minix3/drivers/system/log/liveupdate.c

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2020-02-21 00:59:27 +05:30
#include "log.h"
/* State management variables. */
#define NR_DEVS 1 /* number of minor devices */
EXTERN struct logdevice logdevices[NR_DEVS];
/* State management helpers. */
static int is_read_pending;
static int is_select_callback_pending;
static void load_state_info(void)
{
int i, found_pending;
struct logdevice *log;
/* Check if reads or select callbacks are pending. */
is_read_pending = FALSE;
is_select_callback_pending = FALSE;
found_pending = FALSE;
for (i = 0; i < NR_DEVS && !found_pending; i++) {
log = &logdevices[i];
if(log->log_source != NONE) {
is_read_pending = TRUE;
}
if(log->log_selected) {
is_select_callback_pending = TRUE;
}
found_pending = (is_read_pending && is_select_callback_pending);
}
}
/* Custom states definition. */
#define LOG_STATE_SELECT_PROTOCOL_FREE (SEF_LU_STATE_CUSTOM_BASE + 0)
#define LOG_STATE_IS_CUSTOM(s) ((s) == LOG_STATE_SELECT_PROTOCOL_FREE)
/*===========================================================================*
* sef_cb_lu_prepare *
*===========================================================================*/
int sef_cb_lu_prepare(int state)
{
int is_ready;
/* Load state information. */
load_state_info();
/* Check if we are ready for the target state. */
is_ready = FALSE;
switch(state) {
/* Standard states. */
case SEF_LU_STATE_REQUEST_FREE:
is_ready = (!is_read_pending);
break;
case SEF_LU_STATE_PROTOCOL_FREE:
is_ready = (!is_read_pending && !is_select_callback_pending);
break;
/* Custom states. */
case LOG_STATE_SELECT_PROTOCOL_FREE:
is_ready = (!is_select_callback_pending);
break;
}
/* Tell SEF if we are ready. */
return is_ready ? OK : ENOTREADY;
}
/*===========================================================================*
* sef_cb_lu_state_isvalid *
*===========================================================================*/
int sef_cb_lu_state_isvalid(int state)
{
return SEF_LU_STATE_IS_STANDARD(state) || LOG_STATE_IS_CUSTOM(state);
}
/*===========================================================================*
* sef_cb_lu_state_dump *
*===========================================================================*/
void sef_cb_lu_state_dump(int state)
{
/* Load state information. */
load_state_info();
sef_lu_dprint("log: live update state = %d\n", state);
sef_lu_dprint("log: is_read_pending = %d\n", is_read_pending);
sef_lu_dprint("log: is_select_callback_pending = %d\n",
is_select_callback_pending);
sef_lu_dprint("log: SEF_LU_STATE_WORK_FREE(%d) reached = %d\n",
SEF_LU_STATE_WORK_FREE, TRUE);
sef_lu_dprint("log: SEF_LU_STATE_REQUEST_FREE(%d) reached = %d\n",
SEF_LU_STATE_REQUEST_FREE, (!is_read_pending));
sef_lu_dprint("log: SEF_LU_STATE_PROTOCOL_FREE(%d) reached = %d\n",
SEF_LU_STATE_PROTOCOL_FREE, (!is_read_pending
&& !is_select_callback_pending));
sef_lu_dprint("log: LOG_STATE_SELECT_PROTOCOL_FREE(%d) reached = %d\n",
LOG_STATE_SELECT_PROTOCOL_FREE, (!is_select_callback_pending));
}