Bug fixes from the 5.6-fixes git branch.  This currently contains the

following bug fixes.

commit 167eaf7d283c6077b12e0b37dd7512a3163488c9

Author: David Matthews <dm@prolingua.co.uk>

Date:   Mon Apr 25 19:09:14 2016 +0100

    Only return the "status" value from "wait" if the result is non-zero.

    The calling code in the Posix structure converts the status result to a

    value of type exit_status even if the pid is zero.  The result is

    ignored in that case but it can result in a Fail exception if the

    status is invalid.

    (cherry picked from commit ba608ceb1dbc20db934bd01b0bccdd50c08ac4e9)

    # Conflicts:

    #   libpolyml/unix_specific.cpp

commit 3dea3b67470777d5dca3108cd957129464e8c2e6

Author: David Matthews <dm@prolingua.co.uk>

Date:   Fri Apr 22 14:15:17 2016 +0100

    Ensure the save vector is reset when sleeping in Posix.Process.sleep.

    This is almost the same as commit 57bc974 in basicio.cpp.

    (cherry picked from commit a66e52345ab56fe0af3e4862bb61a7f98a3da1db)

    # Conflicts:

    #   libpolyml/unix_specific.cpp

commit 3bd62174b2a306be50ed0b42f9ff783e6fd0218c

Author: James Clarke <jrtc27@jrtc27.com>

Date:   Tue Apr 12 21:58:22 2016 +0100

    Fix threadExited and interrupt_requested overlapping

    HAVE_PTHREAD isn't necessarily defined when processes.h is included, as

    it is defined in processes.cpp, but not when included by interpret.cpp.

    As a result, the root thread can believe that an interrupted thread has

    been killed, prematurely deleting its task data. This fixes #9.

    (cherry picked from commit 4ce6eee5829c256da2d2709787e19ea83a56f48c)

diff --git a/Tests/Fail/Test073.ML b/Tests/Fail/Test073.ML

new file mode 100644

index 0000000..d9bf6fc

--- /dev/null

+++ b/Tests/Fail/Test073.ML

@@ -0,0 +1,5 @@

+(* Testing Posix is a problem because the Posix structure is not available in Windows. *)

+(* This caused an assertion failure when the save vector overflowed. *)

+Posix.Process.sleep (Time.fromMilliseconds 15000);

+rubbish; (* Generate a "failure" i.e. the correct result *)

+

diff --git a/libpolyml/processes.h b/libpolyml/processes.h

index bf7dfc8..3bc7711 100644

--- a/libpolyml/processes.h

+++ b/libpolyml/processes.h

@@ -172,7 +172,7 @@ private:

 #ifdef HAVE_WINDOWS_H

     LONGLONG lastCPUTime; // Used for profiling

 #endif

-#ifdef HAVE_PTHREAD

+#if ((!defined(_WIN32) || defined(__CYGWIN__)) && defined(HAVE_LIBPTHREAD) && defined(HAVE_PTHREAD_H))

 public:

     bool threadExited;

 private:

diff --git a/libpolyml/unix_specific.cpp b/libpolyml/unix_specific.cpp

index a2624d8..095444e 100644

--- a/libpolyml/unix_specific.cpp

+++ b/libpolyml/unix_specific.cpp

@@ -383,7 +383,6 @@ static void restoreSignals(void)

 Handle OS_spec_dispatch_c(TaskData *taskData, Handle args, Handle code)

 {

     unsigned lastSigCount = receivedSignalCount; // Have we received a signal?

-    TryAgain:

     int c = get_C_long(taskData, DEREFWORDHANDLE(code));

     switch (c)

     {

@@ -580,27 +579,30 @@ Handle OS_spec_dispatch_c(TaskData *taskData, Handle args, Handle code)

         }

     case 21: /* Pause until signal. */

-        {

             /* This never returns.  When a signal is handled it will

                be interrupted. */

+       while (true)

+       {

             processes->ThreadPause(taskData);

             if (lastSigCount != receivedSignalCount)

                 raise_syscall(taskData, "Call interrupted by signal", EINTR);

-            goto TryAgain;

-        }

+       }

     case 22: /* Sleep until given time or until a signal.  Note: this is called

             with an absolute time as an argument and returns a relative time as

             result.  This RTS call is tried repeatedly until either the time has

             expired or a signal has occurred. */

+        while (true)

         {

             struct timeval tv;

             /* We have a value in microseconds.  We need to split

                it into seconds and microseconds. */

+            Handle hSave = taskData->saveVec.mark();

             Handle hTime = args;

             Handle hMillion = Make_arbitrary_precision(taskData, 1000000);

             unsigned long secs = get_C_ulong(taskData, DEREFWORDHANDLE(div_longc(taskData, hMillion, hTime)));

             unsigned long usecs = get_C_ulong(taskData, DEREFWORDHANDLE(rem_longc(taskData, hMillion, hTime)));

+            taskData->saveVec.reset(hSave);

             /* Has the time expired? */

             if (gettimeofday(&tv, NULL) != 0)

                 raise_syscall(taskData, "gettimeofday failed", errno);

@@ -613,11 +615,13 @@ Handle OS_spec_dispatch_c(TaskData *taskData, Handle args, Handle code)

                 processes->ThreadPause(taskData);

                 if (lastSigCount != receivedSignalCount)

                     raise_syscall(taskData, "Call interrupted by signal", EINTR);

-                goto TryAgain;

+                // And loop

+            }

+            else

+            {

+                processes->TestAnyEvents(taskData); // Check for interrupts anyway

+                return Make_arbitrary_precision(taskData, 0);

             }

-            else processes->TestAnyEvents(taskData); // Check for interrupts anyway

-

-            return Make_arbitrary_precision(taskData, 0);

         }

     case 23: /* Set uid. */

@@ -1252,7 +1256,7 @@ TryAgain:

     int callFlags = get_C_long(taskData, DEREFHANDLE(args)->Get(2));

     int flags = callFlags | WNOHANG; // Add in WNOHANG so we never block.

     pid_t pres = 0;

-    int status;

+    int status = 0;

     switch (kind)

     {

     case 0: /* Wait for any child. */

@@ -1288,7 +1292,7 @@ TryAgain:

     {

         Handle result, pidHandle, resHandle;

         pidHandle = Make_arbitrary_precision(taskData, pres);

-        resHandle = Make_arbitrary_precision(taskData, status);

+        resHandle = Make_arbitrary_precision(taskData, pres == 0 ? 0: status);

         result = ALLOC(2);

         DEREFHANDLE(result)->Set(0, DEREFWORDHANDLE(pidHandle));