Limitations

diff -r 4816d766a08a -r f345bda72bc4 Symbian3/PDK/Source/GUID-C585871E-BE82-49EF-A4B9-4340A7154264.dita --- a/Symbian3/PDK/Source/GUID-C585871E-BE82-49EF-A4B9-4340A7154264.dita Tue Mar 30 11:42:04 2010 +0100 +++ b/Symbian3/PDK/Source/GUID-C585871E-BE82-49EF-A4B9-4340A7154264.dita Tue Mar 30 11:56:28 2010 +0100 @@ -1,97 +1,97 @@ - - - - - -Limitations -

Some APIs of the Standard C Library are not implemented because of the -constraints or limitations of Symbian platform:

AF_LOCAL sockets only support SO_SNDBUF and SO_RCVBUF in setsockopt and SO_TYPE, SO_SNDBUF and SO_RCVBUF in getsockopt. -No ioctl commands are available.
AF_LOCAL sockets do not support shutdown().
The stdioserver does not support per-process configurations.
Signals cannot be directed at an individual thread.
kill(self)/sigqueue(self)/raise() is -not synchronous in the current implementation.
Semantics of signal delivery is different from that of *nix OSes.
The tm_tzname in the struct tm is -not updated by localtime() and mktime(). -This is owing to a limitation of localisation resource files in these platforms. -The field will always be set to "UTC".
On S60 emulators started in textshell mode, the time -zone offset returns the wrong value. In GUI mode, the offset is set correctly.
The tm_isdst field in the struct tm (used in localtime() and mktime()) -is not updated properly on the S60 3rd Edition SDK and devices; the field -is simply set to -1.
mktime() and localtime() APIs -are about 3 times slower on the S60 3rd Edition SDK and devices, because of -lack of native support for more efficient code that is used for S60 3rd Edition, -Feature Pack 1 and later SDKs.
In text mode stdio, fseek() to -the return value of ftell() does not behave as expected.
In text-mode, fread(), fwrite() and -their siblings will take approximately twice the time compared to binary mode. -This is because of extra code required to perform newline-translations in -text-mode.
P.I.P.S. applications built using the plug-in with this SDK, will not -run on earlier versions of runtimes.
stat() retrieves the modification time of a directory -incorrectly, if it was set (by utime()) to an odd value.
Owing to the difference in the Symbian platform model (when compared -to UNIX -like OS), fork() and exec() functions -are not supported.
Since fork() and exec() are not -supported, popen() is not complete. It will create a child -process and open a pipe between a parent and a child process either in read -or write mode. It does not copy the address space to a child.
The following are the limitations with waitpid(pid_t waitpid(pid_t -pid, int *stat_loc, int options);
- On OpenC there is no process group Ids. So, passing pid as 0 and -less than -1 does not work as intended.
- On OpenC, support is provided only for options - WNOHANG. -Others are not supported.
- The macros which related to job control which work on the stat_loc do -not work:
  - WIFSIGNALED
  - WTERMSIG
  - WIFSTOPPED
  - WSTOPSIG
  - WIFCONTINUED.
- On Symbian, the following additional macros that work on the stat_loc are -provided:
  - WIFTERMINATED
  - WTERMINATESTATUS
  - WIFPANICED
  - WPANICCODE
For int dup2(int oldfd, int newfd);, the return value -of dup2 can be different from the one the developer expected -it to be (newfd). So, the developer of dup2 should -use the return value of dup2 as the new allocated fd rather -than the one passed to dup2 (newfd). According to the standard, newfd and -return values are the same, if dup2 is successful.
Some of the APIs of Open C assume that a cleanup stack is created and -there is a top-level TRAP for the current thread. All the threads created -using RThread::Create() should create them explicitly.
In case of Open C, libc will have its own console -object maintained and all threads console I/O will be routed to the console. -In case of a hybrid application, if the application creates one more console, -then switching between these consoles will be a problem. The user may not -be aware of this problem.
In case of an emulator, the developer can configure the window size -dynamically. But the console maintained by Open C libc will -remain the same. So, if the configuration is changed, data displayed on the -console may not be aligned properly.

More detailed information about the limitations can be found in the P.I.P.S. -API reference documentation.

+ + + + + +Limitations +

Some APIs of the Standard C Library are not implemented because of the +constraints or limitations of Symbian platform:

AF_LOCAL sockets only support SO_SNDBUF and SO_RCVBUF in setsockopt and SO_TYPE, SO_SNDBUF and SO_RCVBUF in getsockopt. +No ioctl commands are available.
AF_LOCAL sockets do not support shutdown().
The stdioserver does not support per-process configurations.
Signals cannot be directed at an individual thread.
kill(self)/sigqueue(self)/raise() is +not synchronous in the current implementation.
Semantics of signal delivery is different from that of *nix OSes.
The tm_tzname in the struct tm is +not updated by localtime() and mktime(). +This is owing to a limitation of localisation resource files in these platforms. +The field will always be set to "UTC".
On S60 emulators started in textshell mode, the time +zone offset returns the wrong value. In GUI mode, the offset is set correctly.
The tm_isdst field in the struct tm (used in localtime() and mktime()) +is not updated properly on the S60 3rd Edition SDK and devices; the field +is simply set to -1.
mktime() and localtime() APIs +are about 3 times slower on the S60 3rd Edition SDK and devices, because of +lack of native support for more efficient code that is used for S60 3rd Edition, +Feature Pack 1 and later SDKs.
In text mode stdio, fseek() to +the return value of ftell() does not behave as expected.
In text-mode, fread(), fwrite() and +their siblings will take approximately twice the time compared to binary mode. +This is because of extra code required to perform newline-translations in +text-mode.
P.I.P.S. applications built using the plug-in with this SDK, will not +run on earlier versions of runtimes.
stat() retrieves the modification time of a directory +incorrectly, if it was set (by utime()) to an odd value.
Owing to the difference in the Symbian platform model (when compared +to UNIX -like OS), fork() and exec() functions +are not supported.
Since fork() and exec() are not +supported, popen() is not complete. It will create a child +process and open a pipe between a parent and a child process either in read +or write mode. It does not copy the address space to a child.
The following are the limitations with waitpid(pid_t waitpid(pid_t +pid, int *stat_loc, int options);
- On OpenC there is no process group Ids. So, passing pid as 0 and +less than -1 does not work as intended.
- On OpenC, support is provided only for options - WNOHANG. +Others are not supported.
- The macros which related to job control which work on the stat_loc do +not work:
  - WIFSIGNALED
  - WTERMSIG
  - WIFSTOPPED
  - WSTOPSIG
  - WIFCONTINUED.
- On Symbian, the following additional macros that work on the stat_loc are +provided:
  - WIFTERMINATED
  - WTERMINATESTATUS
  - WIFPANICED
  - WPANICCODE
For int dup2(int oldfd, int newfd);, the return value +of dup2 can be different from the one the developer expected +it to be (newfd). So, the developer of dup2 should +use the return value of dup2 as the new allocated fd rather +than the one passed to dup2 (newfd). According to the standard, newfd and +return values are the same, if dup2 is successful.
Some of the APIs of Open C assume that a cleanup stack is created and +there is a top-level TRAP for the current thread. All the threads created +using RThread::Create() should create them explicitly.
In case of Open C, libc will have its own console +object maintained and all threads console I/O will be routed to the console. +In case of a hybrid application, if the application creates one more console, +then switching between these consoles will be a problem. The user may not +be aware of this problem.
In case of an emulator, the developer can configure the window size +dynamically. But the console maintained by Open C libc will +remain the same. So, if the configuration is changed, data displayed on the +console may not be aligned properly.

More detailed information about the limitations can be found in the P.I.P.S. +API reference documentation.

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