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Optimize stack initialization by not using malloc, and remove use of 'goto' (for code review safety) #41

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td1223 merged 4 commits from stack-init-optimize into master 2024-11-14 16:06:23 +00:00
Conversation 5 Commits 4 Files Changed 1 +10 -14
1 changed files with 10 additions and 14 deletions
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Showing only changes of commit 1a2ff35231 - Show all commits

24
src/userprog/process.c
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@@ -65,13 +65,10 @@ process_execute (const char *cmd)
char *cmd_copy; char *cmd_copy;
tid_t tid; tid_t tid;
struct process_start_data *data = malloc (sizeof (struct process_start_data)); struct process_start_data data;
if (data == NULL)
{ sema_init (&data.loaded, 0);
return TID_ERROR; data.success = false;
}
sema_init (&data->loaded, 0);
data->success = false;
/* Make a copy of command. /* Make a copy of command.
Otherwise there's a race between the caller and load(). */ Otherwise there's a race between the caller and load(). */
@@ -85,7 +82,7 @@ process_execute (const char *cmd)
/* Retrieve first argument of command, which is the file name /* Retrieve first argument of command, which is the file name
of the process. */ of the process. */
char *file_name = strtok_r (cmd_copy, " ", &data->cmd_saveptr); char *file_name = strtok_r (cmd_copy, " ", &data.cmd_saveptr);
/* NOTE: Currently, the file being executed is closed in load () and then /* NOTE: Currently, the file being executed is closed in load () and then
reopened here. Because load is an exported public function, this reopened here. Because load is an exported public function, this
@@ -100,19 +97,18 @@ process_execute (const char *cmd)
/* Create a new thread to execute the command, by initializing /* Create a new thread to execute the command, by initializing
it running the function 'start_process' with the appropriate it running the function 'start_process' with the appropriate
arguments. For details of arguments, see 'start_process'. */ arguments. For details of arguments, see 'start_process'. */
data->cmd = cmd_copy; data.cmd = cmd_copy;
strlcpy (data->file_name, file_name, FNAME_MAX_LEN + 1); strlcpy (data.file_name, file_name, FNAME_MAX_LEN + 1);
tid = thread_create (file_name, PRI_DEFAULT, start_process, data); tid = thread_create (file_name, PRI_DEFAULT, start_process, &data);
if (tid == TID_ERROR) if (tid == TID_ERROR)
palloc_free_page (cmd_copy); palloc_free_page (cmd_copy);
else else
{ {
sema_down (&data->loaded); sema_down (&data.loaded);
if (!data->success) if (!data.success)
tid = TID_ERROR; tid = TID_ERROR;
} }
free (data);
return tid; return tid;
} }