+#include <assert.h>
+#include <errno.h>
+#include <poll.h>
+#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
-#include <signal.h>
+#include <unistd.h>
+#include "log.h"
#include "thread.h"
-
+
+using namespace std;
+
Thread::~Thread() {}
void Thread::run()
{
- should_stop = false;
- pthread_create(&worker_thread, NULL, &Thread::do_work_thunk, this);
+ should_stop_status = false;
+ pthread_create(&worker_thread, nullptr, &Thread::do_work_thunk, this);
}
void Thread::stop()
{
- should_stop = true;
- pthread_kill(worker_thread, SIGHUP);
- if (pthread_join(worker_thread, NULL) == -1) {
- perror("pthread_join");
+ {
+ lock_guard<mutex> lock(should_stop_mutex);
+ should_stop_status = true;
+ }
+ wakeup();
+ if (pthread_join(worker_thread, nullptr) == -1) {
+ log_perror("pthread_join");
exit(1);
}
}
void *Thread::do_work_thunk(void *arg)
{
Thread *thread = reinterpret_cast<Thread *>(arg);
+
+ // Block SIGHUP; only the main thread should see that.
+ // (This isn't strictly required, but it makes it easier to debug that indeed
+ // SIGUSR1 was what woke us up.)
+ sigset_t set;
+ sigemptyset(&set);
+ sigaddset(&set, SIGHUP);
+ int err = pthread_sigmask(SIG_BLOCK, &set, nullptr);
+ if (err != 0) {
+ errno = err;
+ log_perror("pthread_sigmask");
+ exit(1);
+ }
+
+ // Block SIGUSR1, and store the old signal mask.
+ sigemptyset(&set);
+ sigaddset(&set, SIGUSR1);
+ err = pthread_sigmask(SIG_BLOCK, &set, &thread->sigset_without_usr1_block);
+ if (err != 0) {
+ errno = err;
+ log_perror("pthread_sigmask");
+ exit(1);
+ }
+
+ // Call the right thunk.
thread->do_work();
- return NULL;
+ return nullptr;
+}
+
+bool Thread::wait_for_activity(int fd, short events, const struct timespec *timeout_ts)
+{
+ pollfd pfd;
+ pfd.fd = fd;
+ pfd.events = events;
+
+ for ( ;; ) {
+ int nfds = ppoll(&pfd, (fd == -1) ? 0 : 1, timeout_ts, &sigset_without_usr1_block);
+ if (nfds == -1 && errno == EINTR) {
+ return false;
+ }
+ if (nfds == -1) {
+ log_perror("poll");
+ usleep(100000);
+ continue;
+ }
+ assert(nfds <= 1);
+ return (nfds == 1);
+ }
}
+void Thread::wakeup()
+{
+ pthread_kill(worker_thread, SIGUSR1);
+}
+
+bool Thread::should_stop()
+{
+ lock_guard<mutex> lock(should_stop_mutex);
+ return should_stop_status;
+}