libprocinfo: introduce.

Add a new library for parsing /proc files. Start with helpers for
parsing /proc/<pid>/status and /proc/<pid>/task.

Bug: http://b/30705528
Test: libprocinfo_test32/64 on host/bullhead
Change-Id: I5757514c0aede8a9d75834b55aae42a5cf762b95
diff --git a/libprocinfo/process_test.cpp b/libprocinfo/process_test.cpp
new file mode 100644
index 0000000..5ffd236
--- /dev/null
+++ b/libprocinfo/process_test.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2016 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 <procinfo/process.h>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <set>
+#include <thread>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include <android-base/stringprintf.h>
+
+#if !defined(__BIONIC__)
+#include <syscall.h>
+static pid_t gettid() {
+  return syscall(__NR_gettid);
+}
+#endif
+
+TEST(process_info, process_info_smoke) {
+  android::procinfo::ProcessInfo self;
+  ASSERT_TRUE(android::procinfo::GetProcessInfo(gettid(), &self));
+  ASSERT_EQ(gettid(), self.tid);
+  ASSERT_EQ(getpid(), self.pid);
+  ASSERT_EQ(getppid(), self.ppid);
+  ASSERT_EQ(getuid(), self.uid);
+  ASSERT_EQ(getgid(), self.gid);
+}
+
+TEST(process_info, process_info_proc_pid_fd_smoke) {
+  android::procinfo::ProcessInfo self;
+  int fd = open(android::base::StringPrintf("/proc/%d", gettid()).c_str(), O_DIRECTORY | O_RDONLY);
+  ASSERT_NE(-1, fd);
+  ASSERT_TRUE(android::procinfo::GetProcessInfoFromProcPidFd(fd, &self));
+
+  // Process name is capped at 15 bytes.
+  ASSERT_EQ("libprocinfo_tes", self.name);
+  ASSERT_EQ(gettid(), self.tid);
+  ASSERT_EQ(getpid(), self.pid);
+  ASSERT_EQ(getppid(), self.ppid);
+  ASSERT_EQ(getuid(), self.uid);
+  ASSERT_EQ(getgid(), self.gid);
+  close(fd);
+}
+
+TEST(process_info, process_tids_smoke) {
+  pid_t main_tid = gettid();
+  std::thread([main_tid]() {
+    pid_t thread_tid = gettid();
+
+    {
+      std::vector<pid_t> vec;
+      ASSERT_TRUE(android::procinfo::GetProcessTids(getpid(), &vec));
+      ASSERT_EQ(1, std::count(vec.begin(), vec.end(), main_tid));
+      ASSERT_EQ(1, std::count(vec.begin(), vec.end(), thread_tid));
+    }
+
+    {
+      std::set<pid_t> set;
+      ASSERT_TRUE(android::procinfo::GetProcessTids(getpid(), &set));
+      ASSERT_EQ(1, std::count(set.begin(), set.end(), main_tid));
+      ASSERT_EQ(1, std::count(set.begin(), set.end(), thread_tid));
+    }
+  }).join();
+}