
buf[pos++] = EVENT_TYPE_LONG;
memcpy(&buf[pos], &longVal, sizeof(longVal));
pos += sizeof(longVal);
} else {
jniThrowException(env,
"java/lang/IllegalArgumentException",
"Invalid payload item type");
return -1;
}
env->DeleteLocalRef(item);
}
buf[0] = EVENT_TYPE_LIST;
buf[1] = copied;
buf[pos++] = '\n';
return android_bWriteLog(tag, buf, pos);
}
/*
* In class android.util.EventLog:
* static native void readEvents(int[] tags, Collection<Event> output)
*
* Reads events from the event log, typically /dev/log/events
*/
static void android_util_EventLog_readEvents(JNIEnv* env, jobject clazz,
jintArray tags,
jobject out) {
if (tags == NULL || out == NULL) {
jniThrowException(env, "java/lang/NullPointerException", NULL);
return;
}
int fd = open("/dev/" LOGGER_LOG_EVENTS, O_RDONLY | O_NONBLOCK);
if (fd < 0) {
jniThrowIOException(env, errno);
return;
}
jsize tagLength = env->GetArrayLength(tags);
jint *tagValues = env->GetIntArrayElements(tags, NULL);
uint8_t buf[LOGGER_ENTRY_MAX_LEN];
struct timeval timeout = {0, 0};
fd_set readset;
FD_ZERO(&readset);
for (;;) {
// Use a short select() to try to avoid problems hanging on read().
// This means we block for 5ms at the end of the log -- oh well.
timeout.tv_usec = 5000;
FD_SET(fd, &readset);
int r = select(fd + 1, &readset, NULL, NULL, &timeout);
if (r == 0) {
break; // no more events
} else if (r < 0 && errno == EINTR) {
continue; // interrupted by signal, try again
} else if (r < 0) {
jniThrowIOException(env, errno); // Will throw on return
break;
}
int len = read(fd, buf, sizeof(buf));
if (len == 0 || (len < 0 && errno == EAGAIN)) {
break; // no more events
} else if (len < 0 && errno == EINTR) {
continue; // interrupted by signal, try again
} else if (len < 0) {
jniThrowIOException(env, errno); // Will throw on return
break;
} else if ((size_t) len < sizeof(logger_entry) + sizeof(int32_t)) {
jniThrowException(env, "java/io/IOException", "Event too short");
break;
}
logger_entry* entry = (logger_entry*) buf;
int32_t tag = * (int32_t*) (buf + sizeof(*entry));
int found = 0;
for (int i = 0; !found && i < tagLength; ++i) {
found = (tag == tagValues[i]);
}
if (found) {
jsize len = sizeof(*entry) + entry->len;
jbyteArray array = env->NewByteArray(len);
if (array == NULL) break;
jbyte *bytes = env->GetByteArrayElements(array, NULL);
memcpy(bytes, buf, len);
env->ReleaseByteArrayElements(array, bytes, 0);
jobject event = env->NewObject(gEventClass, gEventInitID, array);
if (event == NULL) break;
env->CallBooleanMethod(out, gCollectionAddID, event);
env->DeleteLocalRef(event);
env->DeleteLocalRef(array);
}
}
close(fd);
env->ReleaseIntArrayElements(tags, tagValues, 0);
}
/*
* JNI registration.
*/
static JNINativeMethod gRegisterMethods[] = {
/* name, signature, funcPtr */
{ "writeEvent", "(II)I", (void*) android_util_EventLog_writeEvent_Integer },
{ "writeEvent", "(IJ)I", (void*) android_util_EventLog_writeEvent_Long },
{ "writeEvent",
"(ILjava/lang/String;)I",
(void*) android_util_EventLog_writeEvent_String
},
{ "writeEvent",
"(I[Ljava/lang/Object;)I",
(void*) android_util_EventLog_writeEvent_Array
},
{ "readEvents",
"([ILjava/util/Collection;)V",
(void*) android_util_EventLog_readEvents
},
};
static struct { const char *name; jclass *clazz; } gClasses[] = {
{ "android/util/EventLog$Event", &gEventClass },
{ "java/lang/Integer", &gIntegerClass },
{ "java/lang/Long", &gLongClass },
{ "java/lang/String", &gStringClass },
{ "java/util/Collection", &gCollectionClass },
};
static struct { jclass *c; const char *name, *ft; jfieldID *id; } gFields[] = {
{ &gIntegerClass, "value", "I", &gIntegerValueID },
{ &gLongClass, "value", "J", &gLongValueID },
};
static struct { jclass *c; const char *name, *mt; jmethodID *id; } gMethods[] = {
{ &gEventClass, "<init>", "([B)V", &gEventInitID },
{ &gCollectionClass, "add", "(Ljava/lang/Object;)Z", &gCollectionAddID },
};
int register_android_util_EventLog(JNIEnv* env) {
for (int i = 0; i < NELEM(gClasses); ++i) {
jclass clazz = env->FindClass(gClasses[i].name);
if (clazz == NULL) {
LOGE("Can't find class: %s\n", gClasses[i].name);
return -1;
}
*gClasses[i].clazz = (jclass) env->NewGlobalRef(clazz);
}
for (int i = 0; i < NELEM(gFields); ++i) {
*gFields[i].id = env->GetFieldID(
*gFields[i].c, gFields[i].name, gFields[i].ft);
if (*gFields[i].id == NULL) {
LOGE("Can't find field: %s\n", gFields[i].name);
return -1;
}
}
for (int i = 0; i < NELEM(gMethods); ++i) {
*gMethods[i].id = env->GetMethodID(
*gMethods[i].c, gMethods[i].name, gMethods[i].mt);
if (*gMethods[i].id == NULL) {
LOGE("Can't find method: %s\n", gMethods[i].name);
return -1;
}
}
return AndroidRuntime::registerNativeMethods(
env,
"android/util/EventLog",
gRegisterMethods, NELEM(gRegisterMethods));
}
}; // namespace android