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digitalmars.D.bugs - [Heisenbug] std.stream.File opening fails in certain circumstances for apparently no reason at all

reply Stewart Gordon <Stewart_member pathlink.com> writes:
Using DMD 0.101, Windows 98SE.

This code is part of an attempt to add message logging to my SDWF, inserted into
the WindowBase 
class in, unsurprisingly, windowbase.d.  It is totally driving me mad to figure
why it won't work.

Having built the lib with -debug=messageLog throughout, and then built an SDWF
app (such as skel), it 
just refuses to open the output file.  It gets as far as giving me the messages
"Opened log file", "Not 
open" and then the fatal exception "unable to write to stream".

There are two things wrong here.  Firstly that the file fails to open, and
secondly that the File 
constructor isn't telling me this via an exception.

----------
debug (messageLog) {
static {
File messageLogFile;
}

static this() {
messageLogFile = new File("messages.log", FileMode.Out);
MessageBoxA(null, "Opened log file", "Debug", MB_OK);

MessageBoxA(null, messageLogFile.isOpen ? "Not open" : "Open",
"Debug", MB_OK);

messageLogFile.writeLine("Opened log file");
MessageBoxA(null, "Written to log file", "Debug", MB_OK);
}
}
----------

The same bug occurs if I use FileMode.OutNew, or use File.create or File.open
instead of opening it in 
the constructor.  And it doesn't seem to matter whether I link with sdwf.lib,
link all the .obj files 
together or compile the .d files in one go.  Or take away the embracing as debug
code.

I cannot for the life of me determine what's peculiar here.  All attempts to
reduce the problem to a 
small, self-contained program have proven fruitless.

Does anyone have the slightest idea what can cause this failure?  It's
definitely nothing to do with a full 
or write-protected disk, or anything like that!

Stewart.
Sep 21 2004
parent reply "Ben Hinkle" <bhinkle mathworks.com> writes:
"Stewart Gordon" <Stewart_member pathlink.com> wrote in message
news:cipb56$14ne$1 digitaldaemon.com...
 Using DMD 0.101, Windows 98SE.

 This code is part of an attempt to add message logging to my SDWF,

 the WindowBase
 class in, unsurprisingly, windowbase.d.  It is totally driving me mad to

 why it won't work.

 Having built the lib with -debug=messageLog throughout, and then built an

 app (such as skel), it
 just refuses to open the output file.  It gets as far as giving me the

 "Opened log file", "Not
 open" and then the fatal exception "unable to write to stream".

 There are two things wrong here.  Firstly that the file fails to open, and
 secondly that the File
 constructor isn't telling me this via an exception.

 ----------
 debug (messageLog) {
 static {
 File messageLogFile;
 }

 static this() {
 messageLogFile = new File("messages.log", FileMode.Out);
 MessageBoxA(null, "Opened log file", "Debug", MB_OK);

 MessageBoxA(null, messageLogFile.isOpen ? "Not open" : "Open",
 "Debug", MB_OK);

 messageLogFile.writeLine("Opened log file");
 MessageBoxA(null, "Written to log file", "Debug", MB_OK);
 }
 }
 ----------

 The same bug occurs if I use FileMode.OutNew, or use File.create or

 instead of opening it in
 the constructor.  And it doesn't seem to matter whether I link with

 link all the .obj files
 together or compile the .d files in one go.  Or take away the embracing as

 code.

 I cannot for the life of me determine what's peculiar here.  All attempts

 reduce the problem to a
 small, self-contained program have proven fruitless.

 Does anyone have the slightest idea what can cause this failure?  It's
 definitely nothing to do with a full
 or write-protected disk, or anything like that!

 Stewart.

Very wierd. When I use the phobos.lib that is in the zip file for dmd-101 then it does all kinds of strange things like giving an Access Violation when I try to close or it creates empty files or it errors with "Invalid UTF-8 sequence" or "File '' not found". When I recompile phobos it works fine. Can you try recompiling phobos? -Ben
Sep 21 2004
parent reply Stewart Gordon <Stewart_member pathlink.com> writes:
In article <cipens$17ki$1 digitaldaemon.com>, Ben Hinkle says...
<snip>
 It gets as far as giving me the messages "Opened log file", "Not 
 open" and then the fatal exception "unable to write to stream".


Oops, I don't know how I managed to get my sense of "open" vs. "not open" mixed up. The file _is_ opening, and further debugging messages indicate that messageLogFile.writeable == true && messageLogFile.readable == false as expected. It's not until I try to actually do some writing that something goes wrong. <snip>
 Very wierd.  When I use the phobos.lib that is in the zip file for 
 dmd-101 then it does all kinds of strange things like giving an 
 Access Violation when I try to close or it creates empty files or 
 it errors with "Invalid UTF-8 sequence" or "File '' not found".  
 When I recompile phobos it works fine.  Can you try recompiling 
 phobos?

It seems that recompiling Phobos does sometimes work wonders, but sadly for me it hasn't worked this one. But then again, SDWF has progressed a bit on my box. (As has Phobos for that matter.) But not in ways that should've broken code that doesn't depend on it. But I'll try again with DMD 0.102.... Stewart.
Sep 22 2004
parent Stewart Gordon <Stewart_member pathlink.com> writes:
In article <cirj0p$28dd$1 digitaldaemon.com>, Stewart Gordon says...
<snip>
But I'll try again with DMD 0.102....

Done, and the problem has disappeared. Time to get back to fixing the bugs that I can now finally diagnose.... Stewart.
Sep 23 2004