From c6609450b33960a0e9f8c1df045b02f0677e866a Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 13 Apr 2017 16:15:34 +0100 Subject: [PATCH] C++fy thread_apply_all_command This eliminates a couple cleanups. gdb/ChangeLog: 2017-04-13 Pedro Alves * thread.c: Include . (thread_array_cleanup): Delete. (scoped_inc_dec_ref): New class. (live_threads_count): New function. (set_thread_refcount): Delete. (tp_array_compar_ascending): Now a bool. (tp_array_compar): Convert to a std::sort comparison function. (thread_apply_all_command): Use std::vector and scoped_inc_dec_ref and live_threads_count. --- gdb/ChangeLog | 12 +++++ gdb/thread.c | 137 +++++++++++++++++++++++++++----------------------- 2 files changed, 85 insertions(+), 64 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 4160e9f44d4..7b28fa2b934 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2017-04-13 Pedro Alves + + * thread.c: Include . + (thread_array_cleanup): Delete. + (scoped_inc_dec_ref): New class. + (live_threads_count): New function. + (set_thread_refcount): Delete. + (tp_array_compar_ascending): Now a bool. + (tp_array_compar): Convert to a std::sort comparison function. + (thread_apply_all_command): Use std::vector and scoped_inc_dec_ref + and live_threads_count. + 2017-04-13 Pedro Alves * infrun.c (follow_fork_inferior): Also switch the current diff --git a/gdb/thread.c b/gdb/thread.c index abfce71eda5..88fd521a58e 100644 --- a/gdb/thread.c +++ b/gdb/thread.c @@ -44,6 +44,7 @@ #include "cli/cli-utils.h" #include "thread-fsm.h" #include "tid-parse.h" +#include /* Definition of struct thread_info exported to gdbthread.h. */ @@ -69,16 +70,27 @@ static void info_threads_command (char *, int); static void thread_apply_command (char *, int); static void restore_current_thread (ptid_t); -/* Data to cleanup thread array. */ +/* RAII type used to increase / decrease the refcount of each thread + in a given list of threads. */ -struct thread_array_cleanup +class scoped_inc_dec_ref { - /* Array of thread pointers used to set - reference count. */ - struct thread_info **tp_array; +public: + explicit scoped_inc_dec_ref (const std::vector &thrds) + : m_thrds (thrds) + { + for (thread_info *thr : m_thrds) + thr->incref (); + } - /* Thread count in the array. */ - int count; + ~scoped_inc_dec_ref () + { + for (thread_info *thr : m_thrds) + thr->decref (); + } + +private: + const std::vector &m_thrds; }; @@ -565,6 +577,20 @@ thread_count (void) return result; } +/* Return the number of non-exited threads in the thread list. */ + +static int +live_threads_count (void) +{ + int result = 0; + struct thread_info *tp; + + ALL_NON_EXITED_THREADS (tp) + ++result; + + return result; +} + int valid_global_thread_id (int global_id) { @@ -1605,19 +1631,6 @@ restore_current_thread_cleanup_dtor (void *arg) xfree (old); } -/* Set the thread reference count. */ - -static void -set_thread_refcount (void *data) -{ - int k; - struct thread_array_cleanup *ta_cleanup - = (struct thread_array_cleanup *) data; - - for (k = 0; k != ta_cleanup->count; k++) - ta_cleanup->tp_array[k]->decref (); -} - struct cleanup * make_cleanup_restore_current_thread (void) { @@ -1693,30 +1706,30 @@ print_thread_id (struct thread_info *thr) return s; } -/* If non-zero tp_array_compar should sort in ascending order, otherwise in - descending order. */ +/* If true, tp_array_compar should sort in ascending order, otherwise + in descending order. */ -static int tp_array_compar_ascending; +static bool tp_array_compar_ascending; /* Sort an array for struct thread_info pointers by thread ID (first by inferior number, and then by per-inferior thread number). The order is determined by TP_ARRAY_COMPAR_ASCENDING. */ -static int -tp_array_compar (const void *ap_voidp, const void *bp_voidp) +static bool +tp_array_compar (const thread_info *a, const thread_info *b) { - const struct thread_info *a = *(const struct thread_info * const *) ap_voidp; - const struct thread_info *b = *(const struct thread_info * const *) bp_voidp; - if (a->inf->num != b->inf->num) { - return (((a->inf->num > b->inf->num) - (a->inf->num < b->inf->num)) - * (tp_array_compar_ascending ? +1 : -1)); + if (tp_array_compar_ascending) + return a->inf->num < b->inf->num; + else + return a->inf->num > b->inf->num; } - return (((a->per_inf_num > b->per_inf_num) - - (a->per_inf_num < b->per_inf_num)) - * (tp_array_compar_ascending ? +1 : -1)); + if (tp_array_compar_ascending) + return (a->per_inf_num < b->per_inf_num); + else + return (a->per_inf_num > b->per_inf_num); } /* Apply a GDB command to a list of threads. List syntax is a whitespace @@ -1732,15 +1745,13 @@ thread_apply_all_command (char *cmd, int from_tty) { struct cleanup *old_chain; char *saved_cmd; - int tc; - struct thread_array_cleanup ta_cleanup; - tp_array_compar_ascending = 0; + tp_array_compar_ascending = false; if (cmd != NULL && check_for_argument (&cmd, "-ascending", strlen ("-ascending"))) { cmd = skip_spaces (cmd); - tp_array_compar_ascending = 1; + tp_array_compar_ascending = true; } if (cmd == NULL || *cmd == '\000') @@ -1755,42 +1766,40 @@ thread_apply_all_command (char *cmd, int from_tty) saved_cmd = xstrdup (cmd); make_cleanup (xfree, saved_cmd); - /* Note this includes exited threads. */ - tc = thread_count (); + int tc = live_threads_count (); if (tc != 0) { - struct thread_info **tp_array; - struct thread_info *tp; - int i = 0, k; + /* Save a copy of the thread list and increment each thread's + refcount while executing the command in the context of each + thread, in case the command is one that wipes threads. E.g., + detach, kill, disconnect, etc., or even normally continuing + over an inferior or thread exit. */ + std::vector thr_list_cpy; + thr_list_cpy.reserve (tc); - /* Save a copy of the thread_list in case we execute detach - command. */ - tp_array = XNEWVEC (struct thread_info *, tc); - make_cleanup (xfree, tp_array); + { + thread_info *tp; - ALL_NON_EXITED_THREADS (tp) - { - tp_array[i] = tp; - tp->incref (); - i++; - } - /* Because we skipped exited threads, we may end up with fewer - threads in the array than the total count of threads. */ - gdb_assert (i <= tc); + ALL_NON_EXITED_THREADS (tp) + { + thr_list_cpy.push_back (tp); + } + + gdb_assert (thr_list_cpy.size () == tc); + } - if (i != 0) - qsort (tp_array, i, sizeof (*tp_array), tp_array_compar); + /* Increment the refcounts, and restore them back on scope + exit. */ + scoped_inc_dec_ref inc_dec_ref (thr_list_cpy); - ta_cleanup.tp_array = tp_array; - ta_cleanup.count = i; - make_cleanup (set_thread_refcount, &ta_cleanup); + std::sort (thr_list_cpy.begin (), thr_list_cpy.end (), tp_array_compar); - for (k = 0; k != i; k++) - if (thread_alive (tp_array[k])) + for (thread_info *thr : thr_list_cpy) + if (thread_alive (thr)) { - switch_to_thread (tp_array[k]->ptid); + switch_to_thread (thr->ptid); printf_filtered (_("\nThread %s (%s):\n"), - print_thread_id (tp_array[k]), + print_thread_id (thr), target_pid_to_str (inferior_ptid)); execute_command (cmd, from_tty); -- 2.30.2