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Refactor process.c for comments, clarity and readability

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This commit is contained in:
sBubshait
2024-11-15 14:37:38 +00:00
parent 82d45880f7
commit f4c900e56c
1 changed files with 20 additions and 16 deletions
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36
src/userprog/process.c
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@@ -84,9 +84,9 @@ process_execute (const char *cmd)
/* Validates that the current file to be executed can be opened/exists. */
lock_acquire (&filesys_lock);
bool valid_file = filesys_open (file_name) != NULL;
struct file *file = filesys_open (file_name);
lock_release (&filesys_lock);
if (!valid_file)
if (file == NULL)
return TID_ERROR;
/* Create a new thread to execute the command, by initializing
@@ -128,7 +128,6 @@ static void
start_process (void *proc_start_data)
{
struct intr_frame if_;
struct process_start_data *data = proc_start_data;
/* Initialize interrupt frame and load executable. */
@@ -136,41 +135,46 @@ start_process (void *proc_start_data)
if_.gs = if_.fs = if_.es = if_.ds = if_.ss = SEL_UDSEG;
if_.cs = SEL_UCSEG;
if_.eflags = FLAG_IF | FLAG_MBS;
/* Acquire the file system lock to prevent race conditions. */
lock_acquire (&filesys_lock);
/* Prevent writing to the file being executed. */
struct file *exec_file = filesys_open (data->file_name);
if (exec_file == NULL)
{
/* If the executable file cannot be opened, free resources and quit. */
lock_release (&filesys_lock);
sema_up (&data->loaded);
thread_exit ();
}
/* Deny write to the executable file to prevent writing to it and release the
file system lock. */
file_deny_write (exec_file);
lock_release (&filesys_lock);
thread_current ()->exec_file = exec_file;
/* Load the ELF executable file, and store the success of the operation in
the 'success' variable in data. */
data->success = load (data->file_name, &if_.eip, &if_.esp);
/* If load failed, quit. */
if (!data->success)
/* If load was sucessful, initialize user process stack and free page used
to store the command that executed the process. */
if (data->success)
{
sema_up (&data->loaded);
thread_exit ();
data->success =
process_init_stack (data->cmd_saveptr, &if_.esp, data->file_name);
}
/* Initialize user process stack and free page used to store the
command that executed the process. */
data->success = process_init_stack (data->cmd_saveptr, &if_.esp, data->file_name);
/* Signal that the process has finished attempting to load. */
bool success = data->success;
sema_up (&data->loaded);
/* If stack initialization failed, free resources and quit. */
/* If the load was unsuccessful or if it was but the stack initialization
failed, exit the thread. */
if (!success)
{
thread_exit ();
}
/* Start the user process by simulating a return from an
interrupt, implemented by intr_exit (in