mbed library sources. Supersedes mbed-src.
Dependents: Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more
platform/mbed_poll.cpp@188:bcfe06ba3d64, 2018-11-08 (annotated)
- Committer:
- AnnaBridge
- Date:
- Thu Nov 08 11:46:34 2018 +0000
- Revision:
- 188:bcfe06ba3d64
- Parent:
- 186:707f6e361f3e
- Child:
- 189:f392fc9709a3
mbed-dev library. Release version 164
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
AnnaBridge | 167:e84263d55307 | 1 | /* mbed Microcontroller Library |
AnnaBridge | 167:e84263d55307 | 2 | * Copyright (c) 2017 ARM Limited |
AnnaBridge | 167:e84263d55307 | 3 | * |
AnnaBridge | 167:e84263d55307 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
AnnaBridge | 167:e84263d55307 | 5 | * you may not use this file except in compliance with the License. |
AnnaBridge | 167:e84263d55307 | 6 | * You may obtain a copy of the License at |
AnnaBridge | 167:e84263d55307 | 7 | * |
AnnaBridge | 167:e84263d55307 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
AnnaBridge | 167:e84263d55307 | 9 | * |
AnnaBridge | 167:e84263d55307 | 10 | * Unless required by applicable law or agreed to in writing, software |
AnnaBridge | 167:e84263d55307 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
AnnaBridge | 167:e84263d55307 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
AnnaBridge | 167:e84263d55307 | 13 | * See the License for the specific language governing permissions and |
AnnaBridge | 167:e84263d55307 | 14 | * limitations under the License. |
AnnaBridge | 167:e84263d55307 | 15 | */ |
AnnaBridge | 167:e84263d55307 | 16 | #include "mbed_poll.h" |
AnnaBridge | 167:e84263d55307 | 17 | #include "FileHandle.h" |
Anna Bridge |
186:707f6e361f3e | 18 | #if MBED_CONF_RTOS_PRESENT |
Anna Bridge |
186:707f6e361f3e | 19 | #include "rtos/Kernel.h" |
Anna Bridge |
186:707f6e361f3e | 20 | #include "rtos/Thread.h" |
Anna Bridge |
186:707f6e361f3e | 21 | using namespace rtos; |
Anna Bridge |
186:707f6e361f3e | 22 | #else |
AnnaBridge | 188:bcfe06ba3d64 | 23 | #include "drivers/Timer.h" |
AnnaBridge | 188:bcfe06ba3d64 | 24 | #include "drivers/LowPowerTimer.h" |
AnnaBridge | 167:e84263d55307 | 25 | #endif |
AnnaBridge | 167:e84263d55307 | 26 | |
AnnaBridge | 167:e84263d55307 | 27 | namespace mbed { |
AnnaBridge | 167:e84263d55307 | 28 | |
AnnaBridge | 167:e84263d55307 | 29 | // timeout -1 forever, or milliseconds |
AnnaBridge | 167:e84263d55307 | 30 | int poll(pollfh fhs[], unsigned nfhs, int timeout) |
AnnaBridge | 167:e84263d55307 | 31 | { |
AnnaBridge | 188:bcfe06ba3d64 | 32 | /* |
AnnaBridge | 167:e84263d55307 | 33 | * TODO Proper wake-up mechanism. |
AnnaBridge | 167:e84263d55307 | 34 | * In order to correctly detect availability of read/write a FileHandle, we needed |
AnnaBridge | 167:e84263d55307 | 35 | * a select or poll mechanisms. We opted for poll as POSIX defines in |
AnnaBridge | 167:e84263d55307 | 36 | * http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html Currently, |
AnnaBridge | 167:e84263d55307 | 37 | * mbed::poll() just spins and scans filehandles looking for any events we are |
AnnaBridge | 167:e84263d55307 | 38 | * interested in. In future, his spinning behaviour will be replaced with |
AnnaBridge | 167:e84263d55307 | 39 | * condition variables. |
AnnaBridge | 167:e84263d55307 | 40 | */ |
Anna Bridge |
186:707f6e361f3e | 41 | #if MBED_CONF_RTOS_PRESENT |
Anna Bridge |
186:707f6e361f3e | 42 | uint64_t start_time = 0; |
Anna Bridge |
186:707f6e361f3e | 43 | if (timeout > 0) { |
Anna Bridge |
186:707f6e361f3e | 44 | start_time = Kernel::get_ms_count(); |
Anna Bridge |
186:707f6e361f3e | 45 | } |
Anna Bridge |
186:707f6e361f3e | 46 | #define TIME_ELAPSED() int64_t(Kernel::get_ms_count() - start_time) |
Anna Bridge |
186:707f6e361f3e | 47 | #else |
Anna Bridge |
186:707f6e361f3e | 48 | #if MBED_CONF_PLATFORM_POLL_USE_LOWPOWER_TIMER |
Anna Bridge |
186:707f6e361f3e | 49 | LowPowerTimer timer; |
Anna Bridge |
186:707f6e361f3e | 50 | #else |
AnnaBridge | 167:e84263d55307 | 51 | Timer timer; |
Anna Bridge |
186:707f6e361f3e | 52 | #endif |
AnnaBridge | 167:e84263d55307 | 53 | if (timeout > 0) { |
AnnaBridge | 167:e84263d55307 | 54 | timer.start(); |
AnnaBridge | 167:e84263d55307 | 55 | } |
Anna Bridge |
186:707f6e361f3e | 56 | #define TIME_ELAPSED() timer.read_ms() |
Anna Bridge |
186:707f6e361f3e | 57 | #endif // MBED_CONF_RTOS_PRESENT |
AnnaBridge | 167:e84263d55307 | 58 | |
AnnaBridge | 167:e84263d55307 | 59 | int count = 0; |
AnnaBridge | 167:e84263d55307 | 60 | for (;;) { |
AnnaBridge | 167:e84263d55307 | 61 | /* Scan the file handles */ |
AnnaBridge | 167:e84263d55307 | 62 | for (unsigned n = 0; n < nfhs; n++) { |
AnnaBridge | 167:e84263d55307 | 63 | FileHandle *fh = fhs[n].fh; |
AnnaBridge | 167:e84263d55307 | 64 | short mask = fhs[n].events | POLLERR | POLLHUP | POLLNVAL; |
AnnaBridge | 167:e84263d55307 | 65 | if (fh) { |
AnnaBridge | 167:e84263d55307 | 66 | fhs[n].revents = fh->poll(mask) & mask; |
AnnaBridge | 167:e84263d55307 | 67 | } else { |
AnnaBridge | 167:e84263d55307 | 68 | fhs[n].revents = POLLNVAL; |
AnnaBridge | 167:e84263d55307 | 69 | } |
AnnaBridge | 167:e84263d55307 | 70 | if (fhs[n].revents) { |
AnnaBridge | 167:e84263d55307 | 71 | count++; |
AnnaBridge | 167:e84263d55307 | 72 | } |
AnnaBridge | 167:e84263d55307 | 73 | } |
AnnaBridge | 167:e84263d55307 | 74 | |
AnnaBridge | 167:e84263d55307 | 75 | if (count) { |
AnnaBridge | 167:e84263d55307 | 76 | break; |
AnnaBridge | 167:e84263d55307 | 77 | } |
AnnaBridge | 167:e84263d55307 | 78 | |
AnnaBridge | 167:e84263d55307 | 79 | /* Nothing selected - this is where timeout handling would be needed */ |
Anna Bridge |
186:707f6e361f3e | 80 | if (timeout == 0 || (timeout > 0 && TIME_ELAPSED() > timeout)) { |
AnnaBridge | 167:e84263d55307 | 81 | break; |
AnnaBridge | 167:e84263d55307 | 82 | } |
AnnaBridge | 167:e84263d55307 | 83 | #ifdef MBED_CONF_RTOS_PRESENT |
AnnaBridge | 167:e84263d55307 | 84 | // TODO - proper blocking |
AnnaBridge | 167:e84263d55307 | 85 | // wait for condition variable, wait queue whatever here |
AnnaBridge | 176:447f873cad2f | 86 | rtos::Thread::wait(1); |
AnnaBridge | 167:e84263d55307 | 87 | #endif |
AnnaBridge | 167:e84263d55307 | 88 | } |
AnnaBridge | 167:e84263d55307 | 89 | return count; |
AnnaBridge | 167:e84263d55307 | 90 | } |
AnnaBridge | 167:e84263d55307 | 91 | |
AnnaBridge | 167:e84263d55307 | 92 | } // namespace mbed |