From 4cb5e21ba809672b635d18c3750c2e1c4ee599a9 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Sun, 30 Jun 2024 02:26:06 -0700
Subject: [PATCH] Introduce pthread_decimate_np() api

This is useful with CheckForMemoryLeaks().
---
 libc/thread/pthread_decimate_np.c | 37 +++++++++++++++++++++++++++++++
 libc/thread/thread.h              |  1 +
 2 files changed, 38 insertions(+)
 create mode 100644 libc/thread/pthread_decimate_np.c

diff --git a/libc/thread/pthread_decimate_np.c b/libc/thread/pthread_decimate_np.c
new file mode 100644
index 000000000..a6bc591cf
--- /dev/null
+++ b/libc/thread/pthread_decimate_np.c
@@ -0,0 +1,37 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2024 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/thread/posixthread.internal.h"
+#include "libc/thread/thread.h"
+
+/**
+ * Garbage collects POSIX threads runtime.
+ *
+ * Let's say you want to run a memory leak detector. You can say:
+ *
+ *     while (!pthread_orphan_np())
+ *       pthread_decimate_np();
+ *
+ * To wait until all threads have exited.
+ *
+ * @return 0 on success, or errno on error
+ */
+int pthread_decimate_np(void) {
+  _pthread_decimate();
+  return 0;
+}
diff --git a/libc/thread/thread.h b/libc/thread/thread.h
index 76f372b49..a0eaf0167 100644
--- a/libc/thread/thread.h
+++ b/libc/thread/thread.h
@@ -166,6 +166,7 @@ int pthread_mutexattr_setpshared(pthread_mutexattr_t *, int) libcesque paramsnon
 int pthread_mutexattr_settype(pthread_mutexattr_t *, int) libcesque paramsnonnull();
 int pthread_once(pthread_once_t *, void (*)(void)) paramsnonnull();
 int pthread_orphan_np(void) libcesque;
+int pthread_decimate_np(void) libcesque;
 int pthread_rwlock_destroy(pthread_rwlock_t *) libcesque paramsnonnull();
 int pthread_rwlock_init(pthread_rwlock_t *, const pthread_rwlockattr_t *) libcesque paramsnonnull((1));
 int pthread_rwlock_rdlock(pthread_rwlock_t *) libcesque paramsnonnull();