Added a list of death_entry's to the teams structure. It stores the

exit status of (non-main) threads of a team. Fixes bug #1644.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23009 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/thread_types.h

@@ -94,7 +94,9 @@ struct team_watcher {
 };
 
 #define MAX_DEAD_CHILDREN	32
-	// this is a soft limit for the number of dead entries in a team
+	// this is a soft limit for the number of child death entries in a team
+#define MAX_DEAD_THREADS	32
+	// this is a soft limit for the number of thread death entries in a team
 
 typedef struct team_dead_children team_dead_children;
 typedef struct team_job_control_children  team_job_control_children;
@@ -155,6 +157,8 @@ struct team {
 	int				pending_signals;
 	void			*io_context;
 	sem_id			death_sem;		// semaphore to wait on for dying threads
+	struct list		dead_threads;
+	int				dead_threads_count;
 
 	team_dead_children *dead_children;
 	team_job_control_children *stopped_children;

src/system/kernel/team.cpp

@@ -567,6 +567,10 @@ create_team_struct(const char *name, bool kernel)
 	team->dead_threads_kernel_time = 0;
 	team->dead_threads_user_time = 0;
 
+	// dead threads
+	list_init(&team->dead_threads);
+	team->dead_threads_count = 0;
+
 	// dead children
 	team->dead_children = new(nothrow) team_dead_children;
 	if (team->dead_children == NULL)
@@ -636,6 +640,11 @@ delete_team_struct(struct team *team)
 
 	team->dead_children->condition_variable.Unpublish();
 
+	while (death_entry* threadDeathEntry = (death_entry*)list_remove_head_item(
+			&team->dead_threads)) {
+		free(threadDeathEntry);
+	}
+
 	while (job_control_entry* entry = team->dead_children->entries.RemoveHead())
 		delete entry;
 

src/system/kernel/thread.cpp

@@ -1215,11 +1215,14 @@ thread_exit(void)
 	}
 
 	struct job_control_entry *death = NULL;
+	struct death_entry* threadDeathEntry = NULL;
+
 	if (team != team_get_kernel_team()) {
 		if (team->main_thread == thread) {
 			// this was the main thread in this team, so we will delete that as well
 			deleteTeam = true;
-		}
+		} else
+			threadDeathEntry = (death_entry*)malloc(sizeof(death_entry));
 
 		// remove this thread from the current team and add it to the kernel
 		// put the thread into the kernel team until it dies
@@ -1272,8 +1275,30 @@ thread_exit(void)
 				RELEASE_THREAD_LOCK();
 
 			team_remove_team(team, &freeGroup);
-		} else
+		} else {
+			// The thread is not the main thread. We store a thread death
+			// entry for it, unless someone is already waiting it.
+			if (threadDeathEntry != NULL
+				&& list_is_empty(&thread->exit.waiters)) {
+				threadDeathEntry->thread = thread->id;
+				threadDeathEntry->status = thread->exit.status;
+				threadDeathEntry->reason = thread->exit.reason;
+				threadDeathEntry->signal = thread->exit.signal;
+
+				// add entry -- remove and old one, if we hit the limit
+				list_add_item(&team->dead_threads, threadDeathEntry);
+				team->dead_threads_count++;
+				threadDeathEntry = NULL;
+
+				if (team->dead_threads_count > MAX_DEAD_THREADS) {
+					threadDeathEntry = (death_entry*)list_remove_head_item(
+						&team->dead_threads);
+					team->dead_threads_count--;
+				}
+			}
+
 			RELEASE_THREAD_LOCK();
+		}
 
 		RELEASE_TEAM_LOCK();
 
@@ -1284,6 +1309,9 @@ thread_exit(void)
 		TRACE(("thread_exit: thread %ld now a kernel thread!\n", thread->id));
 	}
 
+	if (threadDeathEntry != NULL)
+		free(threadDeathEntry);
+
 	// delete the team if we're its main thread
 	if (deleteTeam) {
 		team_delete_process_group(freeGroup);
@@ -1640,6 +1668,8 @@ wait_for_thread_etc(thread_id id, uint32 flags, bigtime_t timeout,
 		list_add_link_to_head(&thread->exit.waiters, &death);
 	}
 
+	death_entry* threadDeathEntry = NULL;
+
 	RELEASE_THREAD_LOCK();
 
 	if (thread == NULL) {
@@ -1647,15 +1677,31 @@ wait_for_thread_etc(thread_id id, uint32 flags, bigtime_t timeout,
 		// find its death entry in our team
 		GRAB_TEAM_LOCK();
 
+		struct team* team = thread_get_current_thread()->team;
+
+		// check the child death entries first (i.e. main threads of child
+		// teams)
 		bool deleteEntry;
-		freeDeath = team_get_death_entry(thread_get_current_thread()->team, id,
+		freeDeath = team_get_death_entry(team, id, &deleteEntry);
-			&deleteEntry);
 		if (freeDeath != NULL) {
 			death.status = freeDeath->status;
 			if (!deleteEntry)
 				freeDeath = NULL;
-		} else
+		} else {
+			// check the thread death entries of the team (non-main threads)
+			while ((threadDeathEntry = (death_entry*)list_get_next_item(
+					&team->dead_threads, threadDeathEntry)) != NULL) {
+				if (threadDeathEntry->thread == id) {
+					list_remove_item(&team->dead_threads, threadDeathEntry);
+					team->dead_threads_count--;
+					death.status = threadDeathEntry->status;
+					break;
+				}
+			}
+
+			if (threadDeathEntry == NULL)
 				status = B_BAD_THREAD_ID;
+		}
 
 		RELEASE_TEAM_LOCK();
 	}
@@ -1668,6 +1714,7 @@ wait_for_thread_etc(thread_id id, uint32 flags, bigtime_t timeout,
 			*_returnCode = death.status;
 
 		delete freeDeath;
+		free(threadDeathEntry);
 		return B_OK;
 	}