Skip to content

FPGA: better fix for the concurrency issue in buffered_host_streaming #1392

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

Merged
merged 2 commits into from
Feb 28, 2023
Merged

FPGA: better fix for the concurrency issue in buffered_host_streaming #1392

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c76f2a7
implement Sophie's fix
yuguen Feb 28, 2023
c460769
fix indent
yuguen Feb 28, 2023
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
26 changes: 20 additions & 6 deletions ...amming/C++SYCL_FPGA/Tutorials/DesignPatterns/buffered_host_streaming/src/HostStreamer.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -222,6 +222,9 @@ class HostStreamer {
// queue (sycl_q_) to perform the request. It also performs the callbacks
// to the user code when the requests have been completed.
static void KernelLaunchAndWaitThread() {
size_t producer_count = 0;
size_t consumer_count = 0;

// Do this loop until told (by main thread) to stop via the
// 'kill_kernel_thread_flag_' atomic shared variable.
while (!kill_kernel_thread_flag_) {
Expand All @@ -238,6 +241,9 @@ class HostStreamer {

// pop from the Producer queue
produce_q_.Pop();

// accumulate producer count
producer_count += count;
}

// If there is a Consume request to launch, do it
Expand All @@ -247,12 +253,18 @@ class HostStreamer {
size_t count;
std::tie(buf_idx, count) = consume_q_.Front();

// launch the kernel and push the request to the launch queue
auto e = LaunchConsumerKernel(consumer_buffer_[buf_idx], count);
launch_q_.Push(std::make_tuple(buf_idx, count, e, false));
// Only launch consumer when there is enough producer count
if (producer_count >= consumer_count + count) {
// launch the kernel and push the request to the launch queue
auto e = LaunchConsumerKernel(consumer_buffer_[buf_idx], count);
launch_q_.Push(std::make_tuple(buf_idx, count, e, false));

// pop from the Consumer queue
consume_q_.Pop();
// pop from the Consumer queue
consume_q_.Pop();

// accumulate consumer count
consumer_count += count;
}
}

// Wait on the oldest event to finish given 2 conditions:
Expand All @@ -261,7 +273,7 @@ class HostStreamer {
// 2) the user has requested us to flush the launch queue and the
// launch queue is not empty (i.e. flush_ && launch_q_.size() != 0)
if ((launch_q_.Size() >= wait_threshold_) ||
(flush_ && !LaunchQueueEmpty() && ProducerQueueEmpty() && ConsumerQueueEmpty())) {
(flush_ && !LaunchQueueEmpty())) {
// grab the oldest request from the launch queue
size_t buf_idx;
size_t count;
Expand All @@ -276,9 +288,11 @@ class HostStreamer {
if (request_was_producer) {
//std::cout << "Calling Producer Callback" << std::endl;
producer_callback(count);
producer_count -= count;
} else {
//std::cout << "Calling Consumer Callback" << std::endl;
consumer_callback(consumer_buffer_[buf_idx], count);
consumer_count -= count;
}

// Pop from the launch queue. This has to be done AFTER waiting on
Expand Down