add getrlimit and setrlimit wrappers

* README: Some rewording.

* configure.in: Check for getrlimit and setrlimit.

* libguile/posix.h:
* libguile/posix.c: Add some getrlimit and setrlimit wrappers. They're
  documented, but I suspect something else has to be done to get them
  into the manual.

README

@@ -229,10 +229,10 @@ that this is not the same "guile" as the one that is installed; this
 "guile" is a wrapper script that sets up the environment appropriately,
 then invokes the Guile binary.
 
-You may also build against an uninstalled Guile build tree. The
+You may also build external packages against an uninstalled Guile build
-"uninstalled-env" script in the "meta/" subdirectory will set up an
+tree. The "uninstalled-env" script in the "meta/" subdirectory will set
-environment with a path including "meta/", a modified dynamic linker
+up an environment with a path including "meta/", a modified dynamic
-path, a modified PKG_CONFIG_PATH, etc.
+linker path, a modified PKG_CONFIG_PATH, etc.
 
 For example, you can enter this environment via invoking
 

configure.in

@@ -883,6 +883,8 @@ if test -n "$have_sys_un_h" ; then
     [Define if the system supports Unix-domain (file-domain) sockets.])
 fi
 
+AC_CHECK_FUNCS(getrlimit setrlimit)
+
 AC_CHECK_FUNCS(socketpair getgroups setgroups setpwent pause tzset)
 
 AC_CHECK_FUNCS(sethostent   gethostent   endhostent   dnl

libguile/posix.c

@@ -33,6 +33,7 @@
 #include "libguile/srfi-13.h"
 #include "libguile/srfi-14.h"
 #include "libguile/vectors.h"
+#include "libguile/values.h"
 #include "libguile/lang.h"
 
 #include "libguile/validate.h"
@@ -463,6 +464,179 @@ SCM_DEFINE (scm_setgrent, "setgr", 0, 1, 0,
 #endif /* HAVE_GETGRENT */
 
 
+#ifdef HAVE_GETRLIMIT
+#ifdef RLIMIT_AS
+SCM_SYMBOL (sym_as, "as");
+#endif
+#ifdef RLIMIT_CORE
+SCM_SYMBOL (sym_core, "core");
+#endif
+#ifdef RLIMIT_CPU
+SCM_SYMBOL (sym_cpu, "cpu");
+#endif
+#ifdef RLIMIT_DATA
+SCM_SYMBOL (sym_data, "data");
+#endif
+#ifdef RLIMIT_FSIZE
+SCM_SYMBOL (sym_fsize, "fsize");
+#endif
+#ifdef RLIMIT_MEMLOCK
+SCM_SYMBOL (sym_memlock, "memlock");
+#endif
+#ifdef RLIMIT_MSGQUEUE
+SCM_SYMBOL (sym_msgqueue, "msgqueue");
+#endif
+#ifdef RLIMIT_NICE
+SCM_SYMBOL (sym_nice, "nice");
+#endif
+#ifdef RLIMIT_NOFILE
+SCM_SYMBOL (sym_nofile, "nofile");
+#endif
+#ifdef RLIMIT_NPROC
+SCM_SYMBOL (sym_nproc, "nproc");
+#endif
+#ifdef RLIMIT_RSS
+SCM_SYMBOL (sym_rss, "rss");
+#endif
+#ifdef RLIMIT_RTPRIO
+SCM_SYMBOL (sym_rtprio, "rtprio");
+#endif
+#ifdef RLIMIT_RTPRIO
+SCM_SYMBOL (sym_rttime, "rttime");
+#endif
+#ifdef RLIMIT_SIGPENDING
+SCM_SYMBOL (sym_sigpending, "sigpending");
+#endif
+#ifdef RLIMIT_STACK
+SCM_SYMBOL (sym_stack, "stack");
+#endif
+
+static int
+scm_to_resource (SCM s, const char *func, int pos)
+{
+  if (scm_is_number (s))
+    return scm_to_int (s);
+  
+  SCM_ASSERT_TYPE (scm_is_symbol (s), s, pos, func, "symbol");
+
+#ifdef RLIMIT_AS
+  if (s == sym_as)
+    return RLIMIT_AS;
+#endif
+#ifdef RLIMIT_CORE
+  if (s == sym_core)
+    return RLIMIT_CORE;
+#endif
+#ifdef RLIMIT_CPU
+  if (s == sym_cpu)
+    return RLIMIT_CPU;
+#endif
+#ifdef RLIMIT_DATA
+  if (s == sym_data)
+    return RLIMIT_DATA;
+#endif
+#ifdef RLIMIT_FSIZE
+  if (s == sym_fsize)
+    return RLIMIT_FSIZE;
+#endif
+#ifdef RLIMIT_MEMLOCK
+  if (s == sym_memlock)
+    return RLIMIT_MEMLOCK;
+#endif
+#ifdef RLIMIT_MSGQUEUE
+  if (s == sym_msgqueue)
+    return RLIMIT_MSGQUEUE;
+#endif
+#ifdef RLIMIT_NICE
+  if (s == sym_nice)
+    return RLIMIT_NICE;
+#endif
+#ifdef RLIMIT_NOFILE
+  if (s == sym_nofile)
+    return RLIMIT_NOFILE;
+#endif
+#ifdef RLIMIT_NPROC
+  if (s == sym_nproc)
+    return RLIMIT_NPROC;
+#endif
+#ifdef RLIMIT_RSS
+  if (s == sym_rss)
+    return RLIMIT_RSS;
+#endif
+#ifdef RLIMIT_RTPRIO
+  if (s == sym_rtprio)
+    return RLIMIT_RTPRIO;
+#endif
+#ifdef RLIMIT_RTPRIO
+  if (s == sym_rttime)
+    return RLIMIT_RTPRIO;
+#endif
+#ifdef RLIMIT_SIGPENDING
+  if (s == sym_sigpending)
+    return RLIMIT_SIGPENDING;
+#endif
+#ifdef RLIMIT_STACK
+  if (s == sym_stack)
+    return RLIMIT_STACK;
+#endif
+
+  scm_misc_error (func, "invalid rlimit resource ~A", scm_list_1 (s));
+  return 0;
+}
+  
+SCM_DEFINE (scm_getrlimit, "getrlimit", 1, 0, 0,
+            (SCM resource),
+	    "Get a resource limit for this process. @var{resource} identifies the resource,\n"
+            "either as an integer or as a symbol. For example, @code{(getrlimit 'stack)}\n"
+            "gets the limits associated with @code{RLIMIT_STACK}.\n\n"
+	    "@code{getrlimit} returns two values, the soft and the hard limit. If no\n"
+            "limit is set for the resource in question, the returned limit will be @code{#f}.")
+#define FUNC_NAME s_scm_getrlimit
+{
+  int iresource;
+  struct rlimit lim = { 0, 0 };
+  
+  iresource = scm_to_resource (resource, FUNC_NAME, 1);
+  
+  if (getrlimit (iresource, &lim) != 0)
+    scm_syserror (FUNC_NAME);
+
+  return scm_values (scm_list_2 ((lim.rlim_cur == RLIM_INFINITY) ? SCM_BOOL_F
+                                 : scm_from_long (lim.rlim_cur),
+                                 (lim.rlim_max == RLIM_INFINITY) ? SCM_BOOL_F
+                                 : scm_from_long (lim.rlim_max)));
+}
+#undef FUNC_NAME
+
+
+#ifdef HAVE_SETRLIMIT
+SCM_DEFINE (scm_setrlimit, "setrlimit", 3, 0, 0,
+            (SCM resource, SCM soft, SCM hard),
+	    "Set a resource limit for this process. @var{resource} identifies the resource,\n"
+            "either as an integer or as a symbol. @var{soft} and @var{hard} should be integers,\n"
+            "or @code{#f} to indicate no limit (i.e., @code{RLIM_INFINITY}).\n\n"
+            "For example, @code{(setrlimit 'stack 150000 300000)} sets the @code{RLIMIT_STACK}\n"
+            "limit to 150 kilobytes, with a hard limit of 300 kB.")
+#define FUNC_NAME s_scm_setrlimit
+{
+  int iresource;
+  struct rlimit lim = { 0, 0 };
+  
+  iresource = scm_to_resource (resource, FUNC_NAME, 1);
+  
+  lim.rlim_cur = (soft == SCM_BOOL_F) ? RLIM_INFINITY : scm_to_long (soft);
+  lim.rlim_max = (hard == SCM_BOOL_F) ? RLIM_INFINITY : scm_to_long (hard);
+
+  if (setrlimit (iresource, &lim) != 0)
+    scm_syserror (FUNC_NAME);
+
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+#endif /* HAVE_SETRLIMIT */
+#endif /* HAVE_GETRLIMIT */
+
+
 SCM_DEFINE (scm_kill, "kill", 2, 0, 0,
             (SCM pid, SCM sig),
 	    "Sends a signal to the specified process or group of processes.\n\n"

libguile/posix.h

@@ -41,6 +41,8 @@ SCM_API SCM scm_getpwuid (SCM user);
 SCM_API SCM scm_setpwent (SCM arg);
 SCM_API SCM scm_getgrgid (SCM name);
 SCM_API SCM scm_setgrent (SCM arg);
+SCM_API SCM scm_getrlimit (SCM resource);
+SCM_API SCM scm_setrlimit (SCM resource, SCM soft, SCM hard);
 SCM_API SCM scm_kill (SCM pid, SCM sig);
 SCM_API SCM scm_waitpid (SCM pid, SCM options);
 SCM_API SCM scm_status_exit_val (SCM status);