diff options
Diffstat (limited to 'win32/contrib/pthreads/cancel.c')
| -rw-r--r-- | win32/contrib/pthreads/cancel.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/win32/contrib/pthreads/cancel.c b/win32/contrib/pthreads/cancel.c new file mode 100644 index 000000000..6243257be --- /dev/null +++ b/win32/contrib/pthreads/cancel.c @@ -0,0 +1,388 @@ +/*
+ * cancel.c
+ *
+ * Description:
+ * POSIX thread functions related to thread cancellation.
+ *
+ * Pthreads-win32 - POSIX Threads Library for Win32
+ * Copyright (C) 1998
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA
+ */
+
+#include "pthread.h"
+#include "implement.h"
+
+
+#if defined(_M_IX86) || defined(_X86_)
+#define PROGCTR(Context) ((Context).Eip)
+#endif
+
+#if defined(_MIPS_)
+#define PROGCTR(Context) ((Context).Fir)
+#endif
+
+#if defined(_ALPHA_)
+#define PROGCTR(Context) ((Context).Fir)
+#endif
+
+#if defined(_PPC_)
+#define PROGCTR(Context) ((Context).Iar)
+#endif
+
+#if !defined(PROGCTR)
+#error Module contains CPU-specific code; modify and recompile.
+#endif
+
+
+static void
+ptw32_cancel_self(void)
+{
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+}
+
+
+/*
+ * ptw32_cancel_thread implements asynchronous cancellation.
+ */
+static INLINE void
+ptw32_cancel_thread(pthread_t thread)
+{
+ HANDLE threadH = thread->threadH;
+
+ (void) pthread_mutex_lock(&thread->cancelLock);
+
+ SuspendThread(threadH);
+
+ if (WaitForSingleObject(threadH, 0) == WAIT_TIMEOUT)
+ {
+ CONTEXT context;
+ context.ContextFlags = CONTEXT_CONTROL;
+ GetThreadContext(threadH, &context);
+ PROGCTR(context) = (DWORD) ptw32_cancel_self;
+ SetThreadContext(threadH, &context);
+ ResumeThread(threadH);
+ }
+
+ (void) pthread_mutex_unlock(&thread->cancelLock);
+}
+
+
+int
+pthread_setcancelstate (int state, int *oldstate)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function atomically sets the calling thread's
+ * cancelability state to 'state' and returns the previous
+ * cancelability state at the location referenced by
+ * 'oldstate'
+ *
+ * PARAMETERS
+ * state,
+ * oldstate
+ * PTHREAD_CANCEL_ENABLE
+ * cancellation is enabled,
+ *
+ * PTHREAD_CANCEL_DISABLE
+ * cancellation is disabled
+ *
+ *
+ * DESCRIPTION
+ * This function atomically sets the calling thread's
+ * cancelability state to 'state' and returns the previous
+ * cancelability state at the location referenced by
+ * 'oldstate'.
+ *
+ * NOTES:
+ * 1) Use to disable cancellation around 'atomic' code that
+ * includes cancellation points
+ *
+ * COMPATIBILITY ADDITIONS
+ * If 'oldstate' is NULL then the previous state is not returned
+ * but the function still succeeds. (Solaris)
+ *
+ * RESULTS
+ * 0 successfully set cancelability type,
+ * EINVAL 'state' is invalid
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ pthread_t self = pthread_self();
+
+ if (self == NULL
+ || (state != PTHREAD_CANCEL_ENABLE
+ && state != PTHREAD_CANCEL_DISABLE))
+ {
+ return EINVAL;
+ }
+
+ /*
+ * Lock for async-cancel safety.
+ */
+ (void) pthread_mutex_lock(&self->cancelLock);
+
+ if (oldstate != NULL)
+ {
+ *oldstate = self->cancelState;
+ }
+
+ self->cancelState = state;
+
+ /*
+ * Check if there is a pending asynchronous cancel
+ */
+ if (self->cancelState == PTHREAD_CANCEL_ENABLE
+ && self->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
+ && WaitForSingleObject(self->cancelEvent, 0) == WAIT_OBJECT_0)
+ {
+ ResetEvent(self->cancelEvent);
+ (void) pthread_mutex_unlock(&self->cancelLock);
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+ }
+
+ (void) pthread_mutex_unlock(&self->cancelLock);
+
+ return (result);
+
+} /* pthread_setcancelstate */
+
+
+int
+pthread_setcanceltype (int type, int *oldtype)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function atomically sets the calling thread's
+ * cancelability type to 'type' and returns the previous
+ * cancelability type at the location referenced by
+ * 'oldtype'
+ *
+ * PARAMETERS
+ * type,
+ * oldtype
+ * PTHREAD_CANCEL_DEFERRED
+ * only deferred cancelation is allowed,
+ *
+ * PTHREAD_CANCEL_ASYNCHRONOUS
+ * Asynchronous cancellation is allowed
+ *
+ *
+ * DESCRIPTION
+ * This function atomically sets the calling thread's
+ * cancelability type to 'type' and returns the previous
+ * cancelability type at the location referenced by
+ * 'oldtype'
+ *
+ * NOTES:
+ * 1) Use with caution; most code is not safe for use
+ * with asynchronous cancelability.
+ *
+ * COMPATIBILITY ADDITIONS
+ * If 'oldtype' is NULL then the previous type is not returned
+ * but the function still succeeds. (Solaris)
+ *
+ * RESULTS
+ * 0 successfully set cancelability type,
+ * EINVAL 'type' is invalid
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ pthread_t self = pthread_self();
+
+ if (self == NULL
+ || (type != PTHREAD_CANCEL_DEFERRED
+ && type != PTHREAD_CANCEL_ASYNCHRONOUS))
+ {
+ return EINVAL;
+ }
+
+ /*
+ * Lock for async-cancel safety.
+ */
+ (void) pthread_mutex_lock(&self->cancelLock);
+
+ if (oldtype != NULL)
+ {
+ *oldtype = self->cancelType;
+ }
+
+ self->cancelType = type;
+
+ /*
+ * Check if there is a pending asynchronous cancel
+ */
+ if (self->cancelState == PTHREAD_CANCEL_ENABLE
+ && self->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
+ && WaitForSingleObject(self->cancelEvent, 0) == WAIT_OBJECT_0)
+ {
+ ResetEvent(self->cancelEvent);
+ (void) pthread_mutex_unlock(&self->cancelLock);
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+ }
+
+ (void) pthread_mutex_unlock(&self->cancelLock);
+
+ return (result);
+
+} /* pthread_setcanceltype */
+
+void
+pthread_testcancel (void)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function creates a deferred cancellation point
+ * in the calling thread. The call has no effect if the
+ * current cancelability state is
+ * PTHREAD_CANCEL_DISABLE
+ *
+ * PARAMETERS
+ * N/A
+ *
+ *
+ * DESCRIPTION
+ * This function creates a deferred cancellation point
+ * in the calling thread. The call has no effect if the
+ * current cancelability state is
+ * PTHREAD_CANCEL_DISABLE
+ *
+ * NOTES:
+ * 1) Cancellation is asynchronous. Use pthread_join
+ * to wait for termination of thread if necessary
+ *
+ * RESULTS
+ * N/A
+ *
+ * ------------------------------------------------------
+ */
+{
+ pthread_t self = pthread_self();
+
+ if (self != NULL
+ && self->cancelState == PTHREAD_CANCEL_ENABLE
+ && WaitForSingleObject (self->cancelEvent, 0) == WAIT_OBJECT_0
+ )
+ {
+ /*
+ * Canceling!
+ */
+ ptw32_throw(PTW32_EPS_CANCEL);
+ }
+} /* pthread_testcancel */
+
+int
+pthread_cancel (pthread_t thread)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function requests cancellation of 'thread'.
+ *
+ * PARAMETERS
+ * thread
+ * reference to an instance of pthread_t
+ *
+ *
+ * DESCRIPTION
+ * This function requests cancellation of 'thread'.
+ * NOTE: cancellation is asynchronous; use pthread_join to
+ * wait for termination of 'thread' if necessary.
+ *
+ * RESULTS
+ * 0 successfully requested cancellation,
+ * ESRCH no thread found corresponding to 'thread',
+ * ENOMEM implicit self thread create failed.
+ * ------------------------------------------------------
+ */
+{
+ int result;
+ int cancel_self;
+ pthread_t self;
+
+ if (thread == NULL )
+ {
+ return ESRCH;
+ }
+
+ result = 0;
+ if ((self = pthread_self()) == NULL)
+ {
+ return ENOMEM;
+ };
+
+ /*
+ * FIXME!!
+ *
+ * Can a thread cancel itself?
+ *
+ * The standard doesn't
+ * specify an error to be returned if the target
+ * thread is itself.
+ *
+ * If it may, then we need to ensure that a thread can't
+ * deadlock itself trying to cancel itself asyncronously
+ * (pthread_cancel is required to be an async-cancel
+ * safe function).
+ */
+ cancel_self = pthread_equal(thread, self);
+
+ /*
+ * Lock for async-cancel safety.
+ */
+ (void) pthread_mutex_lock(&self->cancelLock);
+
+ if (thread->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
+ && thread->cancelState == PTHREAD_CANCEL_ENABLE )
+ {
+ if (cancel_self)
+ {
+ (void) pthread_mutex_unlock(&self->cancelLock);
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+ }
+
+ ptw32_cancel_thread(thread);
+ }
+ else
+ {
+ /*
+ * Set for deferred cancellation.
+ */
+ if (!SetEvent (thread->cancelEvent))
+ {
+ result = ESRCH;
+ }
+ }
+
+ (void) pthread_mutex_unlock(&self->cancelLock);
+
+ return (result);
+
+}
+
+
+
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