Mojo: Move waiting APIs to public library

mojo/public/c/system/functions.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains basic functions common to different Mojo system APIs.
 //
 // Note: This header should be compilable as C.
 
 #ifndef MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_
 #define MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_
@@ skipping 24 matching lines @@
 MOJO_SYSTEM_EXPORT MojoTimeTicks MojoGetTimeTicksNow(void);
 
 // Closes the given |handle|.
 //
 // Returns:
 //   |MOJO_RESULT_OK| on success.
 //   |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle.
 //
 // Concurrent operations on |handle| may succeed (or fail as usual) if they
 // happen before the close, be cancelled with result |MOJO_RESULT_CANCELLED| if
-// they properly overlap (this is likely the case with |MojoWait()|, etc.), or
-// fail with |MOJO_RESULT_INVALID_ARGUMENT| if they happen after.
+// they properly overlap (this is likely the case with watchers), or fail with
+// |MOJO_RESULT_INVALID_ARGUMENT| if they happen after.
 MOJO_SYSTEM_EXPORT MojoResult MojoClose(MojoHandle handle);
 
 // Queries the last known signals state of a handle.
 //
 // Note that no guarantees can be made about the accuracy of the returned
 // signals state by the time this returns, as other threads in the system may
 // change the handle's state at any time. Use with appropriate discretion.
 //
 // Returns:
 //   |MOJO_RESULT_OK| on success. |*signals_state| is populated with the
 //       last known signals state of |handle|.
 //   |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle or
 //       |signals_state| is null.
 MOJO_SYSTEM_EXPORT MojoResult
 MojoQueryHandleSignalsState(MojoHandle handle,
                             struct MojoHandleSignalsState* signals_state);
 
-// Waits on the given handle until one of the following happens:
-//   - A signal indicated by |signals| is satisfied.
-//   - It becomes known that no signal indicated by |signals| will ever be
-//     satisfied. (See the description of the |MOJO_RESULT_CANCELLED| and
-//     |MOJO_RESULT_FAILED_PRECONDITION| return values below.)
-//   - Until |deadline| has passed.
-//
-// If |deadline| is |MOJO_DEADLINE_INDEFINITE|, this will wait "forever" (until
-// one of the other wait termination conditions is satisfied). If |deadline| is
-// 0, this will return |MOJO_RESULT_DEADLINE_EXCEEDED| only if one of the other
-// termination conditions (e.g., a signal is satisfied, or all signals are
-// unsatisfiable) is not already satisfied.
-//
-// |signals_state| (optional): See documentation for |MojoHandleSignalsState|.
-//
-// Returns:
-//   |MOJO_RESULT_OK| if some signal in |signals| was satisfied (or is already
-//       satisfied).
-//   |MOJO_RESULT_CANCELLED| if |handle| was closed (necessarily from another
-//       thread) during the wait.
-//   |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle (e.g., if
-//       it has already been closed). The |signals_state| value is unchanged.
-//   |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of
-//       the signals being satisfied.
-//   |MOJO_RESULT_FAILED_PRECONDITION| if it becomes known that none of the
-//       signals in |signals| can ever be satisfied (e.g., when waiting on one
-//       end of a message pipe and the other end is closed).
-//
-// If there are multiple waiters (on different threads, obviously) waiting on
-// the same handle and signal, and that signal becomes satisfied, all waiters
-// will be awoken.
-MOJO_SYSTEM_EXPORT MojoResult
-MojoWait(MojoHandle handle,
-         MojoHandleSignals signals,
-         MojoDeadline deadline,
-         struct MojoHandleSignalsState* signals_state);  // Optional out.
-
-// Waits on |handles[0]|, ..., |handles[num_handles-1]| until:
-//   - (At least) one handle satisfies a signal indicated in its respective
-//     |signals[0]|, ..., |signals[num_handles-1]|.
-//   - It becomes known that no signal in some |signals[i]| will ever be
-//     satisfied.
-//   - |deadline| has passed.
-//
-// This means that |MojoWaitMany()| behaves as if |MojoWait()| were called on
-// each handle/signals pair simultaneously, completing when the first
-// |MojoWait()| would complete.
-//
-// See |MojoWait()| for more details about |deadline|.
-//
-// |result_index| (optional) is used to return the index of the handle that
-//     caused the call to return. For example, the index |i| (from 0 to
-//     |num_handles-1|) if |handle[i]| satisfies a signal from |signals[i]|. You
-//     must manually initialize this to a suitable sentinel value (e.g. -1)
-//     before you make this call because this value is not updated if there is
-//     no specific handle that causes the function to return. Pass null if you
-//     don't need this value to be returned.
-//
-// |signals_states| (optional) points to an array of size |num_handles| of
-//     MojoHandleSignalsState. See |MojoHandleSignalsState| for more details
-//     about the meaning of each array entry. This array is not an atomic
-//     snapshot. The array will be updated if the function does not return
-//     |MOJO_RESULT_INVALID_ARGUMENT| or |MOJO_RESULT_RESOURCE_EXHAUSTED|.
-//
-// Returns:
-//   |MOJO_RESULT_CANCELLED| if some |handle[i]| was closed (necessarily from
-//       another thread) during the wait.
-//   |MOJO_RESULT_RESOURCE_EXHAUSTED| if there are too many handles. The
-//       |signals_state| array is unchanged.
-//   |MOJO_RESULT_INVALID_ARGUMENT| if some |handle[i]| is not a valid handle
-//       (e.g., if it is zero or if it has already been closed). The
-//       |signals_state| array is unchanged.
-//   |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of
-//       handles satisfying any of its signals.
-//   |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME
-//       |handle[i]| will ever satisfy any of the signals in |signals[i]|.
-MOJO_SYSTEM_EXPORT MojoResult
-MojoWaitMany(const MojoHandle* handles,
-             const MojoHandleSignals* signals,
-             uint32_t num_handles,
-             MojoDeadline deadline,
-             uint32_t* result_index,                          // Optional out
-             struct MojoHandleSignalsState* signals_states);  // Optional out
-
 // Retrieves system properties. See the documentation for |MojoPropertyType| for
 // supported property types and their corresponding output value type.
 //
 // Returns:
 //     |MOJO_RESULT_OK| on success.
 //     |MOJO_RESULT_INVALID_ARGUMENT| if |type| is not recognized. In this case,
 //         |value| is untouched.
 MOJO_SYSTEM_EXPORT MojoResult MojoGetProperty(MojoPropertyType type,
                                               void* value);
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_