OS Abstractor

Find quick answers to your questions about OS Abstractor product

• I generated source code for Windows XP as the target in AppCOE, compiled, and executed the program in VC++. Are the resultant tasks scheduled by the Windows scheduler?

  OS Abstractor does not do scheduling on any port. We use the OS scheduler. However, we configure the threads to be real-time priority (e.g. on Windows we use the threads priorities that are normally n...

• If I select µITRON as a target OS, who schedules the task? Do the AppCOE libraries call µITRON dispatcher?

  µITRON scheduler will schedule the thread....

• What is the default maximum stack size for QNX in the main thread?

  The stack size defined under OS Abstractor for QNX is as follows: #define OS_MIN_STACK_SIZE 16384 #define OS_MAX_STACK_SIZE 0xffffffff The above defines are in cross_os_def.h. It is recommended that y...

• If three same priority processes, A, B and C are created, which process starts execution first? When will it switch to another process?

  OS Abstractor processes do not compete with each other, but only the threads within them. The process will be started First In First Out (FIFO)....

• If a task is created with priority 100, and it is changed to priority 50, then will the created task start executing? Is it not possible to set higher priority than the parent process?

  You can set any priority when creating tasks. If you want it to run immediately, you pass along the flag parameter START, it will resume, irrespective of the priority....

• There are three processes, A, B and C, created of the same priority and are in ready state. If process A create new task D, with a priority higher than other three processes, then will Process D start first? If priority D is lower, then will process A keep executing? If priority D is equal to other processes, will the application execution be in this series: A -> B -> C -> D -> A,,,, ?

  OS Abstractor Processes do not compete....

• OS Abstractor document says that we can use target OS native IO functions if I set MAP_OS_ANSI_IO to OS_FALSE. Does this mean that I can also call other target OS APIs from application program?

  You should be able to use any native APIs directly from the target OS (as long as the API names are not the same)....

• If target OS is uITRON, can I call set_tim (set system time API)?

  You should be able to set_tim native uITRON API, however, that line of code will not be portable. It is recommended to use the clock routines provided by either the OS Abstractor APIs or the POSIX API...

• How about sig_sem (signal semaphore)?

  You should be able to use sig_sem native API. But it is recommended to use the signal APIs from OS Abstractor APIs to ensure that your code be portable....

• If target OS is uITRON and it has Windows compatible file system and TCP/IP which support BSD Socket, then can the developer use open, close, read, write functions for file related operation?

  The developer has the options to use OS_open, OS_close, etc (OR) they can set MAP_ANSI to TRUE and have open(), close() calls map to OS Abstractor APIs. The developer also has the option to use both A...