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>

(cherry picked from commit 3e76e0a49760c4970b7cda6153e51026af98e4f3)

Author: Nick Kralevich <nnk@google.com>
Change-Id: Ice88b1412d8f9daa7f9119b2b5aaf684a5e28098

1 files changed, 60 insertions, 0 deletions

diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
new file mode 100644
index 000000000..7c69f1bdc
--- /dev/null
+++ b/logd/LogBuffer.h
@@ -0,0 +1,60 @@
+/*
+ * 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_H__
+#define _LOGD_LOG_BUFFER_H__
+
+#include <sys/types.h>
+
+#include <log/log.h>
+#include <sysutils/SocketClient.h>
+#include <utils/List.h>
+
+#include "LogBufferElement.h"
+#include "LogTimes.h"
+
+typedef android::List<LogBufferElement *> LogBufferElementCollection;
+
+class LogBuffer {
+    LogBufferElementCollection mLogElements;
+    pthread_mutex_t mLogElementsLock;
+
+    unsigned long mSizes[LOG_ID_MAX];
+    unsigned long mElements[LOG_ID_MAX];
+
+public:
+    LastLogTimes &mTimes;
+
+    LogBuffer(LastLogTimes *times);
+
+    void log(log_id_t log_id, struct timespec realtime,
+             uid_t uid, pid_t pid, const char *msg, unsigned short len);
+    struct timespec flushTo(SocketClient *writer, const struct timespec start,
+                            bool privileged,
+                            bool (*filter)(const LogBufferElement *element, void *arg) = NULL,
+                            void *arg = NULL);
+
+    void clear(log_id_t id);
+    unsigned long getSize(log_id_t id);
+    unsigned long getSizeUsed(log_id_t id);
+
+private:
+    void maybePrune(log_id_t id);
+    void prune(log_id_t id, unsigned long pruneRows);
+
+};
+
+#endif