Request for review (S, UPDATED) 7017193: Small memory leak in get_stack_bounds // os::create_stack_guard_pages

[Daniel D. Daugherty]

On 2/24/2011 2:24 PM, Dmitry Samersoff wrote:
> [got mailer error for openjdk alias, so resending]
>
> Hi Everyone,
>
> Here is updated fix:
>
> http://cr.openjdk.java.net/~dsamersoff/7017193/webrev.03/

src/os/linux/vm/os_linux.cpp
    line 2662: should be /proc/self/maps

    line 2663: literal '128' should be 'sizeof(buf)'

    line 2664: original logic looks for line ending with "[stack]"
        and your new logic matches a line with "[stack]" anywhere.

    line 2666: You assume that you got a number here. The original
        code would have returned false.

    line 2667: You assert if '-' is not after the first unsigned
        number translated. The orignal code would have returned
        false in case of such a mis-format.

    line 2668: You assume that 'np' is valid here (in product).
        The original code would have returned false.
        The second param to the second strtoul() call should be
        NULL or (char*) NULL.


src/share/vm/runtime/os.cpp
    lines 1296-7 - space after '//'

    "const" on bsize parameter?

    line 1300: please consider adding this comment:
    // read until EOF, EOL or buf is full

    line 1305: please consider the following comment between lines
    1306 and 1307 instead:
        // EOL reached so ignore EOL character and return

    lines 1313-4: please consider the following comment between lines
    1315 and 1316 instead:
        // EOF reached. If we read chars before EOF, return them and
        // return EOF on next call. Otherwise, return EOF.

    line 1321: please move trailing ";" to next line, e.g.:

        while( read(fd, &ch, 1) == 1 && ch != '\n' )
            /* do nothing */ ;

    line 1323: please consider this comment instead:

    // Return initial part of line that fits in buf.
    // If we reached EOF, it will be returned on next call.


src/share/vm/runtime/os.hpp
    "const" on bsize parameter?

    Why add blank lines on 725-6?


>
> I introduce a new convenience function primary designed to read 
> variety of /proc files. It reads first N characters of line and then 
> skip until eol.
>
> Than get_stack_bounds() is changed to use it instead of stdio getline();
>
> -Dmitry
>