Module Name: src
Committed By: riastradh
Date: Wed Jul 24 03:15:59 UTC 2013
Modified Files:
src/sys/external/bsd/drm2/include/linux [riastradh-drm2]: completion.h
Log Message:
Rework <linux/completion.h> to match Linux semantics.
To generate a diff of this commit:
cvs rdiff -u -r1.1.2.1 -r1.1.2.2 \
src/sys/external/bsd/drm2/include/linux/completion.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/include/linux/completion.h
diff -u src/sys/external/bsd/drm2/include/linux/completion.h:1.1.2.1 src/sys/external/bsd/drm2/include/linux/completion.h:1.1.2.2
--- src/sys/external/bsd/drm2/include/linux/completion.h:1.1.2.1 Wed Jul 24 03:07:28 2013
+++ src/sys/external/bsd/drm2/include/linux/completion.h Wed Jul 24 03:15:59 2013
@@ -1,4 +1,4 @@
-/* $NetBSD: completion.h,v 1.1.2.1 2013/07/24 03:07:28 riastradh Exp $ */
+/* $NetBSD: completion.h,v 1.1.2.2 2013/07/24 03:15:59 riastradh Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -36,55 +36,129 @@
#include <sys/condvar.h>
#include <sys/mutex.h>
+#include <machine/limits.h>
+
struct completion {
- kmutex_t c_lock;
- kcondvar_t c_cv;
- bool c_done;
+ kmutex_t c_lock;
+ kcondvar_t c_cv;
+
+ /*
+ * c_done is either
+ *
+ * . -1, meaning it's open season and we're done for good and
+ * nobody need wait any more;
+ *
+ * . 0, meaning nothing is done, so waiters must block; or
+ *
+ * . a positive integer, meaning that many waiters can
+ * proceed before further waiters must block.
+ *
+ * Negative values other than -1 are not allowed.
+ */
+ int c_done;
};
+/*
+ * Initialize a new completion object.
+ */
static inline void
-INIT_COMPLETION(struct completion *completion)
+init_completion(struct completion *completion)
+{
+
+ mutex_init(&completion->c_lock, MUTEX_DEFAULT, IPL_NONE);
+ cv_init(&completion->c_cv, "lnxcmplt");
+ completion->c_done = 0;
+}
+
+/*
+ * Notify one waiter of completion, but not any future ones.
+ */
+static inline void
+complete(struct completion *completion)
{
mutex_enter(&completion->c_lock);
- completion->c_done = false;
+
+ /* If it's not open season, wake one waiter. */
+ if (completion->c_done >= 0) {
+ KASSERT(completion->c_done < INT_MAX); /* XXX check */
+ completion->c_done++;
+ cv_signal(&completion->c_cv);
+ } else {
+ KASSERT(completion->c_done == -1);
+ }
+
mutex_exit(&completion->c_lock);
}
+/*
+ * Notify all waiters, present and future (until INIT_COMPLETION), of
+ * completion.
+ */
static inline void
-init_completion(struct completion *completion)
+complete_all(struct completion *completion)
{
- mutex_init(&completion->c_lock, MUTEX_DEFAULT, IPL_NONE);
- cv_init(&completion->c_cv, "lnxcmplt");
- completion->c_done = false;
+ mutex_enter(&completion->c_lock);
+
+ /* If it's not open season, make it open season and wake everyone. */
+ if (completion->c_done >= 0) {
+ completion->c_done = -1;
+ cv_broadcast(&completion->c_cv);
+ } else {
+ KASSERT(completion->c_done == -1);
+ }
+
+ mutex_exit(&completion->c_lock);
}
+/*
+ * Reverse the effect of complete_all so that subsequent waiters block
+ * until someone calls complete or complete_all.
+ *
+ * This operation is very different from its lowercase counterpart.
+ */
static inline void
-complete_all(struct completion *completion)
+INIT_COMPLETION(struct completion *completion)
{
mutex_enter(&completion->c_lock);
- completion->c_done = true;
- cv_broadcast(&completion->c_cv);
+ completion->c_done = 0;
+ /* No notify -- waiters are interested only in nonzero values. */
mutex_exit(&completion->c_lock);
}
+/*
+ * Wait interruptibly with a timeout for someone to call complete or
+ * complete_all.
+ */
static inline int
wait_for_completion_interruptible_timeout(struct completion *completion,
unsigned long ticks)
{
- int error = 0;
+ int error;
mutex_enter(&completion->c_lock);
- while (!completion->c_done) {
- error = cv_timedwait_sig(&completion->c_cv,
+
+ /* Wait until c_done is nonzero. */
+ while (completion->c_done == 0) {
+ /* XXX errno NetBSD->Linux */
+ error = -cv_timedwait_sig(&completion->c_cv,
&completion->c_lock, ticks);
if (error)
- break;
+ goto out;
}
- mutex_exit(&completion->c_lock);
+ /* Claim a completion if it's not open season. */
+ if (completion->c_done > 0)
+ completion->c_done--;
+ else
+ KASSERT(completion->c_done == -1);
+
+ /* Success! */
+ error = 0;
+
+out: mutex_exit(&completion->c_lock);
return error;
}
