Skip to content

Fix Underflow When Timer Created Inside Timer Handler #7

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

Closed
wants to merge 2 commits into from
Closed

Fix Underflow When Timer Created Inside Timer Handler #7

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
b100e37
Fix underflow when task created inside another task
cwfitzgerald Nov 17, 2019
8c8eba2
Add github issue link
cwfitzgerald Nov 17, 2019
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
8 changes: 7 additions & 1 deletion src/timer.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -92,7 +92,13 @@ class Timer {
struct task * const task = &tasks[i];
const unsigned long duration = t - task->start;

if (task->handler && duration >= task->expires) {
// Tasks that were generated by a task earlier in the loop could have
// a start time larger than the "current time" given as an argument.
//
// Check if t >= task->start to prevent the underflow from triggering tasks early.
//
// See https://github.com/contrem/arduino-timer/pull/7 for more info.
if (task->handler && t >= task->start && duration >= task->expires) {
task->repeat = task->handler(task->opaque) && task->repeat;

if (task->repeat) task->start = t;
Expand Down