RtosLog.h

00001 /*
00002  *  Copyright 2014 Embedded Artists AB
00003  *
00004  *  Licensed under the Apache License, Version 2.0 (the "License");
00005  *  you may not use this file except in compliance with the License.
00006  *  You may obtain a copy of the License at
00007  *
00008  *    http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  *  Unless required by applicable law or agreed to in writing, software
00011  *  distributed under the License is distributed on an "AS IS" BASIS,
00012  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  *  See the License for the specific language governing permissions and
00014  *  limitations under the License.
00015  */
00016 
00017 #ifndef RTOSLOG_H
00018 #define RTOSLOG_H
00019 
00020 #include "mbed.h"
00021 #include "rtos.h"
00022 #include "dm_board_config.h"
00023 
00024 #if defined(DM_BOARD_USE_USBSERIAL_IN_RTOSLOG)
00025   #include "USBSerial.h"
00026 #endif
00027 
00028 /**
00029  * All threads can independantly call the printf function in the RtosLog class
00030  * without risk of getting the output tangled up.
00031  *
00032  * The RtosLog class uses a Thread to process the messages one at a time.
00033  *
00034  *
00035  * Example of using the RtosLog class:
00036  *
00037  * @code
00038  * #include "mbed.h"
00039  * #include "DMBoard.h"
00040  *
00041  * void myTask(void const*args) {
00042  *    RtosLog* log = DMBoard::instance().logger();
00043  *    ...
00044  *    log->printf("Hello world!\n");
00045  *    ...
00046  * }
00047  * @endcode
00048  *
00049  */
00050 class RtosLog {
00051 public:
00052     enum Constants {
00053         MessageLen  = 80,
00054         NumMessages =  16,
00055     };
00056   
00057     RtosLog();
00058     ~RtosLog();
00059     
00060     /** Starts the logger thread, called from DMBoard::instance().init()
00061      */
00062     void init();
00063     
00064     /** Printf that works in an RTOS
00065      *
00066      *  This function will create a string from the specified format and
00067      *  optional extra arguments and put it into a message that the RtosLog
00068      *  thread will write to the log.
00069      *
00070      *  Note that if the underlying queue is full then this function
00071      *  will block until an entry becomes available. This is required to 
00072      *  make sure that all printf calls actually get printed. If this happens
00073      *  too often then increase the priority of the RtosLog thread or reduce
00074      *  the number of printed messages.
00075      *
00076      *  @param format  format string
00077      *  @param ...     optional extra arguments
00078      */
00079     int printf(const char* format, ...);
00080     
00081     /** Printf that works in an RTOS
00082      *
00083      *  This function will create a string from the specified format and
00084      *  optional extra arguments and put it into a message that the RtosLog
00085      *  thread will write to the log.
00086      *
00087      *  Note that if the underlying queue is full then this function
00088      *  discards the message and returns immediately.
00089      *
00090      *  @param format  format string
00091      *  @param ...     optional extra arguments
00092      */
00093     int isr_printf(const char* format, ...);
00094   
00095 private:
00096     
00097     typedef struct {
00098         char*  ptr;                 /* Non-NULL if memory is allocated */
00099         char   msg[MessageLen+1];   /* A counter value                 */
00100     } message_t;
00101  
00102     MemoryPool<message_t, NumMessages> _mpool;
00103     Queue<message_t, NumMessages> _queue;
00104     Semaphore _sem;
00105 #if defined(DM_BOARD_USE_USBSERIAL_IN_RTOSLOG)
00106     USBSerial _serial;
00107 #else
00108     Serial _serial;
00109 #endif
00110     Thread* _thr;
00111     
00112     static void logTask(void const* args);
00113 };
00114 
00115 #endif