diff options
author | Ken Payson <kpayson@google.com> | 2016-08-06 21:27:29 -0700 |
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committer | Ken Payson <kpayson@google.com> | 2016-09-14 14:25:46 -0700 |
commit | 31caabdead52000354c4fdd88b68bb3041ca8c4a (patch) | |
tree | 67ec849190f0211b15c506397fbc78201b44d29b /src/core/lib/iomgr/wakeup_fd_cv.h | |
parent | 93b09478f0264f62e577b215dea7bc908abc6b98 (diff) |
Add shim to support condition variable wakeup fds where pipe/eventfd is not available
Diffstat (limited to 'src/core/lib/iomgr/wakeup_fd_cv.h')
-rw-r--r-- | src/core/lib/iomgr/wakeup_fd_cv.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.h b/src/core/lib/iomgr/wakeup_fd_cv.h new file mode 100644 index 0000000000..22ee6c0bbe --- /dev/null +++ b/src/core/lib/iomgr/wakeup_fd_cv.h @@ -0,0 +1,58 @@ +/* + * + * Copyright 2016, Google Inc. + * 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. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * 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. + * + */ + +/* + * wakeup_fd_cv uses condition variables to implement wakeup fds. + * + * It is intended for use only in cases when eventfd() and pipe() are not + * available. It can only be used with the "poll" engine. + * + * Implementation: + * A global table of cv wakeup fds is mantained. A cv wakeup fd is a negative + * file descriptor. poll() is then run in a background thread with only the + * real socket fds while we wait on a condition variable trigged by either the + * poll() called or a wakeup_fd() call. + * + */ + +#ifndef GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H +#define GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H + +#include "src/core/lib/iomgr/wakeup_fd_posix.h" + +void grpc_global_cv_fd_table_init(); +void grpc_global_cv_fd_table_shutdown(); + +extern grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable; + +#endif /* GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H */ |