1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // This file contains basic functions common to different Mojo system APIs. 6 // 7 // Note: This header should be compilable as C. 8 9 #ifndef MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ 10 #define MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ 11 12 // Note: This header should be compilable as C. 13 14 #include "mojo/public/c/system/system_export.h" 15 #include "mojo/public/c/system/types.h" 16 17 #ifdef __cplusplus 18 extern "C" { 19 #endif 20 21 // Note: Pointer parameters that are labelled "optional" may be null (at least 22 // under some circumstances). Non-const pointer parameters are also labeled 23 // "in", "out", or "in/out", to indicate how they are used. (Note that how/if 24 // such a parameter is used may depend on other parameters or the requested 25 // operation's success/failure. E.g., a separate |flags| parameter may control 26 // whether a given "in/out" parameter is used for input, output, or both.) 27 28 // Platform-dependent monotonically increasing tick count representing "right 29 // now." The resolution of this clock is ~1-15ms. Resolution varies depending 30 // on hardware/operating system configuration. 31 MOJO_SYSTEM_EXPORT MojoTimeTicks MojoGetTimeTicksNow(void); 32 33 // Closes the given |handle|. 34 // 35 // Returns: 36 // |MOJO_RESULT_OK| on success. 37 // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle. 38 // 39 // Concurrent operations on |handle| may succeed (or fail as usual) if they 40 // happen before the close, be cancelled with result |MOJO_RESULT_CANCELLED| if 41 // they properly overlap (this is likely the case with |MojoWait()|, etc.), or 42 // fail with |MOJO_RESULT_INVALID_ARGUMENT| if they happen after. 43 MOJO_SYSTEM_EXPORT MojoResult MojoClose(MojoHandle handle); 44 45 // Waits on the given handle until a signal indicated by |signals| is satisfied 46 // or until |deadline| has passed. 47 // 48 // Returns: 49 // |MOJO_RESULT_OK| if some signal in |signals| was satisfied (or is already 50 // satisfied). 51 // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle (e.g., if 52 // it has already been closed). 53 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of 54 // the signals being satisfied. 55 // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that any 56 // signal in |signals| will ever be satisfied. 57 // 58 // If there are multiple waiters (on different threads, obviously) waiting on 59 // the same handle and signal, and that signal becomes is satisfied, all waiters 60 // will be awoken. 61 MOJO_SYSTEM_EXPORT MojoResult MojoWait(MojoHandle handle, 62 MojoHandleSignals signals, 63 MojoDeadline deadline); 64 65 // Waits on |handles[0]|, ..., |handles[num_handles-1]| for at least one of them 66 // to satisfy a signal indicated by |signals[0]|, ..., |signals[num_handles-1]|, 67 // respectively, or until |deadline| has passed. 68 // 69 // Returns: 70 // The index |i| (from 0 to |num_handles-1|) if |handle[i]| satisfies a signal 71 // from |signals[i]|. 72 // |MOJO_RESULT_INVALID_ARGUMENT| if some |handle[i]| is not a valid handle 73 // (e.g., if it has already been closed). 74 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of 75 // handles satisfying any of its signals. 76 // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME 77 // |handle[i]| will ever satisfy any of the signals in |signals[i]|. 78 MOJO_SYSTEM_EXPORT MojoResult MojoWaitMany(const MojoHandle* handles, 79 const MojoHandleSignals* signals, 80 uint32_t num_handles, 81 MojoDeadline deadline); 82 83 #ifdef __cplusplus 84 } // extern "C" 85 #endif 86 87 #endif // MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ 88