base: add Pipe and Socketpair wrappers.

Also, switch debuggerd_handler over to using android::base::unique_fd.

Test: treehugger
Change-Id: I97b2ce22f1795ce1c4370f95d00d769846cc54b8
diff --git a/include/android-base/unique_fd.h b/include/android-base/unique_fd.h
index 6cfcfcd..fb3dded 100644
--- a/include/android-base/unique_fd.h
+++ b/include/android-base/unique_fd.h
@@ -17,6 +17,13 @@
 #ifndef ANDROID_BASE_UNIQUE_FD_H
 #define ANDROID_BASE_UNIQUE_FD_H
 
+#include <fcntl.h>
+
+#if !defined(_WIN32)
+#include <sys/socket.h>
+#endif
+
+#include <sys/types.h>
 #include <unistd.h>
 
 // DO NOT INCLUDE OTHER LIBBASE HEADERS!
@@ -88,6 +95,35 @@
 
 using unique_fd = unique_fd_impl<DefaultCloser>;
 
+#if !defined(_WIN32)
+
+// Inline functions, so that they can be used header-only.
+inline bool Pipe(unique_fd* read, unique_fd* write) {
+  int pipefd[2];
+  if (pipe2(pipefd, O_CLOEXEC) != 0) {
+    return false;
+  }
+  read->reset(pipefd[0]);
+  write->reset(pipefd[1]);
+  return true;
+}
+
+inline bool Socketpair(int domain, int type, int protocol, unique_fd* left, unique_fd* right) {
+  int sockfd[2];
+  if (socketpair(domain, type, protocol, sockfd) != 0) {
+    return false;
+  }
+  left->reset(sockfd[0]);
+  right->reset(sockfd[1]);
+  return true;
+}
+
+inline bool Socketpair(int type, unique_fd* left, unique_fd* right) {
+  return Socketpair(AF_UNIX, type, 0, left, right);
+}
+
+#endif  // !defined(_WIN32)
+
 }  // namespace base
 }  // namespace android