X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=liblttng-ust-comm%2Fust-cancelstate.c;fp=liblttng-ust-comm%2Fust-cancelstate.c;h=298ffcbe50f0e52235b020b906200c22b990e4d8;hb=595c15773def8e249145c4dead560ba7329810c7;hp=0000000000000000000000000000000000000000;hpb=1a3b8784434bb597b623100a591aeeb835fccf16;p=deliverable%2Flttng-ust.git

diff --git a/liblttng-ust-comm/ust-cancelstate.c b/liblttng-ust-comm/ust-cancelstate.c
new file mode 100644
index 00000000..298ffcbe
--- /dev/null
+++ b/liblttng-ust-comm/ust-cancelstate.c
@@ -0,0 +1,60 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2021 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <pthread.h>
+#include <errno.h>
+#include <error.h>
+#include <urcu/tls-compat.h>
+#include <lttng/ust-cancelstate.h>
+#include <usterr-signal-safe.h>
+
+struct ust_cancelstate {
+	int nesting;
+	int oldstate;	/* oldstate for outermost nesting */
+};
+
+static DEFINE_URCU_TLS(struct ust_cancelstate, thread_state);
+
+int lttng_ust_cancelstate_disable_push(void)
+{
+	struct ust_cancelstate *state = &URCU_TLS(thread_state);
+	int ret, oldstate;
+
+	if (state->nesting++)
+		goto end;
+	ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate);
+	if (ret) {
+		ERR("pthread_setcancelstate: %s", strerror(ret));
+		return -1;
+	}
+	state->oldstate = oldstate;
+end:
+	return 0;
+}
+
+int lttng_ust_cancelstate_disable_pop(void)
+{
+	struct ust_cancelstate *state = &URCU_TLS(thread_state);
+	int ret, oldstate;
+
+	if (!state->nesting)
+		return -1;
+	if (--state->nesting)
+		goto end;
+	ret = pthread_setcancelstate(state->oldstate, &oldstate);
+	if (ret) {
+		ERR("pthread_setcancelstate: %s", strerror(ret));
+		return -1;
+	}
+	if (oldstate != PTHREAD_CANCEL_DISABLE) {
+		ERR("pthread_setcancelstate: unexpected oldstate");
+		return -1;
+	}
+end:
+	return 0;
+}
+
+