rough EV_FEATURES implementation

Changes

@@ -1,9 +1,10 @@
 Revision history for libev, a high-performance and full-featured event loop.
 
-TODO: accept() documentation
+TODO: ABI??? API????? Changes???
 	- ev_embed_stop did not correctly stop the watcher (very good
           testcase by Vladimir Timofeev).
 	- applied win32 fixes by Michael Lenaghan (also James Mansion).
+	- replace EV_MINIMAL by EV_FEATURES.
         - remove dependency on sys/queue.h on freebsd (patch by Vanilla Hsu).
         - configure now prepends -O3, not appends it, so one can still
           override it.

ev.c

@@ -221,7 +221,7 @@ extern "C" {
 
 #ifndef EV_USE_CLOCK_SYSCALL
 # if __linux && __GLIBC__ >= 2
-#  define EV_USE_CLOCK_SYSCALL 1
+#  define EV_USE_CLOCK_SYSCALL EV_FEATURE_OS
 # else
 #  define EV_USE_CLOCK_SYSCALL 0
 # endif
@@ -229,7 +229,7 @@ extern "C" {
 
 #ifndef EV_USE_MONOTONIC
 # if defined (_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0
-#  define EV_USE_MONOTONIC 1
+#  define EV_USE_MONOTONIC EV_FEATURE_OS
 # else
 #  define EV_USE_MONOTONIC 0
 # endif
@@ -241,27 +241,27 @@ extern "C" {
 
 #ifndef EV_USE_NANOSLEEP
 # if _POSIX_C_SOURCE >= 199309L
-#  define EV_USE_NANOSLEEP 1
+#  define EV_USE_NANOSLEEP EV_FEATURE_OS
 # else
 #  define EV_USE_NANOSLEEP 0
 # endif
 #endif
 
 #ifndef EV_USE_SELECT
-# define EV_USE_SELECT 1
+# define EV_USE_SELECT EV_FEATURE_BACKENDS
 #endif
 
 #ifndef EV_USE_POLL
 # ifdef _WIN32
 #  define EV_USE_POLL 0
 # else
-#  define EV_USE_POLL 1
+#  define EV_USE_POLL EV_FEATURE_BACKENDS
 # endif
 #endif
 
 #ifndef EV_USE_EPOLL
 # if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 4))
-#  define EV_USE_EPOLL 1
+#  define EV_USE_EPOLL EV_FEATURE_BACKENDS
 # else
 #  define EV_USE_EPOLL 0
 # endif
@@ -277,31 +277,23 @@ extern "C" {
 
 #ifndef EV_USE_INOTIFY
 # if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 4))
-#  define EV_USE_INOTIFY 1
+#  define EV_USE_INOTIFY EV_FEATURE_OS
 # else
 #  define EV_USE_INOTIFY 0
 # endif
 #endif
 
 #ifndef EV_PID_HASHSIZE
-# if EV_MINIMAL
-#  define EV_PID_HASHSIZE 1
-# else
-#  define EV_PID_HASHSIZE 16
-# endif
+# define EV_PID_HASHSIZE EV_FEATURE_DATA ? 16 : 1
 #endif
 
 #ifndef EV_INOTIFY_HASHSIZE
-# if EV_MINIMAL
-#  define EV_INOTIFY_HASHSIZE 1
-# else
-#  define EV_INOTIFY_HASHSIZE 16
-# endif
+# define EV_INOTIFY_HASHSIZE EV_FEATURE_DATA ? 16 : 1
 #endif
 
 #ifndef EV_USE_EVENTFD
 # if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
-#  define EV_USE_EVENTFD 1
+#  define EV_USE_EVENTFD EV_FEATURE_OS
 # else
 #  define EV_USE_EVENTFD 0
 # endif
@@ -309,7 +301,7 @@ extern "C" {
 
 #ifndef EV_USE_SIGNALFD
 # if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
-#  define EV_USE_SIGNALFD 1
+#  define EV_USE_SIGNALFD EV_FEATURE_OS
 # else
 #  define EV_USE_SIGNALFD 0
 # endif
@@ -322,15 +314,15 @@ extern "C" {
 #endif
 
 #ifndef EV_VERIFY
-# define EV_VERIFY !EV_MINIMAL
+# define EV_VERIFY (EV_FEATURE_API ? 1 : 0)
 #endif
 
 #ifndef EV_USE_4HEAP
-# define EV_USE_4HEAP !EV_MINIMAL
+# define EV_USE_4HEAP EV_FEATURE_DATA
 #endif
 
 #ifndef EV_HEAP_CACHE_AT
-# define EV_HEAP_CACHE_AT !EV_MINIMAL
+# define EV_HEAP_CACHE_AT EV_FEATURE_DATA
 #endif
 
 /* on linux, we can use a (slow) syscall to avoid a dependency on pthread, */
@@ -478,10 +470,10 @@ struct signalfd_siginfo
 #define expect_true(expr)  expect ((expr) != 0, 1)
 #define inline_size        static inline
 
-#if EV_MINIMAL
-# define inline_speed      static noinline
-#else
+#if EV_FEATURE_CODE
 # define inline_speed      static inline
+#else
+# define inline_speed      static noinline
 #endif
 
 #define NUMPRI (EV_MAXPRI - EV_MINPRI + 1)
@@ -698,7 +690,7 @@ typedef struct
 
 #endif
 
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
 # define EV_RELEASE_CB if (expect_false (release_cb)) release_cb (EV_A)
 # define EV_ACQUIRE_CB if (expect_false (acquire_cb)) acquire_cb (EV_A)
 # define EV_INVOKE_PENDING invoke_cb (EV_A)
@@ -1405,7 +1397,7 @@ child_reap (EV_P_ int chain, int pid, int status)
   ev_child *w;
   int traced = WIFSTOPPED (status) || WIFCONTINUED (status);
 
-  for (w = (ev_child *)childs [chain & (EV_PID_HASHSIZE - 1)]; w; w = (ev_child *)((WL)w)->next)
+  for (w = (ev_child *)childs [chain & ((EV_PID_HASHSIZE) - 1)]; w; w = (ev_child *)((WL)w)->next)
     {
       if ((w->pid == pid || !w->pid)
           && (!traced || (w->flags & 1)))
@@ -1440,7 +1432,7 @@ childcb (EV_P_ ev_signal *sw, int revents)
   ev_feed_event (EV_A_ (W)sw, EV_SIGNAL);
 
   child_reap (EV_A_ pid, pid, status);
-  if (EV_PID_HASHSIZE > 1)
+  if ((EV_PID_HASHSIZE) > 1)
     child_reap (EV_A_ 0, pid, status); /* this might trigger a watcher twice, but feed_event catches that */
 }
 
@@ -1539,7 +1531,7 @@ ev_backend (EV_P)
   return backend;
 }
 
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
 unsigned int
 ev_loop_count (EV_P)
 {
@@ -1629,7 +1621,7 @@ loop_init (EV_P_ unsigned int flags)
       mn_now            = get_clock ();
       now_floor         = mn_now;
       rtmn_diff         = ev_rt_now - mn_now;
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
       invoke_cb         = ev_invoke_pending;
 #endif
 
@@ -1876,7 +1868,7 @@ array_verify (EV_P_ W *ws, int cnt)
 }
 #endif
 
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
 void
 ev_loop_verify (EV_P)
 {
@@ -1939,7 +1931,7 @@ ev_loop_verify (EV_P)
 
 # if 0
 #if EV_CHILD_ENABLE
-  for (w = (ev_child *)childs [chain & (EV_PID_HASHSIZE - 1)]; w; w = (ev_child *)((WL)w)->next)
+  for (w = (ev_child *)childs [chain & ((EV_PID_HASHSIZE) - 1)]; w; w = (ev_child *)((WL)w)->next)
   for (signum = EV_NSIG; signum--; ) if (signals [signum].pending)
 #endif
 # endif
@@ -2277,7 +2269,7 @@ time_update (EV_P_ ev_tstamp max_block)
 void
 ev_loop (EV_P_ int flags)
 {
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
   ++loop_depth;
 #endif
 
@@ -2380,7 +2372,7 @@ ev_loop (EV_P_ int flags)
               }
           }
 
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
         ++loop_count;
 #endif
         assert ((loop_done = EVUNLOOP_RECURSE, 1)); /* assert for side effect */
@@ -2419,7 +2411,7 @@ ev_loop (EV_P_ int flags)
   if (loop_done == EVUNLOOP_ONE)
     loop_done = EVUNLOOP_CANCEL;
 
-#if EV_MINIMAL < 2
+#if EV_FEATURE_API
   --loop_depth;
 #endif
 }
@@ -2879,7 +2871,7 @@ ev_child_start (EV_P_ ev_child *w)
   EV_FREQUENT_CHECK;
 
   ev_start (EV_A_ (W)w, 1);
-  wlist_add (&childs [w->pid & (EV_PID_HASHSIZE - 1)], (WL)w);
+  wlist_add (&childs [w->pid & ((EV_PID_HASHSIZE) - 1)], (WL)w);
 
   EV_FREQUENT_CHECK;
 }
@@ -2893,7 +2885,7 @@ ev_child_stop (EV_P_ ev_child *w)
 
   EV_FREQUENT_CHECK;
 
-  wlist_del (&childs [w->pid & (EV_PID_HASHSIZE - 1)], (WL)w);
+  wlist_del (&childs [w->pid & ((EV_PID_HASHSIZE) - 1)], (WL)w);
   ev_stop (EV_A_ (W)w);
 
   EV_FREQUENT_CHECK;
@@ -2976,7 +2968,7 @@ infy_add (EV_P_ ev_stat *w)
     }
 
   if (w->wd >= 0)
-    wlist_add (&fs_hash [w->wd & (EV_INOTIFY_HASHSIZE - 1)].head, (WL)w);
+    wlist_add (&fs_hash [w->wd & ((EV_INOTIFY_HASHSIZE) - 1)].head, (WL)w);
 
   /* now re-arm timer, if required */
   if (ev_is_active (&w->timer)) ev_ref (EV_A);
@@ -2994,7 +2986,7 @@ infy_del (EV_P_ ev_stat *w)
     return;
 
   w->wd = -2;
-  slot = wd & (EV_INOTIFY_HASHSIZE - 1);
+  slot = wd & ((EV_INOTIFY_HASHSIZE) - 1);
   wlist_del (&fs_hash [slot].head, (WL)w);
 
   /* remove this watcher, if others are watching it, they will rearm */
@@ -3006,13 +2998,13 @@ infy_wd (EV_P_ int slot, int wd, struct inotify_event *ev)
 {
   if (slot < 0)
     /* overflow, need to check for all hash slots */
-    for (slot = 0; slot < EV_INOTIFY_HASHSIZE; ++slot)
+    for (slot = 0; slot < (EV_INOTIFY_HASHSIZE); ++slot)
       infy_wd (EV_A_ slot, wd, ev);
   else
     {
       WL w_;
 
-      for (w_ = fs_hash [slot & (EV_INOTIFY_HASHSIZE - 1)].head; w_; )
+      for (w_ = fs_hash [slot & ((EV_INOTIFY_HASHSIZE) - 1)].head; w_; )
         {
           ev_stat *w = (ev_stat *)w_;
           w_ = w_->next; /* lets us remove this watcher and all before it */
@@ -3021,7 +3013,7 @@ infy_wd (EV_P_ int slot, int wd, struct inotify_event *ev)
             {
               if (ev->mask & (IN_IGNORED | IN_UNMOUNT | IN_DELETE_SELF))
                 {
-                  wlist_del (&fs_hash [slot & (EV_INOTIFY_HASHSIZE - 1)].head, (WL)w);
+                  wlist_del (&fs_hash [slot & ((EV_INOTIFY_HASHSIZE) - 1)].head, (WL)w);
                   w->wd = -1;
                   infy_add (EV_A_ w); /* re-add, no matter what */
                 }
@@ -3145,7 +3137,7 @@ infy_fork (EV_P)
       ev_unref (EV_A);
     }
 
-  for (slot = 0; slot < EV_INOTIFY_HASHSIZE; ++slot)
+  for (slot = 0; slot < (EV_INOTIFY_HASHSIZE); ++slot)
     {
       WL w_ = fs_hash [slot].head;
       fs_hash [slot].head = 0;
@@ -3771,7 +3763,7 @@ ev_walk (EV_P_ int types, void (*cb)(EV_P_ int type, void *w))
 
 #if EV_CHILD_ENABLE
   if (types & EV_CHILD)
-    for (i = EV_PID_HASHSIZE; i--; )
+    for (i = (EV_PID_HASHSIZE); i--; )
       for (wl = childs [i]; wl; )
         {
           wn = wl->next;

ev.h

@@ -1,7 +1,7 @@
 /*
  * libev native API header
  *
- * Copyright (c) 2007,2008,2009 Marc Alexander Lehmann <libev@schmorp.de>
+ * Copyright (c) 2007,2008,2009,2010 Marc Alexander Lehmann <libev@schmorp.de>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modifica-
@@ -44,73 +44,79 @@
 extern "C" {
 #endif
 
-typedef double ev_tstamp;
+/*****************************************************************************/
+
+#ifndef EV_FEATURES
+# define EV_FEATURES 0x3f
+#endif
+
+#define EV_FEATURE_CODE     ((EV_FEATURES) &  1)
+#define EV_FEATURE_DATA     ((EV_FEATURES) &  2)
+#define EV_FEATURE_API      ((EV_FEATURES) &  4)
+#define EV_FEATURE_WATCHERS ((EV_FEATURES) &  8)
+#define EV_FEATURE_BACKENDS ((EV_FEATURES) & 16)
+#define EV_FEATURE_OS       ((EV_FEATURES) & 32)
 
 /* these priorities are inclusive, higher priorities will be called earlier */
 #ifndef EV_MINPRI
-# define EV_MINPRI -2
+# define EV_MINPRI (EV_FEATURE_API ? -2 : 0)
 #endif
 #ifndef EV_MAXPRI
-# define EV_MAXPRI +2
+# define EV_MAXPRI (EV_FEATURE_API ? +2 : 0)
 #endif
 
 #ifndef EV_MULTIPLICITY
-# define EV_MULTIPLICITY 1
+# define EV_MULTIPLICITY EV_FEATURE_API
 #endif
 
 #ifndef EV_PERIODIC_ENABLE
-# define EV_PERIODIC_ENABLE 1
+# define EV_PERIODIC_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_STAT_ENABLE
-# define EV_STAT_ENABLE 1
+# define EV_STAT_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_PREPARE_ENABLE
-# define EV_PREPARE_ENABLE 1
+# define EV_PREPARE_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_CHECK_ENABLE
-# define EV_CHECK_ENABLE 1
+# define EV_CHECK_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_IDLE_ENABLE
-# define EV_IDLE_ENABLE 1
+# define EV_IDLE_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_FORK_ENABLE
-# define EV_FORK_ENABLE 1
+# define EV_FORK_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_SIGNAL_ENABLE
-# define EV_SIGNAL_ENABLE 1
+# define EV_SIGNAL_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_CHILD_ENABLE
 # ifdef _WIN32
 #  define EV_CHILD_ENABLE 0
 # else
-#  define EV_CHILD_ENABLE 1
+#  define EV_CHILD_ENABLE EV_FEATURE_WATCHERS
 #endif
 #endif
 
 #ifndef EV_ASYNC_ENABLE
-# define EV_ASYNC_ENABLE 1
+# define EV_ASYNC_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_EMBED_ENABLE
-# define EV_EMBED_ENABLE 1
+# define EV_EMBED_ENABLE EV_FEATURE_WATCHERS
 #endif
 
 #ifndef EV_WALK_ENABLE
 # define EV_WALK_ENABLE 0 /* not yet */
 #endif
 
-#ifndef EV_ATOMIC_T
-# include <signal.h>
-# define EV_ATOMIC_T sig_atomic_t volatile
-#endif
-
 /*****************************************************************************/
 
 #if EV_CHILD_ENABLE && !EV_SIGNAL_ENABLE
@@ -118,6 +124,20 @@ typedef double ev_tstamp;
 # define EV_SIGNAL_ENABLE 1
 #endif
 
+/*****************************************************************************/
+
+#if !EV_FEATURE_CODE && !defined (NDEBUG)
+# define NDEBUG 1
+# include <assert.h>
+#endif
+
+typedef double ev_tstamp;
+
+#ifndef EV_ATOMIC_T
+# include <signal.h>
+# define EV_ATOMIC_T sig_atomic_t volatile
+#endif
+
 #if EV_STAT_ENABLE
 # ifdef _WIN32
 #  include <time.h>
@@ -569,7 +589,7 @@ void ev_unref (EV_P);
  */
 void ev_once (EV_P_ int fd, int events, ev_tstamp timeout, void (*cb)(int revents, void *arg), void *arg);
 
-# if EV_MINIMAL < 2
+# if EV_FEATURE_API
 unsigned int ev_loop_count  (EV_P); /* number of loop iterations */
 unsigned int ev_loop_depth  (EV_P); /* #ev_loop enters - #ev_loop leaves */
 void         ev_loop_verify (EV_P); /* abort if loop data corrupted */

ev.pod

@@ -3886,64 +3886,90 @@ If undefined or defined to be C<1> (and the platform supports it), then
 the respective watcher type is supported. If defined to be C<0>, then it
 is not. Disabling watcher types mainly saves codesize.
 
-=item EV_MINIMAL
+=item EV_FEATURES
 
 If you need to shave off some kilobytes of code at the expense of some
-speed (but with the full API), define this symbol to C<1>. Currently this
-is used to override some inlining decisions, saves roughly 30% code size
-on amd64. It also selects a much smaller 2-heap for timer management over
-the default 4-heap.
-
-You can save even more by disabling watcher types you do not need
-and setting C<EV_MAXPRI> == C<EV_MINPRI>. Also, disabling C<assert>
-(C<-DNDEBUG>) will usually reduce code size a lot. Disabling inotify,
-eventfd and signalfd will further help, and disabling backends one doesn't
-need (e.g. poll, epoll, kqueue, ports) will help further.
-
-Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to
-provide a bare-bones event library. See C<ev.h> for details on what parts
-of the API are still available, and do not complain if this subset changes
-over time.
-
-This example set of settings reduces the compiled size of libev from
-23.9Kb to 7.7Kb on my GNU/Linux amd64 system (and leaves little
-in - there is also an effect on the amount of memory used). With
-an intelligent-enough linker (gcc+binutils do this when you use
-C<-Wl,--gc-sections -ffunction-sections>) further unused functions might
-be left out as well automatically - a binary starting a timer and an I/O
-watcher then might come out at only 5Kb.
-
-   // tuning and API changes
-   #define EV_MINIMAL 2
-   #define EV_MULTIPLICITY 0
-   #define EV_MINPRI 0
-   #define EV_MAXPRI 0
-
-   // OS-specific backends
-   #define EV_USE_INOTIFY 0
-   #define EV_USE_EVENTFD 0
-   #define EV_USE_SIGNALFD 0
-   #define EV_USE_REALTIME 0
-   #define EV_USE_MONOTONIC 0
-   #define EV_USE_CLOCK_SYSCALL 0
-
-   // disable all backends except select
-   #define EV_USE_POLL 0
-   #define EV_USE_PORT 0
-   #define EV_USE_KQUEUE 0
-   #define EV_USE_EPOLL 0
-
-   // disable all watcher types that cna be disabled
-   #define EV_STAT_ENABLE 0
-   #define EV_PERIODIC_ENABLE 0
-   #define EV_IDLE_ENABLE 0
-   #define EV_CHECK_ENABLE 0
-   #define EV_PREPARE_ENABLE 0
-   #define EV_FORK_ENABLE 0
-   #define EV_SIGNAL_ENABLE 0
-   #define EV_CHILD_ENABLE 0
-   #define EV_ASYNC_ENABLE 0
-   #define EV_EMBED_ENABLE 0
+speed (but with the full API), you can define this symbol to request
+certain subsets of functionality. The default is to enable all features
+that can be enabled on the platform.
+
+Note that using autoconf will usually override most of the features, so
+using this symbol makes sense mostly when embedding libev.
+
+A typical way to use this symbol is to define it to C<0> (or to a bitset
+with some broad features you want) and then selectively re-enable
+additional parts you want, for example if you want everything minimal,
+but multiple event loop support, async and child watchers and the poll
+backend, use this:
+
+   #define EV_FEATURES 0
+   #define EV_MULTIPLICITY 1
+   #define EV_USE_POLL 1
+   #define EV_CHILD_ENABLE 1
+   #define EV_ASYNC_ENABLE 1
+
+The actual value is a bitset, it can be a combination of the following
+values:
+
+=over 4
+
+=item C<1> - faster/larger code
+
+Use larger code to speed up some operations.
+
+Currently this is used to override some inlining decisions (enlarging the  roughly
+30% code size on amd64.
+
+Also disables C<assert>'s in the code, unless you define C<NDEBUG>
+explicitly to C<0>.
+
+Use of compiler flags such as C<-Os> with gcc that optimise for size are
+recommended when disabling this feature.
+
+=item C<2> - faster/larger data structures
+
+Replaces the small 2-heap for timer management by a faster 4-heap, larger
+hash table sizes and so on. This will usually further increase codesize
+and can additionally have an effect on the size of data structures at
+runtime.
+
+=item C<4> - full API configuration
+
+This enables priorities (sets C<EV_MAXPRI>=2 and C<EV_MINPRI>=-2), and
+enables multiplicity (C<EV_MULTIPLICITY>=1).
+
+It also enables a lot of the "lesser used" core API functions. See C<ev.h>
+for details on which parts of the API are still available without this
+feature, and do not complain if this subset changes over time.
+
+=item C<8> - enable all optional watcher types
+
+Enables all optional watcher types.  If you want to selectively enable
+only some watcher types other than I/O and timers (e.g. prepare,
+embed, async, child...) you can enable them manually by defining
+C<EV_watchertype_ENABLE> to C<1> instead.
+
+=item C<16> - enable all backends
+
+This enables all backends - without this feature, you need to enable at
+least one backend manually (C<EV_USE_SELECT> is a good choice).
+
+=item C<32> - enable OS-specific "helper" APIs
+
+Enable inotify, eventfd, signalfd and similar OS-specific helper APIs by
+default.
+
+=back
+
+Compiling with C<gcc -Os -DEV_STANDALONE -DEV_USE_EPOLL=1 -DEV_FEATURES=0>
+reduces the compiled size of libev from 24.7Kb to 6.5Kb on my GNU/Linux
+amd64 system, while still giving you I/O watchers, timers and monotonic
+clock support.
+
+With an intelligent-enough linker (gcc+binutils are intelligent enough
+when you use C<-Wl,--gc-sections -ffunction-sections>) functions unused by
+your program might be left out as well - a binary starting a timer and an
+I/O watcher then might come out at only 5Kb.
 
 =item EV_AVOID_STDIO
 
@@ -3968,17 +3994,17 @@ statically allocates some 12-24 bytes per signal number.
 =item EV_PID_HASHSIZE
 
 C<ev_child> watchers use a small hash table to distribute workload by
-pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more
-than enough. If you need to manage thousands of children you might want to
-increase this value (I<must> be a power of two).
+pid. The default size is C<16> (or C<1> with C<EV_FEATURES> disabled),
+usually more than enough. If you need to manage thousands of children you
+might want to increase this value (I<must> be a power of two).
 
 =item EV_INOTIFY_HASHSIZE
 
 C<ev_stat> watchers use a small hash table to distribute workload by
-inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>),
-usually more than enough. If you need to manage thousands of C<ev_stat>
-watchers you might want to increase this value (I<must> be a power of
-two).
+inotify watch id. The default size is C<16> (or C<1> with C<EV_FEATURES>
+disabled), usually more than enough. If you need to manage thousands of
+C<ev_stat> watchers you might want to increase this value (I<must> be a
+power of two).
 
 =item EV_USE_4HEAP
 
@@ -3987,8 +4013,8 @@ timer and periodics heaps, libev uses a 4-heap when this symbol is defined
 to C<1>. The 4-heap uses more complicated (longer) code but has noticeably
 faster performance with many (thousands) of watchers.
 
-The default is C<1> unless C<EV_MINIMAL> is set in which case it is C<0>
-(disabled).
+The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
+will be C<0>.
 
 =item EV_HEAP_CACHE_AT
 
@@ -3999,8 +4025,8 @@ which uses 8-12 bytes more per watcher and a few hundred bytes more code,
 but avoids random read accesses on heap changes. This improves performance
 noticeably with many (hundreds) of watchers.
 
-The default is C<1> unless C<EV_MINIMAL> is set in which case it is C<0>
-(disabled).
+The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
+will be C<0>.
 
 =item EV_VERIFY
 
@@ -4012,8 +4038,8 @@ called once per loop, which can slow down libev. If set to C<3>, then the
 verification code will be called very frequently, which will slow down
 libev considerably.
 
-The default is C<1>, unless C<EV_MINIMAL> is set, in which case it will be
-C<0>.
+The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
+will be C<0>.
 
 =item EV_COMMON
 
@@ -4081,15 +4107,9 @@ file.
 The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file
 that everybody includes and which overrides some configure choices:
 
-   #define EV_MINIMAL 1
-   #define EV_USE_POLL 0
-   #define EV_MULTIPLICITY 0
-   #define EV_PERIODIC_ENABLE 0
-   #define EV_STAT_ENABLE 0
-   #define EV_FORK_ENABLE 0
+   #define EV_FEATURES 0
+   #define EV_USE_SELECT 1
    #define EV_CONFIG_H <config.h>
-   #define EV_MINPRI 0
-   #define EV_MAXPRI 0
 
    #include "ev++.h"