1 /**
2  * \file render_queue.c
3  * \brief Manage a queue of rendered backbuffers to display
4  *
5  * \author David Hogan <david.q.hogan@gmail.com>
6  */
7 
8 /* This file is part of VICE, the Versatile Commodore Emulator.
9  * See README for copyright notice.
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *  GNU General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; if not, write to the Free Software
23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24  *  02111-1307  USA.
25  *
26  */
27 
28 #include "vice.h"
29 #include "render_thread.h"
30 
31 #include <glib.h>
32 #include <pthread.h>
33 #include <stdbool.h>
34 #include <string.h>
35 
36 #include "archdep.h"
37 #include "lib.h"
38 #include "log.h"
39 
40 struct render_thread_s {
41     int index;
42     GThreadPool *executor;
43     bool is_shutdown_initiated;
44     bool is_shut_down;
45 };
46 
47 #define RENDER_THREAD_MAX 2 /* Current max of two windows (x128) */
48 
49 static struct render_thread_s threads[RENDER_THREAD_MAX];
50 static int thread_count;
51 
52 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
53 
54 #define LOCK() pthread_mutex_lock(&lock)
55 #define UNLOCK() pthread_mutex_unlock(&lock)
56 
render_thread_create(render_thread_callback_t callback,void * thread_context)57 render_thread_t render_thread_create(render_thread_callback_t callback, void *thread_context)
58 {
59     render_thread_t thread;
60 
61     LOCK();
62 
63     if (thread_count == RENDER_THREAD_MAX) {
64         log_error(LOG_ERR, "Reach maximum render thread count (%d), cannot create another", RENDER_THREAD_MAX);
65         UNLOCK();
66         archdep_vice_exit(-1);
67     }
68 
69     thread = threads + thread_count;
70     memset(thread, 0, sizeof(struct render_thread_s));
71     thread->index = thread_count++;
72 
73     thread->executor = g_thread_pool_new(callback, thread_context, 1, TRUE, NULL);
74 
75     /* Schedule the init job */
76     g_thread_pool_push(thread->executor, (void *)render_thread_init, NULL);
77 
78     UNLOCK();
79 
80     log_message(LOG_DEFAULT, "Created render thread %d", thread->index);
81 
82     return thread;
83 }
84 
render_thread_initiate_shutdown(render_thread_t thread)85 void render_thread_initiate_shutdown(render_thread_t thread)
86 {
87     LOCK();
88 
89     if (thread->is_shutdown_initiated) {
90         UNLOCK();
91         return;
92     }
93 
94     log_message(LOG_DEFAULT, "Initiating render thread %d shutdown", thread->index);
95     thread->is_shutdown_initiated = true;
96 
97     /* Schedule the shutdown job */
98     g_thread_pool_push(thread->executor, (void *)render_thread_shutdown, NULL);
99 
100     UNLOCK();
101 }
102 
render_thread_join(render_thread_t thread)103 void render_thread_join(render_thread_t thread)
104 {
105     log_message(LOG_DEFAULT, "Joining render thread %d ...", thread->index);
106 
107     /* TODO: We should block until all jobs are done - but there's a race condition deadlock outcome here. Fix needed */
108     g_thread_pool_free(thread->executor, TRUE, TRUE);
109 
110     LOCK();
111     thread->is_shut_down = true;
112     UNLOCK();
113 
114     log_message(LOG_DEFAULT, "Joined render thread %d.", thread->index);
115 }
116 
render_thread_shutdown_and_join_all(void)117 void render_thread_shutdown_and_join_all(void)
118 {
119     for (int i = 0; i < thread_count; i++) {
120         render_thread_initiate_shutdown(threads + i);
121     }
122 
123     for (int i = 0; i < thread_count; i++) {
124         render_thread_join(threads + i);
125     }
126 }
127 
render_thread_push_job(render_thread_t thread,render_job_t job)128 void render_thread_push_job(render_thread_t thread, render_job_t job)
129 {
130     LOCK();
131 
132     if (thread->is_shutdown_initiated)
133     {
134         log_message(LOG_DEFAULT, "Ignoring new render job as render thread %d %s down", thread->index, thread->is_shut_down ? "has shut" : "is shutting");
135         UNLOCK();
136         return;
137     }
138 
139     g_thread_pool_push(thread->executor, (void *)job, NULL);
140 
141     UNLOCK();
142 }
143 
144 
145 
146 
147