threads: add new mp_thread abstraction

This will allow to avoid hacky pthreads symbols/header override.

Inspired by pl_thread from libplacebo.

osdep/threads-posix.h

@@ -0,0 +1,135 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <errno.h>
+#include <pthread.h>
+#include <stdio.h>
+
+#include "common/common.h"
+#include "timer.h"
+
+typedef pthread_cond_t  mp_cond;
+typedef pthread_mutex_t mp_mutex;
+typedef pthread_mutex_t mp_static_mutex;
+typedef pthread_once_t  mp_once;
+typedef pthread_t       mp_thread;
+
+#define MP_STATIC_COND_INITIALIZER PTHREAD_COND_INITIALIZER
+#define MP_STATIC_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
+#define MP_STATIC_ONCE_INITIALIZER PTHREAD_ONCE_INIT
+
+static inline int mp_mutex_init_type_internal(mp_mutex *mutex, enum mp_mutex_type mtype)
+{
+    int mutex_type;
+    switch (mtype) {
+    case MP_MUTEX_RECURSIVE:
+        mutex_type = PTHREAD_MUTEX_RECURSIVE;
+        break;
+    case MP_MUTEX_NORMAL:
+    default:
+#ifndef NDEBUG
+        mutex_type = PTHREAD_MUTEX_ERRORCHECK;
+#else
+        mutex_type = PTHREAD_MUTEX_DEFAULT;
+#endif
+        break;
+    }
+
+    int ret = 0;
+    pthread_mutexattr_t attr;
+    ret = pthread_mutexattr_init(&attr);
+    if (ret != 0)
+        return ret;
+
+    pthread_mutexattr_settype(&attr, mutex_type);
+    ret = pthread_mutex_init(mutex, &attr);
+    pthread_mutexattr_destroy(&attr);
+    return ret;
+}
+
+#define mp_mutex_destroy    pthread_mutex_destroy
+#define mp_mutex_lock       pthread_mutex_lock
+#define mp_mutex_trylock    pthread_mutex_trylock
+#define mp_mutex_unlock     pthread_mutex_unlock
+
+#define mp_cond_init(cond)  pthread_cond_init(cond, NULL)
+#define mp_cond_destroy     pthread_cond_destroy
+#define mp_cond_broadcast   pthread_cond_broadcast
+#define mp_cond_signal      pthread_cond_signal
+#define mp_cond_wait        pthread_cond_wait
+
+static inline int mp_cond_timedwait(mp_cond *cond, mp_mutex *mutex, int64_t timeout)
+{
+    timeout = MPMAX(0, timeout);
+    // consider anything above 1000 days as infinity
+    if (timeout > MP_TIME_S_TO_NS(1000 * 24 * 60 * 60))
+        return pthread_cond_wait(cond, mutex);
+
+    struct timespec ts;
+    clock_gettime(CLOCK_REALTIME, &ts);
+    ts.tv_sec  += timeout / MP_TIME_S_TO_NS(1);
+    ts.tv_nsec += timeout % MP_TIME_S_TO_NS(1);
+    if (ts.tv_nsec >= MP_TIME_S_TO_NS(1)) {
+        ts.tv_nsec -= MP_TIME_S_TO_NS(1);
+        ts.tv_sec++;
+    }
+
+    return pthread_cond_timedwait(cond, mutex, &ts);
+}
+
+static inline int mp_cond_timedwait_until(mp_cond *cond, mp_mutex *mutex, int64_t until)
+{
+    return mp_cond_timedwait(cond, mutex, until - mp_time_ns());
+}
+
+#define mp_exec_once pthread_once
+
+#define MP_THREAD_VOID void *
+#define MP_THREAD_RETURN() return NULL
+
+#define mp_thread_create(t, f, a) pthread_create(t, NULL, f, a)
+#define mp_thread_join(t)         pthread_join(t, NULL)
+#define mp_thread_self            pthread_self
+#define mp_thread_equal           pthread_equal
+
+static inline void mp_thread_set_name(const char *name)
+{
+#if HAVE_GLIBC_THREAD_NAME
+    if (pthread_setname_np(pthread_self(), name) == ERANGE) {
+        char tname[16] = {0}; // glibc-checked kernel limit
+        strncpy(tname, name, sizeof(tname) - 1);
+        pthread_setname_np(pthread_self(), tname);
+    }
+#elif HAVE_BSD_THREAD_NAME
+    pthread_set_name_np(pthread_self(), name);
+#elif HAVE_OSX_THREAD_NAME
+    pthread_setname_np(name);
+#endif
+}
+
+static inline int64_t mp_thread_cpu_time_ns(mp_thread thread)
+{
+#if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 && defined(_POSIX_THREAD_CPUTIME)
+    clockid_t id;
+    struct timespec ts;
+    if (pthread_getcpuclockid(thread, &id) == 0 && clock_gettime(id, &ts) == 0)
+        return MP_TIME_S_TO_NS(ts.tv_sec) + ts.tv_nsec;
+#endif
+    return 0;
+}

osdep/threads.h

@@ -70,4 +70,17 @@ int mp_ptwrap_mutex_trylock(const char *file, int line, pthread_mutex_t *m);
 
 #endif
 
+enum mp_mutex_type {
+    MP_MUTEX_NORMAL = 0,
+    MP_MUTEX_RECURSIVE,
+};
+
+#define mp_mutex_init(mutex) \
+    mp_mutex_init_type(mutex, MP_MUTEX_NORMAL)
+
+#define mp_mutex_init_type(mutex, mtype) \
+    assert(!mp_mutex_init_type_internal(mutex, mtype))
+
+#include "threads-posix.h"
+
 #endif