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Subject: Re: [boost] [interprocess] SHARING_VIOLATION due to antivirus
From: Lars Hagstrom (lars_at_[hidden])
Date: 2009-08-19 12:01:51


Yes, I quite expected Ion to move the constant to where all the other
constants are, at the top of that file. I didn't really mean for the
patch to go in as is (and I'm pretty sure Ion wouldn't anyway, my patch
isn't really in the same coding style...;-)

But you are right!

Lars

Stewart, Robert wrote:
> Lars Hagstrom wrote:
>> I made a quick patch to create_file in win32_api.hpp (the patch is
>> rather verbose, to make its workings obvious):
>>
>> static inline void *create_file(const char *name, unsigned
>> long access,
>> unsigned long creation_flags, unsigned long attributes = 0)
>> {
>> int tries = 0;
>> for (;;)
>> {
>> void * const res = CreateFileA(name, access,
>> file_share_read | file_share_write | file_share_delete,
>> 0, creation_flags, attributes, 0);
>> if (tries > 100)
>> {
>> //ran out of attempts, return and let the exceptions fly
>> return res;
>> }
>> if (res != invalid_handle_value)
>> {
>> //all went well, return
>> return res;
>> }
>> else if (GetLastError() != 32)
>> {
>> //we got some other error than an ERROR_SHARING_VIOLATION,
>> //let the caller handle the error.
>> return res;
>> }
>>
>> Sleep(1);
>> ++tries;
>> }
>> }
>
> I think this would be more readable and do the same:
>
> static inline void *
> create_file(const char * name, unsigned long access,
> unsigned long creation_flags, unsigned long attributes = 0)
> {
> for (int attempt(0); attempt < 100; ++attempt)
> {
> void * const handle(
> CreateFileA(name, access,
> file_share_read | file_share_write | file_share_delete,
> 0, creation_flags, attributes, 0));
> bool const invalid(invalid_handle_value == handle);
> if (!invalid)
> {
> return handle;
> }
> bool const sharing_violation(32 == GetLastError());
> if (!sharing_violation)
> {
> return handle;
> }
> Sleep(1);
> }
> return invalid_handle_value;
> }
>
> This makes the magic number more obvious, too (assuming it were to remain a magic number).
>
> _____
> Rob Stewart robert.stewart_at_[hidden]
> Software Engineer, Core Software using std::disclaimer;
> Susquehanna International Group, LLP http://www.sig.com
>
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