[PATCH] Windows: a minimal pthread_cond_broadcast

From: Johannes Sixt <j6t@kdbg.org>
Date: Jan 29, 2010, 22:16 UTC
Message-ID: <201001292316.03858.j6t@kdbg.org>
In-Reply-To: <201001292102.49105.j6t@kdbg.org>

[Cc msysgit list]

On Freitag, 29. Januar 2010, Johannes Sixt wrote:

> cond_broadcast is not that trivial.

... except when it can be tailor-made for a particular use-case. What do people think about this?

I had implemented a full-blown pthread_cond_broadcast, taking ACE as an example, but I had doubts about its correctness. Then I noticed that we do not need a complete implementation anyway. So here we go...

--- 8< ---
From: Johannes Sixt <j6t@kdbg.org>
Subject: [PATCH] Windows: a minimal pthread_cond_broadcast

This is not an implementation, but more a fake of pthread_cond_broadcast. It is sufficient for the only call site in builtin-grep.c that we have at this time. It works because the threads that wake up due to this call do not call pthread_cond_wait anymore and terminate.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
 compat/win32/pthread.c |   10 ++++++++++
 compat/win32/pthread.h |    4 +---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/compat/win32/pthread.c b/compat/win32/pthread.c
index 631c0a4..7b5cac1 100644
--- a/compat/win32/pthread.c
+++ b/compat/win32/pthread.c
@@ -108,3 +108,13 @@ int pthread_cond_signal(pthread_cond_t *cond)
 	else
 		return 0;
 }
+
+/*
+ * FIXME: This is a fake implementation that is tailored for the only
+ * user that we currently have.
+ */
+int pthread_cond_broadcast(pthread_cond_t *cond)
+{
+	ReleaseSemaphore(cond->sema, cond->waiters, NULL);
+	return 0;
+}
diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
index b8e1bcb..7c360d5 100644
--- a/compat/win32/pthread.h
+++ b/compat/win32/pthread.h
@@ -37,12 +37,10 @@ typedef struct {
 } pthread_cond_t;
 
 extern int pthread_cond_init(pthread_cond_t *cond, const void *unused);
-
 extern int pthread_cond_destroy(pthread_cond_t *cond);
-
 extern int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex);
-
 extern int pthread_cond_signal(pthread_cond_t *cond);
+extern int pthread_cond_broadcast(pthread_cond_t *cond);
 
 /*
  * Simple thread creation implementation using pthread API

-- 
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