Andy Dustman: add GNU pth user-space thread support.

1 files changed, 328 insertions, 0 deletions

diff --git a/Python/thread_pth.h b/Python/thread_pth.h
new file mode 100644
index 0000000..305121e
--- /dev/null
+++ b/Python/thread_pth.h
@@ -0,0 +1,328 @@
+/***********************************************************
+Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
+The Netherlands.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI or Corporation for National Research Initiatives or
+CNRI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior
+permission.
+
+While CWI is the initial source for this software, a modified version
+is made available by the Corporation for National Research Initiatives
+(CNRI) at the Internet address ftp://ftp.python.org.
+
+STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
+CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
+
+/* GNU pth threads interface
+   http://www.gnu.org/software/pth
+   2000-05-03 Andy Dustman <andy@dustman.net>
+
+   Adapted from Posix threads interface 
+   12 May 1997 -- david arnold <davida@pobox.com>
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <pth.h>
+
+/* A pth mutex isn't sufficient to model the Python lock type
+ * because pth mutexes can be acquired multiple times by the
+ * same thread.
+ *
+ * The pth_lock struct implements a Python lock as a "locked?" bit
+ * and a <condition, mutex> pair.  In general, if the bit can be acquired
+ * instantly, it is, else the pair is used to block the thread until the
+ * bit is cleared.
+ */
+
+typedef struct {
+	char             locked; /* 0=unlocked, 1=locked */
+	/* a <cond, mutex> pair to handle an acquire of a locked lock */
+	pth_cond_t   lock_released;
+	pth_mutex_t  mut;
+} pth_lock;
+
+#define CHECK_STATUS(name)  if (status == -1) { printf("%d ", status); perror(name); error = 1; }
+
+/*
+ * Initialization.
+ */
+
+static void PyThread__init_thread _P0()
+{
+	pth_init();
+}
+
+/*
+ * Thread support.
+ */
+
+
+int PyThread_start_new_thread _P2(func, void (*func) _P((void *)), arg, void *arg)
+{
+	pth_t th;
+	int success;
+	dprintf(("PyThread_start_new_thread called\n"));
+	if (!initialized)
+		PyThread_init_thread();
+
+	th = pth_spawn(PTH_ATTR_DEFAULT,
+				 (void* (*)_P((void *)))func,
+				 (void *)arg
+				 );
+
+	return th == NULL ? 0 : 1;
+}
+
+long PyThread_get_thread_ident _P0()
+{
+	volatile pth_t threadid;
+	if (!initialized)
+		PyThread_init_thread();
+	/* Jump through some hoops for Alpha OSF/1 */
+	threadid = pth_self();
+	return (long) *(long *) &threadid;
+}
+
+static void do_PyThread_exit_thread _P1(no_cleanup, int no_cleanup)
+{
+	dprintf(("PyThread_exit_thread called\n"));
+	if (!initialized) {
+		if (no_cleanup)
+			_exit(0);
+		else
+			exit(0);
+	}
+}
+
+void PyThread_exit_thread _P0()
+{
+	do_PyThread_exit_thread(0);
+}
+
+void PyThread__exit_thread _P0()
+{
+	do_PyThread_exit_thread(1);
+}
+
+#ifndef NO_EXIT_PROG
+static void do_PyThread_exit_prog _P2(status, int status, no_cleanup, int no_cleanup)
+{
+	dprintf(("PyThread_exit_prog(%d) called\n", status));
+	if (!initialized)
+		if (no_cleanup)
+			_exit(status);
+		else
+			exit(status);
+}
+
+void PyThread_exit_prog _P1(status, int status)
+{
+	do_PyThread_exit_prog(status, 0);
+}
+
+void PyThread__exit_prog _P1(status, int status)
+{
+	do_PyThread_exit_prog(status, 1);
+}
+#endif /* NO_EXIT_PROG */
+
+/*
+ * Lock support.
+ */
+PyThread_type_lock PyThread_allocate_lock _P0()
+{
+	pth_lock *lock;
+	int status, error = 0;
+
+	dprintf(("PyThread_allocate_lock called\n"));
+	if (!initialized)
+		PyThread_init_thread();
+
+	lock = (pth_lock *) malloc(sizeof(pth_lock));
+        memset((void *)lock, '\0', sizeof(pth_lock));
+	if (lock) {
+		lock->locked = 0;
+		status = pth_mutex_init(&lock->mut);
+		CHECK_STATUS("pth_mutex_init");
+		status = pth_cond_init(&lock->lock_released);
+		CHECK_STATUS("pth_cond_init");
+		if (error) {
+			free((void *)lock);
+			lock = NULL;
+		}
+	}
+	dprintf(("PyThread_allocate_lock() -> %lx\n", (long)lock));
+	return (PyThread_type_lock) lock;
+}
+
+void PyThread_free_lock _P1(lock, PyThread_type_lock lock)
+{
+	pth_lock *thelock = (pth_lock *)lock;
+	int status, error = 0;
+
+	dprintf(("PyThread_free_lock(%lx) called\n", (long)lock));
+
+	free((void *)thelock);
+}
+
+int PyThread_acquire_lock _P2(lock, PyThread_type_lock lock, waitflag, int waitflag)
+{
+	int success;
+	pth_lock *thelock = (pth_lock *)lock;
+	int status, error = 0;
+
+	dprintf(("PyThread_acquire_lock(%lx, %d) called\n", (long)lock, waitflag));
+
+	status = pth_mutex_acquire(&thelock->mut, !waitflag, NULL);
+	CHECK_STATUS("pth_mutex_acquire[1]");
+	success = thelock->locked == 0;
+        if (success) thelock->locked = 1;
+        status = pth_mutex_release( &thelock->mut );
+        CHECK_STATUS("pth_mutex_release[1]");
+
+        if ( !success && waitflag ) {
+                /* continue trying until we get the lock */
+
+                /* mut must be locked by me -- part of the condition
+                 * protocol */
+                status = pth_mutex_acquire( &thelock->mut, !waitflag, NULL );
+                CHECK_STATUS("pth_mutex_acquire[2]");
+                while ( thelock->locked ) {
+                        status = pth_cond_await(&thelock->lock_released,
+                                                &thelock->mut, NULL);
+                        CHECK_STATUS("pth_cond_await");
+                }
+                thelock->locked = 1;
+                status = pth_mutex_release( &thelock->mut );
+                CHECK_STATUS("pth_mutex_release[2]");
+                success = 1;
+        }
+        if (error) success = 0;
+        dprintf(("PyThread_acquire_lock(%lx, %d) -> %d\n", (long)lock, waitflag, success));
+	return success;
+}
+
+void PyThread_release_lock _P1(lock, PyThread_type_lock lock)
+{
+        pth_lock *thelock = (pth_lock *)lock;
+        int status, error = 0;
+
+        dprintf(("PyThread_release_lock(%lx) called\n", (long)lock));
+
+        status = pth_mutex_acquire( &thelock->mut, 0, NULL );
+        CHECK_STATUS("pth_mutex_acquire[3]");
+
+        thelock->locked = 0;
+
+        status = pth_mutex_release( &thelock->mut );
+        CHECK_STATUS("pth_mutex_release[3]");
+
+        /* wake up someone (anyone, if any) waiting on the lock */
+        status = pth_cond_notify( &thelock->lock_released, 0 );
+        CHECK_STATUS("pth_cond_notify");
+}
+
+/*
+ * Semaphore support.
+ */
+
+struct semaphore {
+	pth_mutex_t mutex;
+	pth_cond_t cond;
+	int value;
+};
+
+PyThread_type_sema PyThread_allocate_sema _P1(value, int value)
+{
+	struct semaphore *sema;
+	int status, error = 0;
+
+	dprintf(("PyThread_allocate_sema called\n"));
+	if (!initialized)
+		PyThread_init_thread();
+
+	sema = (struct semaphore *) malloc(sizeof(struct semaphore));
+	if (sema != NULL) {
+		sema->value = value;
+		status = pth_mutex_init(&sema->mutex);
+		CHECK_STATUS("pth_mutex_init");
+		status = pth_cond_init(&sema->cond);
+		CHECK_STATUS("pth_mutex_init");
+		if (error) {
+			free((void *) sema);
+			sema = NULL;
+		}
+	}
+	dprintf(("PyThread_allocate_sema() -> %lx\n", (long) sema));
+	return (PyThread_type_sema) sema;
+}
+
+void PyThread_free_sema _P1(sema, PyThread_type_sema sema)
+{
+	int status, error = 0;
+	struct semaphore *thesema = (struct semaphore *) sema;
+
+	dprintf(("PyThread_free_sema(%lx) called\n", (long) sema));
+	free((void *) thesema);
+}
+
+int PyThread_down_sema _P2(sema, PyThread_type_sema sema, waitflag, int waitflag)
+{
+	int status, error = 0, success;
+	struct semaphore *thesema = (struct semaphore *) sema;
+
+	dprintf(("PyThread_down_sema(%lx, %d) called\n", (long) sema, waitflag));
+	status = pth_mutex_acquire(&thesema->mutex, !waitflag, NULL);
+	CHECK_STATUS("pth_mutex_acquire");
+	if (waitflag) {
+		while (!error && thesema->value <= 0) {
+			status = pth_cond_await(&thesema->cond,
+						&thesema->mutex, NULL);
+			CHECK_STATUS("pth_cond_await");
+		}
+	}
+	if (error)
+		success = 0;
+	else if (thesema->value > 0) {
+		thesema->value--;
+		success = 1;
+	}
+	else
+		success = 0;
+	status = pth_mutex_release(&thesema->mutex);
+	CHECK_STATUS("pth_mutex_release");
+	dprintf(("PyThread_down_sema(%lx) return\n", (long) sema));
+	return success;
+}
+
+void PyThread_up_sema _P1(sema, PyThread_type_sema sema)
+{
+	int status, error = 0;
+	struct semaphore *thesema = (struct semaphore *) sema;
+
+	dprintf(("PyThread_up_sema(%lx)\n", (long) sema));
+	status = pth_mutex_acquire(&thesema->mutex, 0, NULL);
+	CHECK_STATUS("pth_mutex_acquire");
+	thesema->value++;
+	status = pth_cond_notify(&thesema->cond, 1);
+	CHECK_STATUS("pth_cond_notify");
+	status = pth_mutex_release(&thesema->mutex);
+	CHECK_STATUS("pth_mutex_release");
+}