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Re: [RFC PATCH 21/28] lkl tools: host lib: posix host operations

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On Sun, Nov 8, 2015 at 1:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 03 November 2015 22:20:52 Octavian Purdila wrote:
>> +struct pthread_sem {
>> +     pthread_mutex_t lock;
>> +     int count;
>> +     pthread_cond_t cond;
>> +};
>> +
>> +static void *sem_alloc(int count)
>> +{
>> +     struct pthread_sem *sem;
>> +
>> +     sem = malloc(sizeof(*sem));
>> +     if (!sem)
>> +             return NULL;
>> +
>> +     pthread_mutex_init(&sem->lock, NULL);
>> +     sem->count = count;
>> +     pthread_cond_init(&sem->cond, NULL);
>> +
>> +     return sem;
>> +}
>
> What is the reason to have generalized semaphores in the
> host API rather than a simple mutex?
>

Currently waking up from idle after an IRQ event requires a semaphore.
I'll see if we can use a simple mutex for this.

>> +static unsigned long long time_ns(void)
>> +{
>> +     struct timeval tv;
>> +
>> +     gettimeofday(&tv, NULL);
>> +
>> +     return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000ULL;
>> +}
>
> clock_gettime() has been around since POSIX.1-2001 and provides the
> nanosecond resolution you use in the interface.
>

Good point, I will change it to clock_gettime.

Thanks for the review Arnd !
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[RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 21/28] lkl tools: host lib: posix host operations Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
    Re: [RFC PATCH 21/28] lkl tools: host lib: posix host operations Arnd Bergmann <arnd@arndb.de> - 2015-11-08 00:20 +0100
      Re: [RFC PATCH 21/28] lkl tools: host lib: posix host operations Octavian Purdila <octavian.purdila@intel.com> - 2015-11-08 05:10 +0100
        Re: [RFC PATCH 21/28] lkl tools: host lib: posix host operations Arnd Bergmann <arnd@arndb.de> - 2015-11-08 11:40 +0100
  [RFC PATCH 18/28] lkl tools: host lib: virtio devices Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 19/28] lkl tools: host lib: virtio block device Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
    Re: [RFC PATCH 19/28] lkl tools: host lib: virtio block device Richard Weinberger <richard.weinberger@gmail.com> - 2015-11-07 13:30 +0100
      Re: [RFC PATCH 19/28] lkl tools: host lib: virtio block device Octavian Purdila <octavian.purdila@intel.com> - 2015-11-08 05:20 +0100
        Re: [RFC PATCH 19/28] lkl tools: host lib: virtio block device Richard Weinberger <richard@nod.at> - 2015-11-08 14:40 +0100
  [RFC PATCH 13/28] lkl: initialization and cleanup Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 20/28] lkl tools: host lib: filesystem helpers Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 24/28] lkl tools: tool that reads/writes to/from a filesystem image Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 22/28] lkl tools: "boot" test Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 02/28] kbuild: allow architectures to automatically define kconfig symbols Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 17/28] lkl tools: host lib: memory mapped I/O helpers Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 28/28] lkl tools: add support for Windows host Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 09/28] lkl: timers, time and delay support Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 16/28] lkl tools: host lib: add lkl_strerror and lkl_printf Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:30 +0100
  [RFC PATCH 01/28] asm-generic: atomic64: allow using generic atomic64 on 64bit platforms Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
  [RFC PATCH 04/28] lkl: host interface Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
    Re: [RFC PATCH 04/28] lkl: host interface Hajime Tazaki <thehajime@gmail.com> - 2015-11-04 00:40 +0100
  [RFC PATCH 05/28] lkl: memory handling Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
  [RFC PATCH 07/28] lkl: interrupt support Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
  [RFC PATCH 06/28] lkl: kernel threads support Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
  [RFC PATCH 03/28] lkl: architecture skeleton for Linux kernel library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-03 21:40 +0100
  Re: [RFC PATCH 00/28] Linux Kernel Library Richard Weinberger <richard.weinberger@gmail.com> - 2015-11-03 22:50 +0100
    Re: [RFC PATCH 00/28] Linux Kernel Library "Richard W.M. Jones" <rjones@redhat.com> - 2015-11-03 23:50 +0100
      Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-04 00:30 +0100
        Re: [RFC PATCH 00/28] Linux Kernel Library Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-11-04 14:30 +0100
        Re: [RFC PATCH 00/28] Linux Kernel Library "Richard W.M. Jones" <rjones@redhat.com> - 2015-11-04 15:00 +0100
          Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-04 15:30 +0100
            Re: [RFC PATCH 00/28] Linux Kernel Library Richard Weinberger <richard@nod.at> - 2015-11-07 01:40 +0100
              Re: [RFC PATCH 00/28] Linux Kernel Library "Richard W.M. Jones" <rjones@redhat.com> - 2015-11-07 08:20 +0100
              Re: [RFC PATCH 00/28] Linux Kernel Library "Richard W.M. Jones" <rjones@redhat.com> - 2015-11-07 11:50 +0100
                Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-09 17:40 +0100
              Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-08 05:20 +0100
              Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-08 05:40 +0100
      Re: [RFC PATCH 00/28] Linux Kernel Library Hajime Tazaki <thehajime@gmail.com> - 2015-11-04 00:30 +0100
    Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-04 00:10 +0100
      Re: [RFC PATCH 00/28] Linux Kernel Library Octavian Purdila <octavian.purdila@intel.com> - 2015-11-09 16:20 +0100
  Re: [RFC PATCH 00/28] Linux Kernel Library Hajime Tazaki <thehajime@gmail.com> - 2015-11-08 14:50 +0100

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