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authorIngo Molnar <mingo@elte.hu>2008-08-14 14:58:01 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-14 14:58:01 +0200
commit51ca3c679194e7435c25b8e77b0a73c597e41ae9 (patch)
treea681dca369607ab0f371d5246b0f75140b860a8a /include/linux/completion.h
parentb55793f7528ce1b73c25b3ac8a86a6cda2a0f9a4 (diff)
parentb635acec48bcaa9183fcbf4e3955616b0d4119b5 (diff)
downloadop-kernel-dev-51ca3c679194e7435c25b8e77b0a73c597e41ae9.zip
op-kernel-dev-51ca3c679194e7435c25b8e77b0a73c597e41ae9.tar.gz
Merge branch 'linus' into x86/core
Conflicts: arch/x86/kernel/genapic_64.c include/asm-x86/kvm_host.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/completion.h')
-rw-r--r--include/linux/completion.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h
index d2961b6..57faa60 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -55,4 +55,49 @@ extern void complete_all(struct completion *);
#define INIT_COMPLETION(x) ((x).done = 0)
+
+/**
+ * try_wait_for_completion - try to decrement a completion without blocking
+ * @x: completion structure
+ *
+ * Returns: 0 if a decrement cannot be done without blocking
+ * 1 if a decrement succeeded.
+ *
+ * If a completion is being used as a counting completion,
+ * attempt to decrement the counter without blocking. This
+ * enables us to avoid waiting if the resource the completion
+ * is protecting is not available.
+ */
+static inline bool try_wait_for_completion(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ else
+ x->done--;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+
+/**
+ * completion_done - Test to see if a completion has any waiters
+ * @x: completion structure
+ *
+ * Returns: 0 if there are waiters (wait_for_completion() in progress)
+ * 1 if there are no waiters.
+ *
+ */
+static inline bool completion_done(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+
#endif
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