Fix waiting for several processes. Add the test.

SIGCHLD signal could be triggered for several exited children. So
let's call waitpid untill no more children change state.

Fix #30

Makefile

@@ -11,10 +11,10 @@ GPRINSTALL_FLAGS = --prefix=$(PREFIX) --sources-subdir=$(INSTALL_INCLUDE_DIR)\
  --lib-subdir=$(INSTALL_ALI_DIR) --project-subdir=$(INSTALL_PROJECT_DIR)\
  --link-lib-subdir=$(INSTALL_LIBRARY_DIR)
 
-SPAWN_TESTS=.obj/spawn_test/spawn_test .obj/spawn_test/spawn_unexpected
+SPAWN_TESTS=spawn_test spawn_unexpected wait_all
 
 ifneq ($(OS),Windows_NT)
-   SPAWN_TESTS += .obj/spawn_test/spawn_kill .obj/spawn_test/spawn_stty
+   SPAWN_TESTS += spawn_kill spawn_stty
 endif
 
 all:
@@ -23,7 +23,7 @@ all:
 check:
 	export LD_LIBRARY_PATH=.libs/spawn/relocatable; \
 	for TEST in ${SPAWN_TESTS}; do \
-	  echo $$TEST; $$TEST; \
+	  echo $$TEST; .obj/spawn_test/$$TEST; \
 	done
 
 install:

gnat/spawn_tests.gpr

@@ -8,7 +8,9 @@ with "spawn";
 
 project Spawn_Tests is
 
-   Main := ("spawn_test.adb", "spawn_unexpected.adb", "spawn_stty.adb");
+   Main :=
+     ("spawn_test.adb", "spawn_unexpected.adb", "spawn_stty.adb",
+      "wait_all.adb");
 
    case Spawn.OS_API is
       when "unix" | "osx" =>

source/spawn/spawn-internal-monitor__posix.adb

@@ -139,37 +139,47 @@ package body Spawn.Internal.Monitor is
          return Imported (Status) /= 0;
       end WIFSIGNALED;
 
-      status : aliased Interfaces.C.unsigned := 0;
-      pid    : constant Interfaces.C.int :=
-        Posix.waitpid (-1, status'Unchecked_Access, Posix.WNOHANG);
-
-      Cursor  : constant Process_Maps.Cursor := Map.Find (pid);
+      status  : aliased Interfaces.C.unsigned := 0;
       Process : Process_Access;
 
    begin
-      if Process_Maps.Has_Element (Cursor) then
-         Process := Process_Maps.Element (Cursor);
+      loop
+         declare
+            pid : constant Interfaces.C.int :=
+              Posix.waitpid (-1, status'Unchecked_Access, Posix.WNOHANG);
 
-         Process.Exit_Status := (if WIFEXITED (status) then Normal else Crash);
+            Cursor : constant Process_Maps.Cursor := Map.Find (pid);
+         begin
+            exit when pid <= 0;  --  no more children change state
 
-         case Process.Exit_Status is
-            when Normal =>
-               Process.Exit_Code := Process_Exit_Code (WEXITSTATUS (status));
+            if Process_Maps.Has_Element (Cursor) then
+               Process := Process_Maps.Element (Cursor);
 
-            when Crash =>
-               Process.Exit_Code :=
-                 (if WIFSIGNALED (status)
-                  then Process_Exit_Code (WTERMSIG (status))
-                  else Process_Exit_Code'Last);
-         end case;
+               Process.Exit_Status :=
+                 (if WIFEXITED (status) then Normal else Crash);
 
-         if Spawn.Channels.Is_Active (Process.Channels) then
-            Process.Pending_Finish := True;
-         else
-            Process.Status := Not_Running;
-            Process.Emit_Finished (Process.Exit_Status, Process.Exit_Code);
-         end if;
-      end if;
+               case Process.Exit_Status is
+                  when Normal =>
+                     Process.Exit_Code :=
+                       Process_Exit_Code (WEXITSTATUS (status));
+
+                  when Crash =>
+                     Process.Exit_Code :=
+                       (if WIFSIGNALED (status)
+                        then Process_Exit_Code (WTERMSIG (status))
+                        else Process_Exit_Code'Last);
+               end case;
+
+               if Spawn.Channels.Is_Active (Process.Channels) then
+                  Process.Pending_Finish := True;
+               else
+                  Process.Status := Not_Running;
+                  Process.Emit_Finished
+                    (Process.Exit_Status, Process.Exit_Code);
+               end if;
+            end if;
+         end;
+      end loop;
    end Check_Children;
 
    -------------------

testsuite/spawn/wait_all.adb

@@ -0,0 +1,69 @@
+--
+--  Copyright (C) 2023, AdaCore
+--
+--  SPDX-License-Identifier: Apache-2.0
+--
+
+--  Spawn several subprocess and wait all of them is finished.
+
+with Ada.Command_Line;
+with Ada.Calendar;
+with Ada.Directories;
+
+with Spawn.String_Vectors;
+with Spawn.Processes;
+with Spawn.Processes.Monitor_Loop;
+
+procedure Wait_All is
+   use all type Spawn.Process_Status;
+
+   package Listeners is
+      type Listener is limited new Spawn.Processes.Process_Listener with record
+         Process : Spawn.Processes.Process;
+      end record;
+   end Listeners;
+
+   Command : constant String := Ada.Directories.Full_Name
+     (Ada.Command_Line.Command_Name);
+
+   Args : Spawn.String_Vectors.UTF_8_String_Vector;
+   List : array (1 .. 10) of aliased Listeners.Listener;
+
+begin
+   if Ada.Command_Line.Argument_Count > 0 then
+      --  Child process: wait next second boundary and exit
+      declare
+         Seconds : constant Duration :=
+           Ada.Calendar.Seconds (Ada.Calendar.Clock);
+
+         Sleep   : constant Duration :=
+          Duration (Integer (Seconds + 0.5)) - Seconds;
+      begin
+         delay Sleep;
+
+         return;
+      end;
+   end if;
+
+   Args.Append ("wait");
+
+   for Item of List loop
+      Item.Process.Set_Program (Command);
+      Item.Process.Set_Arguments (Args);
+      Item.Process.Set_Listener (Item'Unchecked_Access);
+      Item.Process.Start;
+   end loop;
+
+   for J in 1 .. 6 loop
+      Spawn.Processes.Monitor_Loop (0.001);
+      delay 0.5;
+
+      if (for all Item of List => Item.Process.Status = Not_Running) then
+         --  Success
+         return;
+      end if;
+   end loop;
+
+   --  Some process is till running
+   Ada.Command_Line.Set_Exit_Status (Ada.Command_Line.Failure);
+end Wait_All;