[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v2 12/12] replay: assert time only goes forward
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [PATCH v2 12/12] replay: assert time only goes forward |
Date: |
Wed, 5 Apr 2017 14:25:03 +0100 |
If we find ourselves trying to add an event to the log where time has
gone backwards it is because a vCPU event has occurred and the
main-loop is not yet aware of time moving forward. This should not
happen and if it does its better to fail early than generate a log
that will have weird behaviour.
Signed-off-by: Alex Bennée <address@hidden>
---
replay/replay-internal.c | 4 ++++
replay/replay.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index bea7b4aa6b..fca8514012 100644
--- a/replay/replay-internal.c
+++ b/replay/replay-internal.c
@@ -195,6 +195,10 @@ void replay_save_instructions(void)
if (replay_file && replay_mode == REPLAY_MODE_RECORD) {
replay_mutex_lock();
int diff = (int)(replay_get_current_step() -
replay_state.current_step);
+
+ /* Time can only go forward */
+ assert(diff >= 0);
+
if (diff > 0) {
replay_put_event(EVENT_INSTRUCTION);
replay_put_dword(diff);
diff --git a/replay/replay.c b/replay/replay.c
index 9e0724e756..f810628cac 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -84,6 +84,10 @@ void replay_account_executed_instructions(void)
if (replay_state.instructions_count > 0) {
int count = (int)(replay_get_current_step()
- replay_state.current_step);
+
+ /* Time can only go forward */
+ assert(count >= 0);
+
replay_state.instructions_count -= count;
replay_state.current_step += count;
if (replay_state.instructions_count == 0) {
--
2.11.0
- [Qemu-devel] [PATCH v2 05/12] cpus: remove icount handling from qemu_tcg_cpu_thread_fn, (continued)
- [Qemu-devel] [PATCH v2 05/12] cpus: remove icount handling from qemu_tcg_cpu_thread_fn, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 04/12] target/i386/misc_helper: wrap BQL around another IRQ generator, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 06/12] cpus: check cpu->running in cpu_get_icount_raw(), Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 01/12] scripts/qemugdb/mtree.py: fix up mtree dump, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 08/12] cpus: don't credit executed instructions before they have run, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 07/12] cpus: move icount preparation out of tcg_exec_cpu, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 09/12] cpus: introduce cpu_update_icount helper, Alex Bennée, 2017/04/05
- [Qemu-devel] [PATCH v2 12/12] replay: assert time only goes forward,
Alex Bennée <=
[Qemu-devel] [PATCH v2 11/12] cpus: call cpu_update_icount on read, Alex Bennée, 2017/04/05
[Qemu-devel] [PATCH v2 10/12] cpu-exec: update icount after each TB_EXIT, Alex Bennée, 2017/04/05