auto import from //depot/cupcake/@135843
diff --git a/libthread_db/libthread_db.c b/libthread_db/libthread_db.c
new file mode 100644
index 0000000..f1a78ac
--- /dev/null
+++ b/libthread_db/libthread_db.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2006 The Android Open Source Project
+ */
+
+#include <dirent.h>
+#include <sys/ptrace.h>
+#include <stdint.h>
+#include <thread_db.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+extern int ps_pglobal_lookup (void *, const char *obj, const char *name, void **sym_addr);
+
+struct ps_prochandle
+{
+ pid_t pid;
+};
+
+
+/*
+ * This is the list of "special" symbols we care about whose addresses are
+ * cached by gdbserver from the host at init time.
+ */
+enum {
+ SYM_TD_CREATE,
+ SYM_THREAD_LIST,
+ NUM_SYMS
+};
+
+static char const * gSymbols[] = {
+ [SYM_TD_CREATE] = "_thread_created_hook",
+ NULL
+};
+
+
+char const **
+td_symbol_list(void)
+{
+ return gSymbols;
+}
+
+
+td_err_e
+td_ta_new(struct ps_prochandle const * proc_handle, td_thragent_t ** agent_out)
+{
+ td_thragent_t * agent;
+
+ agent = (td_thragent_t *)malloc(sizeof(td_thragent_t));
+ if (!agent) {
+ return TD_MALLOC;
+ }
+
+ agent->pid = proc_handle->pid;
+ *agent_out = agent;
+
+ return TD_OK;
+}
+
+
+td_err_e
+td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * events)
+{
+ return TD_OK;
+}
+
+
+static td_thrhandle_t gEventMsgHandle;
+
+static int
+_event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
+{
+ void * pc;
+
+ pc = (void *)ptrace(PTRACE_PEEKUSR, handle->tid, (void *)60 /* r15/pc */, NULL);
+
+ if (pc == bkpt_addr) {
+ // The hook function takes the id of the new thread as it's first param,
+ // so grab it from r0.
+ gEventMsgHandle.pid = ptrace(PTRACE_PEEKUSR, handle->tid, (void *)0 /* r0 */, NULL);
+ gEventMsgHandle.tid = gEventMsgHandle.pid;
+ return 0x42;
+ }
+ return 0;
+}
+
+td_err_e
+td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event)
+{
+ td_err_e err;
+ void * bkpt_addr;
+
+ err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], &bkpt_addr);
+ if (err) {
+ return err;
+ }
+
+ err = td_ta_thr_iter(agent, _event_getmsg_helper, bkpt_addr, 0, 0, NULL, 0);
+ if (err != 0x42) {
+ return TD_NOMSG;
+ }
+
+ event->event = TD_CREATE;
+ event->th_p = &gEventMsgHandle; // Nasty hack, but it's the only way!
+
+ return TD_OK;
+}
+
+
+td_err_e
+td_thr_get_info(td_thrhandle_t const * handle, td_thrinfo_t * info)
+{
+ info->ti_tid = handle->tid;
+ info->ti_lid = handle->tid; // Our pthreads uses kernel ids for tids
+ info->ti_state = TD_THR_SLEEP; /* XXX this needs to be read from /proc/<pid>/task/<tid>.
+ This is only used to see if the thread is a zombie or not */
+ return TD_OK;
+}
+
+
+td_err_e
+td_thr_event_enable(td_thrhandle_t const * handle, td_event_e event)
+{
+ // I don't think we need to do anything here...
+ return TD_OK;
+}
+
+
+td_err_e
+td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify_out)
+{
+ int32_t err;
+
+ /*
+ * This is nasty, ps_pglobal_lookup is implemented in gdbserver and looks up
+ * the symbol from it's cache, which is populated at start time with the
+ * symbols returned from td_symbol_list via calls back to the host.
+ */
+
+ switch (event) {
+ case TD_CREATE:
+ err = ps_pglobal_lookup(NULL, NULL, gSymbols[SYM_TD_CREATE], ¬ify_out->u.bptaddr);
+ if (err) {
+ return TD_NOEVENT;
+ }
+ return TD_OK;
+ }
+ return TD_NOEVENT;
+}
+
+
+td_err_e
+td_ta_thr_iter(td_thragent_t const * agent, td_thr_iter_f * func, void * cookie,
+ td_thr_state_e state, int32_t prio, sigset_t * sigmask, uint32_t user_flags)
+{
+ td_err_e err = TD_OK;
+ char path[32];
+ DIR * dir;
+ struct dirent * entry;
+ td_thrhandle_t handle;
+
+ snprintf(path, sizeof(path), "/proc/%d/task/", agent->pid);
+ dir = opendir(path);
+ if (!dir) {
+ return TD_NOEVENT;
+ }
+
+ handle.pid = agent->pid;
+ while ((entry = readdir(dir)) != NULL) {
+ if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
+ continue;
+ }
+ handle.tid = atoi(entry->d_name);
+ err = func(&handle, cookie);
+ if (err) {
+ break;
+ }
+ }
+
+ closedir(dir);
+
+ return err;
+}
+