1 files changed, 7 insertions, 76 deletions

diff --git a/src/daemon/signals.c b/src/daemon/signals.c
index c014452b7..4e4d7c4d4 100644
--- a/src/daemon/signals.c
+++ b/src/daemon/signals.c
@@ -2,6 +2,12 @@
 
 #include "common.h"
 
+/*
+ * IMPORTANT: Libuv uv_spawn() uses SIGCHLD internally:
+ * https://github.com/libuv/libuv/blob/cc51217a317e96510fbb284721d5e6bc2af31e33/src/unix/process.c#L485
+ * Extreme care is needed when mixing and matching POSIX and libuv.
+ */
+
 typedef enum signal_action {
     NETDATA_SIGNAL_END_OF_LIST,
     NETDATA_SIGNAL_IGNORE,
@@ -9,7 +15,6 @@ typedef enum signal_action {
     NETDATA_SIGNAL_REOPEN_LOGS,
     NETDATA_SIGNAL_RELOAD_HEALTH,
     NETDATA_SIGNAL_FATAL,
-    NETDATA_SIGNAL_CHILD,
 } SIGNAL_ACTION;
 
 static struct {
@@ -25,7 +30,6 @@ static struct {
         { SIGHUP,  "SIGHUP",  0, NETDATA_SIGNAL_REOPEN_LOGS   },
         { SIGUSR2, "SIGUSR2", 0, NETDATA_SIGNAL_RELOAD_HEALTH },
         { SIGBUS,  "SIGBUS",  0, NETDATA_SIGNAL_FATAL         },
-        { SIGCHLD, "SIGCHLD", 0, NETDATA_SIGNAL_CHILD         },
 
         // terminator
         { 0,       "NONE",    0, NETDATA_SIGNAL_END_OF_LIST   }
@@ -93,18 +97,6 @@ void signals_init(void) {
     }
 }
 
-void signals_restore_SIGCHLD(void)
-{
-    struct sigaction sa;
-
-    sa.sa_flags = 0;
-    sigfillset(&sa.sa_mask);
-    sa.sa_handler = signal_handler;
-
-    if(sigaction(SIGCHLD, &sa, NULL) == -1)
-        netdata_log_error("SIGNAL: Failed to change signal handler for: SIGCHLD");
-}
-
 void signals_reset(void) {
     struct sigaction sa;
     sigemptyset(&sa.sa_mask);
@@ -118,64 +110,6 @@ void signals_reset(void) {
     }
 }
 
-// reap_child reaps the child identified by pid.
-static void reap_child(pid_t pid) {
-    siginfo_t i;
-
-    errno = 0;
-    netdata_log_debug(D_CHILDS, "SIGNAL: reap_child(%d)...", pid);
-    if (netdata_waitid(P_PID, (id_t)pid, &i, WEXITED|WNOHANG) == -1) {
-        if (errno != ECHILD)
-            netdata_log_error("SIGNAL: waitid(%d): failed to wait for child", pid);
-        else
-            netdata_log_info("SIGNAL: waitid(%d): failed - it seems the child is already reaped", pid);
-        return;
-    }
-    else if (i.si_pid == 0) {
-        // Process didn't exit, this shouldn't happen.
-        netdata_log_error("SIGNAL: waitid(%d): reports pid 0 - child has not exited", pid);
-        return;
-    }
-
-    switch (i.si_code) {
-        case CLD_EXITED:
-            netdata_log_info("SIGNAL: reap_child(%d) exited with code: %d", pid, i.si_status);
-            break;
-        case CLD_KILLED:
-            netdata_log_info("SIGNAL: reap_child(%d) killed by signal: %d", pid, i.si_status);
-            break;
-        case CLD_DUMPED:
-            netdata_log_info("SIGNAL: reap_child(%d) dumped core by signal: %d", pid, i.si_status);
-            break;
-        case CLD_STOPPED:
-            netdata_log_info("SIGNAL: reap_child(%d) stopped by signal: %d", pid, i.si_status);
-            break;
-        case CLD_TRAPPED:
-            netdata_log_info("SIGNAL: reap_child(%d) trapped by signal: %d", pid, i.si_status);
-            break;
-        case CLD_CONTINUED:
-            netdata_log_info("SIGNAL: reap_child(%d) continued by signal: %d", pid, i.si_status);
-            break;
-        default:
-            netdata_log_info("SIGNAL: reap_child(%d) gave us a SIGCHLD with code %d and status %d.", pid, i.si_code, i.si_status);
-            break;
-    }
-}
-
-// reap_children reaps all pending children which are not managed by myp.
-static void reap_children() {
-    siginfo_t i;
-
-    while(1) {
-        i.si_pid = 0;
-        if (netdata_waitid(P_ALL, (id_t)0, &i, WEXITED|WNOHANG|WNOWAIT) == -1 || i.si_pid == 0)
-            // nothing to do
-            return;
-
-        reap_child(i.si_pid);
-    }
-}
-
 void signals_handle(void) {
     while(1) {
 
@@ -183,6 +117,7 @@ void signals_handle(void) {
         // is delivered that either terminates the process or causes the invocation
         // of a signal-catching function.
         if(pause() == -1 && errno == EINTR) {
+            errno_clear();
 
             // loop once, but keep looping while signals are coming in
             // this is needed because a few operations may take some time
@@ -226,10 +161,6 @@ void signals_handle(void) {
                                 fatal("SIGNAL: Received %s. netdata now exits.", name);
                                 break;
 
-                            case NETDATA_SIGNAL_CHILD:
-                                reap_children();
-                                break;
-
                             default:
                                 netdata_log_info("SIGNAL: Received %s. No signal handler configured. Ignoring it.", name);
                                 break;