Merge "Keep common libs in sync with android-cuttlefish repo" into main

4 files changed, 108 insertions, 1 deletions

diff --git a/common/libs/utils/Android.bp b/common/libs/utils/Android.bp
index ee5d565e1..6ac56bfc7 100644
--- a/common/libs/utils/Android.bp
+++ b/common/libs/utils/Android.bp
@@ -30,6 +30,7 @@ cc_library {
         "network.cpp",
         "proc_file_utils.cpp",
         "shared_fd_flag.cpp",
+        "signals.cpp",
         "subprocess.cpp",
         "tcp_socket.cpp",
         "tee_logging.cpp",
diff --git a/common/libs/utils/signals.cpp b/common/libs/utils/signals.cpp
new file mode 100644
index 000000000..ab6fb9388
--- /dev/null
+++ b/common/libs/utils/signals.cpp
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2024 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 "common/libs/utils/signals.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+
+#include <vector>
+
+#include <android-base/logging.h>
+
+namespace cuttlefish {
+
+SignalMasker::SignalMasker(sigset_t signals) {
+  auto res = sigprocmask(SIG_SETMASK, &signals, &old_mask_);
+  auto err = errno;
+  CHECK(res == 0) << "Failed to set thread's blocked signal mask: "
+                  << strerror(err);
+}
+
+SignalMasker::~SignalMasker() {
+  auto res = sigprocmask(SIG_SETMASK, &old_mask_, NULL);
+  auto err = errno;
+  CHECK(res == 0) << "Failed to reset thread's blocked signal mask: "
+                  << strerror(err);
+}
+
+void ChangeSignalHandlers(void (*handler)(int), std::vector<int> signals) {
+  struct sigaction act;
+  act.sa_handler = handler;
+  sigemptyset(&act.sa_mask);
+  for (auto signal: signals) {
+    sigaddset(&act.sa_mask, signal);
+  }
+  act.sa_flags = 0;
+
+  for (auto signal : signals) {
+    sigaction(signal, &act, NULL);
+  }
+}
+
+}  // namespace cuttlefish
+
diff --git a/common/libs/utils/signals.h b/common/libs/utils/signals.h
new file mode 100644
index 000000000..4eb68437d
--- /dev/null
+++ b/common/libs/utils/signals.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2024 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.
+ */
+
+#pragma once
+
+#include <signal.h>
+
+#include <vector>
+
+namespace cuttlefish {
+
+/**
+ * Blocks signals for the current thread for the lifetime of the object.
+ *
+ * Provides a RAII interface to sigprocmask.
+ */
+class SignalMasker {
+ public:
+  /**
+   * Blocks the given signals until the object is destroyed.
+   */
+  SignalMasker(sigset_t signals);
+  SignalMasker(const SignalMasker&) = delete;
+  SignalMasker(SignalMasker&&) = delete;
+  SignalMasker operator=(const SignalMasker&) = delete;
+  SignalMasker operator=(SignalMasker&&) = delete;
+  ~SignalMasker();
+
+ private:
+  sigset_t old_mask_;
+};
+
+void ChangeSignalHandlers(void(*handler)(int), std::vector<int> signals);
+
+}  // namespace cuttlefish
diff --git a/common/libs/utils/subprocess.cpp b/common/libs/utils/subprocess.cpp
index 40b13c3cf..2ef5957d3 100644
--- a/common/libs/utils/subprocess.cpp
+++ b/common/libs/utils/subprocess.cpp
@@ -230,7 +230,7 @@ int Subprocess::Wait(siginfo_t* infop, int options) {
     return -1;
   }
   *infop = {};
-  auto retval = waitid(P_PID, pid_, infop, options);
+  auto retval = TEMP_FAILURE_RETRY(waitid(P_PID, pid_, infop, options));
   // We don't want to wait twice for the same process
   bool exited = infop->si_code == CLD_EXITED || infop->si_code == CLD_DUMPED;
   bool reaped = !(options & WNOWAIT);