add pthread_atfork interface

[musl] / src / thread / pthread_atfork.c

diff --git a/src/thread/pthread_atfork.c b/src/thread/pthread_atfork.c
new file mode 100644 (file)
index 0000000..0773dc8
--- /dev/null
+++ b/src/thread/pthread_atfork.c
@@ -0,0 +1,48 @@
+#include <pthread.h>
+#include "libc.h"
+
+static struct atfork_funcs {
+       void (*prepare)(void);
+       void (*parent)(void);
+       void (*child)(void);
+       struct atfork_funcs *prev, *next;
+} *funcs;
+
+static int lock;
+
+static void fork_handler(int who)
+{
+       struct atfork_funcs *p;
+       if (who < 0) {
+               LOCK(&lock);
+               for (p=funcs; p; p = p->next) {
+                       if (p->prepare) p->prepare();
+                       funcs = p;
+               }
+       } else {
+               for (p=funcs; p; p = p->prev) {
+                       if (!who && p->parent) p->parent();
+                       else if (who && p->child) p->child();
+                       funcs = p;
+               }
+               UNLOCK(&lock);
+       }
+}
+
+int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))
+{
+       struct atfork_funcs *new = malloc(sizeof *new);
+       if (!new) return -1;
+
+       LOCK(&lock);
+       libc.fork_handler = fork_handler;
+       new->next = funcs;
+       new->prev = 0;
+       new->prepare = prepare;
+       new->parent = parent;
+       new->child = child;
+       if (funcs) funcs->prev = new;
+       funcs = new;
+       UNLOCK(&lock);
+       return 0;
+}