From 34aea6f7ad99671b66b20533ddf0887729128618 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 10 Apr 2008 20:14:47 +0000
Subject: [PATCH] fix scheduler related to subprocesses

svn: r9240
---
 src/mzscheme/src/env.c    |  2 ++
 src/mzscheme/src/port.c   | 13 +++++++++----
 src/mzscheme/src/thread.c |  8 ++++++--
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/mzscheme/src/env.c b/src/mzscheme/src/env.c
index 0c602c3023..0055f88bed 100644
--- a/src/mzscheme/src/env.c
+++ b/src/mzscheme/src/env.c
@@ -403,6 +403,8 @@ Scheme_Env *scheme_basic_env()
 
   scheme_starting_up = 0;
 
+  --scheme_current_thread->suspend_break; /* created with breaks suspended */
+
 #ifdef TIME_STARTUP_PROCESS
   printf("done @ %ld\n#endif\n", scheme_get_process_milliseconds());
 #endif
diff --git a/src/mzscheme/src/port.c b/src/mzscheme/src/port.c
index 227f01a25a..190a2cd1c3 100644
--- a/src/mzscheme/src/port.c
+++ b/src/mzscheme/src/port.c
@@ -6483,10 +6483,10 @@ static void init_sigchld(void)
   }
 }
 
-void scheme_check_child_done()
+int scheme_check_child_done()
 {
   pid_t result;
-  int status;
+  int status, did_one = 0;
   System_Child *sc, *prev;
 
   if (scheme_system_children) {
@@ -6512,12 +6512,14 @@ void scheme_check_child_done()
             } else
               scheme_system_children = sc->next;
             
-            break;
+            did_one = 1;
           }
         }
       }
     } while (result > 0);
   }
+
+  return did_one;
 }
 
 #endif
@@ -7980,7 +7982,10 @@ void scheme_signal_received(void)
 {
 #if defined(FILES_HAVE_FDS)
   if (put_external_event_fd) {
-    write(put_external_event_fd, "!", 1);
+    int v;
+    do {
+      v = write(put_external_event_fd, "!", 1);
+    } while ((v == -1) && (errno == EINTR));
   }
 #endif
 #if defined(WINDOWS_PROCESSES) || defined(WINDOWS_FILE_HANDLES)
diff --git a/src/mzscheme/src/thread.c b/src/mzscheme/src/thread.c
index 048ed5e580..8b99bd8e75 100644
--- a/src/mzscheme/src/thread.c
+++ b/src/mzscheme/src/thread.c
@@ -96,7 +96,7 @@ extern HANDLE scheme_break_semaphore;
 #include "schfd.h"
 
 #if defined(UNIX_PROCESSES)
-extern void scheme_check_child_done();
+extern int scheme_check_child_done();
 #endif
 
 #define DEFAULT_INIT_STACK_SIZE 1000
@@ -2093,6 +2093,8 @@ static Scheme_Thread *make_thread(Scheme_Config *config,
     process->prev = NULL;
     process->next = NULL;
 
+    process->suspend_break = 1; /* until start-up finished */
+
     process->error_buf = &main_init_error_buf;
 
     thread_swap_callbacks = scheme_null;
@@ -2175,7 +2177,6 @@ static Scheme_Thread *make_thread(Scheme_Config *config,
 
   process->current_local_env = NULL;
 
-  process->suspend_break = 0;
   process->external_break = 0;
 
   process->ran_some = 1;
@@ -3457,6 +3458,9 @@ static int check_sleep(int need_activity, int sleep_now)
     if (needs_sleep_cancelled)
       return 0;
 
+    if (scheme_check_child_done())
+      return 0;
+
     if (post_system_idle()) {
       return 0;
     }