--- /dev/null
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License Version 2 or later (the
+ * "GPL"), in which case the provisions of the GPL are applicable
+ * instead of those above. If you wish to allow use of your
+ * version of this file only under the terms of the GPL and not to
+ * allow others to use your version of this file under the MPL,
+ * indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by
+ * the GPL. If you do not delete the provisions above, a recipient
+ * may use your version of this file under either the MPL or the
+ * GPL.
+ */
+
+#ifndef prthread_h___
+#define prthread_h___
+
+/*
+** API for NSPR threads. On some architectures (MAC and WIN16
+** notably) pre-emptibility is not guaranteed. Hard priority scheduling
+** is not guaranteed, so programming using priority based synchronization
+** is a no-no.
+**
+** NSPR threads are scheduled based loosly on their client set priority.
+** In general, a thread of a higher priority has a statistically better
+** chance of running relative to threads of lower priority. However,
+** NSPR uses multiple strategies to provide execution vehicles for thread
+** abstraction of various host platforms. As it turns out, there is little
+** NSPR can do to affect the scheduling attributes of "GLOBAL" threads.
+** However, a semblance of GLOBAL threads is used to implement "LOCAL"
+** threads. An arbitrary number of such LOCAL threads can be assigned to
+** a single GLOBAL thread.
+**
+** For scheduling, NSPR will attempt to run the highest priority LOCAL
+** thread associated with a given GLOBAL thread. It is further assumed
+** that the host OS will apply some form of "fair" scheduling on the
+** GLOBAL threads.
+**
+** Threads have a "system flag" which when set indicates the thread
+** doesn't count for determining when the process should exit (the
+** process exits when the last user thread exits).
+**
+** Threads also have a "scope flag" which controls whether the threads
+** are scheduled in the local scope or scheduled by the OS globally. This
+** indicates whether a thread is permanently bound to a native OS thread.
+** An unbound thread competes for scheduling resources in the same process.
+**
+** Another flag is "state flag" which control whether the thread is joinable.
+** It allows other threads to wait for the created thread to reach completion.
+**
+** Threads can have "per-thread-data" attached to them. Each thread has a
+** per-thread error number and error string which are updated when NSPR
+** operations fail.
+*/
+#include "prtypes.h"
+#include "prinrval.h"
+
+PR_BEGIN_EXTERN_C
+
+typedef struct PRThread PRThread;
+typedef struct PRThreadStack PRThreadStack;
+
+typedef enum PRThreadType {
+ PR_USER_THREAD,
+ PR_SYSTEM_THREAD
+} PRThreadType;
+
+typedef enum PRThreadScope {
+ PR_LOCAL_THREAD,
+ PR_GLOBAL_THREAD,
+ PR_GLOBAL_BOUND_THREAD
+} PRThreadScope;
+
+typedef enum PRThreadState {
+ PR_JOINABLE_THREAD,
+ PR_UNJOINABLE_THREAD
+} PRThreadState;
+
+typedef enum PRThreadPriority
+{
+ PR_PRIORITY_FIRST = 0, /* just a placeholder */
+ PR_PRIORITY_LOW = 0, /* the lowest possible priority */
+ PR_PRIORITY_NORMAL = 1, /* most common expected priority */
+ PR_PRIORITY_HIGH = 2, /* slightly more aggressive scheduling */
+ PR_PRIORITY_URGENT = 3, /* it does little good to have more than one */
+ PR_PRIORITY_LAST = 3 /* this is just a placeholder */
+} PRThreadPriority;
+
+/*
+** Create a new thread:
+** "type" is the type of thread to create
+** "start(arg)" will be invoked as the threads "main"
+** "priority" will be created thread's priority
+** "scope" will specify whether the thread is local or global
+** "state" will specify whether the thread is joinable or not
+** "stackSize" the size of the stack, in bytes. The value can be zero
+** and then a machine specific stack size will be chosen.
+**
+** This can return NULL if some kind of error occurs, such as if memory is
+** tight.
+**
+** If you want the thread to start up waiting for the creator to do
+** something, enter a lock before creating the thread and then have the
+** threads start routine enter and exit the same lock. When you are ready
+** for the thread to run, exit the lock.
+**
+** If you want to detect the completion of the created thread, the thread
+** should be created joinable. Then, use PR_JoinThread to synchrnoize the
+** termination of another thread.
+**
+** When the start function returns the thread exits. If it is the last
+** PR_USER_THREAD to exit then the process exits.
+*/
+NSPR_API(PRThread*) PR_CreateThread(PRThreadType type,
+ void (PR_CALLBACK *start)(void *arg),
+ void *arg,
+ PRThreadPriority priority,
+ PRThreadScope scope,
+ PRThreadState state,
+ PRUint32 stackSize);
+
+/*
+** Wait for thread termination:
+** "thread" is the target thread
+**
+** This can return PR_FAILURE if no joinable thread could be found
+** corresponding to the specified target thread.
+**
+** The calling thread is blocked until the target thread completes.
+** Several threads cannot wait for the same thread to complete; one thread
+** will operate successfully and others will terminate with an error PR_FAILURE.
+** The calling thread will not be blocked if the target thread has already
+** terminated.
+*/
+NSPR_API(PRStatus) PR_JoinThread(PRThread *thread);
+
+/*
+** Return the current thread object for the currently running code.
+** Never returns NULL.
+*/
+NSPR_API(PRThread*) PR_GetCurrentThread(void);
+#ifndef NO_NSPR_10_SUPPORT
+#define PR_CurrentThread() PR_GetCurrentThread() /* for nspr1.0 compat. */
+#endif /* NO_NSPR_10_SUPPORT */
+
+/*
+** Get the priority of "thread".
+*/
+NSPR_API(PRThreadPriority) PR_GetThreadPriority(const PRThread *thread);
+
+/*
+** Change the priority of the "thread" to "priority".
+*/
+NSPR_API(void) PR_SetThreadPriority(PRThread *thread, PRThreadPriority priority);
+
+/*
+** This routine returns a new index for per-thread-private data table.
+** The index is visible to all threads within a process. This index can
+** be used with the PR_SetThreadPrivate() and PR_GetThreadPrivate() routines
+** to save and retrieve data associated with the index for a thread.
+**
+** Each index is associationed with a destructor function ('dtor'). The function
+** may be specified as NULL when the index is created. If it is not NULL, the
+** function will be called when:
+** - the thread exits and the private data for the associated index
+** is not NULL,
+** - new thread private data is set and the current private data is
+** not NULL.
+**
+** The index independently maintains specific values for each binding thread.
+** A thread can only get access to its own thread-specific-data.
+**
+** Upon a new index return the value associated with the index for all threads
+** is NULL, and upon thread creation the value associated with all indices for
+** that thread is NULL.
+**
+** Returns PR_FAILURE if the total number of indices will exceed the maximun
+** allowed.
+*/
+typedef void (PR_CALLBACK *PRThreadPrivateDTOR)(void *priv);
+
+NSPR_API(PRStatus) PR_NewThreadPrivateIndex(
+ PRUintn *newIndex, PRThreadPrivateDTOR destructor);
+
+/*
+** Define some per-thread-private data.
+** "tpdIndex" is an index into the per-thread private data table
+** "priv" is the per-thread-private data
+**
+** If the per-thread private data table has a previously registered
+** destructor function and a non-NULL per-thread-private data value,
+** the destructor function is invoked.
+**
+** This can return PR_FAILURE if the index is invalid.
+*/
+NSPR_API(PRStatus) PR_SetThreadPrivate(PRUintn tpdIndex, void *priv);
+
+/*
+** Recover the per-thread-private data for the current thread. "tpdIndex" is
+** the index into the per-thread private data table.
+**
+** The returned value may be NULL which is indistinguishable from an error
+** condition.
+**
+** A thread can only get access to its own thread-specific-data.
+*/
+NSPR_API(void*) PR_GetThreadPrivate(PRUintn tpdIndex);
+
+/*
+** This routine sets the interrupt request for a target thread. The interrupt
+** request remains in the thread's state until it is delivered exactly once
+** or explicitly canceled.
+**
+** A thread that has been interrupted will fail all NSPR blocking operations
+** that return a PRStatus (I/O, waiting on a condition, etc).
+**
+** PR_Interrupt may itself fail if the target thread is invalid.
+*/
+NSPR_API(PRStatus) PR_Interrupt(PRThread *thread);
+
+/*
+** Clear the interrupt request for the calling thread. If no such request
+** is pending, this operation is a noop.
+*/
+NSPR_API(void) PR_ClearInterrupt(void);
+
+/*
+** Block the interrupt for the calling thread.
+*/
+NSPR_API(void) PR_BlockInterrupt(void);
+
+/*
+** Unblock the interrupt for the calling thread.
+*/
+NSPR_API(void) PR_UnblockInterrupt(void);
+
+/*
+** Make the current thread sleep until "ticks" time amount of time
+** has expired. If "ticks" is PR_INTERVAL_NO_WAIT then the call is
+** equivalent to calling PR_Yield. Calling PR_Sleep with an argument
+** equivalent to PR_INTERVAL_NO_TIMEOUT is an error and will result
+** in a PR_FAILURE error return.
+*/
+NSPR_API(PRStatus) PR_Sleep(PRIntervalTime ticks);
+
+/*
+** Get the scoping of this thread.
+*/
+NSPR_API(PRThreadScope) PR_GetThreadScope(const PRThread *thread);
+
+/*
+** Get the type of this thread.
+*/
+NSPR_API(PRThreadType) PR_GetThreadType(const PRThread *thread);
+
+/*
+** Get the join state of this thread.
+*/
+NSPR_API(PRThreadState) PR_GetThreadState(const PRThread *thread);
+
+PR_END_EXTERN_C
+
+#endif /* prthread_h___ */
projects / apple / security.git / blobdiff