[src/trunk]: src/lib/libpthread Arrange to pause for a while if pthread_cond_...

[nathanw <nathanw%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d7b06738e72e
branches:  trunk
changeset: 542531:d7b06738e72e
user:      nathanw <nathanw%NetBSD.org@localhost>
date:      Sat Feb 01 00:57:31 2003 +0000

description:
Arrange to pause for a while if pthread_cond_wait() or
pthread_cond_timedwait() is called before any threads have been
created and the SA infrastructure is up and running.

Addresses PR lib/20139.

XXX probably need to do this for all of the pthread_*_timedlock()
functions, too.

diffstat:

 lib/libpthread/pthread_cond.c |  58 +++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 56 insertions(+), 2 deletions(-)

diffs (105 lines):

diff -r 26ba1fceb459 -r d7b06738e72e lib/libpthread/pthread_cond.c
--- a/lib/libpthread/pthread_cond.c     Sat Feb 01 00:42:03 2003 +0000
+++ b/lib/libpthread/pthread_cond.c     Sat Feb 01 00:57:31 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_cond.c,v 1.5 2003/01/31 04:59:40 nathanw Exp $ */
+/*     $NetBSD: pthread_cond.c,v 1.6 2003/02/01 00:57:31 nathanw Exp $ */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -39,6 +39,8 @@
 #include <assert.h>
 #include <errno.h>
 #include <sys/cdefs.h>
+#include <sys/time.h>
+#include <sys/types.h>
 
 #include "pthread.h"
 #include "pthread_int.h"
@@ -51,7 +53,13 @@
 #define SDPRINTF(x)
 #endif
 
+int    _sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
+
+extern int pthread__started;
+
 static void pthread_cond_wait__callback(void *);
+static int pthread_cond_wait_nothread(pthread_t, pthread_mutex_t *,
+    const struct timespec *);
 
 __strong_alias(__libc_cond_init,pthread_cond_init)
 __strong_alias(__libc_cond_signal,pthread_cond_signal)
@@ -107,6 +115,11 @@
 #endif
        self = pthread__self();
        PTHREADD_ADD(PTHREADD_COND_WAIT);
+
+       /* Just hang out for a while if threads aren't running yet. */
+       if (__predict_false(pthread__started == 0))
+               return pthread_cond_wait_nothread(self, mutex, NULL);
+
        pthread_spinlock(self, &cond->ptc_lock);
 #ifdef ERRORCHECK
        if (cond->ptc_mutex == NULL)
@@ -174,6 +187,12 @@
                return EINVAL;
 #endif
        self = pthread__self();
+       PTHREADD_ADD(PTHREADD_COND_TIMEDWAIT);
+
+       /* Just hang out for a while if threads aren't running yet. */
+       if (__predict_false(pthread__started == 0))
+               return pthread_cond_wait_nothread(self, mutex, abstime);
+
        pthread_spinlock(self, &cond->ptc_lock);
 #ifdef ERRORCHECK
        if (cond->ptc_mutex == NULL)
@@ -190,7 +209,7 @@
                }
        }
 #endif
-       PTHREADD_ADD(PTHREADD_COND_TIMEDWAIT);
+       
        wait.ptw_thread = self;
        wait.ptw_cond = cond;
        retval = 0;
@@ -348,3 +367,38 @@
 
        return 0;
 }
+
+/* Utility routine to hang out for a while if threads haven't started yet. */
+static int
+pthread_cond_wait_nothread(pthread_t self, pthread_mutex_t *mutex,
+    const struct timespec *abstime)
+{
+       struct timeval now, tv, *tvp;
+       int retval;
+
+       if (abstime == NULL)
+               tvp = NULL;
+       else {
+               tvp = &tv;
+               gettimeofday(&now, NULL);
+               TIMESPEC_TO_TIMEVAL(tvp, abstime);
+               timersub(tvp, &now, tvp);
+       }
+
+       /*
+        * The libpthread select() wrapper has cancellation tests, but
+        * we need to have the mutex locked when testing for
+        * cancellation and unlocked while we sleep.  So, skip the
+        * wrapper.
+        */
+       pthread__testcancel(self);
+       pthread_mutex_unlock(mutex);
+       retval = _sys_select(0, NULL, NULL, NULL, tvp);
+       pthread_mutex_lock(mutex);
+       pthread__testcancel(self);
+
+       if (retval == 0)
+               return ETIMEDOUT;
+       else
+               return EINTR;
+}