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authorPeter Maydell <peter.maydell@linaro.org>2017-09-04 19:08:25 +0100
committerPeter Maydell <peter.maydell@linaro.org>2017-09-04 19:08:25 +0100
commit24940548be036f5243d3cd623b2ea3abf0dabbfe (patch)
tree665338179ff85e3c7ef753335a3bb11d4f81067b
parent2b483739791b33c46e6084b51edcf62107058ae1 (diff)
downloadqemu-arm-better-ifdefs.tar.gz
util/qemu-thread-posix.c: Replace OS ifdefs with CONFIG_HAVE_SEM_TIMEDWAITbetter-ifdefs
In qemu-thread-posix.c we have two implementations of the various qemu_sem_* functions, one of which uses native POSIX sem_* and the other of which emulates them with pthread conditions. This is necessary because not all our host OSes support sem_timedwait(). Instead of a hard-coded list of OSes which don't implement sem_timedwait(), which gets out of date, make configure test for the presence of the function and set a new CONFIG_HAVE_SEM_TIMEDWAIT appropriately. In particular, newer NetBSDs have sem_timedwait(), so this commit will switch them over to using it. OSX still does not have an implementation. Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rwxr-xr-xconfigure15
-rw-r--r--include/qemu/thread-posix.h2
-rw-r--r--util/qemu-thread-posix.c10
3 files changed, 21 insertions, 6 deletions
diff --git a/configure b/configure
index fb7e34a..aa8d4d9 100755
--- a/configure
+++ b/configure
@@ -4448,6 +4448,18 @@ if compile_prog "" "" ; then
fi
##########################################
+# check if we have sem_timedwait
+
+sem_timedwait=no
+cat > $TMPC << EOF
+#include <semaphore.h>
+int main(void) { return sem_timedwait(0, 0); }
+EOF
+if compile_prog "" "" ; then
+ sem_timedwait=yes
+fi
+
+##########################################
# check if trace backend exists
$python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null
@@ -5680,6 +5692,9 @@ fi
if test "$inotify1" = "yes" ; then
echo "CONFIG_INOTIFY1=y" >> $config_host_mak
fi
+if test "$sem_timedwait" = "yes" ; then
+ echo "CONFIG_SEM_TIMEDWAIT=y" >> $config_host_mak
+fi
if test "$byteswap_h" = "yes" ; then
echo "CONFIG_BYTESWAP_H=y" >> $config_host_mak
fi
diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
index e5e3a0f..f4296d3 100644
--- a/include/qemu/thread-posix.h
+++ b/include/qemu/thread-posix.h
@@ -21,7 +21,7 @@ struct QemuCond {
};
struct QemuSemaphore {
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
pthread_mutex_t lock;
pthread_cond_t cond;
unsigned int count;
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 4e95d27..7306475 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -168,7 +168,7 @@ void qemu_sem_init(QemuSemaphore *sem, int init)
{
int rc;
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
rc = pthread_mutex_init(&sem->lock, NULL);
if (rc != 0) {
error_exit(rc, __func__);
@@ -196,7 +196,7 @@ void qemu_sem_destroy(QemuSemaphore *sem)
assert(sem->initialized);
sem->initialized = false;
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
rc = pthread_cond_destroy(&sem->cond);
if (rc < 0) {
error_exit(rc, __func__);
@@ -218,7 +218,7 @@ void qemu_sem_post(QemuSemaphore *sem)
int rc;
assert(sem->initialized);
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
pthread_mutex_lock(&sem->lock);
if (sem->count == UINT_MAX) {
rc = EINVAL;
@@ -256,7 +256,7 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
struct timespec ts;
assert(sem->initialized);
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
rc = 0;
compute_abs_deadline(&ts, ms);
pthread_mutex_lock(&sem->lock);
@@ -304,7 +304,7 @@ void qemu_sem_wait(QemuSemaphore *sem)
int rc;
assert(sem->initialized);
-#if defined(__APPLE__) || defined(__NetBSD__)
+#ifndef CONFIG_SEM_TIMEDWAIT
pthread_mutex_lock(&sem->lock);
while (sem->count == 0) {
rc = pthread_cond_wait(&sem->cond, &sem->lock);