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Diffstat (limited to 'winsup/cygwin/sigproc.cc')
| -rw-r--r-- | winsup/cygwin/sigproc.cc | 1310 |
1 files changed, 0 insertions, 1310 deletions
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc deleted file mode 100644 index b453e8f03..000000000 --- a/winsup/cygwin/sigproc.cc +++ /dev/null @@ -1,1310 +0,0 @@ -/* sigproc.cc: inter/intra signal and sub process handler - - Copyright 1997, 1998, 1999, 2000, 2001, 2002 Red Hat, Inc. - - Written by Christopher Faylor <cgf@cygnus.com> - -This file is part of Cygwin. - -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 <stdlib.h> -#include <time.h> -#include <sys/wait.h> -#include <errno.h> -#include <stdlib.h> -#include <sys/cygwin.h> -#include <assert.h> -#include "cygerrno.h" -#include "sync.h" -#include "sigproc.h" -#include "pinfo.h" -#include "security.h" -#include "fhandler.h" -#include "path.h" -#include "dtable.h" -#include "cygheap.h" -#include "child_info_magic.h" -#define NEED_VFORK -#include "perthread.h" -#include "shared_info.h" -#include "cygthread.h" - -/* - * Convenience defines - */ -#define WSSC 60000 // Wait for signal completion -#define WPSP 40000 // Wait for proc_subproc mutex -#define WSPX 20000 // Wait for wait_sig to terminate -#define WWSP 20000 // Wait for wait_subproc to terminate - -#define TOTSIGS (NSIG + __SIGOFFSET) - -#define wake_wait_subproc() SetEvent (events[0]) - -#define no_signals_available() (!hwait_sig || !sig_loop_wait) - -#define NZOMBIES 256 - -/* - * Global variables - */ -const char *__sp_fn ; -int __sp_ln; - -char NO_COPY myself_nowait_dummy[1] = {'0'};// Flag to sig_send that signal goes to - // current process but no wait is required -char NO_COPY myself_nowait_nonmain_dummy[1] = {'1'};// Flag to sig_send that signal goes to - // current process but no wait is required - // if this is not the main thread. - -HANDLE NO_COPY signal_arrived; // Event signaled when a signal has - // resulted in a user-specified - // function call -/* - * Common variables - */ - - -/* How long to wait for message/signals. Normally this is infinite. - * On termination, however, these are set to zero as a flag to exit. - */ - -#define Static static NO_COPY - -Static DWORD proc_loop_wait = 1000; // Wait for subprocesses to exit -Static DWORD sig_loop_wait = INFINITE; // Wait for signals to arrive - -Static HANDLE sigcatch_nonmain; // The semaphore signaled when - // signals are available for - // processing from non-main thread -Static HANDLE sigcatch_main; // Signalled when main thread sends a - // signal -Static HANDLE sigcatch_nosync; // Signal wait_sig to scan sigtodo - // but not to bother with any - // synchronization -Static HANDLE sigcomplete_main; // Event signaled when a signal has - // finished processing for the main - // thread -Static HANDLE sigcomplete_nonmain; // Semaphore raised for non-main - // threads when a signal has finished - // processing -HANDLE NO_COPY sigCONT; // Used to "STOP" a process -Static cygthread *hwait_sig; // Handle of wait_sig thread -Static cygthread *hwait_subproc; // Handle of sig_subproc thread - -Static HANDLE wait_sig_inited; // Control synchronization of - // message queue startup - -/* Used by WaitForMultipleObjects. These are handles to child processes. - */ -Static HANDLE events[PSIZE + 1]; // All my children's handles++ -#define hchildren (events + 1) // Where the children handles begin -Static char cpchildren[PSIZE * sizeof (pinfo)]; // All my children info -Static int nchildren; // Number of active children -Static char czombies[(NZOMBIES + 1) * sizeof (pinfo)]; // All my deceased children info -Static int nzombies; // Number of deceased children - -#define pchildren ((pinfo *) cpchildren) -#define zombies ((pinfo *) czombies) - -Static waitq waitq_head = {0, 0, 0, 0, 0, 0, 0};// Start of queue for wait'ing threads -Static waitq waitq_main; // Storage for main thread - -muto NO_COPY *sync_proc_subproc = NULL; // Control access to subproc stuff - -DWORD NO_COPY sigtid = 0; // ID of the signal thread - -int NO_COPY pending_signals = 0; // TRUE if signals pending - -/* Functions - */ -static int __stdcall checkstate (waitq *); -static __inline__ BOOL get_proc_lock (DWORD, DWORD); -static HANDLE __stdcall getsem (_pinfo *, const char *, int, int); -static void __stdcall remove_zombie (int); -static DWORD WINAPI wait_sig (VOID *arg); -static int __stdcall stopped_or_terminated (waitq *, _pinfo *); -static DWORD WINAPI wait_subproc (VOID *); - -/* Determine if the parent process is alive. - */ - -BOOL __stdcall -my_parent_is_alive () -{ - DWORD res; - if (!myself->ppid_handle) - { - debug_printf ("No myself->ppid_handle"); - res = FALSE; - } - else - for (int i = 0; i < 2; i++) - switch (res = WaitForSingleObject (myself->ppid_handle, 0)) - { - case WAIT_OBJECT_0: - debug_printf ("parent dead."); - res = FALSE; - goto out; - case WAIT_TIMEOUT: - debug_printf ("parent still alive"); - res = TRUE; - goto out; - case WAIT_FAILED: - DWORD werr = GetLastError (); - if (werr == ERROR_INVALID_HANDLE && i == 0) - continue; - system_printf ("WFSO for myself->ppid_handle(%p) failed, error %d", - myself->ppid_handle, werr); - res = FALSE; - goto out; - } -out: - return res; -} - -void __stdcall -wait_for_sigthread () -{ - assert (wait_sig_inited); - (void) WaitForSingleObject (wait_sig_inited, INFINITE); - (void) ForceCloseHandle (wait_sig_inited); - wait_sig_inited = NULL; -} - -/* Get the sync_proc_subproc muto to control access to - * children, zombie arrays. - * Attempt to handle case where process is exiting as we try to grab - * the mutex. - */ -static BOOL -get_proc_lock (DWORD what, DWORD val) -{ - Static int lastwhat = -1; - if (!sync_proc_subproc) - return FALSE; - if (sync_proc_subproc->acquire (WPSP)) - { - lastwhat = what; - return TRUE; - } - if (!sync_proc_subproc) - return FALSE; - system_printf ("Couldn't aquire sync_proc_subproc for(%d,%d), %E, last %d", - what, val, lastwhat); - return TRUE; -} - -static BOOL __stdcall -proc_can_be_signalled (_pinfo *p) -{ - if (p == myself_nowait || p == myself_nowait_nonmain || p == myself) - { - assert (!wait_sig_inited); - return 1; - } - - return ISSTATE (p, PID_INITIALIZING) || - (((p)->process_state & (PID_ACTIVE | PID_IN_USE)) == - (PID_ACTIVE | PID_IN_USE)); -} - -BOOL __stdcall -pid_exists (pid_t pid) -{ - pinfo p (pid); - return proc_exists (p); -} - -/* Test to determine if a process really exists and is processing signals. - */ -BOOL __stdcall -proc_exists (_pinfo *p) -{ - return p && !(p->process_state & PID_EXITED); -} - -/* Return 1 if this is one of our children, zero otherwise. - FIXME: This really should be integrated with the rest of the proc_subproc - testing. Scanning these lists twice is inefficient. */ -int __stdcall -mychild (int pid) -{ - for (int i = 0; i < nchildren; i++) - if (pchildren[i]->pid == pid) - return 1; - for (int i = 0; i < nzombies; i++) - if (zombies[i]->pid == pid) - return 1; - return 0; -} - -/* Handle all subprocess requests - */ -#define vchild (*((pinfo *) val)) -int __stdcall -proc_subproc (DWORD what, DWORD val) -{ - int rc = 1; - int potential_match; - _pinfo *child; - int clearing; - waitq *w; - -#define wval ((waitq *) val) - - sigproc_printf ("args: %x, %d", what, val); - - if (!get_proc_lock (what, val)) // Serialize access to this function - { - system_printf ("couldn't get proc lock. Something is wrong."); - goto out1; - } - - switch (what) - { - /* Add a new subprocess to the children arrays. - * (usually called from the main thread) - */ - case PROC_ADDCHILD: - if (nchildren >= PSIZE - 1) - { - rc = 0; - break; - } - pchildren[nchildren] = vchild; - hchildren[nchildren] = vchild->hProcess; - if (!DuplicateHandle (hMainProc, vchild->hProcess, hMainProc, &vchild->pid_handle, - 0, 0, DUPLICATE_SAME_ACCESS)) - system_printf ("Couldn't duplicate child handle for pid %d, %E", vchild->pid); - ProtectHandle1 (vchild->pid_handle, pid_handle); - - if (!DuplicateHandle (hMainProc, hMainProc, vchild->hProcess, &vchild->ppid_handle, - 0, TRUE, DUPLICATE_SAME_ACCESS)) - system_printf ("Couldn't duplicate my handle<%p> for pid %d, %E", hMainProc, vchild->pid); - vchild->ppid = myself->pid; - vchild->uid = myself->uid; - vchild->gid = myself->gid; - vchild->pgid = myself->pgid; - vchild->sid = myself->sid; - vchild->ctty = myself->ctty; - vchild->process_state |= PID_INITIALIZING | (myself->process_state & PID_USETTY); - - sigproc_printf ("added pid %d to wait list, slot %d, winpid %p, handle %p", - vchild->pid, nchildren, vchild->dwProcessId, - vchild->hProcess); - nchildren++; - - wake_wait_subproc (); - break; - - /* A child process had terminated. - Possibly this is just due to an exec(). Cygwin implements an exec() - as a "handoff" from one windows process to another. If child->hProcess - is different from what is recorded in hchildren, then this is an exec(). - Otherwise this is a normal child termination event. - (called from wait_subproc thread) */ - case PROC_CHILDTERMINATED: - if (hchildren[val] != pchildren[val]->hProcess) - { - sigproc_printf ("pid %d[%d], reparented old hProcess %p, new %p", - pchildren[val]->pid, val, hchildren[val], pchildren[val]->hProcess); - HANDLE h = hchildren[val]; - hchildren[val] = pchildren[val]->hProcess; /* Filled out by child */ - sync_proc_subproc->release (); // Release the lock ASAP - ForceCloseHandle1 (h, childhProc); - ProtectHandle1 (pchildren[val]->hProcess, childhProc); - rc = 0; - goto out; // This was an exec() - } - - sigproc_printf ("pid %d[%d] terminated, handle %p, nchildren %d, nzombies %d", - pchildren[val]->pid, val, hchildren[val], nchildren, nzombies); - - int thiszombie; - thiszombie = nzombies; - zombies[nzombies] = pchildren[val]; // Add to zombie array - zombies[nzombies++]->process_state = PID_ZOMBIE;// Walking dead - - sigproc_printf ("zombifying [%d], pid %d, handle %p, nchildren %d", - val, pchildren[val]->pid, hchildren[val], nchildren); - if ((int) val < --nchildren) - { - hchildren[val] = hchildren[nchildren]; - pchildren[val] = pchildren[nchildren]; - } - - /* See if we should care about the this terminated process. If we've - filled up our table or if we're ignoring SIGCHLD, then we immediately - remove the process and move on. Otherwise, this process becomes a zombie - which must be reaped by a wait() call. */ - if (nzombies >= NZOMBIES - || myself->getsig (SIGCHLD).sa_handler == (void *) SIG_IGN) - { - sigproc_printf ("automatically removing zombie %d", thiszombie); - remove_zombie (thiszombie); - } - - /* Don't scan the wait queue yet. Caller will send SIGCHLD to this process. - This will cause an eventual scan of waiters. */ - break; - - /* Handle a wait4() operation. Allocates an event for the calling - * thread which is signaled when the appropriate pid exits or stops. - * (usually called from the main thread) - */ - case PROC_WAIT: - wval->ev = NULL; // Don't know event flag yet - - if (wval->pid <= 0) - child = NULL; // Not looking for a specific pid - else if (!mychild (wval->pid)) - goto out; // invalid pid. flag no such child - - wval->status = 0; // Don't know status yet - sigproc_printf ("wval->pid %d, wval->options %d", wval->pid, wval->options); - - /* If the first time for this thread, create a new event, otherwise - * reset the event. - */ - if ((wval->ev = wval->thread_ev) == NULL) - { - wval->ev = wval->thread_ev = CreateEvent (&sec_none_nih, TRUE, - FALSE, NULL); - ProtectHandle (wval->ev); - } - - ResetEvent (wval->ev); - w = waitq_head.next; - waitq_head.next = wval; /* Add at the beginning. */ - wval->next = w; /* Link in rest of the list. */ - clearing = 0; - goto scan_wait; - - /* Clear all waiting threads. Called from exceptions.cc prior to - * the main thread's dispatch to a signal handler function. - * (called from wait_sig thread) - */ - case PROC_CLEARWAIT: - /* Clear all "wait"ing threads. */ - if (val) - sigproc_printf ("clear waiting threads"); - else - sigproc_printf ("looking for processes to reap"); - clearing = val; - - scan_wait: - /* Scan the linked list of wait()ing threads. If a wait's parameters - * match this pid, then activate it. - */ - for (w = &waitq_head; w->next != NULL; w = w->next) - { - if ((potential_match = checkstate (w)) > 0) - sigproc_printf ("released waiting thread"); - else if (!clearing && !(w->next->options & WNOHANG) && potential_match < 0) - sigproc_printf ("only found non-terminated children"); - else if (potential_match <= 0) // nothing matched - { - sigproc_printf ("waiting thread found no children"); - HANDLE oldw = w->next->ev; - w->next->pid = 0; - if (clearing) - w->next->status = -1; /* flag that a signal was received */ - else if (!potential_match || !(w->next->options & WNOHANG)) - w->next->ev = NULL; - if (!SetEvent (oldw)) - system_printf ("couldn't wake up wait event %p, %E", oldw); - w->next = w->next->next; - } - if (w->next == NULL) - break; - } - - if (!clearing) - sigproc_printf ("finished processing terminated/stopped child"); - else - { - waitq_head.next = NULL; - sigproc_printf ("finished clearing"); - } - break; - } - -out: - sync_proc_subproc->release (); // Release the lock -out1: - sigproc_printf ("returning %d", rc); - return rc; -} - -/* Terminate the wait_subproc thread. - * Called on process exit. - * Also called by spawn_guts to disassociate any subprocesses from this - * process. Subprocesses will then know to clean up after themselves and - * will not become zombies. - */ -void __stdcall -proc_terminate (void) -{ - sigproc_printf ("nchildren %d, nzombies %d", nchildren, nzombies); - /* Signal processing is assumed to be blocked in this routine. */ - if (hwait_subproc) - { - proc_loop_wait = 0; // Tell wait_subproc thread to exit - sync_proc_subproc->acquire (WPSP); - wake_wait_subproc (); // Wake wait_subproc loop - hwait_subproc = NULL; - - (void) proc_subproc (PROC_CLEARWAIT, 1); - - /* Clean out zombie processes from the pid list. */ - int i; - for (i = 0; i < nzombies; i++) - { - if (zombies[i]->hProcess) - { - ForceCloseHandle1 (zombies[i]->hProcess, childhProc); - ForceCloseHandle1 (zombies[i]->pid_handle, pid_handle); - } - zombies[i]->ppid = 1; - zombies[i]->process_state = PID_EXITED; /* CGF FIXME - still needed? */ - zombies[i].release (); // FIXME: this breaks older gccs for some reason - } - - /* Disassociate my subprocesses */ - for (i = 0; i < nchildren; i++) - { - if (!pchildren[i]->hProcess) - sigproc_printf ("%d(%d) hProcess cleared already?", pchildren[i]->pid, - pchildren[i]->dwProcessId); - else - { - ForceCloseHandle1 (pchildren[i]->hProcess, childhProc); - sigproc_printf ("%d(%d) closed child handle", pchildren[i]->pid, - pchildren[i]->dwProcessId); - pchildren[i]->ppid = 1; - if (pchildren[i]->pgid == myself->pid) - pchildren[i]->process_state |= PID_ORPHANED; - } - pchildren[i].release (); - } - nchildren = nzombies = 0; - /* Just zero sync_proc_subproc as the delete below seems to cause - problems for older gccs. */ - sync_proc_subproc = NULL; - } - sigproc_printf ("leaving"); -} - -/* Clear pending signal from the sigtodo array - */ -void __stdcall -sig_clear (int sig) -{ - (void) InterlockedExchange (myself->getsigtodo (sig), 0L); - return; -} - -/* Force the wait_sig thread to wake up and scan the sigtodo array. - */ -extern "C" int __stdcall -sig_dispatch_pending (int justwake) -{ - if (!hwait_sig) - return 0; - DWORD tid = GetCurrentThreadId (); - - sigframe thisframe (mainthread); - - if (tid == sigtid && !justwake) - justwake = 1; - - int was_pending = pending_signals; -#ifdef DEBUGGING - sigproc_printf ("pending_signals %d", was_pending); -#endif - if (!was_pending && !justwake) -#ifdef DEBUGGING - sigproc_printf ("no need to wake anything up"); -#else - ; -#endif - else - { - if (!justwake) - (void) sig_send (myself, __SIGFLUSH); - else if (ReleaseSemaphore (sigcatch_nosync, 1, NULL)) -#ifdef DEBUGGING - sigproc_printf ("woke up wait_sig"); -#else - ; -#endif - else if (no_signals_available ()) - /*sigproc_printf ("I'm going away now")*/; - else - system_printf ("%E releasing sigcatch_nosync(%p)", sigcatch_nosync); - - } - if (was_pending && !justwake) - thisframe.call_signal_handler (); - - return was_pending; -} - -/* Message initialization. Called from dll_crt0_1 - * - * This routine starts the signal handling thread. The wait_sig_inited - * event is used to signal that the thread is ready to handle signals. - * We don't wait for this during initialization but instead detect it - * in sig_send to gain a little concurrency. - */ -void __stdcall -sigproc_init () -{ - wait_sig_inited = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL); - ProtectHandle (wait_sig_inited); - - /* sync_proc_subproc is used by proc_subproc. It serialises - * access to the children and zombie arrays. - */ - new_muto (sync_proc_subproc); - - /* local event signaled when main thread has been dispatched - to a signal handler function. */ - signal_arrived = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL); - ProtectHandle (signal_arrived); - - hwait_sig = new cygthread (wait_sig, cygself, "sig"); - hwait_sig->zap_h (); - - /* Initialize waitq structure for main thread. A waitq structure is - * allocated for each thread that executes a wait to allow multiple threads - * to perform waits. Pre-allocate a waitq structure for the main thread. - */ - waitq *w; - if ((w = (waitq *)waitq_storage.get ()) == NULL) - { - w = &waitq_main; - waitq_storage.set (w); - } - memset (w, 0, sizeof *w); // Just to be safe - - myself->getsig (SIGSTOP).sa_flags = SA_RESTART | SA_NODEFER; - sigproc_printf ("process/signal handling enabled(%x)", myself->process_state); - return; -} - -/* Called on process termination to terminate signal and process threads. - */ -void __stdcall -sigproc_terminate (void) -{ - hwait_sig = NULL; - - if (!sig_loop_wait) - sigproc_printf ("sigproc_terminate: sigproc handling not active"); - else - { - sigproc_printf ("entering"); - sig_loop_wait = 0; // Tell wait_sig to exit when it is - // finished with anything it is doing - sig_dispatch_pending (1); - } - - if (GetCurrentThreadId () == sigtid) - { - ForceCloseHandle (sigcomplete_main); - for (int i = 0; i < 20; i++) - (void) ReleaseSemaphore (sigcomplete_nonmain, 1, NULL); - // ForceCloseHandle (sigcomplete_nonmain); - // ForceCloseHandle (sigcatch_main); - // ForceCloseHandle (sigcatch_nonmain); - // ForceCloseHandle (sigcatch_nosync); - } - proc_terminate (); // Terminate process handling thread - - return; -} - -/* Send a signal to another process by raising its signal semaphore. - * If pinfo *p == NULL, send to the current process. - * If sending to this process, wait for notification that a signal has - * completed before returning. - */ -int __stdcall -sig_send (_pinfo *p, int sig, DWORD ebp, bool exception) -{ - int rc = 1; - DWORD tid = GetCurrentThreadId (); - BOOL its_me; - HANDLE thiscatch = NULL; - HANDLE thiscomplete = NULL; - BOOL wait_for_completion; - sigframe thisframe; - - if (p == myself_nowait_nonmain) - p = (tid == mainthread.id) ? (_pinfo *) myself : myself_nowait; - if (!(its_me = (p == NULL || p == myself || p == myself_nowait))) - wait_for_completion = FALSE; - else - { - if (no_signals_available ()) - goto out; // Either exiting or not yet initializing - assert (!wait_sig_inited); - wait_for_completion = p != myself_nowait; - p = myself; - } - - /* It is possible that the process is not yet ready to receive messages - * or that it has exited. Detect this. - */ - if (!proc_can_be_signalled (p)) /* Is the process accepting messages? */ - { - sigproc_printf ("invalid pid %d(%x), signal %d", - p->pid, p->process_state, sig); - set_errno (ESRCH); - goto out; - } - - sigproc_printf ("pid %d, signal %d, its_me %d", p->pid, sig, its_me); - - if (its_me) - { - if (!wait_for_completion) - thiscatch = sigcatch_nosync; - else if (tid != mainthread.id) - { - thiscatch = sigcatch_nonmain; - thiscomplete = sigcomplete_nonmain; - } - else - { - thiscatch = sigcatch_main; - thiscomplete = sigcomplete_main; - thisframe.set (mainthread, ebp, exception); - } - } - else if (!(thiscatch = getsem (p, "sigcatch", 0, 0))) - goto out; // Couldn't get the semaphore. getsem issued - // an error, if appropriate. - -#if WHEN_MULTI_THREAD_SIGNALS_WORK - signal_dispatch *sd; - sd = signal_dispatch_storage.get (); - if (sd == NULL) - sd = signal_dispatch_storage.create (); -#endif - - /* Increment the sigtodo array to signify which signal to assert. - */ - (void) InterlockedIncrement (p->getsigtodo (sig)); - - /* Notify the process that a signal has arrived. - */ - SetLastError (0); - -#if 0 - int prio; - prio = GetThreadPriority (GetCurrentThread ()); - (void) SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_TIME_CRITICAL); -#endif - - if (!ReleaseSemaphore (thiscatch, 1, NULL) && (int) GetLastError () > 0) - { - /* Couldn't signal the semaphore. This probably means that the - * process is exiting. - */ - if (!its_me) - ForceCloseHandle (thiscatch); - else - { - if (no_signals_available ()) - sigproc_printf ("I'm going away now"); - else if ((int) GetLastError () == -1) - rc = WaitForSingleObject (thiscomplete, 500); - else - system_printf ("error sending signal %d to pid %d, semaphore %p, %E", - sig, p->pid, thiscatch); - } - goto out; - } - - /* No need to wait for signal completion unless this was a signal to - * this process. - * - * If it was a signal to this process, wait for a dispatched signal. - * Otherwise just wait for the wait_sig to signal that it has finished - * processing the signal. - */ - if (!wait_for_completion) - { - rc = WAIT_OBJECT_0; - sigproc_printf ("Not waiting for sigcomplete. its_me %d signal %d", its_me, sig); - if (!its_me) - ForceCloseHandle (thiscatch); - } - else - { - sigproc_printf ("Waiting for thiscomplete %p", thiscomplete); - - SetLastError (0); - rc = WaitForSingleObject (thiscomplete, WSSC); - /* Check for strangeness due to this thread being redirected by the - signal handler. Sometimes a WAIT_TIMEOUT will occur when the - thread hasn't really timed out. So, check again. - FIXME: This isn't foolproof. */ - if (rc != WAIT_OBJECT_0 && - WaitForSingleObject (thiscomplete, 0) == WAIT_OBJECT_0) - rc = WAIT_OBJECT_0; - } - -#if 0 - SetThreadPriority (GetCurrentThread (), prio); -#endif - - if (rc == WAIT_OBJECT_0) - rc = 0; // Successful exit - else - { - /* It's an error unless sig_loop_wait == 0 (the process is exiting). */ - if (!no_signals_available ()) - system_printf ("wait for sig_complete event failed, signal %d, rc %d, %E", - sig, rc); - set_errno (ENOSYS); - rc = -1; - } - -out: - sigproc_printf ("returning %d from sending signal %d", rc, sig); - return rc; -} - -/* Set pending signal from the sigtodo array - */ -void __stdcall -sig_set_pending (int sig) -{ - (void) InterlockedIncrement (myself->getsigtodo (sig)); - return; -} - -/* Initialize the wait_subproc thread. - * Called from fork() or spawn() to initialize the handling of subprocesses. - */ -void __stdcall -subproc_init (void) -{ - if (hwait_subproc) - return; - - /* A "wakeup" handle which can be toggled to make wait_subproc reexamine - * the hchildren array. - */ - events[0] = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL); - hwait_subproc = new cygthread (wait_subproc, NULL, "proc"); - hwait_subproc->zap_h (); - ProtectHandle (events[0]); - sigproc_printf ("started wait_subproc thread"); -} - -/* Initialize some of the memory block passed to child processes - by fork/spawn/exec. */ - -void __stdcall -init_child_info (DWORD chtype, child_info *ch, pid_t pid, HANDLE subproc_ready) -{ - memset (ch, 0, sizeof *ch); - ch->cb = chtype == PROC_FORK ? sizeof (child_info_fork) : sizeof (child_info); - ch->intro = PROC_MAGIC_GENERIC; - ch->magic = CHILD_INFO_MAGIC; - ch->type = chtype; - ch->cygpid = pid; - ch->subproc_ready = subproc_ready; - ch->pppid_handle = myself->ppid_handle; - ch->fhandler_union_cb = sizeof (fhandler_union); - ch->mount_h = cygwin_mount_h; -} - -/* Check the state of all of our children to see if any are stopped or - * terminated. - */ -static int __stdcall -checkstate (waitq *parent_w) -{ - int potential_match = 0; - - sigproc_printf ("nchildren %d, nzombies %d", nchildren, nzombies); - - /* Check already dead processes first to see if they match the criteria - * given in w->next. - */ - for (int i = 0; i < nzombies; i++) - switch (stopped_or_terminated (parent_w, zombies[i])) - { - case -1: - potential_match = -1; - break; - case 1: - remove_zombie (i); - potential_match = 1; - goto out; - } - - sigproc_printf ("checking alive children"); - - /* No dead terminated children matched. Check for stopped children. */ - for (int i = 0; i < nchildren; i++) - switch (stopped_or_terminated (parent_w, pchildren[i])) - { - case -1: - potential_match = -1; - break; - case 1: - potential_match = 1; - goto out; - } - -out: - sigproc_printf ("returning %d", potential_match); - return potential_match; -} - -/* Get or create a process specific semaphore used in message passing. - */ -static HANDLE __stdcall -getsem (_pinfo *p, const char *str, int init, int max) -{ - HANDLE h; - - if (p != NULL) - { - if (!proc_can_be_signalled (p)) - { - set_errno (ESRCH); - return NULL; - } - int wait = 1000; - /* Wait for new process to generate its semaphores. */ - sigproc_printf ("pid %d, ppid %d, wait %d, initializing %x", p->pid, p->ppid, wait, - ISSTATE (p, PID_INITIALIZING)); - for (int i = 0; ISSTATE (p, PID_INITIALIZING) && i < wait; i++) - low_priority_sleep (1); - } - - SetLastError (0); - if (p == NULL) - { - char sa_buf[1024]; - - DWORD winpid = GetCurrentProcessId (); - h = CreateSemaphore (sec_user_nih (sa_buf), init, max, - str = shared_name (str, winpid)); - p = myself; - if (!h) - { - system_printf ("can't create semaphore %s, %E", str); - __seterrno (); - } - } - else - { - h = OpenSemaphore (SEMAPHORE_ALL_ACCESS, FALSE, - shared_name (str, p->dwProcessId)); - - if (!h) - { - if (GetLastError () == ERROR_FILE_NOT_FOUND && !proc_exists (p)) - set_errno (ESRCH); /* No such process */ - else - set_errno (EPERM); /* Couldn't access the semaphore -- - different cygwin DLL maybe? */ - } - } - - return h; -} - -/* Remove a zombie from zombies by swapping it with the last child in the list. - */ -static void __stdcall -remove_zombie (int ci) -{ - sigproc_printf ("removing %d, pid %d, nzombies %d", ci, zombies[ci]->pid, - nzombies); - - if (zombies[ci]) - { - ForceCloseHandle1 (zombies[ci]->hProcess, childhProc); - ForceCloseHandle1 (zombies[ci]->pid_handle, pid_handle); - zombies[ci].release (); - } - - if (ci < --nzombies) - zombies[ci] = zombies[nzombies]; - - return; -} - -/* Check status of child process vs. waitq member. - * - * parent_w is the pointer to the parent of the waitq member in question. - * child is the subprocess being considered. - * - * Returns - * 1 if stopped or terminated child matches parent_w->next criteria - * -1 if a non-stopped/terminated child matches parent_w->next criteria - * 0 if child does not match parent_w->next criteria - */ -static int __stdcall -stopped_or_terminated (waitq *parent_w, _pinfo *child) -{ - int potential_match; - waitq *w = parent_w->next; - - sigproc_printf ("considering pid %d", child->pid); - if (w->pid == -1) - potential_match = 1; - else if (w->pid == 0) - potential_match = child->pgid == myself->pgid; - else if (w->pid < 0) - potential_match = child->pgid == -w->pid; - else - potential_match = (w->pid == child->pid); - - if (!potential_match) - return 0; - - BOOL terminated; - - if ((terminated = child->process_state == PID_ZOMBIE) || - ((w->options & WUNTRACED) && child->stopsig)) - { - parent_w->next = w->next; /* successful wait. remove from wait queue */ - w->pid = child->pid; - - if (!terminated) - { - sigproc_printf ("stopped child"); - w->status = (child->stopsig << 8) | 0x7f; - child->stopsig = 0; - } - else /* Should only get here when child has been moved to the zombies array */ - { - DWORD status; - if (!GetExitCodeProcess (child->hProcess, &status)) - status = 0xffff; - if (status & EXIT_SIGNAL) - w->status = (status >> 8) & 0xff; /* exited due to signal */ - else - w->status = (status & 0xff) << 8; /* exited via "exit ()" */ - - add_rusage (&myself->rusage_children, &child->rusage_children); - add_rusage (&myself->rusage_children, &child->rusage_self); - - if (w->rusage) - { - add_rusage ((struct rusage *) w->rusage, &child->rusage_children); - add_rusage ((struct rusage *) w->rusage, &child->rusage_self); - } - } - - if (!SetEvent (w->ev)) /* wake up wait4 () immediately */ - system_printf ("couldn't wake up wait event %p, %E", w->ev); - return 1; - } - - return -potential_match; -} - -static void -talktome () -{ - winpids pids; - for (unsigned i = 0; i < pids.npids; i++) - if (pids[i]->hello_pid == myself->pid) - pids[i]->commune_recv (); -} - -/* Process signals by waiting for a semaphore to become signaled. - * Then scan an in-memory array representing queued signals. - * Executes in a separate thread. - * - * Signals sent from this process are sent a completion signal so - * that returns from kill/raise do not occur until the signal has - * has been handled, as per POSIX. - */ -static DWORD WINAPI -wait_sig (VOID *self) -{ - /* Initialization */ - (void) SetThreadPriority (GetCurrentThread (), WAIT_SIG_PRIORITY); - - /* sigcatch_nosync - semaphore incremented by sig_dispatch_pending and - * by foreign processes to force an examination of - * the sigtodo array. - * sigcatch_main - ditto for local main thread. - * sigcatch_nonmain - ditto for local non-main threads. - * - * sigcomplete_main - event used to signal main thread on signal - * completion - * sigcomplete_nonmain - semaphore signaled for non-main thread on signal - * completion - */ - sigcatch_nosync = getsem (NULL, "sigcatch", 0, MAXLONG); - sigcatch_nonmain = CreateSemaphore (&sec_none_nih, 0, MAXLONG, NULL); - sigcatch_main = CreateSemaphore (&sec_none_nih, 0, MAXLONG, NULL); - sigcomplete_nonmain = CreateSemaphore (&sec_none_nih, 0, MAXLONG, NULL); - sigcomplete_main = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL); - sigproc_printf ("sigcatch_nonmain %p, sigcatch_main %p", sigcatch_nonmain, sigcatch_main); - sigCONT = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL); - - /* Setting dwProcessId flags that this process is now capable of receiving - * signals. Prior to this, dwProcessId was set to the windows pid of - * of the original windows process which spawned us unless this was a - * "toplevel" process. - */ - myself->dwProcessId = GetCurrentProcessId (); - myself->process_state |= PID_ACTIVE; - myself->process_state &= ~PID_INITIALIZING; - - ProtectHandle (sigcatch_nosync); - ProtectHandle (sigcatch_nonmain); - ProtectHandle (sigcatch_main); - ProtectHandle (sigcomplete_nonmain); - ProtectHandle (sigcomplete_main); - - /* If we've been execed, then there is still a stub left in the previous - * windows process waiting to see if it's started a cygwin process or not. - * Signalling subproc_ready indicates that we are a cygwin process. - */ - if (child_proc_info && child_proc_info->type == PROC_EXEC) - { - debug_printf ("subproc_ready %p", child_proc_info->subproc_ready); - if (!SetEvent (child_proc_info->subproc_ready)) - system_printf ("SetEvent (subproc_ready) failed, %E"); - ForceCloseHandle1 (child_proc_info->subproc_ready, subproc_ready); - /* Initialize an "indirect" pid block so that if someone looks up this - process via its Windows PID it will be redirected to the appropriate - Cygwin PID shared memory block. */ - static pinfo NO_COPY myself_identity; - myself_identity.init (cygwin_pid (myself->dwProcessId), PID_EXECED); - } - - SetEvent (wait_sig_inited); - sigtid = GetCurrentThreadId (); - - HANDLE catchem[] = {sigcatch_main, sigcatch_nonmain, sigcatch_nosync}; - sigproc_printf ("Ready. dwProcessid %d", myself->dwProcessId); - for (;;) - { - DWORD rc = WaitForMultipleObjects (3, catchem, FALSE, sig_loop_wait); - (void) SetThreadPriority (GetCurrentThread (), WAIT_SIG_PRIORITY); - - /* sigproc_terminate sets sig_loop_wait to zero to indicate that - * this thread should terminate. - */ - if (rc == WAIT_TIMEOUT) - { - if (!sig_loop_wait) - break; // Exiting - else - continue; - } - - if (rc == WAIT_FAILED) - { - if (sig_loop_wait != 0) - system_printf ("WFMO failed, %E"); - break; - } - - rc -= WAIT_OBJECT_0; - sigproc_printf ("awake"); - /* A sigcatch semaphore has been signaled. Scan the sigtodo - * array looking for any unprocessed signals. - */ - pending_signals = -1; - int saw_pending_signals = 0; - int saw_sigchld = 0; - for (int sig = -__SIGOFFSET; sig < NSIG; sig++) - { - while (InterlockedDecrement (myself->getsigtodo (sig)) >= 0) - { - if (sig == SIGCHLD) - saw_sigchld = 1; - - if (sig > 0 && sig != SIGKILL && sig != SIGSTOP && - (sigismember (&myself->getsigmask (), sig) || - main_vfork->pid || - (sig != SIGCONT && ISSTATE (myself, PID_STOPPED)))) - { - sigproc_printf ("signal %d blocked", sig); - break; - } - - /* Found a signal to process */ - sigproc_printf ("processing signal %d", sig); - switch (sig) - { - case __SIGFLUSH: - /* just forcing the loop */ - break; - - /* Internal signal to turn on stracing. */ - case __SIGSTRACE: - strace.hello (); - break; - - case __SIGCOMMUNE: - talktome (); - break; - - /* A normal UNIX signal */ - default: - sigproc_printf ("Got signal %d", sig); - sig_handle (sig, rc != 2); - /* Need to decrement again to offset increment below since - we really do want to decrement in this case. */ - InterlockedDecrement (myself->getsigtodo (sig)); - goto nextsig; /* FIXME: shouldn't this allow the loop to continue? */ - } - } - - nextsig: - /* Decremented too far. */ - if (InterlockedIncrement (myself->getsigtodo (sig)) > 0) - saw_pending_signals = 1; - } - - if (pending_signals < 0 && !saw_pending_signals) - pending_signals = 0; - - if (saw_sigchld) - proc_subproc (PROC_CLEARWAIT, 0); - - /* Signal completion of signal handling depending on which semaphore - * woke up the WaitForMultipleObjects above. - */ - switch (rc) - { - case 0: - SetEvent (sigcomplete_main); - sigproc_printf ("set main thread completion event"); - break; - case 1: - ReleaseSemaphore (sigcomplete_nonmain, 1, NULL); - break; - default: - /* Signal from another process. No need to synchronize. */ - break; - } - sigproc_printf ("looping"); - } - - sigproc_printf ("done"); - ExitThread (0); -} - -/* Wait for subprocesses to terminate. Executes in a separate thread. */ -static DWORD WINAPI -wait_subproc (VOID *) -{ - sigproc_printf ("starting"); - int errloop = 0; - - for (;;) - { - DWORD rc = WaitForMultipleObjects (nchildren + 1, events, FALSE, - proc_loop_wait); - if (rc == WAIT_TIMEOUT) - if (!proc_loop_wait) - break; // Exiting - else - continue; - - if (rc == WAIT_FAILED) - { - if (!proc_loop_wait) - break; - - /* It's ok to get an ERROR_INVALID_HANDLE since another thread may have - closed a handle in the children[] array. So, we try looping a couple - of times to stabilize. FIXME - this is not foolproof. Probably, this - thread should be responsible for closing the children. */ - if (!errloop++) - proc_subproc (PROC_NOTHING, 0); // Just synchronize and continue - if (errloop < 10) - continue; - - system_printf ("wait failed. nchildren %d, wait %d, %E", - nchildren, proc_loop_wait); - - for (int i = 0; i <= nchildren; i++) - if ((rc = WaitForSingleObject (events[i], 0)) == WAIT_OBJECT_0 || - rc == WAIT_TIMEOUT) - continue; - else if (i == 0) - system_printf ("nchildren %d, event[%d] %p, %E", nchildren, i, events[i]); - else - { - system_printf ("nchildren %d, event[%d] %p, pchildren[%d] %p, events[0] %p, %E", - nchildren, i, events[i], i - 1, (_pinfo *) pchildren[i - 1], events[0]); - system_printf ("pid %d, dwProcessId %u, hProcess %p, progname '%s'", - pchildren[i - 1]->pid, pchildren[i - 1]->dwProcessId, - pchildren[i - 1]->hProcess, pchildren[i - 1]->progname); - } - break; - } - - errloop = 0; - rc -= WAIT_OBJECT_0; - if (rc-- != 0) - { - rc = proc_subproc (PROC_CHILDTERMINATED, rc); - if (!proc_loop_wait) // Don't bother if wait_subproc is - break; // exiting - - /* Send a SIGCHLD to myself. We do this here, rather than in proc_subproc - to avoid the proc_subproc lock since the signal thread will eventually - be calling proc_subproc and could unnecessarily block. */ - if (rc) - sig_send (myself_nowait, SIGCHLD); - } - sigproc_printf ("looping"); - } - - ForceCloseHandle (events[0]); - events[0] = NULL; - sigproc_printf ("done"); - ExitThread (0); -} - -extern "C" { -/* Provide a stack frame when calling WaitFor* functions */ - -#undef WaitForSingleObject - -DWORD __stdcall -WFSO (HANDLE hHandle, DWORD dwMilliseconds) -{ - DWORD ret; - sigframe thisframe (mainthread); - ret = WaitForSingleObject (hHandle, dwMilliseconds); - return ret; -} - -#undef WaitForMultipleObjects - -DWORD __stdcall -WFMO (DWORD nCount, CONST HANDLE *lpHandles, BOOL fWaitAll, DWORD dwMilliseconds) -{ - DWORD ret; - sigframe thisframe (mainthread); - ret = WaitForMultipleObjects (nCount, lpHandles, fWaitAll, dwMilliseconds); - return ret; -} -} |