1 files changed, 134 insertions, 0 deletions
diff --git a/accel-pptpd/sigchld.c b/accel-pptpd/sigchld.c
new file mode 100644
index 00000000..478f44c7
--- /dev/null
+++ b/accel-pptpd/sigchld.c
@@ -0,0 +1,134 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/signalfd.h>
+#include <sys/wait.h>
+
+#include "triton.h"
+#include "spinlock.h"
+#include "log.h"
+
+#include "sigchld.h"
+
+static LIST_HEAD(handlers);
+static int refs;
+static int sleeping = 1;
+static pthread_mutex_t handlers_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t refs_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static struct triton_context_t sigchld_ctx;
+
+static void sigchld_handler(void *arg)
+{
+	struct sigchld_handler_t *h, *h0;
+	pid_t pid;
+	int status;
+
+	while (1) {	
+		pid = waitpid(0, &status, WNOHANG);
+		pthread_mutex_lock(&handlers_lock);
+		if (pid == 0 || (pid == -1 && errno == ECHILD)) {
+			sleeping = 1;
+			pthread_mutex_unlock(&handlers_lock);
+			return;
+		} else if (pid < 0) {
+			pthread_mutex_unlock(&handlers_lock);
+			log_error("sigchld: waitpid: %s\n", strerror(errno));
+			return;
+		}
+		h0 = NULL;
+		list_for_each_entry(h, &handlers, entry) {
+			if (h->pid == pid) {
+				h0 = h;
+				pthread_mutex_lock(&h0->lock);
+				break;
+			}
+		}
+		pthread_mutex_unlock(&handlers_lock);
+		if (h0) {
+			h0->handler(h0, WEXITSTATUS(status));
+			list_del(&h0->entry);
+			h0->pid = 0;
+			pthread_mutex_unlock(&h0->lock);
+		}
+	}
+}
+
+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()
+{
+	sigset_t set;
+
+	pthread_mutex_lock(&refs_lock);
+	if (refs == 0) {
+		sigemptyset(&set);
+		sigaddset(&set, SIGCHLD);
+		sigprocmask(SIG_BLOCK, &set, NULL);
+	}
+	++refs;
+	pthread_mutex_unlock(&refs_lock);
+}
+
+void __export sigchld_unlock()
+{
+	sigset_t set;
+
+	pthread_mutex_lock(&refs_lock);
+	if (refs == 1) {
+		sigemptyset(&set);
+		sigaddset(&set, SIGCHLD);
+		sigprocmask(SIG_UNBLOCK, &set, NULL);
+	}
+	--refs;
+	pthread_mutex_unlock(&refs_lock);
+
+}
+
+static void sigchld(int num)
+{
+	int s;
+	
+	pthread_mutex_lock(&handlers_lock);
+	s = sleeping;
+	sleeping = 0;
+	pthread_mutex_unlock(&handlers_lock);
+
+	if (s)
+		triton_context_call(&sigchld_ctx, sigchld_handler, NULL);
+}
+
+static void __init init(void)
+{
+	struct sigaction sa_sigchld = {
+		.sa_handler = sigchld,
+		.sa_flags = SA_NOCLDSTOP,
+	};
+
+	if (sigaction(SIGCHLD, &sa_sigchld, NULL)) {
+		fprintf(stderr, "sigchld: sigaction: %s\n", strerror(errno));
+		return;
+	}
+
+	triton_context_register(&sigchld_ctx, NULL);
+}