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sem_timedwait与Android NDK

[英]sem_timedwait with Android NDK

原文 2014-09-17 07:33:43 5 1 android/ c++/ android-ndk/ pthreads/ semaphore

During investigation I have found several gaps in Semaphore primitives implementation in NDK. 在调查过程中，我发现NDK中的信号量原语实现方面存在一些空白。 My current task needs sem_timedwait (like sem_wait just with timeout), but I can't find it in NDK. 我当前的任务需要sem_timedwait （就像sem_wait只是超时），但是我在NDK中找不到它。 One more important thing: code should be portable on iOS platform. 还有一件事很重要：代码应该可以在iOS平台上移植。

My current suggestion: 我目前的建议：

Step 1: Create separate thread ( thrd_id1 ) with sem_wait (wait until sem_post, can stuck there for ever) 第1步：使用sem_wait创建单独的线程（ thrd_id1 ）（等到sem_post永久停留在那里）

Step 2: Create separate thread ( thrd_id2 ) with sleep in seconds and when we are wake 步骤2：创建单独的线程（ thrd_id2 ），并在几秒钟内以及我们醒来时进入睡眠状态

Step 3: When we are wake on ( thrd_id2 ) try to cancel thread with sem_wait ( thrd_id1 ), in case of success return ETIMEOUT , otherwise sem_wait unlocked by sem_post from another thread. 步骤3：当我们唤醒（ thrd_id2 ）时，尝试使用sem_wait（ thrd_id1 ）取消线程，如果成功返回ETIMEOUT ，否则sem_wait由另一个线程的sem_post解锁。 However NDK implementation of pthread has no cancellable threads. 但是NDK的pthread实现没有可取消的线程。

Have another idea with pthread_kill , but how can I know was it killed or terminated normally? 对pthread_kill有另一个想法，但是我怎么知道它被杀死或正常终止了？

Please advise. 请指教。

1 个解决方案

sem_timedwait is present in Android NDK at least from version r9d (I don't have earlier versions) - check platforms/android-%yourplatform%/arch-%yourarch%/usr/include/semaphore.h . sem_timedwait至少存在于r9d版本的Android NDK中（我没有更早的版本）-检查platforms/android-%yourplatform%/arch-%yourarch%/usr/include/semaphore.h 。

If switching to newer NDK is not an option, I would advise you to just take GNU implementation . 如果不能切换到较新的NDK，我建议您仅采用GNU实现。