Several of the devctl() commands use a procfs_status
structure (which is the same as debug_thread_t), so let's
look at this structure before going into the commands themselves:
The debug_thread_t structure is defined as follows in
<sys/debug.h>:
typedef struct _debug_thread_info {
pid_t pid;
pthread_t tid;
uint32_t flags;
uint16_t why;
uint16_t what;
uint64_t ip;
uint64_t sp;
uint64_t stkbase;
uint64_t tls;
uint32_t stksize;
uint32_t tid_flags;
uint8_t priority;
uint8_t real_priority;
uint8_t policy;
uint8_t state;
int16_t syscall;
uint16_t last_cpu;
uint32_t timeout;
int32_t last_chid;
sigset_t sig_blocked;
sigset_t sig_pending;
siginfo_t info;
union {
struct {
pthread_t tid;
} join;
struct {
int32_t id;
uintptr_t sync;
} sync;
struct {
uint32_t nd;
pid_t pid;
int32_t coid;
int32_t chid;
int32_t scoid;
} connect;
struct {
int32_t chid;
} channel;
struct {
pid_t pid;
uintptr_t vaddr;
uint32_t flags;
} waitpage;
struct {
uint32_t size;
} stack;
uint64_t filler[4];
} blocked;
uint64_t start_time;
uint64_t sutime;
uint8_t extsched[8];
uint64_t reserved2[5];
} debug_thread_t;
Note:
If you ask for information about a specific thread, and the thread
no longer exists, the process manager returns information about the one
with the next higher thread ID.
If all the process's threads have exited, the tid member of
the structure is set to 0.
The members include:
-
pid, tid
- The process and thread IDs.
-
flags
- A combination of the following bits:
-
_DEBUG_FLAG_STOPPED — the thread isn't running.
-
_DEBUG_FLAG_ISTOP — the thread is stopped at a
point of interest.
-
_DEBUG_FLAG_IPINVAL — the instruction pointer
isn't valid.
-
_DEBUG_FLAG_ISSYS — system process.
-
_DEBUG_FLAG_SSTEP — stopped because of
single-stepping.
-
_DEBUG_FLAG_CURTID — the thread is the current
thread.
-
_DEBUG_FLAG_TRACE_EXEC — stopped because of a
breakpoint.
-
_DEBUG_FLAG_TRACE_RD — stopped because of read
access.
-
_DEBUG_FLAG_TRACE_WR — stopped because of write
access.
-
_DEBUG_FLAG_TRACE_MODIFY — stopped because of
modified memory.
-
_DEBUG_FLAG_RLC — the Run-on-Last-Close flag is set.
-
_DEBUG_FLAG_KLC — the Kill-on-Last-Close flag is
set.
-
_DEBUG_FLAG_FORK — the child inherits flags
(stop on fork or spawn).
-
why
- One of the following:
-
_DEBUG_WHY_REQUESTED
-
_DEBUG_WHY_SIGNALLED
-
_DEBUG_WHY_FAULTED
-
_DEBUG_WHY_JOBCONTROL
-
_DEBUG_WHY_TERMINATED
-
_DEBUG_WHY_CHILD
-
_DEBUG_WHY_EXEC
-
what
- The contents of this field depend on the why field:
|
why
|
what
|
|
_DEBUG_WHY_TERMINATED
|
The process's exit status
|
|
_DEBUG_WHY_SIGNALLED
|
si_signo
|
|
_DEBUG_WHY_FAULTED
|
si_fltno
|
|
_DEBUG_WHY_REQUESTED
|
0
|
-
ip
- The current instruction pointer.
-
sp
- The thread's stack pointer.
-
stkbase
- The base address of the thread's stack region.
-
tls
- A pointer to the struct thread_local_storage *tls
(which will be on the thread's stack).
For more information, see
"Local storage for private data"
in the entry for ThreadCreate() in the
QNX Neutrino C Library Reference.
-
stksize
- The stack size.
-
tid_flags
- The thread flags; see _NTO_TF_* in
<sys/neutrino.h>.
-
priority
- The priority the thread is actually running at (e.g. its priority
may have been boosted).
-
real_priority
- The actual priority the thread would be at with no boosting and so on.
-
policy
- The scheduling policy; one of SCHED_FIFO,
SCHED_RR, SCHED_OTHER, or
SCHED_SPORADIC.
-
state
- The thread's state.
The states themselves are defined in <sys/states.h>;
for descriptions, see
"Thread life cycle"
in the QNX Neutrino Microkernel chapter of the
System Architecture guide.
If the thread is waiting for something, the blocked member
may hold additional information, as described below.
-
syscall
- The last system call; one of the __KER_* values
defined in <sys/kercalls.h>.
-
last_cpu
- The processor the thread last ran on.
-
timeout
-
_NTO_TF_ACTIVE|_NTO_TF_IMMEDIATE|(1 << state) —
set by
TimerTimeout()
.
-
last_chid
- The ID of the last channel this thread received a message on.
-
sig_blocked
- The set of signals that are blocked for the thread.
-
sig_pending
- The set of signals that are pending for the thread.
-
info
- The struct siginfo of the last signal or fault received.
-
blocked
- A union of the following:
-
join — if the state is
STATE_JOIN or STATE_WAITTHREAD,
this structure contains tid,
the ID of the thread that this thread is waiting for.
-
sync — if the state is
STATE_CONDVAR, STATE_MUTEX, or
STATE_SEM, this structure contains:
-
id
- The address of the synchronization object.
-
sync
- For a condvar, this is a pointer to the associated mutex;
for a mutex, it's a pointer to the mutex.
-
connect — if the state is
STATE_SEND or STATE_REPLY,
this structure contains the
node descriptor (nd), process ID (pid),
connection ID (coid), channel ID (chid),
and server connection ID (scoid) that the thread is
waiting for.
-
channel — if the state is
STATE_RECEIVE, this structure contains chid,
the ID of the channel that the thread is waiting for.
-
waitpage — if the state is
STATE_WAITPAGE, this structure contains:
-
pid
- The ID of the process whose address space was active when the
page fault occurred.
-
vaddr
- The virtual address for which the thread is waiting for physical
memory to be allocated.
-
flags
- Internal use only.
-
stack — if the state is
STATE_STACK, this structure contains size,
the amount of stack that the thread is waiting for to be allocated.
-
start_time
- The thread's starting time, in nanoseconds.
-
sutime
- The thread's system plus user running time, in nanoseconds.
-
extsched
- Extended scheduling information; a
struct extsched_aps_dbg_thread structure if the
adaptive partitioning thread scheduler is installed.