newlib-cygwin/winsup/cygwin/debug.cc

362 lines
8.1 KiB
C++

/* debug.cc
Copyright 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include "exceptions.h"
#include "sync.h"
#include "sigproc.h"
#include "pinfo.h"
#include "perthread.h"
#include "perprocess.h"
#include "security.h"
#include "cygerrno.h"
#undef CloseHandle
static muto NO_COPY *threadname_lock = NULL;
#define lock_threadname() \
do {if (threadname_lock) threadname_lock->acquire (INFINITE); } while (0)
#define unlock_threadname() \
do {if (threadname_lock) threadname_lock->release (); } while (0)
typedef struct
{
DWORD id;
const char *name;
} thread_info;
static NO_COPY thread_info threads[32] = {{0, NULL}}; // increase as necessary
#define NTHREADS (sizeof (threads) / sizeof (threads[0]))
void
threadname_init ()
{
new_muto (threadname_lock);
}
void __stdcall
regthread (const char *name, DWORD tid)
{
lock_threadname ();
for (DWORD i = 0; i < NTHREADS; i++)
if (threads[i].name == NULL || strcmp (threads[i].name, name) == 0 ||
threads[i].id == tid)
{
threads[i].name = name;
threads[i].id = tid;
break;
}
unlock_threadname ();
}
int __stdcall
iscygthread ()
{
DWORD tid = GetCurrentThreadId ();
if (tid != mainthread.id)
for (DWORD i = 0; i < NTHREADS && threads[i].name != NULL; i++)
if (threads[i].id == tid)
return 1;
return 0;
}
struct thread_start
{
LONG notavail;
LPTHREAD_START_ROUTINE func;
VOID *arg;
};
/* A place to store arguments to thread_stub since they can't be
stored on the stack. An available element is !notavail. */
thread_start NO_COPY start_buf[NTHREADS] = {{0, NULL,NULL}};
/* Initial stub called by makethread. Performs initial per-thread
initialization. */
static DWORD WINAPI
thread_stub (VOID *arg)
{
DECLARE_TLS_STORAGE;
LPTHREAD_START_ROUTINE threadfunc = ((thread_start *) arg)->func;
VOID *threadarg = ((thread_start *) arg)->arg;
exception_list except_entry;
/* Give up our slot in the start_buf array */
(void) InterlockedExchange (&((thread_start *) arg)->notavail, 0);
/* Initialize this thread's ability to respond to things like
SIGSEGV or SIGFPE. */
init_exceptions (&except_entry);
ExitThread (threadfunc (threadarg));
}
/* Wrapper for CreateThread. Registers the thread name/id and ensures that
cygwin threads are properly initialized. */
HANDLE __stdcall
makethread (LPTHREAD_START_ROUTINE start, LPVOID param, DWORD flags,
const char *name)
{
DWORD tid;
HANDLE h;
thread_start *info; /* Various information needed by the newly created thread */
for (;;)
{
/* Search the start_buf array for an empty slot to use */
for (info = start_buf; info < start_buf + NTHREADS; info++)
if (!InterlockedExchange (&info->notavail, 1))
goto out;
/* Should never hit here, but be defensive anyway. */
Sleep (0);
}
out:
info->func = start; /* Real function to start */
info->arg = param; /* The single parameter to the thread */
if ((h = CreateThread (&sec_none_nih, 0, thread_stub, (VOID *) info, flags,
&tid)))
regthread (name, tid); /* Register for debugging output. */
return h;
}
/* Return the symbolic name of the current thread for debugging.
*/
const char * __stdcall
threadname (DWORD tid, int lockit)
{
const char *res = NULL;
if (!tid)
tid = GetCurrentThreadId ();
if (lockit)
lock_threadname ();
for (DWORD i = 0; i < NTHREADS && threads[i].name != NULL; i++)
if (threads[i].id == tid)
{
res = threads[i].name;
break;
}
if (lockit)
unlock_threadname ();
if (!res)
{
static char buf[30] NO_COPY = {0};
__small_sprintf (buf, "unknown (%p)", tid);
res = buf;
}
return res;
}
#ifdef DEBUGGING
/* Here lies extra debugging routines which help track down internal
Cygwin problems when compiled with -DDEBUGGING . */
#include <stdlib.h>
typedef struct _h
{
BOOL allocated;
HANDLE h;
const char *name;
const char *func;
int ln;
DWORD clexec_pid;
struct _h *next;
} handle_list;
static NO_COPY handle_list starth = {0, NULL, NULL, NULL, 0, 0, NULL};
static NO_COPY handle_list *endh = NULL;
static handle_list NO_COPY freeh[1000] = {{0, NULL, NULL, NULL, 0, 0, NULL}};
#define NFREEH (sizeof (freeh) / sizeof (freeh[0]))
static muto NO_COPY *debug_lock = NULL;
struct lock_debug
{
lock_debug () {if (debug_lock) debug_lock->acquire (INFINITE);}
void unlock () {if (debug_lock) debug_lock->release ();}
~lock_debug () {unlock ();}
};
static bool __stdcall mark_closed (const char *, int, HANDLE, const char *, BOOL);
void
debug_init ()
{
new_muto (debug_lock);
}
/* Find a registered handle in the linked list of handles. */
static handle_list * __stdcall
find_handle (HANDLE h)
{
handle_list *hl;
for (hl = &starth; hl->next != NULL; hl = hl->next)
if (hl->next->h == h)
goto out;
endh = hl;
hl = NULL;
out:
return hl;
}
void
setclexec_pid (HANDLE oh, HANDLE nh, bool setit)
{
handle_list *hl = find_handle (oh);
if (hl)
{
hl->clexec_pid = setit ? GetCurrentProcessId () : 0;
hl->h = nh;
}
}
/* Create a new handle record */
static handle_list * __stdcall
newh ()
{
handle_list *hl;
lock_debug here;
for (hl = freeh; hl < freeh + NFREEH; hl++)
if (hl->name == NULL)
goto out;
/* All used up??? */
if ((hl = (handle_list *) malloc (sizeof *hl)) != NULL)
{
memset (hl, 0, sizeof (*hl));
hl->allocated = TRUE;
}
out:
return hl;
}
/* Add a handle to the linked list of known handles. */
void __stdcall
add_handle (const char *func, int ln, HANDLE h, const char *name)
{
handle_list *hl;
lock_debug here;
if ((hl = find_handle (h)))
{
hl = hl->next;
system_printf ("%s:%d - multiple attempts to add handle %s<%p>", func,
ln, name, h);
system_printf (" previously allocated by %s:%d(%s<%p>)",
hl->func, hl->ln, hl->name, hl->h);
return;
}
if ((hl = newh ()) == NULL)
{
here.unlock ();
system_printf ("couldn't allocate memory for %s(%d): %s(%p)",
func, ln, name, h);
return;
}
hl->h = h;
hl->name = name;
hl->func = func;
hl->ln = ln;
hl->next = NULL;
endh->next = hl;
endh = hl;
return;
}
static void __stdcall
delete_handle (handle_list *hl)
{
handle_list *hnuke = hl->next;
hl->next = hl->next->next;
if (hnuke->allocated)
free (hnuke);
else
memset (hnuke, 0, sizeof (*hnuke));
}
void
debug_fixup_after_fork ()
{
handle_list *hl;
for (hl = &starth; hl->next != NULL; hl = hl->next)
if (hl->next->clexec_pid)
delete_handle (hl);
}
static bool __stdcall
mark_closed (const char *func, int ln, HANDLE h, const char *name, BOOL force)
{
handle_list *hl;
lock_debug here;
if ((hl = find_handle (h)) && !force)
{
hl = hl->next;
here.unlock (); // race here
system_printf ("attempt to close protected handle %s:%d(%s<%p>)",
hl->func, hl->ln, hl->name, hl->h);
system_printf (" by %s:%d(%s<%p>)", func, ln, name, h);
return FALSE;
}
handle_list *hln;
if (hl && (hln = hl->next) && strcmp (name, hln->name))
{
system_printf ("closing protected handle %s:%d(%s<%p>)",
hln->func, hln->ln, hln->name, hln->h);
system_printf (" by %s:%d(%s<%p>)", func, ln, name, h);
}
if (hl)
delete_handle (hl);
return TRUE;
}
/* Close a known handle. Complain if !force and closing a known handle or
if the name of the handle being closed does not match the registered name. */
BOOL __stdcall
close_handle (const char *func, int ln, HANDLE h, const char *name, BOOL force)
{
BOOL ret;
lock_debug here;
if (!mark_closed (func, ln, h, name, force))
return FALSE;
ret = CloseHandle (h);
#if 0 /* Uncomment to see CloseHandle failures */
if (!ret)
small_printf ("CloseHandle(%s) failed %s:%d\n", name, func, ln);
#endif
return ret;
}
int __stdcall
__set_errno (const char *func, int ln, int val)
{
debug_printf ("%s:%d val %d", func, ln, val);
return _impure_ptr->_errno = val;
}
#endif /*DEBUGGING*/