[RFC,v6,09/32] replay: introduce icount event

This patch adds icount event to the replay subsystem. This event corresponds
to execution of several instructions and used to synchronize input events
in the replay phase.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 replay/replay-internal.c |   14 ++++++++++++++
 replay/replay-internal.h |   18 ++++++++++++++++++
 replay/replay.c          |   45 +++++++++++++++++++++++++++++++++++++++++++++
 replay/replay.h          |    7 +++++++
 4 files changed, 84 insertions(+), 0 deletions(-)

On 2014/12/8 15:53, Pavel Dovgalyuk wrote:

> This patch adds icount event to the replay subsystem. This event corresponds
> to execution of several instructions and used to synchronize input events
> in the replay phase.
> 
> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
> ---
>  replay/replay-internal.c |   14 ++++++++++++++
>  replay/replay-internal.h |   18 ++++++++++++++++++
>  replay/replay.c          |   45 +++++++++++++++++++++++++++++++++++++++++++++
>  replay/replay.h          |    7 +++++++
>  4 files changed, 84 insertions(+), 0 deletions(-)
> 
> diff --git a/replay/replay-internal.c b/replay/replay-internal.c
> index 429b13c..83a53bd 100755
> --- a/replay/replay-internal.c
> +++ b/replay/replay-internal.c
> @@ -10,6 +10,7 @@
>   */
>  
>  #include "qemu-common.h"
> +#include "replay.h"
>  #include "replay-internal.h"
>  
>  volatile unsigned int replay_data_kind = -1;
> @@ -139,3 +140,16 @@ void replay_fetch_data_kind(void)
>          }
>      }
>  }
> +
> +/*! Saves cached instructions. */
> +void replay_save_instructions(void)
> +{
> +    if (replay_file && replay_mode == REPLAY_MODE_RECORD) {
> +        int diff = (int)(replay_get_current_step() - replay_state.current_step);
> +        if (first_cpu != NULL && diff > 0) {
> +            replay_put_event(EVENT_INSTRUCTION);
> +            replay_put_dword(diff);
> +            replay_state.current_step += diff;
> +        }
> +    }
> +}
> diff --git a/replay/replay-internal.h b/replay/replay-internal.h
> index 927f7c7..582b44c 100755
> --- a/replay/replay-internal.h
> +++ b/replay/replay-internal.h
> @@ -14,6 +14,17 @@
>  
>  #include <stdio.h>
>  
> +/* for instruction event */
> +#define EVENT_INSTRUCTION           32
> +
> +typedef struct ReplayState {
> +    /*! Current step - number of processed instructions and timer events. */
> +    uint64_t current_step;
> +    /*! Number of instructions to be executed before other events happen. */
> +    int instructions_count;
> +} ReplayState;
> +extern ReplayState replay_state;
> +
>  extern volatile unsigned int replay_data_kind;
>  extern volatile unsigned int replay_has_unread_data;
>  
> @@ -47,4 +58,11 @@ void replay_save_instructions(void);
>      Terminates the program in case of error. */
>  void validate_data_kind(int kind);
>  
> +/*! Skips async events until some sync event will be found. */
> +bool skip_async_events(int stop_event);
> +/*! Skips async events invocations from the input,
> +    until required data kind is found. If the requested data is not found
> +    reports an error and stops the execution. */
> +void skip_async_events_until(unsigned int kind);
> +
>  #endif
> diff --git a/replay/replay.c b/replay/replay.c
> index ac976b2..93d3d7e 100755
> --- a/replay/replay.c
> +++ b/replay/replay.c
> @@ -9,7 +9,10 @@
>   *
>   */
>  
> +#include "qemu-common.h"
>  #include "replay.h"
> +#include "replay-internal.h"
> +#include "qemu/timer.h"
>  
>  ReplayMode replay_mode = REPLAY_MODE_NONE;
>  /*! Stores current submode for PLAY mode */
> @@ -18,8 +21,50 @@ ReplaySubmode play_submode = REPLAY_SUBMODE_UNKNOWN;
>  /* Suffix for the disk images filenames */
>  char *replay_image_suffix;
>  
> +ReplayState replay_state;
>  
>  ReplaySubmode replay_get_play_submode(void)
>  {
>      return play_submode;
>  }
> +
> +bool skip_async_events(int stop_event)
> +{
> +    /* nothing to skip - not all instructions used */
> +    if (replay_state.instructions_count != 0
> +        && replay_has_unread_data) {
> +        return stop_event == EVENT_INSTRUCTION;
> +    }
> +
> +    bool res = false;

The variable declaration should be placed head of the function.

Regards,
-Gonglei

> +    while (true) {
> +        replay_fetch_data_kind();
> +        if (stop_event == replay_data_kind) {
> +            res = true;
> +        }
> +        switch (replay_data_kind) {
> +        case EVENT_INSTRUCTION:
> +            replay_state.instructions_count = replay_get_dword();
> +            return res;
> +        default:
> +            /* clock, time_t, checkpoint and other events */
> +            return res;
> +        }
> +    }
> +
> +    return res;
> +}
> +
> +void skip_async_events_until(unsigned int kind)
> +{
> +    if (!skip_async_events(kind)) {
> +        fprintf(stderr, "%"PRId64": Read data kind %d instead of expected %d\n",
> +            replay_get_current_step(), replay_data_kind, kind);
> +        exit(1);
> +    }
> +}
> +
> +uint64_t replay_get_current_step(void)
> +{
> +    return cpu_get_icount_raw();
> +}
> diff --git a/replay/replay.h b/replay/replay.h
> index 51a18fe..e40daf5 100755
> --- a/replay/replay.h
> +++ b/replay/replay.h
> @@ -12,6 +12,8 @@
>   *
>   */
>  
> +#include <stdbool.h>
> +#include <stdint.h>
>  #include "qapi-types.h"
>  
>  extern ReplayMode replay_mode;
> @@ -20,4 +22,9 @@ extern char *replay_image_suffix;
>  /*! Returns replay play submode */
>  ReplaySubmode replay_get_play_submode(void);
>  
> +/* Processing the instructions */
> +
> +/*! Returns number of executed instructions. */
> +uint64_t replay_get_current_step(void);
> +
>  #endif
> 
>