1 files changed, 116 insertions, 0 deletions
diff --git a/accel-pppd/extra/sigchld.c b/accel-pppd/extra/sigchld.c
new file mode 100644
index 00000000..abfd42f1
--- /dev/null
+++ b/accel-pppd/extra/sigchld.c
@@ -0,0 +1,116 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include "triton.h"
+#include "spinlock.h"
+#include "log.h"
+
+#include "sigchld.h"
+
+#include "memdebug.h"
+
+static LIST_HEAD(handlers);
+static int lock_refs;
+static pthread_mutex_t handlers_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t refs_cond = PTHREAD_COND_INITIALIZER;
+static pthread_t sigchld_thr;
+
+static void* sigchld_thread(void *arg)
+{
+	sigset_t set;
+	struct sigchld_handler_t *h, *h0;
+	pid_t pid;
+	int status, sig;
+
+	sigfillset(&set);
+	sigdelset(&set, SIGKILL);
+	sigdelset(&set, SIGSTOP);
+	pthread_sigmask(SIG_BLOCK, &set, NULL);
+
+	sigemptyset(&set);
+	sigaddset(&set, SIGCHLD);
+	sigaddset(&set, SIGQUIT);
+
+	while (1) {	
+		pid = waitpid(0, &status, 0);
+		if (pid < 0) {
+			if (errno == EINTR)
+				continue;
+			if (errno == ECHILD) {
+				sigwait(&set, &sig);
+				if (sig == SIGQUIT)
+					break;
+				continue;
+			}
+			log_error("sigchld: waitpid: %s\n", strerror(errno));
+			continue;
+		}
+
+		pthread_mutex_lock(&handlers_lock);
+		while (lock_refs)
+			pthread_cond_wait(&refs_cond, &handlers_lock);
+
+		h0 = NULL;
+		list_for_each_entry(h, &handlers, entry) {
+			if (h->pid == pid) {
+				h0 = h;
+				list_del(&h0->entry);
+				pthread_mutex_lock(&h0->lock);
+				break;
+			}
+		}
+		pthread_mutex_unlock(&handlers_lock);
+		if (h0) {
+			h0->handler(h0, WEXITSTATUS(status));
+			h0->pid = 0;
+			pthread_mutex_unlock(&h0->lock);
+		}
+	}
+
+	return NULL;
+}
+
+void __export sigchld_register_handler(struct sigchld_handler_t *h)
+{
+	pthread_mutex_init(&h->lock, NULL);
+
+	pthread_mutex_lock(&handlers_lock);
+	list_add_tail(&h->entry, &handlers);
+	pthread_mutex_unlock(&handlers_lock);
+}
+
+void __export sigchld_unregister_handler(struct sigchld_handler_t *h)
+{
+	pthread_mutex_lock(&handlers_lock);
+	pthread_mutex_lock(&h->lock);
+	if (h->pid) {
+		list_del(&h->entry);
+		h->pid = 0;
+	}
+	pthread_mutex_unlock(&h->lock);
+	pthread_mutex_unlock(&handlers_lock);
+}
+
+void __export sigchld_lock()
+{
+	pthread_mutex_lock(&handlers_lock);
+	++lock_refs;
+	pthread_mutex_unlock(&handlers_lock);
+}
+
+void __export sigchld_unlock()
+{
+	pthread_mutex_lock(&handlers_lock);
+	if (--lock_refs == 0)
+		pthread_cond_signal(&refs_cond);
+	pthread_mutex_unlock(&handlers_lock);
+}
+
+static void __init init(void)
+{
+	if (pthread_create(&sigchld_thr, NULL, sigchld_thread, NULL))
+		log_emerg("sigchld: pthread_create: %s\n", strerror(errno));
+}