[Emacs-diffs] Changes to emacs/src/vm-limit.c

[Richard M. Stallman]

Index: emacs/src/vm-limit.c
diff -u emacs/src/vm-limit.c:1.17 emacs/src/vm-limit.c:1.18
--- emacs/src/vm-limit.c:1.17   Mon Feb 20 00:00:18 2006
+++ emacs/src/vm-limit.c        Sat Mar 11 15:23:45 2006
@@ -32,6 +32,9 @@
 #endif
 
 #include "mem-limits.h"
+#include <sys/resource.h>
+
+#define HAVE_GETRLIMIT
 
 #ifdef HAVE_GETRLIMIT
 #include <sys/resource.h>
@@ -44,13 +47,102 @@
   2 -- 85% warning already issued.
   3 -- 95% warning issued; keep warning frequently.
 */
-static int warnlevel;
+enum warnlevel { not_warned, warned_75, warned_85, warned_95 };
+
+static enum warnlevel warnlevel;
 
 /* Function to call to issue a warning;
    0 means don't issue them.  */
 static void (*warn_function) ();
 
-/* Get more memory space, complaining if we're near the end. */
+/* Start of data space; can be changed by calling malloc_init.  */
+static POINTER data_space_start;
+
+/* Number of bytes of writable memory we can expect to be able to get.  */
+static unsigned long lim_data;
+
+
+#ifdef NO_LIM_DATA
+static void
+get_lim_data ()
+{
+  lim_data = -1;
+}
+#else /* not NO_LIM_DATA */
+
+#ifdef USG
+
+static void
+get_lim_data ()
+{
+  extern long ulimit ();
+
+  lim_data = -1;
+
+  /* Use the ulimit call, if we seem to have it.  */
+#if !defined (ULIMIT_BREAK_VALUE) || defined (GNU_LINUX)
+  lim_data = ulimit (3, 0);
+#endif
+
+  /* If that didn't work, just use the macro's value.  */
+#ifdef ULIMIT_BREAK_VALUE
+  if (lim_data == -1)
+    lim_data = ULIMIT_BREAK_VALUE;
+#endif
+
+  lim_data -= (long) data_space_start;
+}
+
+#else /* not USG */
+#ifdef WINDOWSNT
+
+static void
+get_lim_data ()
+{
+  extern unsigned long reserved_heap_size;
+  lim_data = reserved_heap_size;
+}
+
+#else
+#if !defined (BSD4_2) && !defined (__osf__)
+
+#ifdef MSDOS
+void
+get_lim_data ()
+{
+  _go32_dpmi_meminfo info;
+
+  _go32_dpmi_get_free_memory_information (&info);
+  lim_data = info.available_memory;
+}
+#else /* not MSDOS */
+static void
+get_lim_data ()
+{
+  lim_data = vlimit (LIM_DATA, -1);
+}
+#endif /* not MSDOS */
+
+#else /* BSD4_2 */
+
+static void
+get_lim_data ()
+{
+  struct rlimit XXrlimit;
+
+  getrlimit (RLIMIT_DATA, &XXrlimit);
+#ifdef RLIM_INFINITY
+  lim_data = XXrlimit.rlim_cur & RLIM_INFINITY; /* soft limit */
+#else
+  lim_data = XXrlimit.rlim_cur;        /* soft limit */
+#endif
+}
+#endif /* BSD4_2 */
+#endif /* not WINDOWSNT */
+#endif /* not USG */
+#endif /* not NO_LIM_DATA */
+
+/* Verify amount of memory available, complaining if we're near the end. */
 
 static void
 check_memory_limits ()
@@ -64,14 +156,19 @@
   register POINTER cp;
   unsigned long five_percent;
   unsigned long data_size;
+  enum warnlevel new_warnlevel;
 
 #ifdef HAVE_GETRLIMIT
-  struct rlimit {
-    rlim_t rlim_cur;
-    rlim_t rlim_max;
-  } rlimit;
+  struct rlimit rlimit;
 
-  getrlimit (RLIMIT_DATA, &rlimit);
+  getrlimit (RLIMIT_AS, &rlimit);
+
+  if (RLIM_INFINITY == rlimit.rlim_max)
+    return;
+
+  /* This is a nonsensical case, but it happens -- rms.  */
+  if (rlimit.rlim_cur > rlimit.rlim_max)
+    return;
 
   five_percent = rlimit.rlim_max / 20;
   data_size = rlimit.rlim_cur;
@@ -93,57 +190,61 @@
 
 #endif /* not HAVE_GETRLIMIT */
 
-  if (warn_function)
-    switch (warnlevel)
-      {
-      case 0:
-       if (data_size > five_percent * 15)
-         {
-           warnlevel++;
-           (*warn_function) ("Warning: past 75% of memory limit");
-         }
-       break;
-
-      case 1:
-       if (data_size > five_percent * 17)
-         {
-           warnlevel++;
-           (*warn_function) ("Warning: past 85% of memory limit");
-         }
-       break;
-
-      case 2:
-       if (data_size > five_percent * 19)
-         {
-           warnlevel++;
-           (*warn_function) ("Warning: past 95% of memory limit");
-         }
-       break;
-
-      default:
-       (*warn_function) ("Warning: past acceptable memory limits");
-       break;
-      }
-
-  /* If we go down below 70% full, issue another 75% warning
-     when we go up again.  */
-  if (data_size < five_percent * 14)
-    warnlevel = 0;
-  /* If we go down below 80% full, issue another 85% warning
-     when we go up again.  */
-  else if (warnlevel > 1 && data_size < five_percent * 16)
-    warnlevel = 1;
-  /* If we go down below 90% full, issue another 95% warning
-     when we go up again.  */
-  else if (warnlevel > 2 && data_size < five_percent * 18)
-    warnlevel = 2;
+  if (!warn_function)
+    return;
+
+  /* What level of warning does current memory usage demand?  */
+  if (data_size > five_percent * 19)
+    new_warnlevel = warned_95;
+  else if (data_size > five_percent * 17)
+    new_warnlevel = warned_85;
+  else if (data_size > five_percent * 15)
+    new_warnlevel = warned_75;
+  else
+    new_warnlevel = not_warned;
+
+  /* If we have gone up a level, give the appropriate warning.  */
+  if (new_warnlevel > warnlevel || new_warnlevel == warned_95)
+    {
+      warnlevel = new_warnlevel;
+      switch (warnlevel)
+       {
+       case warned_75:
+         (*warn_function) ("Warning: past 75% of memory limit");
+         break;
+
+       case warned_85:
+         (*warn_function) ("Warning: past 85% of memory limit");
+         break;
+
+       case warned_95:
+         (*warn_function) ("Warning: past 95% of memory limit");
+       }
+    }
+  /* Handle going down in usage levels, with some hysteresis.  */
+  else
+    {
+      /* If we go down below 70% full, issue another 75% warning
+        when we go up again.  */
+      if (data_size < five_percent * 14)
+       warnlevel = not_warned;
+      /* If we go down below 80% full, issue another 85% warning
+        when we go up again.  */
+      else if (warnlevel > warned_75 && data_size < five_percent * 16)
+       warnlevel = warned_75;
+      /* If we go down below 90% full, issue another 95% warning
+        when we go up again.  */
+      else if (warnlevel > warned_85 && data_size < five_percent * 18)
+       warnlevel = warned_85;
+    }
 
   if (EXCEEDS_LISP_PTR (cp))
     (*warn_function) ("Warning: memory in use exceeds lisp pointer size");
 }
-
-/* Cause reinitialization based on job parameters;
-   also declare where the end of pure storage is. */
+
+/* Enable memory usage warnings.
+   START says where the end of pure storage is.
+   WARNFUN specifies the function to call to issue a warning.  */
 
 void
 memory_warnings (start, warnfun)
@@ -160,10 +261,8 @@
   warn_function = warnfun;
   __after_morecore_hook = check_memory_limits;
 
-#ifdef WINDOWSNT
   /* Force data limit to be recalculated on each run.  */
   lim_data = 0;
-#endif
 }
 
 /* arch-tag: eab04eda-1f69-447a-8d9f-95f0a3983ca5