diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /nsprpub/pr/include/prcvar.h | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'nsprpub/pr/include/prcvar.h')
-rw-r--r-- | nsprpub/pr/include/prcvar.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/nsprpub/pr/include/prcvar.h b/nsprpub/pr/include/prcvar.h new file mode 100644 index 0000000000..413a3646ac --- /dev/null +++ b/nsprpub/pr/include/prcvar.h @@ -0,0 +1,94 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef prcvar_h___ +#define prcvar_h___ + +#include "prlock.h" +#include "prinrval.h" + +PR_BEGIN_EXTERN_C + +typedef struct PRCondVar PRCondVar; + +/* +** Create a new condition variable. +** +** "lock" is the lock used to protect the condition variable. +** +** Condition variables are synchronization objects that threads can use +** to wait for some condition to occur. +** +** This may fail if memory is tight or if some operating system resource +** is low. In such cases, a NULL will be returned. +*/ +NSPR_API(PRCondVar*) PR_NewCondVar(PRLock *lock); + +/* +** Destroy a condition variable. There must be no thread +** waiting on the condvar. The caller is responsible for guaranteeing +** that the condvar is no longer in use. +** +*/ +NSPR_API(void) PR_DestroyCondVar(PRCondVar *cvar); + +/* +** The thread that waits on a condition is blocked in a "waiting on +** condition" state until another thread notifies the condition or a +** caller specified amount of time expires. The lock associated with +** the condition variable will be released, which must have be held +** prior to the call to wait. +** +** Logically a notified thread is moved from the "waiting on condition" +** state and made "ready." When scheduled, it will attempt to reacquire +** the lock that it held when wait was called. +** +** The timeout has two well known values, PR_INTERVAL_NO_TIMEOUT and +** PR_INTERVAL_NO_WAIT. The former value requires that a condition be +** notified (or the thread interrupted) before it will resume from the +** wait. If the timeout has a value of PR_INTERVAL_NO_WAIT, the effect +** is to release the lock, possibly causing a rescheduling within the +** runtime, then immediately attempting to reacquire the lock and resume. +** +** Any other value for timeout will cause the thread to be rescheduled +** either due to explicit notification or an expired interval. The latter +** must be determined by treating time as one part of the monitored data +** being protected by the lock and tested explicitly for an expired +** interval. +** +** Returns PR_FAILURE if the caller has not locked the lock associated +** with the condition variable or the thread was interrupted (PR_Interrupt()). +** The particular reason can be extracted with PR_GetError(). +*/ +NSPR_API(PRStatus) PR_WaitCondVar(PRCondVar *cvar, PRIntervalTime timeout); + +/* +** Notify ONE thread that is currently waiting on 'cvar'. Which thread is +** dependent on the implementation of the runtime. Common sense would dictate +** that all threads waiting on a single condition have identical semantics, +** therefore which one gets notified is not significant. +** +** The calling thead must hold the lock that protects the condition, as +** well as the invariants that are tightly bound to the condition, when +** notify is called. +** +** Returns PR_FAILURE if the caller has not locked the lock associated +** with the condition variable. +*/ +NSPR_API(PRStatus) PR_NotifyCondVar(PRCondVar *cvar); + +/* +** Notify all of the threads waiting on the condition variable. The order +** that the threads are notified is indeterminant. The lock that protects +** the condition must be held. +** +** Returns PR_FAILURE if the caller has not locked the lock associated +** with the condition variable. +*/ +NSPR_API(PRStatus) PR_NotifyAllCondVar(PRCondVar *cvar); + +PR_END_EXTERN_C + +#endif /* prcvar_h___ */ |