Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Handle possible counter overflow cases in scheduler tick #455

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Handle possible counter overflow cases in scheduler tick #455

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 26 additions & 5 deletions src/common/pf_scheduler.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -273,6 +273,7 @@ void pf_scheduler_init (pnet_t * net, uint32_t tick_interval)

net->scheduler_timeout_first = PF_MAX_TIMEOUTS; /* Nothing in queue */
net->scheduler_timeout_free = PF_MAX_TIMEOUTS; /* Nothing in queue. */
net->scheduler_previous_time = os_get_current_time_us();

if (net->scheduler_timeout_mutex == NULL)
{
Expand Down Expand Up @@ -443,20 +444,40 @@ void pf_scheduler_remove (pnet_t * net, pf_scheduler_handle_t * handle)
void pf_scheduler_tick (pnet_t * net)
{
uint32_t ix;
uint32_t when;
pf_scheduler_timeout_ftn_t ftn;
void * arg;
uint32_t pf_current_time = os_get_current_time_us();
uint32_t pf_previous_time = net->scheduler_previous_time;
net->scheduler_previous_time = pf_current_time;

os_mutex_lock (net->scheduler_timeout_mutex);

/* Send event to all expired delay entries. */
while ((net->scheduler_timeout_first < PF_MAX_TIMEOUTS) &&
((int32_t) (
pf_current_time -
net->scheduler_timeouts[net->scheduler_timeout_first].when) >= 0))
while (net->scheduler_timeout_first < PF_MAX_TIMEOUTS)
{
/* Unlink from busy list */
ix = net->scheduler_timeout_first;
when = net->scheduler_timeouts[ix].when;

/* Exit loop if not yet expired */
if (pf_current_time < when) {
if (pf_previous_time <= pf_current_time) {
/* Most common case; |--------PCW--------| */
break;
} else if (pf_previous_time > when) {
/* Overflow of both current time and when; |CW----------------P| */
break;
}
/* Else overflow of current time; |C-----------------PW| */
} else if (
pf_current_time > when &&
pf_previous_time > when &&
pf_previous_time <= pf_current_time) {
/* Overflow of when; |W-----------------PC| */
break;
}

/* Unlink from busy list */
pf_scheduler_unlink (net, &net->scheduler_timeout_first, ix);

ftn = net->scheduler_timeouts[ix].cb;
Expand Down
1 change: 1 addition & 0 deletions src/pf_types.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2614,6 +2614,7 @@ struct pnet
volatile uint32_t scheduler_timeout_free;
os_mutex_t * scheduler_timeout_mutex;
uint32_t scheduler_tick_interval; /* microseconds */
uint32_t scheduler_previous_time;
bool cmdev_initialized;
pf_device_t cmdev_device; /* APIs and diag items */
pf_cmina_dcp_ase_t cmina_nonvolatile_dcp_ase; /* Reflects what is/should be
Expand Down