From 65431c5a724f35563a349b84f8ae3d1cdefca808 Mon Sep 17 00:00:00 2001
From: Mario Roy <marioeroy@gmail.com>
Date: Wed, 5 Jun 2024 22:43:54 -0500
Subject: [PATCH] Apply workaround for PDL srand

---
 lib/MCE.pm       | 43 ++++++++++++++++++++++++++++++++-----------
 lib/MCE/Child.pm | 39 +++++++++++++++++++++++++++++++--------
 2 files changed, 63 insertions(+), 19 deletions(-)

diff --git a/lib/MCE.pm b/lib/MCE.pm
index 09c55f4..5cf859e 100644
--- a/lib/MCE.pm
+++ b/lib/MCE.pm
@@ -641,7 +641,25 @@ sub spawn {
          for (0 .. $_max_workers - 1);
    }
 
-   $self->{_seed} = int(rand() * 1e9);
+   # The PDL module 2.062 ~ 2.089 exports its own srand() function, that
+   # silently clobbers Perl's srand function, and does not seed Perl's
+   # pseudo-random generator. https://perlmonks.org/?node_id=11159773
+
+   if ( $INC{'PDL/Primitive.pm'} && PDL::Primitive->can('srand') ) {
+      # Call PDL's random() function if exported i.e. use PDL.
+
+      my $caller = caller(); local $@;
+      $caller = caller(1) if ( $caller =~ /^MCE/ );
+      $caller = caller(2) if ( $caller =~ /^MCE/ );
+      $caller = caller(3) if ( $caller =~ /^MCE/ );
+
+      $self->{_seed} = eval "$caller->can('random')"
+         ? int(PDL::Primitive::random() * 1e9)
+         : int(CORE::rand() * 1e9);
+   }
+   else {
+      $self->{_seed} = int(CORE::rand() * 1e9);
+   }
 
    ## -------------------------------------------------------------------------
 
@@ -2010,24 +2028,27 @@ sub _dispatch {
    $self->{_is_thread} = $_is_thread;
    $self->{_pid}       = $_is_thread ? $$ .'.'. threads->tid() : $$;
 
+   if (!$self->{use_threads}) {
+      MCE::Child->_clear() if $INC{'MCE/Child.pm'};
+      MCE::Hobo->_clear() if $INC{'MCE/Hobo.pm'};
+   }
+
    ## Sets the seed of the base generator uniquely between workers.
    ## The new seed is computed using the current seed and $_wid value.
    ## One may set the seed at the application level for predictable
-   ## results (non-thread workers only). Ditto for Math::Prime::Util,
+   ## results (non-thread workers only). Ditto for PDL, Math::Prime::Util,
    ## Math::Random, and Math::Random::MT::Auto.
 
    {
-      my ($_wid, $_seed) = ($_args[1], $self->{_seed});
-      srand(abs($_seed - ($_wid * 100000)) % 2147483560);
+      my $_wid  = $_args[1];
+      my $_seed = abs($self->{_seed} - ($_wid * 100000)) % 2147483560;
 
-      if (!$self->{use_threads}) {
-         Math::Prime::Util::srand(abs($_seed - ($_wid * 100000)) % 2147483560)
-            if ( $INC{'Math/Prime/Util.pm'} );
+      CORE::srand($_seed);
 
-         MCE::Hobo->_clear()
-            if ( $INC{'MCE/Hobo.pm'} && MCE::Hobo->can('_clear') );
-
-         MCE::Child->_clear() if $INC{'MCE/Child.pm'};
+      if (!$self->{use_threads}) {
+         PDL::srand($_seed) if $INC{'PDL.pm'} && PDL->can('srand'); # PDL 2.062 ~ 2.089
+         PDL::srandom($_seed) if $INC{'PDL.pm'} && PDL->can('srandom'); # PDL 2.089_01+
+         Math::Prime::Util::srand($_seed) if $INC{'Math/Prime/Util.pm'};
       }
    }
 
diff --git a/lib/MCE/Child.pm b/lib/MCE/Child.pm
index c3ad0a9..501d166 100644
--- a/lib/MCE/Child.pm
+++ b/lib/MCE/Child.pm
@@ -109,8 +109,27 @@ sub init {
       $_LIST->{ $pkg } = MCE::Child::_ordhash->new();
       $_DELY->{ $pkg } = MCE::Child::_delay->new( $chnl );
       $_DATA->{ $pkg } = MCE::Child::_hash->new( $chnl );
-      $_DATA->{"$pkg:seed"} = int(rand() * 1e9);
-      $_DATA->{"$pkg:id"  } = 0;
+      $_DATA->{"$pkg:id"} = 0;
+
+      # The PDL module 2.062 ~ 2.089 exports its own srand() function, that
+      # silently clobbers Perl's srand function, and does not seed Perl's
+      # pseudo-random generator. https://perlmonks.org/?node_id=11159773
+
+      if ( $INC{'PDL/Primitive.pm'} && PDL::Primitive->can('srand') ) {
+         # Call PDL's random() function if exported i.e. use PDL.
+
+         my $caller = caller(); local $@;
+         $caller = caller(1) if ( $caller =~ /^MCE/ );
+         $caller = caller(2) if ( $caller =~ /^MCE/ );
+         $caller = caller(3) if ( $caller =~ /^MCE/ );
+
+         $_DATA->{"$pkg:seed"} = eval "$caller->can('random')"
+            ? int(PDL::Primitive::random() * 1e9)
+            : int(CORE::rand() * 1e9);
+      }
+      else {
+         $_DATA->{"$pkg:seed"} = int(CORE::rand() * 1e9);
+      }
 
       $MCE::_GMUTEX->unlock() if ( $_tid && $MCE::_GMUTEX );
    }
@@ -242,18 +261,22 @@ sub create {
          $_DATA->{ $_SELF->{PKG} }->set('S'.$$, '') unless $self->{IGNORE};
          CORE::kill($killed, $$) if $killed;
 
+         MCE::Child->_clear() if $INC{'MCE/Child.pm'};
+         MCE::Hobo->_clear() if $INC{'MCE/Hobo.pm'};
+
          # Sets the seed of the base generator uniquely between workers.
          # The new seed is computed using the current seed and ID value.
          # One may set the seed at the application level for predictable
-         # results. Ditto for Math::Prime::Util, Math::Random, and
+         # results. Ditto for PDL, Math::Prime::Util, Math::Random, and
          # Math::Random::MT::Auto.
 
-         srand( abs($_DATA->{"$pkg:seed"} - ($id * 100000)) % 2147483560 );
+         {
+            my $seed = abs($_DATA->{"$pkg:seed"} - ($id * 100000)) % 2147483560;
 
-         if ( $INC{'Math/Prime/Util.pm'} ) {
-            Math::Prime::Util::srand(
-                abs($_DATA->{"$pkg:seed"} - ($id * 100000)) % 2147483560
-            );
+            CORE::srand($seed);
+            PDL::srand($seed) if $INC{'PDL.pm'} && PDL->can('srand'); # PDL 2.062 ~ 2.089
+            PDL::srandom($seed) if $INC{'PDL.pm'} && PDL->can('srandom'); # PDL 2.089_01+
+            Math::Prime::Util::srand($seed) if $INC{'Math/Prime/Util.pm'};
          }
 
          if ( $INC{'Math/Random.pm'} ) {