From f0b4463b7d29b7b22d4dcb49859cbf4acc677afb Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Mon, 7 Nov 2005 23:41:10 +0000
Subject: implement __pthread_init_max_stacksize() which is required for
 FLOATING_STACKS

---
 libpthread/linuxthreads/internals.h |  1 +
 libpthread/linuxthreads/pthread.c   | 47 +++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

(limited to 'libpthread/linuxthreads')

diff --git a/libpthread/linuxthreads/internals.h b/libpthread/linuxthreads/internals.h
index a91682df1..98dcf4db2 100644
--- a/libpthread/linuxthreads/internals.h
+++ b/libpthread/linuxthreads/internals.h
@@ -283,6 +283,7 @@ extern size_t __pagesize;
 
 void __pthread_destroy_specifics(void);
 void __pthread_perform_cleanup(void);
+void __pthread_init_max_stacksize (void);
 int __pthread_initialize_manager(void);
 void __pthread_message(char * fmt, ...);
 int __pthread_manager(void *reqfd);
diff --git a/libpthread/linuxthreads/pthread.c b/libpthread/linuxthreads/pthread.c
index 5b038acb8..ad75b950d 100644
--- a/libpthread/linuxthreads/pthread.c
+++ b/libpthread/linuxthreads/pthread.c
@@ -214,6 +214,9 @@ char *__pthread_manager_thread_tos = NULL;
 int __pthread_exit_requested = 0;
 int __pthread_exit_code = 0;
 
+/* Maximum stack size.  */
+size_t __pthread_max_stacksize;
+
 /* Communicate relevant LinuxThreads constants to gdb */
 
 const int __pthread_threads_max = PTHREAD_THREADS_MAX;
@@ -314,6 +317,50 @@ void __pthread_initialize_minimal(void)
 }
 
 
+void
+__pthread_init_max_stacksize(void)
+{
+  struct rlimit limit;
+  size_t max_stack;
+
+  getrlimit(RLIMIT_STACK, &limit);
+#ifdef FLOATING_STACKS
+  if (limit.rlim_cur == RLIM_INFINITY)
+    limit.rlim_cur = ARCH_STACK_MAX_SIZE;
+# ifdef NEED_SEPARATE_REGISTER_STACK
+  max_stack = limit.rlim_cur / 2;
+# else
+  max_stack = limit.rlim_cur;
+# endif
+#else
+  /* Play with the stack size limit to make sure that no stack ever grows
+     beyond STACK_SIZE minus one page (to act as a guard page). */
+# ifdef NEED_SEPARATE_REGISTER_STACK
+  /* STACK_SIZE bytes hold both the main stack and register backing
+     store. The rlimit value applies to each individually.  */
+  max_stack = STACK_SIZE/2 - __getpagesize ();
+# else
+  max_stack = STACK_SIZE - __getpagesize();
+# endif
+  if (limit.rlim_cur > max_stack) {
+    limit.rlim_cur = max_stack;
+    setrlimit(RLIMIT_STACK, &limit);
+  }
+#endif
+  __pthread_max_stacksize = max_stack;
+#define __MAX_ALLOCA_CUTOFF 65536
+  if (max_stack / 4 < __MAX_ALLOCA_CUTOFF)
+    {
+#ifdef USE_TLS
+      pthread_descr self = THREAD_SELF;
+      self->p_alloca_cutoff = max_stack / 4;
+#else
+      __pthread_initial_thread.p_alloca_cutoff = max_stack / 4;
+#endif
+    }
+}
+
+
 static void pthread_initialize(void)
 {
   struct sigaction sa;
-- 
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