Re: ErrnoException
On 3/1/16 12:44 AM, Mike Parker wrote: On Tuesday, 1 March 2016 at 01:31:56 UTC, Jirka wrote: Ok, that would throw some OOM exception instead so I wouldn't need to bother with it, is there something else in the GC that would override it during class instance allocation? I am finding it weird that ErrnoException doesn't let you specify the errno value explicitly, you usually check it in your code anyway (e.g. for EINTR and repeat the operation and not throw this error). An additional constructor that accepts and errno value sounds like a good potential PR. Yes, please file an enhancement request. -Steve
Re: ErrnoException
On Tuesday, 1 March 2016 at 01:31:56 UTC, Jirka wrote: Ok, that would throw some OOM exception instead so I wouldn't need to bother with it, is there something else in the GC that would override it during class instance allocation? I am finding it weird that ErrnoException doesn't let you specify the errno value explicitly, you usually check it in your code anyway (e.g. for EINTR and repeat the operation and not throw this error). An additional constructor that accepts and errno value sounds like a good potential PR.
Re: ErrnoException
On Monday, 29 February 2016 at 23:41:51 UTC, Chris Wright wrote: On Mon, 29 Feb 2016 21:55:49 +, Jirka wrote: Yes, that I understand, but the "new" operator can lead to other system calls (?), could they overwrite it? Yes. Most obviously, the GC uses malloc, which will set errno to ENOMEM on failure. Ok, that would throw some OOM exception instead so I wouldn't need to bother with it, is there something else in the GC that would override it during class instance allocation? I am finding it weird that ErrnoException doesn't let you specify the errno value explicitly, you usually check it in your code anyway (e.g. for EINTR and repeat the operation and not throw this error).
Re: ErrnoException
On Mon, 29 Feb 2016 21:55:49 +, Jirka wrote: > Yes, that I understand, but the "new" operator can lead to other system > calls (?), could they overwrite it? Yes. Most obviously, the GC uses malloc, which will set errno to ENOMEM on failure.
Re: ErrnoException
On Sunday, 28 February 2016 at 14:59:22 UTC, Mike Parker wrote: On Sunday, 28 February 2016 at 13:10:20 UTC, Jirka wrote: I have a question about ErrnoException. When I throw it (throw new ErrnoException()), won't it overwrite the errno value before it can capture it? Its constructor [1] simply fetches the current errno and gets an error message from it. [1] https://github.com/D-Programming-Language/phobos/blob/master/std/exception.d#L1491 Yes, that I understand, but the "new" operator can lead to other system calls (?), could they overwrite it?
Re: ErrnoException
On Sunday, 28 February 2016 at 13:10:20 UTC, Jirka wrote: I have a question about ErrnoException. When I throw it (throw new ErrnoException()), won't it overwrite the errno value before it can capture it? Its constructor [1] simply fetches the current errno and gets an error message from it. [1] https://github.com/D-Programming-Language/phobos/blob/master/std/exception.d#L1491
ErrnoException
I have a question about ErrnoException. When I throw it (throw new ErrnoException()), won't it overwrite the errno value before it can capture it?
Re: ErrnoException in Windows
Thans guys! wenforce not sutable - error code is lost. may be, i will use modified wenforce, wich throws ErrnoException.
Re: ErrnoException in Windows
Ha, i found std.windows.syserror: WindowsException, wenforce;
Re: ErrnoException in Windows
On Sun, 01 Mar 2015 16:39:27 +, novice2 wrote: Could you, please, help me to understand, why code: 'cause winapi functions never sets `errno`. `errno` is a libc feature, and winapi knows nothing about libc. besides, `GetLastError()` is not required to return correct errno codes. so you have to either use libc funcions, or translate `GetLastError()` codes to errno manually. signature.asc Description: PGP signature
ErrnoException in Windows
Could you, please, help me to understand, why code:
import std.c.windows.windows;
import std.exception: ErrnoException;
import std.stdio: writefln;
import std.string: toStringz;
void main ()
{
CreateFileA(toStringz(nonexisting file name), GENERIC_READ,
FILE_SHARE_READ, null, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
null);
auto ex = new ErrnoException(CreateFileA);
writefln(ex.errno=%d, ex.msg=%s, lasterror=%d, ex.errno,
ex.msg, GetLastError());
}
prints:
ex.errno=0, ex.msg=CreateFileA (No error), lasterror=2
I wanted it will be:
ex.errno=2, ex.msg=CreateFileA (File not found), lasterror=2
Re: ErrnoException in Windows
On Sunday, 1 March 2015 at 16:39:29 UTC, novice2 wrote:
I wanted it will be:
ex.errno=2, ex.msg=CreateFileA (File not found), lasterror=2
Here's the right way to do this:
// test.d //
import std.c.windows.windows;
import std.string : toStringz;
import std.windows.syserror : wenforce;
void main ()
{
auto handle = CreateFileA(toStringz(nonexisting),
GENERIC_READ, FILE_SHARE_READ, null, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
null);
wenforce(handle != INVALID_HANDLE_VALUE, CreateFileA);
}
See std.windows.syserror for more information.
