1 files changed, 113 insertions, 0 deletions
diff --git a/CpuInfo.cpp b/CpuInfo.cpp
new file mode 100644
index 0000000..88eeecb
--- /dev/null
+++ b/CpuInfo.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2021 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 <unistd.h>
+
+#include <iostream>
+#include <iomanip>
+#include <fstream>
+#include <regex>
+
+#include <hidl/HidlTransportSupport.h>
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+
+#include "CpuInfo.h"
+
+namespace android {
+namespace hardware {
+namespace thermal {
+namespace V2_0 {
+namespace implementation {
+
+#define CPU_USAGE "/proc/stat"
+	
+bool CpuInfo::parseCpuUsagesFileAndAssignUsages(hidl_vec<CpuUsage> &cpuUsages)
+{
+	std::string line;
+	std::ifstream file;
+	std::regex regEx("^cpu[0-9](.+)");
+
+	file.open(CPU_USAGE);
+	if (!file) {
+		LOG(ERROR) << "Failed to open: " << CPU_USAGE;
+		return false;
+	}
+
+	while (std::getline(file, line)) {
+
+		uint64_t cpuNum, cpuUser, cpuNice, cpuSys, cpuIdle;
+		std::vector<std::string> fields;
+
+		if (!regex_match(line, regEx))
+			continue;
+
+		fields = android::base::Split(line, " ");
+
+		/*
+		 * The /proc/stat file is an ABI and not supposed to
+		 * change. We can trust its content and the
+		 * format. There is no need to check if the CPU is
+		 * online as it will be removed from the file if it is
+		 * offline. Consequently, if we can read the usage for
+		 * a particular CPU, that means it is in the list,
+		 * thus online.
+		 */
+                cpuNum	= std::stoi(fields[0].substr(3));
+                cpuUser	= std::stoi(fields[1]);
+                cpuNice	= std::stoi(fields[2]);
+                cpuSys	= std::stoi(fields[3]);
+                cpuIdle	= std::stoi(fields[4]);
+
+		cpuUsages[cpuNum].name = fields[0];
+                cpuUsages[cpuNum].active = cpuUser + cpuNice + cpuSys;
+                cpuUsages[cpuNum].total = cpuUser + cpuNice + cpuSys + cpuIdle;
+                cpuUsages[cpuNum].isOnline = true;
+	}
+
+	file.close();
+	
+	return true;
+}
+
+bool CpuInfo::CpuUsages(hidl_vec<CpuUsage> &cpuUsages)
+{
+	if (!m_NrCpus)
+		return false;
+
+	/*
+	 * Set the vector size to the number of possible CPUs
+	 */
+	cpuUsages.resize(m_NrCpus);
+
+	/*
+	 * Parse the stat file 
+	 */
+	parseCpuUsagesFileAndAssignUsages(cpuUsages);
+
+	return true;
+}
+
+CpuInfo::CpuInfo()
+{
+	m_NrCpus = sysconf(_SC_NPROCESSORS_CONF);
+}
+	
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace thermal
+}  // namespace hardware
+}  // namespace android