src/hotspot/os/posix/semaphore_posix.cpp
changeset 48635 612dfa1d8aad
child 53461 08d6edeb3145
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/os/posix/semaphore_posix.cpp	Thu Jan 11 18:42:36 2018 -0500
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled/precompiled.hpp"
+#ifndef __APPLE__
+#include "runtime/os.hpp"
+// POSIX unamed semaphores are not supported on OS X.
+#include "semaphore_posix.hpp"
+#include <semaphore.h>
+
+#define check_with_errno(check_type, cond, msg)                             \
+  do {                                                                      \
+    int err = errno;                                                        \
+    check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err),   \
+               os::errno_name(err));                                        \
+} while (false)
+
+#define assert_with_errno(cond, msg)    check_with_errno(assert, cond, msg)
+#define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
+
+PosixSemaphore::PosixSemaphore(uint value) {
+  int ret = sem_init(&_semaphore, 0, value);
+
+  guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
+}
+
+PosixSemaphore::~PosixSemaphore() {
+  sem_destroy(&_semaphore);
+}
+
+void PosixSemaphore::signal(uint count) {
+  for (uint i = 0; i < count; i++) {
+    int ret = sem_post(&_semaphore);
+
+    assert_with_errno(ret == 0, "sem_post failed");
+  }
+}
+
+void PosixSemaphore::wait() {
+  int ret;
+
+  do {
+    ret = sem_wait(&_semaphore);
+  } while (ret != 0 && errno == EINTR);
+
+  assert_with_errno(ret == 0, "sem_wait failed");
+}
+
+bool PosixSemaphore::trywait() {
+  int ret;
+
+  do {
+    ret = sem_trywait(&_semaphore);
+  } while (ret != 0 && errno == EINTR);
+
+  assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
+
+  return ret == 0;
+}
+
+bool PosixSemaphore::timedwait(struct timespec ts) {
+  while (true) {
+    int result = sem_timedwait(&_semaphore, &ts);
+    if (result == 0) {
+      return true;
+    } else if (errno == EINTR) {
+      continue;
+    } else if (errno == ETIMEDOUT) {
+      return false;
+    } else {
+      assert_with_errno(false, "timedwait failed");
+      return false;
+    }
+  }
+}
+#endif // __APPLE__
+