Improve error reporting for process component on POSIX systems

STEllAR-GROUP · Sep 20, 2017 · 0f4b982 · 0f4b982
1 parent 0bc6e4e
commit 0f4b982
Showing 1 changed file with 20 additions and 4 deletions.
diff --git a/hpx/components/process/util/posix/initializers/throw_on_error.hpp b/hpx/components/process/util/posix/initializers/throw_on_error.hpp
@@ -16,32 +16,46 @@
 #include <hpx/components/process/util/posix/initializers/initializer_base.hpp>
 #include <hpx/runtime/serialization/serialization_fwd.hpp>
 #include <hpx/throw_exception.hpp>
+
 #include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <string.h>
+
+#include <string>
 
 namespace hpx { namespace components { namespace process { namespace posix {
 
 namespace initializers {
 
 class throw_on_error : public initializer_base
 {
+    std::string extract_error_string(int code)
+    {
+        constexpr std::size_t const buffer_len = 256;
+        char buffer[buffer_len+1];
+        strerror_r(code, buffer, buffer_len);
+        return buffer;
+    }
+
 public:
     template <class PosixExecutor>
     void on_fork_setup(PosixExecutor&) const
     {
         if (::pipe(fds_) == -1)
         {
             HPX_THROW_EXCEPTION(kernel_error,
-                "throw_on_error::on_fork_setup", "pipe(2) failed");
+                "throw_on_error::on_fork_setup",
+                "pipe(2) failed: " + extract_error_string(errno));
         }
         if (::fcntl(fds_[1], F_SETFD, FD_CLOEXEC) == -1)
         {
             ::close(fds_[0]);
             ::close(fds_[1]);
 
             HPX_THROW_EXCEPTION(kernel_error,
-                "throw_on_error::on_fork_setup", "fcntl(2) failed");
+                "throw_on_error::on_fork_setup",
+                "fcntl(2) failed: " + extract_error_string(errno));
         }
     }
 
@@ -52,7 +66,8 @@ class throw_on_error : public initializer_base
         ::close(fds_[1]);
 
         HPX_THROW_EXCEPTION(kernel_error,
-            "throw_on_error::on_fork_error", "fork(2) failed");
+            "throw_on_error::on_fork_error",
+            "fork(2) failed: " + extract_error_string(errno));
     }
 
     template <class PosixExecutor>
@@ -65,7 +80,8 @@ class throw_on_error : public initializer_base
             ::close(fds_[0]);
 
             HPX_THROW_EXCEPTION(kernel_error,
-                "throw_on_error::on_fork_success", "execve(2) failed");
+                "throw_on_error::on_fork_success",
+                "execve(2) failed: " + extract_error_string(code));
         }
         ::close(fds_[0]);
     }