path: root/src/thread/synccall.c
diff options
authorRich Felker <>2011-08-12 10:32:22 -0400
committerRich Felker <>2011-08-12 10:32:22 -0400
commit407d933052c310ebc5541dae2ecd8c4bd8f55fb9 (patch)
treef2beac6cf0a1a253ab4ab60e35d795c098346f4e /src/thread/synccall.c
parentb1a7102d832220066e7352f40e5744da932f5a28 (diff)
pthread and synccall cleanup, new __synccall_wait op
fix up clone signature to match the actual behavior. the new __syncall_wait function allows a __synccall callback to wait for other threads to continue without returning, so that it can resume action after the caller finishes. this interface could be made significantly more general/powerful with minimal effort, but i'll wait to do that until it's actually useful for something.
Diffstat (limited to 'src/thread/synccall.c')
1 files changed, 10 insertions, 2 deletions
diff --git a/src/thread/synccall.c b/src/thread/synccall.c
index 91ac5eb7..2cd25e4b 100644
--- a/src/thread/synccall.c
+++ b/src/thread/synccall.c
@@ -4,7 +4,7 @@
static struct chain {
struct chain *next;
sem_t sem, sem2;
-} *head;
+} *head, *cur;
static void (*callback)(void *), *context;
static int chainlen;
@@ -47,11 +47,19 @@ static void handler(int sig, siginfo_t *si, void *ctx)
errno = old_errno;
+void __synccall_wait()
+ struct chain *ch = cur;
+ sem_post(&ch->sem2);
+ while (sem_wait(&ch->sem));
+ sem_post(&ch->sem);
void __synccall(void (*func)(void *), void *ctx)
pthread_t self;
struct sigaction sa;
- struct chain *cur, *next;
+ struct chain *next;
uint64_t oldmask;
if (!libc.threads_minus_1) {