OLD | NEW |
1 // Copyright 2014 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // This file contains basic functions common to different Mojo system APIs. | 5 // This file contains basic functions common to different Mojo system APIs. |
6 // | 6 // |
7 // Note: This header should be compilable as C. | 7 // Note: This header should be compilable as C. |
8 | 8 |
9 #ifndef MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ | 9 #ifndef MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ |
10 #define MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ | 10 #define MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ |
11 | 11 |
12 // Note: This header should be compilable as C. | 12 // Note: This header should be compilable as C. |
13 | 13 |
14 #include "mojo/public/c/system/system_export.h" | 14 #include "mojo/public/c/system/system_export.h" |
15 #include "mojo/public/c/system/types.h" | 15 #include "mojo/public/c/system/types.h" |
16 | 16 |
17 #ifdef __cplusplus | 17 #ifdef __cplusplus |
18 extern "C" { | 18 extern "C" { |
19 #endif | 19 #endif |
20 | 20 |
21 // Note: Pointer parameters that are labelled "optional" may be null (at least | 21 // Note: Pointer parameters that are labelled "optional" may be null (at least |
22 // under some circumstances). Non-const pointer parameters are also labeled | 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 | 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 | 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 | 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.) | 26 // whether a given "in/out" parameter is used for input, output, or both.) |
27 | 27 |
28 // Platform-dependent monotonically increasing tick count representing "right | 28 // Platform-dependent monotonically increasing tick count representing "right |
29 // now." The resolution of this clock is ~1-15ms. Resolution varies depending | 29 // now." The resolution of this clock is ~1-15ms. Resolution varies depending |
30 // on hardware/operating system configuration. | 30 // on hardware/operating system configuration. |
31 MOJO_SYSTEM_EXPORT MojoTimeTicks MojoGetTimeTicksNow(void); | 31 MOJO_SYSTEM_EXPORT MojoTimeTicks MojoGetTimeTicksNow(void); |
32 | 32 |
33 // Closes the given |handle|. | 33 // Closes the given |handle|. |
34 // | 34 // |
35 // Returns: | 35 // Returns: |
36 // |MOJO_RESULT_OK| on success. | 36 // |MOJO_RESULT_OK| on success. |
37 // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle. | 37 // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle. |
38 // | 38 // |
39 // Concurrent operations on |handle| may succeed (or fail as usual) if they | 39 // Concurrent operations on |handle| may succeed (or fail as usual) if they |
(...skipping 54 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
94 // (e.g., if it has already been closed). | 94 // (e.g., if it has already been closed). |
95 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of | 95 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of |
96 // handles satisfying any of its signals. | 96 // handles satisfying any of its signals. |
97 // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME | 97 // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME |
98 // |handle[i]| will ever satisfy any of the signals in |signals[i]|. | 98 // |handle[i]| will ever satisfy any of the signals in |signals[i]|. |
99 MOJO_SYSTEM_EXPORT MojoResult MojoWaitMany(const MojoHandle* handles, | 99 MOJO_SYSTEM_EXPORT MojoResult MojoWaitMany(const MojoHandle* handles, |
100 const MojoHandleSignals* signals, | 100 const MojoHandleSignals* signals, |
101 uint32_t num_handles, | 101 uint32_t num_handles, |
102 MojoDeadline deadline); | 102 MojoDeadline deadline); |
103 | 103 |
| 104 // Waits on the given handle until one of the following happens: |
| 105 // - A signal indicated by |signals| is satisfied. |
| 106 // - It becomes known that no signal indicated by |signals| will ever be |
| 107 // satisfied. (See the description of the |MOJO_RESULT_CANCELLED| and |
| 108 // |MOJO_RESULT_FAILED_PRECONDITION| return values below.) |
| 109 // - Until |deadline| has passed. |
| 110 // |
| 111 // If |deadline| is |MOJO_DEADLINE_INDEFINITE|, this will wait "forever" (until |
| 112 // one of the other wait termination conditions is satisfied). If |deadline| is |
| 113 // 0, this will return |MOJO_RESULT_DEADLINE_EXCEEDED| only if one of the other |
| 114 // termination conditions (e.g., a signal is satisfied, or all signals are |
| 115 // unsatisfiable) is not already satisfied. |
| 116 // |
| 117 // |signals_state| (optional): See documentation for |MojoHandleSignalsState|. |
| 118 // |
| 119 // Returns: |
| 120 // |MOJO_RESULT_OK| if some signal in |signals| was satisfied (or is already |
| 121 // satisfied). |
| 122 // |MOJO_RESULT_CANCELLED| if |handle| was closed (necessarily from another |
| 123 // thread) during the wait. |
| 124 // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle (e.g., if |
| 125 // it has already been closed). The |signals_state| value is unchanged. |
| 126 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of |
| 127 // the signals being satisfied. |
| 128 // |MOJO_RESULT_FAILED_PRECONDITION| if it becomes known that none of the |
| 129 // signals in |signals| can ever be satisfied (e.g., when waiting on one |
| 130 // end of a message pipe and the other end is closed). |
| 131 // |
| 132 // If there are multiple waiters (on different threads, obviously) waiting on |
| 133 // the same handle and signal, and that signal becomes is satisfied, all waiters |
| 134 // will be awoken. |
| 135 MOJO_SYSTEM_EXPORT MojoResult |
| 136 MojoNewWait(MojoHandle handle, |
| 137 MojoHandleSignals signals, |
| 138 MojoDeadline deadline, |
| 139 struct MojoHandleSignalsState* signals_state); // Optional out. |
| 140 |
| 141 // Waits on |handles[0]|, ..., |handles[num_handles-1]| until: |
| 142 // - (At least) one handle satisfies a signal indicated in its respective |
| 143 // |signals[0]|, ..., |signals[num_handles-1]|. |
| 144 // - It becomes known that no signal in some |signals[i]| will ever be |
| 145 // satisfied. |
| 146 // - |deadline| has passed. |
| 147 // |
| 148 // This means that |MojoWaitMany()| behaves as if |MojoWait()| were called on |
| 149 // each handle/signals pair simultaneously, completing when the first |
| 150 // |MojoWait()| would complete. |
| 151 // |
| 152 // See |MojoWait()| for more details about |deadline|. |
| 153 // |
| 154 // |result_index| (optional) is used to return the index of the handle that |
| 155 // caused the call to return. For example, the index |i| (from 0 to |
| 156 // |num_handles-1|) if |handle[i]| satisfies a signal from |signals[i]|. You |
| 157 // must manually initialize this to a suitable sentinel value (e.g. -1) |
| 158 // before you make this call because this value is not updated if there is |
| 159 // no specific handle that causes the function to return. Pass null if you |
| 160 // don't need this value to be returned. |
| 161 // |
| 162 // |signals_states| (optional) points to an array of size |num_handles| of |
| 163 // MojoHandleSignalsState. See |MojoHandleSignalsState| for more details |
| 164 // about the meaning of each array entry. This array is not an atomic |
| 165 // snapshot. The array will be updated if the function does not return |
| 166 // |MOJO_RESULT_INVALID_ARGUMENT| or |MOJO_RESULT_RESOURCE_EXHAUSTED|. |
| 167 // |
| 168 // Returns: |
| 169 // |MOJO_RESULT_CANCELLED| if some |handle[i]| was closed (necessarily from |
| 170 // another thread) during the wait. |
| 171 // |MOJO_RESULT_RESOURCE_EXHAUSTED| if there are too many handles. The |
| 172 // |signals_state| array is unchanged. |
| 173 // |MOJO_RESULT_INVALID_ARGUMENT| if some |handle[i]| is not a valid handle |
| 174 // (e.g., if it is zero or if it has already been closed). The |
| 175 // |signals_state| array is unchanged. |
| 176 // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of |
| 177 // handles satisfying any of its signals. |
| 178 // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME |
| 179 // |handle[i]| will ever satisfy any of the signals in |signals[i]|. |
| 180 MOJO_SYSTEM_EXPORT MojoResult |
| 181 MojoNewWaitMany(const MojoHandle* handles, |
| 182 const MojoHandleSignals* signals, |
| 183 uint32_t num_handles, |
| 184 MojoDeadline deadline, |
| 185 uint32_t* result_index, // Optional out |
| 186 struct MojoHandleSignalsState* signals_states); // Optional out |
| 187 |
104 #ifdef __cplusplus | 188 #ifdef __cplusplus |
105 } // extern "C" | 189 } // extern "C" |
106 #endif | 190 #endif |
107 | 191 |
108 #endif // MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ | 192 #endif // MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_ |
OLD | NEW |