logd: initial checkin.

* Create a new userspace log daemon for handling logging messages.

Original-Change-Id: I75267df16359684490121e6c31cca48614d79856
Signed-off-by: Nick Kralevich <nnk@google.com>

* Merge conflicts
* rename new syslog daemon to logd to prevent confusion with bionic syslog
* replace racy getGroups call with KISS call to client->getGid()
* Timestamps are filed at logging source
* insert entries into list in timestamp order
* Added LogTimeEntry tail filtration handling
* Added region locking around LogWriter list
* separate threads for each writer
* /dev/socket/logd* permissions

Signed-off-by: Mark Salyzyn <salyzyn@google.com>

Change-Id: Ice88b1412d8f9daa7f9119b2b5aaf684a5e28098
diff --git a/logd/LogBufferElement.h b/logd/LogBufferElement.h
new file mode 100644
index 0000000..390c97c
--- /dev/null
+++ b/logd/LogBufferElement.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2012-2014 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.
+ */
+
+#ifndef _LOGD_LOG_BUFFER_ELEMENT_H__
+#define _LOGD_LOG_BUFFER_ELEMENT_H__
+
+#include <sys/types.h>
+#include <sysutils/SocketClient.h>
+#include <log/log.h>
+#include <log/log_read.h>
+
+class LogBufferElement {
+    const log_id_t mLogId;
+    const uid_t mUid;
+    const pid_t mPid;
+    char *mMsg;
+    const unsigned short mMsgLen;
+    const log_time mMonotonicTime;
+    const log_time mRealTime;
+
+public:
+    LogBufferElement(log_id_t log_id, struct timespec realtime,
+                     uid_t uid, pid_t pid, const char *msg, unsigned short len);
+    virtual ~LogBufferElement();
+
+    log_id_t getLogId() const { return mLogId; }
+    uid_t getUid(void) const { return mUid; }
+    pid_t getPid(void) const { return mPid; }
+    unsigned short getMsgLen() const { return mMsgLen; }
+    log_time getMonotonicTime(void) const { return mMonotonicTime; }
+    log_time getRealTime(void) const { return mRealTime; }
+
+    static const struct timespec FLUSH_ERROR;
+    struct timespec flushTo(SocketClient *writer);
+};
+
+#endif