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Fix an async signal delivery flake on Windows

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This commit is contained in:
Justine Tunney 2024-10-02 04:55:06 -07:00
parent e4d6eb382a
commit 85c58be942
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GPG key ID: BE714B4575D6E328
2 changed files with 107 additions and 46 deletions
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46
test/posix/signal_latency_async_test.c
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@ -27,6 +27,7 @@ pthread_t sender_thread;
pthread_t receiver_thread;
struct timespec send_time;
atomic_int sender_got_signal;
atomic_int receiver_got_signal;
double latencies[ITERATIONS];
void sender_signal_handler(int signo) {
@ -34,24 +35,7 @@ void sender_signal_handler(int signo) {
}
void receiver_signal_handler(int signo) {
struct timespec receive_time;
clock_gettime(CLOCK_MONOTONIC, &receive_time);
long sec_diff = receive_time.tv_sec - send_time.tv_sec;
long nsec_diff = receive_time.tv_nsec - send_time.tv_nsec;
double latency_ns = sec_diff * 1e9 + nsec_diff;
static int iteration = 0;
if (iteration < ITERATIONS)
latencies[iteration++] = latency_ns;
// Pong sender
if (pthread_kill(sender_thread, SIGUSR2))
exit(2);
// Exit if done
if (iteration >= ITERATIONS)
pthread_exit(0);
receiver_got_signal = 1;
}
void *sender_func(void *arg) {
@ -84,9 +68,29 @@ void *sender_func(void *arg) {
void *receiver_func(void *arg) {
// Wait for asynchronous signals
volatile unsigned v = 0;
for (;;)
++v;
for (;;) {
if (atomic_exchange_explicit(&receiver_got_signal, 0,
memory_order_acq_rel)) {
struct timespec receive_time;
clock_gettime(CLOCK_MONOTONIC, &receive_time);
long sec_diff = receive_time.tv_sec - send_time.tv_sec;
long nsec_diff = receive_time.tv_nsec - send_time.tv_nsec;
double latency_ns = sec_diff * 1e9 + nsec_diff;
static int iteration = 0;
if (iteration < ITERATIONS)
latencies[iteration++] = latency_ns;
// Pong sender
if (pthread_kill(sender_thread, SIGUSR2))
exit(2);
// Exit if done
if (iteration >= ITERATIONS)
pthread_exit(0);
}
}
return 0;
}