merge revision(s) 32749:

	* vm.c (th_init): preallocate alternative stack.
	  NoMemoryError is better than rb_bug, of course.
	  Patch by Eric Wong. [ruby-core:38572][ruby-core:38594].

	* signal.c (rb_register_sigaltstack): ditto.

	* vm_core.h: moved ALT_STACK_SIZE definition from signal.c.

	* vm.c (thread_free): use xfree() instead of free().


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@32750 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 25 insertions, 12 deletions

diff --git a/ChangeLog b/ChangeLog
index 72d5dbe790..1c1d92f888 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Sat Jul 30 10:58:10 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* vm.c (th_init): preallocate alternative stack.
+	  NoMemoryError is better than rb_bug, of course.
+	  Patch by Eric Wong. [ruby-core:38572][ruby-core:38594].
+
+	* signal.c (rb_register_sigaltstack): ditto.
+
+	* vm_core.h: moved ALT_STACK_SIZE definition from signal.c.
+	* vm.c (thread_free): use xfree() instead of free().
+
 Sat Jul 30 07:20:49 2011  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/lib/socket.rb (udp_server_sockets): unused variable
diff --git a/signal.c b/signal.c
index 7bad8c1d8a..3b91616a7c 100644
--- a/signal.c
+++ b/signal.c
@@ -423,29 +423,22 @@ typedef RETSIGTYPE ruby_sigaction_t(int);
 #ifdef POSIX_SIGNAL
 
 #ifdef USE_SIGALTSTACK
-#ifdef SIGSTKSZ
-#define ALT_STACK_SIZE (SIGSTKSZ*2)
-#else
-#define ALT_STACK_SIZE (4*1024)
-#endif
 /* alternate stack for SIGSEGV */
 void
 rb_register_sigaltstack(rb_thread_t *th)
 {
     stack_t newSS, oldSS;
 
-    if (th->altstack) return;
+    if (!th->altstack)
+	rb_bug("rb_register_sigaltstack: th->altstack not initialized\n");
 
-    newSS.ss_sp = th->altstack = malloc(ALT_STACK_SIZE);
-    if (newSS.ss_sp == NULL)
-	/* should handle error */
-	rb_bug("rb_register_sigaltstack. malloc error\n");
+    newSS.ss_sp = th->altstack;
     newSS.ss_size = ALT_STACK_SIZE;
     newSS.ss_flags = 0;
 
     sigaltstack(&newSS, &oldSS); /* ignore error. */
 }
-#endif
+#endif /* USE_SIGALTSTACK */
 
 static sighandler_t
 ruby_signal(int signum, sighandler_t handler)
diff --git a/vm.c b/vm.c
index d945fba0d7..3c1e8b4113 100644
--- a/vm.c
+++ b/vm.c
@@ -1754,7 +1754,7 @@ thread_free(void *ptr)
 	else {
 #ifdef USE_SIGALTSTACK
 	    if (th->altstack) {
-		free(th->altstack);
+		xfree(th->altstack);
 	    }
 #endif
 	    ruby_xfree(ptr);
@@ -1826,6 +1826,9 @@ th_init(rb_thread_t *th, VALUE self)
     th->self = self;
 
     /* allocate thread stack */
+#ifdef USE_SIGALTSTACK
+    th->altstack = xmalloc(ALT_STACK_SIZE);
+#endif
     th->stack_size = RUBY_VM_THREAD_STACK_SIZE;
     th->stack = thread_recycle_stack(th->stack_size);
 
diff --git a/vm_core.h b/vm_core.h
index 678a515bdf..b5433f9094 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -383,6 +383,12 @@ struct rb_unblock_callback {
 
 struct rb_mutex_struct;
 
+#ifdef SIGSTKSZ
+#define ALT_STACK_SIZE (SIGSTKSZ*2)
+#else
+#define ALT_STACK_SIZE (4*1024)
+#endif
+
 typedef struct rb_thread_struct {
     VALUE self;
     rb_vm_t *vm;