upload android base code part6

android/system/core/logd/FlushCommand.cpp

@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+#include <stdlib.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "FlushCommand.h"
+#include "LogBuffer.h"
+#include "LogBufferElement.h"
+#include "LogCommand.h"
+#include "LogReader.h"
+#include "LogTimes.h"
+#include "LogUtils.h"
+
+FlushCommand::FlushCommand(LogReader& reader, bool nonBlock, unsigned long tail,
+                           unsigned int logMask, pid_t pid, log_time start,
+                           uint64_t timeout)
+    : mReader(reader),
+      mNonBlock(nonBlock),
+      mTail(tail),
+      mLogMask(logMask),
+      mPid(pid),
+      mStart(start),
+      mTimeout((start != log_time::EPOCH) ? timeout : 0) {
+}
+
+// runSocketCommand is called once for every open client on the
+// log reader socket. Here we manage and associated the reader
+// client tracking and log region locks LastLogTimes list of
+// LogTimeEntrys, and spawn a transitory per-client thread to
+// work at filing data to the  socket.
+//
+// global LogTimeEntry::wrlock() is used to protect access,
+// reference counts are used to ensure that individual
+// LogTimeEntry lifetime is managed when not protected.
+void FlushCommand::runSocketCommand(SocketClient* client) {
+    LogTimeEntry* entry = NULL;
+    LastLogTimes& times = mReader.logbuf().mTimes;
+
+    LogTimeEntry::wrlock();
+    LastLogTimes::iterator it = times.begin();
+    while (it != times.end()) {
+        entry = (*it);
+        if (entry->mClient == client) {
+            if (entry->mTimeout.tv_sec || entry->mTimeout.tv_nsec) {
+                if (mReader.logbuf().isMonotonic()) {
+                    LogTimeEntry::unlock();
+                    return;
+                }
+                // If the user changes the time in a gross manner that
+                // invalidates the timeout, fall through and trigger.
+                log_time now(CLOCK_REALTIME);
+                if (((entry->mEnd + entry->mTimeout) > now) &&
+                    (now > entry->mEnd)) {
+                    LogTimeEntry::unlock();
+                    return;
+                }
+            }
+            entry->triggerReader_Locked();
+            if (entry->runningReader_Locked()) {
+                LogTimeEntry::unlock();
+                return;
+            }
+            entry->incRef_Locked();
+            break;
+        }
+        it++;
+    }
+
+    if (it == times.end()) {
+        // Create LogTimeEntry in notifyNewLog() ?
+        if (mTail == (unsigned long)-1) {
+            LogTimeEntry::unlock();
+            return;
+        }
+        entry = new LogTimeEntry(mReader, client, mNonBlock, mTail, mLogMask,
+                                 mPid, mStart, mTimeout);
+        times.push_front(entry);
+    }
+
+    client->incRef();
+
+    // release client and entry reference counts once done
+    entry->startReader_Locked();
+    LogTimeEntry::unlock();
+}
+
+bool FlushCommand::hasReadLogs(SocketClient* client) {
+    return clientHasLogCredentials(client);
+}
+
+static bool clientHasSecurityCredentials(SocketClient* client) {
+    return (client->getUid() == AID_SYSTEM) || (client->getGid() == AID_SYSTEM);
+}
+
+bool FlushCommand::hasSecurityLogs(SocketClient* client) {
+    return clientHasSecurityCredentials(client);
+}