Implemented a generic system watching mechanism with a userland API. Currently

only a few events can be watched (team creation/deletion/exec, thread creation/
deletion/name changes). The functions start_system_watching()/
stop_system_watching start/stop watching events.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39862 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/ksystem_info.h

@@ -8,6 +8,7 @@
 
 #include <OS.h>
 
+
 struct kernel_args;
 
 
@@ -15,15 +16,24 @@ struct kernel_args;
 extern "C" {
 #endif
 
-extern status_t system_info_init(struct kernel_args *args);
-extern uint32 get_haiku_revision(void);
 
-extern status_t _user_get_system_info(system_info *userInfo, size_t size);
-extern status_t _user_get_system_info_etc(int32 id, void *buffer,
-	size_t bufferSize);
+status_t system_info_init(struct kernel_args *args);
+status_t system_notifications_init();
+uint32 get_haiku_revision(void);
+
+status_t _user_get_system_info(system_info *userInfo, size_t size);
+status_t _user_get_system_info_etc(int32 id, void *buffer,
+			size_t bufferSize);
+
+status_t _user_start_system_watching(int32 object, uint32 flags,
+			port_id port, int32 token);
+status_t _user_stop_system_watching(int32 object, uint32 flags,
+			port_id port, int32 token);
+
 
 #ifdef __cplusplus
 }
 #endif
 
+
 #endif	/* _KERNEL_SYSTEM_INFO_H */

headers/private/system/syscalls.h

@@ -174,6 +174,11 @@ extern status_t		_kern_get_team_usage_info(team_id team, int32 who,
 extern status_t		_kern_get_extended_team_info(team_id teamID, uint32 flags,
 						void* buffer, size_t size, size_t* _sizeNeeded);
 
+extern status_t		_kern_start_system_watching(int32 object, uint32 flags,
+						port_id port, int32 token);
+extern status_t		_kern_stop_system_watching(int32 object, uint32 flags,
+						port_id port, int32 token);
+
 extern status_t		_kern_block_thread(uint32 flags, bigtime_t timeout);
 extern status_t		_kern_unblock_thread(thread_id thread, status_t status);
 extern status_t		_kern_unblock_threads(thread_id* threads, uint32 count,

headers/private/system/system_info.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008 Haiku, Inc. All rights reserved.
+ * Copyright 2008-2010, Haiku, Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _SYSTEM_INFO_H
@@ -24,14 +24,56 @@ struct system_memory_info {
 };
 
 
+enum {
+	// team creation or deletion; object == -1; either one also triggers on
+	// exec()
+	B_WATCH_SYSTEM_TEAM_CREATION		= 0x01,
+	B_WATCH_SYSTEM_TEAM_DELETION		= 0x02,
+
+	// thread creation or deletion or property (name, priority) changes;
+	// object == team ID or -1 for all teams
+	B_WATCH_SYSTEM_THREAD_CREATION		= 0x04,
+	B_WATCH_SYSTEM_THREAD_DELETION		= 0x08,
+	B_WATCH_SYSTEM_THREAD_PROPERTIES	= 0x10,
+
+	B_WATCH_SYSTEM_ALL
+		= B_WATCH_SYSTEM_TEAM_CREATION
+		| B_WATCH_SYSTEM_TEAM_DELETION
+		| B_WATCH_SYSTEM_THREAD_CREATION
+		| B_WATCH_SYSTEM_THREAD_DELETION
+		| B_WATCH_SYSTEM_THREAD_PROPERTIES
+};
+
+enum {
+	// message what for the notification messages
+	B_SYSTEM_OBJECT_UPDATE				= 'SOUP',
+
+	// "opcode" values
+	B_TEAM_CREATED						= 0,
+	B_TEAM_DELETED						= 1,
+	B_TEAM_EXEC							= 2,
+	B_THREAD_CREATED					= 3,
+	B_THREAD_DELETED					= 4,
+	B_THREAD_NAME_CHANGED				= 5
+};
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-extern status_t get_system_info_etc(int32 id, void *buffer, size_t bufferSize);
+
+status_t get_system_info_etc(int32 id, void* buffer, size_t bufferSize);
+
+status_t start_system_watching(int32 object, uint32 flags, port_id port,
+			int32 token);
+status_t stop_system_watching(int32 object, uint32 flags, port_id port,
+			int32 token);
+
 
 #ifdef __cplusplus
 }
 #endif
 
+
 #endif	/* _SYSTEM_INFO_H */