1 files changed, 119 insertions, 0 deletions
diff --git a/libs/binderdebug/BinderDebug.cpp b/libs/binderdebug/BinderDebug.cpp
new file mode 100644
index 0000000000..b435dba197
--- /dev/null
+++ b/libs/binderdebug/BinderDebug.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2020 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 <android-base/parseint.h>
+#include <android-base/strings.h>
+#include <binder/Binder.h>
+#include <sys/types.h>
+#include <fstream>
+#include <regex>
+
+#include <binderdebug/BinderDebug.h>
+
+namespace android {
+
+static std::string contextToString(BinderDebugContext context) {
+    switch (context) {
+        case BinderDebugContext::BINDER:
+            return "binder";
+        case BinderDebugContext::HWBINDER:
+            return "hwbinder";
+        case BinderDebugContext::VNDBINDER:
+            return "vndbinder";
+        default:
+            return std::string();
+    }
+}
+
+static status_t scanBinderContext(pid_t pid, const std::string& contextName,
+                                  std::function<void(const std::string&)> eachLine) {
+    std::ifstream ifs("/dev/binderfs/binder_logs/proc/" + std::to_string(pid));
+    if (!ifs.is_open()) {
+        ifs.open("/d/binder/proc/" + std::to_string(pid));
+        if (!ifs.is_open()) {
+            return -errno;
+        }
+    }
+    static const std::regex kContextLine("^context (\\w+)$");
+
+    bool isDesiredContext = false;
+    std::string line;
+    std::smatch match;
+    while (getline(ifs, line)) {
+        if (std::regex_search(line, match, kContextLine)) {
+            isDesiredContext = match.str(1) == contextName;
+            continue;
+        }
+        if (!isDesiredContext) {
+            continue;
+        }
+        eachLine(line);
+    }
+    return OK;
+}
+
+status_t getBinderPidInfo(BinderDebugContext context, pid_t pid, BinderPidInfo* pidInfo) {
+    std::smatch match;
+    static const std::regex kReferencePrefix("^\\s*node \\d+:\\s+u([0-9a-f]+)\\s+c([0-9a-f]+)\\s+");
+    static const std::regex kThreadPrefix("^\\s*thread \\d+:\\s+l\\s+(\\d)(\\d)");
+    std::string contextStr = contextToString(context);
+    status_t ret = scanBinderContext(pid, contextStr, [&](const std::string& line) {
+        if (std::regex_search(line, match, kReferencePrefix)) {
+            const std::string& ptrString = "0x" + match.str(2); // use number after c
+            uint64_t ptr;
+            if (!::android::base::ParseUint(ptrString.c_str(), &ptr)) {
+                // Should not reach here, but just be tolerant.
+                return;
+            }
+            const std::string proc = " proc ";
+            auto pos = line.rfind(proc);
+            if (pos != std::string::npos) {
+                for (const std::string& pidStr : base::Split(line.substr(pos + proc.size()), " ")) {
+                    int32_t pid;
+                    if (!::android::base::ParseInt(pidStr, &pid)) {
+                        return;
+                    }
+                    pidInfo->refPids[ptr].push_back(pid);
+                }
+            }
+
+            return;
+        }
+        if (std::regex_search(line, match, kThreadPrefix)) {
+            // "1" is waiting in binder driver
+            // "2" is poll. It's impossible to tell if these are in use.
+            //     and HIDL default code doesn't use it.
+            bool isInUse = match.str(1) != "1";
+            // "0" is a thread that has called into binder
+            // "1" is looper thread
+            // "2" is main looper thread
+            bool isBinderThread = match.str(2) != "0";
+            if (!isBinderThread) {
+                return;
+            }
+            if (isInUse) {
+                pidInfo->threadUsage++;
+            }
+
+            pidInfo->threadCount++;
+            return;
+        }
+        return;
+    });
+    return ret;
+}
+
+} // namespace  android