Only have one copy of the kernel_sigset_t hack, and add more tests.

Change-Id: I377522fcba6fb4b5fd2754ab15b091014bd7c16f

libc/bionic/sigwait.cpp

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <time.h>
+
+#include <private/kernel_sigset_t.h>
+
+extern "C" int __rt_sigtimedwait(const sigset_t* uthese, siginfo_t* uinfo, const struct timespec* uts, size_t sigsetsize);
+
+int sigwait(const sigset_t* set, int* sig) {
+  kernel_sigset_t sigset(set);
+  while (true) {
+    // __rt_sigtimedwait can return EAGAIN or EINTR, we need to loop
+    // around them since sigwait is only allowed to return EINVAL.
+    int result = __rt_sigtimedwait(sigset.get(), NULL, NULL, sizeof(sigset));
+    if (result >= 0) {
+      *sig = result;
+      return 0;
+    }
+
+    if (errno != EAGAIN && errno != EINTR) {
+      return errno;
+    }
+  }
+}