Fix: unbreak picom compilation on OpenBSD using libepoxy

Fix: clang style

Fix: src/meson.build style

src/backend/gl/gl_common.c

@@ -1,7 +1,12 @@
 // SPDX-License-Identifier: MPL-2.0
 // Copyright (c) Yuxuan Shui <[email protected]>
+#ifndef __OpenBSD__
 #include <GL/gl.h>
 #include <GL/glext.h>
+#else
+#include <epoxy/gl.h>
+#include <epoxy/glx.h>
+#endif
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>

src/meson.build

@@ -82,8 +82,11 @@ host_system = host_machine.system()
 if host_system == 'linux'
 	cflags += ['-DHAS_INOTIFY']
 elif (host_system == 'freebsd' or host_system == 'netbsd' or
-      host_system == 'dragonfly' or host_system == 'openbsd')
+      host_system == 'dragonfly')
 	cflags += ['-DHAS_KQUEUE']
+elif host_system == 'openbsd'
+	cflags += ['-DHAS_KQUEUE']
+        deps += [dependency('epoxy', required: true)]
 endif
 
 subdir('backend')

src/picom.c

@@ -2583,6 +2583,7 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 /// This requires the user to set up permissions for the real-time scheduling. e.g. by
 /// setting `ulimit -r`, or giving us the CAP_SYS_NICE capability.
 void set_rr_scheduling(void) {
+#ifndef __OpenBSD__
 	int priority = sched_get_priority_min(SCHED_RR);
 
 	int ret;
@@ -2597,12 +2598,31 @@ void set_rr_scheduling(void) {
 	param.sched_priority = priority;
 	ret = sched_setscheduler(0, SCHED_RR, &param);
 	if (ret != 0) {
-		log_info("Failed to set real-time scheduling priority to %d. Consider "
-		         "giving picom the CAP_SYS_NICE capability",
-		         priority);
+		log_info("Failed to set real-time scheduling priority to %d.", priority);
 		return;
 	}
 	log_info("Set real-time scheduling priority to %d", priority);
+#else        // OpenBSD real-time scheduling support
+	int priority = sched_get_priority_min(SCHED_RR);
+
+	int old_policy;
+	int ret;
+	struct sched_param param;
+
+	ret = pthread_getschedparam(pthread_self(), &old_policy, &param);
+	if (ret != 0) {
+		log_debug("Failed to get old scheduling priority");
+		return;
+	}
+
+	param.sched_priority = priority;
+	ret = pthread_setschedparam(pthread_self(), SCHED_RR, &param);
+	if (ret != 0) {
+		log_info("Failed to set real-time scheduling priority to %d.", priority);
+		return;
+	}
+	log_info("Set real-time scheduling priority to %d", priority);
+#endif
 }
 
 /**