2 files changed, 130 insertions, 0 deletions
diff --git a/src/libnetdata/completion/completion.c b/src/libnetdata/completion/completion.c
new file mode 100644
index 000000000..113423835
--- /dev/null
+++ b/src/libnetdata/completion/completion.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "completion.h"
+
+void completion_init(struct completion *p)
+{
+    p->completed = 0;
+    p->completed_jobs = 0;
+    fatal_assert(0 == uv_cond_init(&p->cond));
+    fatal_assert(0 == uv_mutex_init(&p->mutex));
+}
+
+void completion_destroy(struct completion *p)
+{
+    uv_cond_destroy(&p->cond);
+    uv_mutex_destroy(&p->mutex);
+}
+
+void completion_wait_for(struct completion *p)
+{
+    uv_mutex_lock(&p->mutex);
+    while (0 == p->completed) {
+        uv_cond_wait(&p->cond, &p->mutex);
+    }
+    fatal_assert(1 == p->completed);
+    uv_mutex_unlock(&p->mutex);
+}
+
+bool completion_timedwait_for(struct completion *p, uint64_t timeout)
+{
+    timeout *= NSEC_PER_SEC;
+
+    uint64_t start_time = uv_hrtime();
+    bool result = true;
+
+    uv_mutex_lock(&p->mutex);
+    while (!p->completed) {
+        int rc = uv_cond_timedwait(&p->cond, &p->mutex, timeout);
+
+        if (rc == 0) {
+            result = true;
+            break;
+        } else if (rc == UV_ETIMEDOUT) {
+            result = false;
+            break;
+        }
+
+        /*
+         * handle spurious wakeups
+        */
+
+        uint64_t elapsed = uv_hrtime() - start_time;
+        if (elapsed >= timeout) {
+            result = false;
+            break;
+        }
+        timeout -= elapsed;
+    }
+    uv_mutex_unlock(&p->mutex);
+
+    return result;
+}
+
+void completion_mark_complete(struct completion *p)
+{
+    uv_mutex_lock(&p->mutex);
+    p->completed = 1;
+    uv_cond_broadcast(&p->cond);
+    uv_mutex_unlock(&p->mutex);
+}
+
+unsigned completion_wait_for_a_job(struct completion *p, unsigned completed_jobs)
+{
+    uv_mutex_lock(&p->mutex);
+    while (0 == p->completed && p->completed_jobs <= completed_jobs) {
+        uv_cond_wait(&p->cond, &p->mutex);
+    }
+    completed_jobs = p->completed_jobs;
+    uv_mutex_unlock(&p->mutex);
+
+    return completed_jobs;
+}
+
+void completion_mark_complete_a_job(struct completion *p)
+{
+    uv_mutex_lock(&p->mutex);
+    p->completed_jobs++;
+    uv_cond_broadcast(&p->cond);
+    uv_mutex_unlock(&p->mutex);
+}
+
+bool completion_is_done(struct completion *p)
+{
+    bool ret;
+    uv_mutex_lock(&p->mutex);
+    ret = p->completed;
+    uv_mutex_unlock(&p->mutex);
+    return ret;
+}
diff --git a/src/libnetdata/completion/completion.h b/src/libnetdata/completion/completion.h
new file mode 100644
index 000000000..908ccfaf6
--- /dev/null
+++ b/src/libnetdata/completion/completion.h
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_COMPLETION_H
+#define NETDATA_COMPLETION_H
+
+#include "../libnetdata.h"
+
+struct completion {
+    uv_mutex_t mutex;
+    uv_cond_t cond;
+    volatile unsigned completed;
+    volatile unsigned completed_jobs;
+};
+
+void completion_init(struct completion *p);
+
+void completion_destroy(struct completion *p);
+
+void completion_wait_for(struct completion *p);
+
+// Wait for at most `timeout` seconds. Return true on success, false on
+// error or timeout.
+bool completion_timedwait_for(struct completion *p, uint64_t timeout);
+
+void completion_mark_complete(struct completion *p);
+
+unsigned completion_wait_for_a_job(struct completion *p, unsigned completed_jobs);
+void completion_mark_complete_a_job(struct completion *p);
+bool completion_is_done(struct completion *p);
+
+#endif /* NETDATA_COMPLETION_H */