Various fixes/updates

- Update HOWTO to note that directio and fallocate don't work with ZFS
  on Solaris.

Refactor the Makefile's to add CPPFLAGS and LIBS.
- Add -fno-omit-frame-pointer from Linux Makefile to every platform
- Change undefined $(ALL_CFLAGS) to $(CFLAGS)
- Pass -std=gnu99, without which OS X fails to build.
- Add -D__EXTENSIONS__ on Solaris since some functions we need are
  behind it.

- Pull in <limits.h> in fio.c to get PTHREAD_STACK_MIN.
- NetBSD doesn't define PTHREAD_STACK_MIN so set it to 4k in
   os-netbsd.h

- If we have posix_fallocate don't error out if it fails during mutex
  and malloc operations since it will fail on Solaris with a ZFS
  filesystem. As I understand it these aren't performance-critical
  operations so do they need to be considered critical?

- Remove fio_unused from os-* files since it's defined in fio.h and we
  don't really need it.

- FreeBSD has an idprio command but not the API so don't claim it does.

- OS X doesn't have the timer_* API so emulate it using
  setitimer/sigaction.

- NetBSD and Solaris don't support CLOCK_MONOTONIC in timer_create so
  remove FIO_HAVE_CLOCK_MONOTONIC from their os-* files.

I've noticed that a change I made a while ago to use fmin/fmax could
cause issues on older OSes - I had a CD with NetBSD 5.0.2 and found
they had only been implemented in 5.1 so I'm not sure if I should
revert it.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/os/os-mac.h b/os/os-mac.h
index 068bc5c..1a0a887 100644
--- a/os/os-mac.h
+++ b/os/os-mac.h
@@ -3,6 +3,9 @@
 
 #include <errno.h>
 #include <sys/sysctl.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <signal.h>
 
 #include "../file.h"
 
@@ -21,10 +24,90 @@
 
 #define OS_MAP_ANON		MAP_ANON
 
-typedef unsigned int clockid_t;
 typedef off_t off64_t;
 
-static inline int blockdev_invalidate_cache(struct fio_file fio_unused *f)
+/* OS X as of 10.6 doesn't have the timer_* functions. 
+ * Emulate the functionality using setitimer and sigaction here
+ */
+
+#define MAX_TIMERS 64
+
+typedef unsigned int clockid_t;
+typedef unsigned int timer_t;
+
+struct itimerspec {
+	struct timespec it_value;
+	struct timespec it_interval;
+};
+
+static struct sigevent fio_timers[MAX_TIMERS];
+static unsigned int num_timers = 0;
+
+static inline int timer_create(clockid_t clockid, struct sigevent *restrict evp,
+				 timer_t *restrict timerid)
+{
+	int current_timer = num_timers;
+	fio_timers[current_timer] = *evp;
+	num_timers++;
+	
+	*timerid = current_timer;
+	return 0;
+}
+
+static void sig_alrm(int signum)
+{
+	union sigval sv;
+	
+	for (int i = 0; i < num_timers; i++) {
+		if (fio_timers[i].sigev_notify_function == NULL)
+			continue;
+		
+		if (fio_timers[i].sigev_notify == SIGEV_THREAD)
+			fio_timers[i].sigev_notify_function(sv);
+		else if (fio_timers[i].sigev_notify == SIGEV_SIGNAL)
+			kill(getpid(), fio_timers[i].sigev_signo);
+	}
+}
+
+static inline int timer_settime(timer_t timerid, int flags,
+								const struct itimerspec *value, struct itimerspec *ovalue)
+{
+	struct sigaction sa;
+	struct itimerval tv;
+	struct itimerval tv_out;
+	int rc;
+	
+	tv.it_interval.tv_sec = value->it_interval.tv_sec;
+	tv.it_interval.tv_usec = value->it_interval.tv_nsec / 1000;
+
+	tv.it_value.tv_sec = value->it_value.tv_sec;
+	tv.it_value.tv_usec = value->it_value.tv_nsec / 1000;
+
+	sa.sa_handler = sig_alrm;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;
+	
+	rc = sigaction(SIGALRM, &sa, NULL);
+
+	if (!rc)
+		rc = setitimer(ITIMER_REAL, &tv, &tv_out);
+	
+	if (!rc && ovalue != NULL) {
+		ovalue->it_interval.tv_sec = tv_out.it_interval.tv_sec;
+		ovalue->it_interval.tv_nsec = tv_out.it_interval.tv_usec * 1000;
+		ovalue->it_value.tv_sec = tv_out.it_value.tv_sec;
+		ovalue->it_value.tv_nsec = tv_out.it_value.tv_usec * 1000;
+	}
+
+	return rc;
+}
+
+static inline int timer_delete(timer_t timer)
+{
+	return 0;
+}
+
+static inline int blockdev_invalidate_cache(struct fio_file *f)
 {
 	return EINVAL;
 }