1 files changed, 72 insertions, 0 deletions
diff --git a/src/libnetdata/os/waitid.c b/src/libnetdata/os/waitid.c
new file mode 100644
index 000000000..b78d704ed
--- /dev/null
+++ b/src/libnetdata/os/waitid.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+int os_waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options) {
+#if defined(HAVE_WAITID)
+    return waitid(idtype, id, infop, options);
+#else
+    // emulate waitid() using waitpid()
+
+    // a cache for WNOWAIT
+    static const struct pid_status empty = { 0, 0 };
+    static __thread struct pid_status last = { 0, 0 }; // the cache
+    struct pid_status current = { 0, 0 };
+
+    // zero the infop structure
+    memset(infop, 0, sizeof(*infop));
+
+    // from the infop structure we use only 3 fields:
+    // - si_pid
+    // - si_code
+    // - si_status
+    // so, we update only these 3
+
+    switch(idtype) {
+        case P_ALL:
+            current.pid = waitpid((pid_t)-1, &current.status, options);
+            if(options & WNOWAIT)
+                last = current;
+            else
+                last = empty;
+            break;
+
+        case P_PID:
+            if(last.pid == (pid_t)id) {
+                current = last;
+                last = empty;
+            }
+            else
+                current.pid = waitpid((pid_t)id, &current.status, options);
+
+            break;
+
+        default:
+            errno = ENOSYS;
+            return -1;
+    }
+
+    if (current.pid > 0) {
+        if (WIFEXITED(current.status)) {
+            infop->si_code = CLD_EXITED;
+            infop->si_status = WEXITSTATUS(current.status);
+        } else if (WIFSIGNALED(current.status)) {
+            infop->si_code = WTERMSIG(current.status) == SIGABRT ? CLD_DUMPED : CLD_KILLED;
+            infop->si_status = WTERMSIG(current.status);
+        } else if (WIFSTOPPED(current.status)) {
+            infop->si_code = CLD_STOPPED;
+            infop->si_status = WSTOPSIG(current.status);
+        } else if (WIFCONTINUED(current.status)) {
+            infop->si_code = CLD_CONTINUED;
+            infop->si_status = SIGCONT;
+        }
+        infop->si_pid = current.pid;
+        return 0;
+    } else if (current.pid == 0) {
+        // No change in state, depends on WNOHANG
+        return 0;
+    }
+
+    return -1;
+#endif
+}