diff options
Diffstat (limited to 'winsup/cygserver/bsd_mutex.cc')
| -rw-r--r-- | winsup/cygserver/bsd_mutex.cc | 386 |
1 files changed, 0 insertions, 386 deletions
diff --git a/winsup/cygserver/bsd_mutex.cc b/winsup/cygserver/bsd_mutex.cc deleted file mode 100644 index d4cad5678..000000000 --- a/winsup/cygserver/bsd_mutex.cc +++ /dev/null @@ -1,386 +0,0 @@ -/* bsd_mutex.cc - - Copyright 2003, 2004, 2005, 2007 Red Hat Inc. - -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. */ -#ifdef __OUTSIDE_CYGWIN__ -#include "woutsup.h" -#include <errno.h> -#define _KERNEL 1 -#define __BSD_VISIBLE 1 -#include <sys/smallprint.h> -#include <limits.h> -#include <stdlib.h> -#include <sys/msg.h> -#include <sys/sem.h> - -#include "process.h" -#include "cygserver_ipc.h" - -/* A BSD kernel global mutex. */ -struct mtx Giant; - -void -mtx_init (mtx *m, const char *name, const void *, int) -{ - m->name = name; - m->owner = 0; - m->cnt = 0; - /* Can't use Windows Mutexes here since Windows Mutexes are only - unlockable by the lock owner. */ - m->h = CreateSemaphore (NULL, 1, 1, NULL); - if (!m->h) - panic ("couldn't allocate %s mutex, %lu\n", name, GetLastError ()); -} - -void -_mtx_lock (mtx *m, DWORD winpid, const char *file, int line) -{ - _log (file, line, LOG_DEBUG, "Try locking mutex %s (%u) (hold: %u)", - m->name, winpid, m->owner); - if (WaitForSingleObject (m->h, INFINITE) != WAIT_OBJECT_0) - _panic (file, line, "wait for %s in %d failed, %lu", m->name, winpid, - GetLastError ()); - m->owner = winpid; - _log (file, line, LOG_DEBUG, "Locked mutex %s/%u (%u)", - m->name, ++m->cnt, winpid); -} - -int -mtx_owned (mtx *m, DWORD winpid) -{ - return m->owner == winpid; -} - -void -_mtx_assert (mtx *m, int what, DWORD winpid, const char *file, int line) -{ - switch (what) - { - case MA_OWNED: - if (!mtx_owned (m, winpid)) - _panic (file, line, "Mutex %s not owned", m->name); - break; - case MA_NOTOWNED: - if (mtx_owned (m, winpid)) - _panic (file, line, "Mutex %s is owned", m->name); - break; - default: - break; - } -} - -void -_mtx_unlock (mtx *m, const char *file, int line) -{ - DWORD owner = m->owner; - unsigned long cnt = m->cnt; - m->owner = 0; - /* Cautiously check if mtx_destroy has been called (shutdown). - In that case, m->h is NULL. */ - if (m->h && !ReleaseSemaphore (m->h, 1, NULL)) - { - /* Check if the semaphore was already on it's max value. */ - if (GetLastError () != ERROR_TOO_MANY_POSTS) - _panic (file, line, "release of mutex %s failed, %lu", m->name, - GetLastError ()); - } - _log (file, line, LOG_DEBUG, "Unlocked mutex %s/%u (owner: %u)", - m->name, cnt, owner); -} - -void -mtx_destroy (mtx *m) -{ - HANDLE tmp = m->h; - m->h = NULL; - if (tmp) - CloseHandle (tmp); -} - -/* - * Helper functions for msleep/wakeup. - */ - -static int -win_priority (int priority) -{ - int p = (int)((priority) & PRIO_MASK) - PZERO; - /* Generating a valid priority value is a bit tricky. The only valid - values on NT4 are -15, -2, -1, 0, 1, 2, 15. */ - switch (p) - { - case -15: case -14: case -13: case -12: case -11: - return THREAD_PRIORITY_IDLE; - case -10: case -9: case -8: case -7: case -6: - return THREAD_PRIORITY_LOWEST; - case -5: case -4: case -3: case -2: case -1: - return THREAD_PRIORITY_BELOW_NORMAL; - case 0: - return THREAD_PRIORITY_NORMAL; - case 1: case 2: case 3: case 4: case 5: - return THREAD_PRIORITY_ABOVE_NORMAL; - case 6: case 7: case 8: case 9: case 10: - return THREAD_PRIORITY_HIGHEST; - case 11: case 12: case 13: case 14: case 15: - return THREAD_PRIORITY_TIME_CRITICAL; - } - return THREAD_PRIORITY_NORMAL; -} - -/* - * Sets the thread priority, returns the old priority. - */ -static int -set_priority (int priority) -{ - int old_prio = GetThreadPriority (GetCurrentThread ()); - if (!SetThreadPriority (GetCurrentThread (), win_priority (priority))) - log (LOG_WARNING, - "Warning: Setting thread priority to %d failed with error %lu\n", - win_priority (priority), GetLastError ()); - return old_prio; -} - -/* - * Original description from BSD code: - * - * General sleep call. Suspends the current process until a wakeup is - * performed on the specified identifier. The process will then be made - * runnable with the specified priority. Sleeps at most timo/hz seconds - * (0 means no timeout). If pri includes PCATCH flag, signals are checked - * before and after sleeping, else signals are not checked. Returns 0 if - * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a - * signal needs to be delivered, ERESTART is returned if the current system - * call should be restarted if possible, and EINTR is returned if the system - * call should be interrupted by the signal (return EINTR). - * - * The mutex argument is exited before the caller is suspended, and - * entered before msleep returns. If priority includes the PDROP - * flag the mutex is not entered before returning. - */ -static HANDLE msleep_glob_evt; - -class msleep_sync_array -{ - enum msleep_action { - MSLEEP_ENTER = 0, - MSLEEP_LEAVE, - MSLEEP_WAKEUP - }; - - CRITICAL_SECTION cs; - long cnt; - long max_cnt; - struct msleep_record { - void *ident; - HANDLE wakeup_evt; - LONG threads; - } *a; - - int find_ident (void *ident, msleep_action action) - { - int i; - for (i = 0; i < cnt; ++i) - if (a[i].ident == ident) - return i; - if (i >= max_cnt) - panic ("ident %x not found and run out of slots.", ident); - if (i >= cnt && action == MSLEEP_LEAVE) - panic ("ident %x not found (%d).", ident, action); - return i; - } - - HANDLE first_entry (int i, void *ident) - { - debug ("New ident %x, index %d", ident, i); - a[i].ident = ident; - a[i].wakeup_evt = CreateEvent (NULL, TRUE, FALSE, NULL); - if (!a[i].wakeup_evt) - panic ("CreateEvent failed: %lu", GetLastError ()); - debug ("i = %d, CreateEvent: %x", i, a[i].wakeup_evt); - a[i].threads = 1; - ++cnt; - return a[i].wakeup_evt; - } - - HANDLE next_entry (int i) - { - if (a[i].ident && WaitForSingleObject (a[i].wakeup_evt, 0) != WAIT_OBJECT_0) - { - ++a[i].threads; - return a[i].wakeup_evt; - } - return NULL; - } - -public: - - msleep_sync_array (int count) : cnt (0), max_cnt (count) - { - InitializeCriticalSection (&cs); - if (!(a = new msleep_record[count])) - panic ("Allocating msleep records failed: %d", errno); - } - - HANDLE enter (void *ident) - { - HANDLE evt = NULL; - while (!evt) - { - EnterCriticalSection (&cs); - int i = find_ident (ident, MSLEEP_ENTER); - if (i >= cnt) - evt = first_entry (i, ident); - else if (!(evt = next_entry (i))) - { - /* wakeup has been called, so sleep to wait until all - formerly waiting threads have left and retry. */ - LeaveCriticalSection (&cs); - Sleep (1L); - } - } - LeaveCriticalSection (&cs); - return evt; - } - - void leave (void *ident) - { - EnterCriticalSection (&cs); - int i = find_ident (ident, MSLEEP_LEAVE); - if (--a[i].threads == 0) - { - debug ("i = %d, CloseEvent: %x", i, a[i].wakeup_evt); - CloseHandle (a[i].wakeup_evt); - a[i].ident = NULL; - --cnt; - if (i < cnt) - a[i] = a[cnt]; - } - LeaveCriticalSection (&cs); - } - - void wakeup (void *ident) - { - EnterCriticalSection (&cs); - int i = find_ident (ident, MSLEEP_WAKEUP); - if (i < cnt && a[i].ident) - SetEvent (a[i].wakeup_evt); - LeaveCriticalSection (&cs); - } -}; - -static msleep_sync_array *msleep_sync; - -void -msleep_init (void) -{ - extern struct msginfo msginfo; - extern struct seminfo seminfo; - - msleep_glob_evt = CreateEvent (NULL, TRUE, FALSE, NULL); - if (!msleep_glob_evt) - panic ("CreateEvent in msleep_init failed: %lu", GetLastError ()); - long msgmni = support_msgqueues ? msginfo.msgmni : 0; - long semmni = support_semaphores ? seminfo.semmni : 0; - TUNABLE_INT_FETCH ("kern.ipc.msgmni", &msgmni); - TUNABLE_INT_FETCH ("kern.ipc.semmni", &semmni); - debug ("Try allocating msgmni (%d) + semmni (%d) msleep records", - msgmni, semmni); - msleep_sync = new msleep_sync_array (msgmni + semmni); - if (!msleep_sync) - panic ("Allocating msleep records in msleep_init failed: %d", errno); -} - -int -_msleep (void *ident, struct mtx *mtx, int priority, - const char *wmesg, int timo, struct thread *td) -{ - int ret = -1; - - HANDLE evt = msleep_sync->enter (ident); - - if (mtx) - mtx_unlock (mtx); - int old_priority = set_priority (priority); - HANDLE obj[4] = - { - evt, - msleep_glob_evt, - td->client->handle (), - td->client->signal_arrived () - }; - /* PCATCH handling. If PCATCH is given and signal_arrived is a valid - handle, then it's used in the WaitFor call and EINTR is returned. */ - int obj_cnt = 3; - if ((priority & PCATCH) - && td->client->signal_arrived () != INVALID_HANDLE_VALUE) - obj_cnt = 4; - switch (WaitForMultipleObjects (obj_cnt, obj, FALSE, timo ?: INFINITE)) - { - case WAIT_OBJECT_0: /* wakeup() has been called. */ - ret = 0; - debug ("msleep wakeup called for %d", td->td_proc->winpid); - break; - case WAIT_OBJECT_0 + 1: /* Shutdown event (triggered by wakeup_all). */ - priority |= PDROP; - /*FALLTHRU*/ - case WAIT_OBJECT_0 + 2: /* The dependent process has exited. */ - debug ("msleep process exit or shutdown for %d", td->td_proc->winpid); - ret = EIDRM; - break; - case WAIT_OBJECT_0 + 3: /* Signal for calling process arrived. */ - debug ("msleep process got signal for %d", td->td_proc->winpid); - ret = EINTR; - break; - case WAIT_TIMEOUT: - ret = EWOULDBLOCK; - break; - default: - /* There's a chance that a process has been terminated before - WaitForMultipleObjects has been called. In this case the handles - might be invalid. The error code returned is ERROR_INVALID_HANDLE. - Since we can trust the values of these handles otherwise, we - treat an ERROR_INVALID_HANDLE as a normal process termination and - hope for the best. */ - if (GetLastError () != ERROR_INVALID_HANDLE) - panic ("wait in msleep (%s) failed, %lu", wmesg, GetLastError ()); - debug ("wait in msleep (%s) failed for %d, %lu", wmesg, - td->td_proc->winpid, GetLastError ()); - ret = EIDRM; - break; - } - - msleep_sync->leave (ident); - - set_priority (old_priority); - - if (mtx && !(priority & PDROP)) - mtx_lock (mtx); - return ret; -} - -/* - * Make all threads sleeping on the specified identifier runnable. - */ -int -wakeup (void *ident) -{ - msleep_sync->wakeup (ident); - return 0; -} - -/* - * Wakeup all sleeping threads. Only called in the context of cygserver - * shutdown. - */ -void -wakeup_all (void) -{ - SetEvent (msleep_glob_evt); -} -#endif /* __OUTSIDE_CYGWIN__ */ |