From: Lancelot SIX <lsix@lancelotsix.com>
To: Tom Tromey <tromey@adacore.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH] Let user C-c when waiting for DWARF index finalization
Date: Wed, 14 Dec 2022 14:49:28 +0000 [thread overview]
Message-ID: <20221214144831.5ybamv6tpyrqsi53@ubuntu.lan> (raw)
In-Reply-To: <20221206192743.2827834-1-tromey@adacore.com>
On Tue, Dec 06, 2022 at 12:27:43PM -0700, Tom Tromey via Gdb-patches wrote:
> In PR gdb/29854, Simon pointed out that it would be good to be able to
> use C-c when the DWARF cooked index is waiting for finalization. The
> idea here is to be able to interrupt a command like "break" -- not to
> stop the finalization process itself, which runs in a worker thread.
>
> This patch implements this idea, by changing the index wait functions
> to, by default, allow a quit. Polling is done, because there doesn't
> seem to be a better way to interrupt a wait on a std::future.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29854
> ---
> gdb/dwarf2/cooked-index.c | 17 +++++++++++++++++
> gdb/dwarf2/cooked-index.h | 11 +++++------
> 2 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/gdb/dwarf2/cooked-index.c b/gdb/dwarf2/cooked-index.c
> index 0aa026c7779..a0b75a311b1 100644
> --- a/gdb/dwarf2/cooked-index.c
> +++ b/gdb/dwarf2/cooked-index.c
> @@ -25,6 +25,7 @@
> #include "ada-lang.h"
> #include "split-name.h"
> #include <algorithm>
> +#include <chrono>
>
> /* Hash function for cooked_index_entry. */
>
> @@ -282,6 +283,22 @@ cooked_index::find (gdb::string_view name, bool completing)
> return range (lower, upper);
> }
>
> +/* See cooked-index.h. */
> +
> +void
> +cooked_index::wait (bool allow_quit)
> +{
> + if (allow_quit)
> + {
> + using namespace std::chrono_literals;
> + auto duration = 15ms;
> + while (m_future.wait_for (duration) == std::future_status::timeout)
> + QUIT;
Hi,
Thanks for doing this!
I think the "ms" suffix from chrono_literals have been introduced in
c++14 which we do not support.
I guess that something like this should work for c++11:
std::chrono::milliseconds duration { 15 };
I still have on my todo list to ensure that major distros do have a
decent and easily installable c++14 compiler so we can bump this
requirement in gdb, but I have not done this yet…
Except for this, and for what it is worth, this patch looks nice!
Best,
Lancelot.
> + }
> + else
> + m_future.wait ();
> +}
> +
> cooked_index_vector::cooked_index_vector (vec_type &&vec)
> : m_vector (std::move (vec))
> {
> diff --git a/gdb/dwarf2/cooked-index.h b/gdb/dwarf2/cooked-index.h
> index 2ea32781be5..5412149588a 100644
> --- a/gdb/dwarf2/cooked-index.h
> +++ b/gdb/dwarf2/cooked-index.h
> @@ -212,10 +212,7 @@ class cooked_index
> void finalize ();
>
> /* Wait for this index's finalization to be complete. */
> - void wait ()
> - {
> - m_future.wait ();
> - }
> + void wait (bool allow_quit = true);
>
> friend class cooked_index_vector;
>
> @@ -325,8 +322,10 @@ class cooked_index_vector : public dwarf_scanner_base
> end up writing to freed memory. Waiting for finalization to
> complete avoids this problem; and the cost seems ignorable
> because creating and immediately destroying the debug info is a
> - relatively rare thing to do. */
> - wait ();
> + relatively rare thing to do. Do not allow quitting from this
> + wait. */
> + for (auto &item : m_vector)
> + item->wait (false);
> }
>
> /* A range over a vector of subranges. */
> --
> 2.34.3
>
next prev parent reply other threads:[~2022-12-14 14:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-06 19:27 Tom Tromey
2022-12-06 20:35 ` Simon Marchi
2022-12-14 14:49 ` Lancelot SIX [this message]
2022-12-14 18:00 ` Tom Tromey
2023-01-27 19:22 ` Tom Tromey
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