Skip to content

Commit

Permalink
Add pause duration report for contended lock access
Browse files Browse the repository at this point in the history
  • Loading branch information
@kdnilsen
kdnilsen committed Jul 18, 2022
1 parent 7a773ce commit e9efc91
Showing 1 changed file with 97 additions and 3 deletions.
100 changes: 97 additions & 3 deletions Extremem/src/main/java/com/amazon/corretto/benchmark/extremem/ConcurrencyControl.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,16 @@ class ConcurrencyControl extends ExtrememObject {
private long total_reader_waits;
private long total_writer_waits;

// Contended read and write delays are tallied in microseconds
private long total_contended_reads;
private long total_contended_read_delay;
private long maximum_contended_read_delay;

private long total_contended_writes;
private long total_contended_write_delay;
private long maximum_contended_write_delay;


private final String cc_id;

static synchronized int assignId() {
Expand Down Expand Up @@ -70,17 +80,31 @@ static synchronized int assignId() {
private synchronized void acquireLockForRead () {
waiting_readers++;
int num_waits = 0;
long start_time = -1;
Trace.msg(4, cc_id, ": acquiring read lock, contention(",
Integer.toString(waiting_readers), ", ",
Integer.toString(num_writers), ")");
while ((num_writers > 0) || (waiting_writers > 0)) {
try {
num_waits++;
if (num_waits++ == 0) {
start_time = System.nanoTime();
}
wait ();
} catch (InterruptedException x) {
; // ignore the interrupt, wait some more
}
}
if (start_time != -1) {
long stop_time = System.nanoTime();
long delay_ns = stop_time - start_time;
long delay_us = delay_ns / 1_000;
total_contended_read_delay += delay_us;
if (maximum_contended_read_delay < delay_us) {
maximum_contended_read_delay = delay_us;
}
total_contended_reads++;
}

if (num_waits < min_waits_per_read)
min_waits_per_read = num_waits;
if (num_waits > max_waits_per_read)
Expand All @@ -95,17 +119,31 @@ private synchronized void acquireLockForRead () {
private synchronized void acquireLockForWrite () {
waiting_writers++;
int num_waits = 0;
long start_time = -1;
Trace.msg(4, cc_id, ": acquring write lock, contention(",
Integer.toString(waiting_readers + num_readers), ", ",
Integer.toString(waiting_writers + num_writers), ")");
while ((num_readers > 0) || (num_writers > 0)) {
try {
num_waits++;
if (num_waits++ == 0) {
start_time = System.nanoTime();
}
wait ();
} catch (InterruptedException x) {
; // ignore the interrupt, wait some more
}
}
if (start_time != -1) {
long stop_time = System.nanoTime();
long delay_ns = stop_time - start_time;
long delay_us = delay_ns / 1_000;
total_contended_write_delay += delay_us;
if (maximum_contended_write_delay < delay_us) {
maximum_contended_write_delay = delay_us;
}
total_contended_writes++;
}

if (num_waits < min_waits_per_write)
min_waits_per_write = num_waits;
if (num_waits > max_waits_per_write)
Expand Down Expand Up @@ -181,6 +219,15 @@ void report(ExtrememThread t, boolean reportCSV) {
Report.output(" Total read requests: ", s);
Util.abandonEphemeralString(t, l);

s = Long.toString(total_contended_reads);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Total contended reads,", s);
else
Report.output(" Total contended reads: ", s);
Util.abandonEphemeralString(t, l);

s = Long.toString(total_reader_waits);
l = s.length();
Util.ephemeralString(t, l);
Expand All @@ -190,6 +237,25 @@ void report(ExtrememThread t, boolean reportCSV) {
Report.output(" requiring this many waits: ", s);
Util.abandonEphemeralString(t, l);

double average_delay_us = ((double) total_contended_read_delay) / total_contended_reads;
s = Double.toString(average_delay_us);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Average delay for contended read (microseconds),", s);
else
Report.output(" Average delay for contended read (microseconds): ", s);
Util.abandonEphemeralString(t, l);

s = Long.toString(maximum_contended_read_delay);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Maximum delay for contended read (microseconds),", s);
else
Report.output(" Maximum delay for contended read (microseconds): ", s);
Util.abandonEphemeralString(t, l);

float average;
int min, max;
if (total_reader_requests > 0) {
Expand Down Expand Up @@ -238,7 +304,16 @@ void report(ExtrememThread t, boolean reportCSV) {
else
Report.output(" Total writer requests: ", s);
Util.abandonEphemeralString(t, l);


s = Long.toString(total_contended_writes);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Total contended writes,", s);
else
Report.output(" Total contended writes: ", s);
Util.abandonEphemeralString(t, l);

s = Long.toString(total_writer_waits);
l = s.length();
Util.ephemeralString(t, l);
Expand All @@ -248,6 +323,25 @@ void report(ExtrememThread t, boolean reportCSV) {
Report.output(" requiring this many waits: ", s);
Util.abandonEphemeralString(t, l);

average_delay_us = ((double) total_contended_write_delay) / total_contended_writes;
s = Double.toString(average_delay_us);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Average delay for contended write (microseconds),", s);
else
Report.output(" Average delay for contended write (microseconds): ", s);
Util.abandonEphemeralString(t, l);

s = Long.toString(maximum_contended_write_delay);
l = s.length();
Util.ephemeralString(t, l);
if (reportCSV)
Report.output("Maximum delay for contended write (microseconds),", s);
else
Report.output(" Maximum delay for contended write (microseconds): ", s);
Util.abandonEphemeralString(t, l);

if (total_writer_requests > 0) {
average = ((float) total_writer_waits) / total_writer_requests;
min = min_waits_per_write;
Expand Down

0 comments on commit e9efc91

Please sign in to comment.