1 files changed, 60 insertions, 5 deletions

diff --git a/boost/process/detail/posix/wait_group.hpp b/boost/process/detail/posix/wait_group.hpp
index ff2fe6d30d..9dc2498031 100644
--- a/boost/process/detail/posix/wait_group.hpp
+++ b/boost/process/detail/posix/wait_group.hpp
@@ -16,6 +16,7 @@
 #include <system_error>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
 namespace boost { namespace process { namespace detail { namespace posix {
 
@@ -61,8 +62,9 @@ inline bool wait_until(
     ::sigset_t  sigset;
     ::siginfo_t siginfo;
 
-    ::sigemptyset(&sigset);
-    ::sigaddset(&sigset, SIGCHLD);
+    sigemptyset(&sigset);
+    sigaddset(&sigset, SIGCHLD);
+
 
     auto get_timespec = 
             [](const Duration & dur)
@@ -84,6 +86,7 @@ inline bool wait_until(
         return false;
     }
 
+#if defined(BOOST_POSIX_HAS_SIGTIMEDWAIT)
     do
     {
         auto ts = get_timespec(time_out - Clock::now());
@@ -99,13 +102,65 @@ inline bool wait_until(
             return false; 
         }
 
-
         //check if we're done
         ret = ::waitid(P_PGID, p.grp, &siginfo, WEXITED | WNOHANG);
 
     } 
-    while (((ret != -1) || (errno != ECHILD)) && !(timed_out = (Clock::now() > time_out)))  ;
-   
+    while (((ret != -1) || (errno != ECHILD)) && !(timed_out = (Clock::now() > time_out)));
+#else
+    //if we do not have sigtimedwait, we fork off a child process  to get the signal in time
+    pid_t timeout_pid = ::fork();
+    if (timeout_pid == -1)
+    {
+        ec = boost::process::detail::get_last_error();
+        return true;
+    }
+    else if (timeout_pid == 0)
+    {
+        auto ts = get_timespec(time_out - Clock::now());
+        ::setpgid(0, p.grp);
+        ::nanosleep(&ts, nullptr);
+        ::exit(0);
+    }
+
+    struct child_cleaner_t
+    {
+        pid_t pid;
+        ~child_cleaner_t()
+        {
+            int res;
+            ::kill(pid, -15);
+            ::waitpid(pid, &res, WNOHANG);
+        }
+    };
+    child_cleaner_t child_cleaner{timeout_pid};
+
+    do
+    {
+        int ret_sig = 0;
+        int status;
+        if ((::waitpid(timeout_pid, &status, WNOHANG) != 0)
+            && (WIFEXITED(status) || WIFSIGNALED(status)))
+            ret = ::sigwait(&sigset, nullptr);
+        errno = 0;
+        if ((ret == SIGCHLD) && (old_sig.sa_handler != SIG_DFL) && (old_sig.sa_handler != SIG_IGN))
+            old_sig.sa_handler(ret);
+
+        ret = ::waitpid(-p.grp, &siginfo.si_status, 0); //so in case it exited, we wanna reap it first
+        if (ret == -1)
+        {
+            ec = get_last_error();
+            return false;
+        }
+
+        //check if we're done
+        ret = ::waitid(P_PGID, p.grp, &siginfo, WEXITED | WNOHANG);
+
+    }
+    while (((ret != -1) || (errno != ECHILD)) && !(timed_out = (Clock::now() > time_out)));
+
+#endif
+
     if (errno != ECHILD)
     {
         ec = boost::process::detail::get_last_error();