1 files changed, 66 insertions, 0 deletions
diff --git a/runtime/thread_linux.cc b/runtime/thread_linux.cc
new file mode 100644
index 0000000000..ee66ccc29a
--- /dev/null
+++ b/runtime/thread_linux.cc
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2011 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 "thread.h"
+
+namespace art {
+
+void Thread::SetNativePriority(int) {
+  // Do nothing.
+}
+
+int Thread::GetNativePriority() {
+  return kNormThreadPriority;
+}
+
+static void SigAltStack(stack_t* new_stack, stack_t* old_stack) {
+  if (sigaltstack(new_stack, old_stack) == -1) {
+    PLOG(FATAL) << "sigaltstack failed";
+  }
+}
+
+void Thread::SetUpAlternateSignalStack() {
+  // Create and set an alternate signal stack.
+  stack_t ss;
+  ss.ss_sp = new uint8_t[SIGSTKSZ];
+  ss.ss_size = SIGSTKSZ;
+  ss.ss_flags = 0;
+  CHECK(ss.ss_sp != NULL);
+  SigAltStack(&ss, NULL);
+
+  // Double-check that it worked.
+  ss.ss_sp = NULL;
+  SigAltStack(NULL, &ss);
+  VLOG(threads) << "Alternate signal stack is " << PrettySize(ss.ss_size) << " at " << ss.ss_sp;
+}
+
+void Thread::TearDownAlternateSignalStack() {
+  // Get the pointer so we can free the memory.
+  stack_t ss;
+  SigAltStack(NULL, &ss);
+  uint8_t* allocated_signal_stack = reinterpret_cast<uint8_t*>(ss.ss_sp);
+
+  // Tell the kernel to stop using it.
+  ss.ss_sp = NULL;
+  ss.ss_flags = SS_DISABLE;
+  ss.ss_size = SIGSTKSZ;  // Avoid ENOMEM failure with Mac OS' buggy libc.
+  SigAltStack(&ss, NULL);
+
+  // Free it.
+  delete[] allocated_signal_stack;
+}
+
+}  // namespace art