<!DOCTYPE html><htmllang="en"><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1.0"><metaname="generator"content="rustdoc"><metaname="description"content="API documentation for the Rust `RwLock` struct in crate `lock_api`."><metaname="keywords"content="rust, rustlang, rust-lang, RwLock"><title>lock_api::RwLock - Rust</title><linkrel="stylesheet"type="text/css"href="../normalize.css"><linkrel="stylesheet"type="text/css"href="../rustdoc.css"id="mainThemeStyle"><linkrel="stylesheet"type="text/css"href="../dark.css"><linkrel="stylesheet"type="text/css"href="../light.css"id="themeStyle"><scriptsrc="../storage.js"></script><noscript><linkrel="stylesheet"href="../noscript.css"></noscript><linkrel="shortcut icon"href="../favicon.ico"><styletype="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><bodyclass="rustdoc struct"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><navclass="sidebar"><divclass="sidebar-menu">☰</div><ahref='../lock_api/index.html'><divclass='logo-container'><imgsrc='../rust-logo.png'alt='logo'></div></a><pclass='location'>Struct RwLock</p><divclass="sidebar-elems"><divclass="block items"><aclass="sidebar-title"href="#methods">Methods</a><divclass="sidebar-links"><ahref="#method.force_unlock_read">force_unlock_read</a><ahref="#method.force_unlock_read_fair">force_unlock_read_fair</a><ahref="#method.force_unlock_write">force_unlock_write</a><ahref="#method.force_unlock_write_fair">force_unlock_write_fair</a><ahref="#method.get_mut">get_mut</a><ahref="#method.into_inner">into_inner</a><ahref="#method.new">new</a><ahref="#method.raw">raw</a><ahref="#method.read">read</a><ahref="#method.read_recursive">read_recursive</a><ahref="#method.try_read">try_read</a><ahref="#method.try_read_for">try_read_for</a><ahref="#method.try_read_recursive">try_read_recursive</a><ahref="#method.try_read_recursive_for">try_read_recursive_for</a><ahref="#method.try_read_recursive_until">try_read_recursive_until</a><ahref="#method.try_read_until">try_read_until</a><ahref="#method.try_upgradable_read">try_upgradable_read</a><ahref="#method.try_upgradable_read_for">try_upgradable_read_for</a><ahref="#method.try_upgradable_read_until">try_upgradable_read_until</a><ahref="#method.try_write">try_write</a><ahref="#method.try_write_for">try_write_for</a><ahref="#method.try_write_until">try_write_until</a><ahref="#method.upgradable_read">upgradable_read</a><ahref="#method.write">write</a></div><aclass="sidebar-title"href="#implementations">Trait Implementations</a><divclass="sidebar-links"><ahref="#impl-Debug">Debug</a><ahref="#impl-Default">Default</a><ahref="#impl-From%3CT%3E">From<T></a><ahref="#impl-Send">Send</a><ahref="#impl-Sync">Sync</a></div><aclass="sidebar-title"href="#synthetic-implementations">Auto Trait Implementations</a><divclass="sidebar-links"><ahref="#impl-Unpin">Unpin</a></div><aclass="sidebar-title"href="#blanket-implementations">Blanket Implementations</a><divclass="sidebar-links"><ahref="#impl-Any">Any</a><ahref="#impl-Borrow%3CT%3E">Borrow<T></a><ahref="#impl-BorrowMut%3CT%3E">BorrowMut<T></a><ahref="#impl-From%3CT%3E">From<T></a><ahref="#impl-Into%3CU%3E">Into<U></a><ahref="#impl-TryFrom%3CU%3E">TryFrom<U></a><ahref="#impl-TryInto%3CU%3E">TryInto<U></a></div></div><pclass='location'><ahref='index.html'>lock_api</a></p><script>window.sidebarCurrent={name:'RwLock',ty:'struct',relpath:''};</script><scriptdefersrc="sidebar-items.js"></script></div></nav><divclass="theme-picker"><buttonid="theme-picker"aria-label="Pick another theme!"><imgsrc="../brush.svg"width="18"alt="Pick another theme!"></button><divid="theme-choices"></div></div><scriptsrc="../theme.js"></script><navclass="sub"><formclass="search-form js-only"><divclass="search-container"><div><selectid="crate-search"><optionvalue="All crates">All crates</
<p>This type of lock allows a number of readers or at most one writer at any
point in time. The write portion of this lock typically allows modification
of the underlying data (exclusive access) and the read portion of this lock
typically allows for read-only access (shared access).</p>
<p>The type parameter <code>T</code> represents the data that this lock protects. It is
required that <code>T</code> satisfies <code>Send</code> to be shared across threads and <code>Sync</code> to
allow concurrent access through readers. The RAII guards returned from the
locking methods implement <code>Deref</code> (and <code>DerefMut</code> for the <code>write</code> methods)
to allow access to the contained of the lock.</p>
</div><h2id='methods'class='small-section-header'>Methods<ahref='#methods'class='anchor'></a></h2><h3id='impl'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLock.html"title="trait lock_api::RawRwLock">RawRwLock</a>, T><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#268-289'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.new'class="method"><codeid='new.v'>pub fn <ahref='#method.new'class='fnname'>new</a>(val: T) -><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#279-281'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Creates a new instance of an <code>RwLock<T></code> which is unlocked.</p>
</div><h4id='method.into_inner'class="method"><codeid='into_inner.v'>pub fn <ahref='#method.into_inner'class='fnname'>into_inner</a>(self) -> T</code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#286-288'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Consumes this <code>RwLock</code>, returning the underlying data.</p>
</div></div><h3id='impl-1'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLock.html"title="trait lock_api::RawRwLock">RawRwLock</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-1'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#291-430'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.read'class="method"><codeid='read.v'>pub fn <ahref='#method.read'class='fnname'>read</a>(&self) -><aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#321-325'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Locks this <code>RwLock</code> with shared read access, blocking the current thread
until it can be acquired.</p>
<p>The calling thread will be blocked until there are no more writers which
hold the lock. There may be other readers currently inside the lock when
this method returns.</p>
<p>Note that attempts to recursively acquire a read lock on a <code>RwLock</code> when
the current thread already holds one may result in a deadlock.</p>
<p>Returns an RAII guard which will release this thread's shared access
once it is dropped.</p>
</div><h4id='method.try_read'class="method"><codeid='try_read.v'>pub fn <ahref='#method.try_read'class='fnname'>try_read</a>(&self) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#335-342'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access.</p>
<p>If the access could not be granted at this time, then <code>None</code> is returned.
Otherwise, an RAII guard is returned which will release the shared access
when it is dropped.</p>
<p>This function does not block.</p>
</div><h4id='method.write'class="method"><codeid='write.v'>pub fn <ahref='#method.write'class='fnname'>write</a>(&self) -><aclass="struct"href="../lock_api/struct.RwLockWriteGuard.html"title="struct lock_api::RwLockWriteGuard">RwLockWriteGuard</a><R, T></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#353-357'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Locks this <code>RwLock</code> with exclusive write access, blocking the current
thread until it can be acquired.</p>
<p>This function will not return while other writers or other readers
currently have access to the lock.</p>
<p>Returns an RAII guard which will drop the write access of this <code>RwLock</code>
when dropped.</p>
</div><h4id='method.try_write'class="method"><codeid='try_write.v'>pub fn <ahref='#method.try_write'class='fnname'>try_write</a>(&self) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockWriteGuard.html"title="struct lock_api::RwLockWriteGuard">RwLockWriteGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#367-374'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to lock this <code>RwLock</code> with exclusive write access.</p>
<p>If the lock could not be acquired at this time, then <code>None</code> is returned.
Otherwise, an RAII guard is returned which will release the lock when
it is dropped.</p>
<p>This function does not block.</p>
</div><h4id='method.get_mut'class="method"><codeid='get_mut.v'>pub fn <ahref='#method.get_mut'class='fnname'>get_mut</a>(&mut self) ->&mut T</code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#381-383'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Returns a mutable reference to the underlying data.</p>
<p>Since this call borrows the <code>RwLock</code> mutably, no actual locking needs to
take place---the mutable borrow statically guarantees no locks exist.</p>
</div><h4id='method.force_unlock_read'class="method"><codeid='force_unlock_read.v'>pub unsafe fn <ahref='#method.force_unlock_read'class='fnname'>force_unlock_read</a>(&self)</code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#397-399'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Forcibly unlocks a read lock.</p>
<p>This is useful when combined with <code>mem::forget</code> to hold a lock without
the need to maintain a <code>RwLockReadGuard</code> object alive, for example when
<p>This method must only be called if the current thread logically owns a
<code>RwLockReadGuard</code> but that guard has be discarded using <code>mem::forget</code>.
Behavior is undefined if a rwlock is read-unlocked when not read-locked.</p>
</div><h4id='method.force_unlock_write_fair'class="method"><codeid='force_unlock_write_fair.v'>pub unsafe fn <ahref='#method.force_unlock_write_fair'class='fnname'>force_unlock_write_fair</a>(&self)</code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#461-463'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Forcibly unlocks a write lock using a fair unlock procotol.</p>
<p>This is useful when combined with <code>mem::forget</code> to hold a lock without
the need to maintain a <code>RwLockWriteGuard</code> object alive, for example when
<p>This method must only be called if the current thread logically owns a
<code>RwLockWriteGuard</code> but that guard has be discarded using <code>mem::forget</code>.
Behavior is undefined if a rwlock is write-unlocked when not write-locked.</p>
</div></div><h3id='impl-3'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLockTimed.html"title="trait lock_api::RawRwLockTimed">RawRwLockTimed</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-3'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#466-530'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.try_read_for'class="method"><codeid='try_read_for.v'>pub fn <ahref='#method.try_read_for'class='fnname'>try_read_for</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Duration"title="type lock_api::RawRwLockTimed::Duration">Duration</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#474-481'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the shared access when it is dropped.</p>
</div><h4id='method.try_read_until'class="method"><codeid='try_read_until.v'>pub fn <ahref='#method.try_read_until'class='fnname'>try_read_until</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Instant"title="type lock_api::RawRwLockTimed::Instant">Instant</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#490-497'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the shared access when it is dropped.</p>
</div><h4id='method.try_write_for'class="method"><codeid='try_write_for.v'>pub fn <ahref='#method.try_write_for'class='fnname'>try_write_for</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Duration"title="type lock_api::RawRwLockTimed::Duration">Duration</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockWriteGuard.html"title="struct lock_api::RwLockWriteGuard">RwLockWriteGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#506-513'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with exclusive write access until a
timeout is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the exclusive access when it is dropped.</p>
</div><h4id='method.try_write_until'class="method"><codeid='try_write_until.v'>pub fn <ahref='#method.try_write_until'class='fnname'>try_write_until</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Instant"title="type lock_api::RawRwLockTimed::Instant">Instant</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockWriteGuard.html"title="struct lock_api::RwLockWriteGuard">RwLockWriteGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#522-529'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with exclusive write access until a
timeout is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the exclusive access when it is dropped.</p>
</div></div><h3id='impl-4'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLockRecursive.html"title="trait lock_api::RawRwLockRecursive">RawRwLockRecursive</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-4'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#532-574'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.read_recursive'class="method"><codeid='read_recursive.v'>pub fn <ahref='#method.read_recursive'class='fnname'>read_recursive</a>(&self) -><aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#549-553'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Locks this <code>RwLock</code> with shared read access, blocking the current thread
until it can be acquired.</p>
<p>The calling thread will be blocked until there are no more writers which
hold the lock. There may be other readers currently inside the lock when
this method returns.</p>
<p>Unlike <code>read</code>, this method is guaranteed to succeed without blocking if
another read lock is held at the time of the call. This allows a thread
to recursively lock a <code>RwLock</code>. However using this method can cause
writers to starve since readers no longer block if a writer is waiting
for the lock.</p>
<p>Returns an RAII guard which will release this thread's shared access
once it is dropped.</p>
</div><h4id='method.try_read_recursive'class="method"><codeid='try_read_recursive.v'>pub fn <ahref='#method.try_read_recursive'class='fnname'>try_read_recursive</a>(&self) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#566-573'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access.</p>
<p>If the access could not be granted at this time, then <code>None</code> is returned.
Otherwise, an RAII guard is returned which will release the shared access
when it is dropped.</p>
<p>This method is guaranteed to succeed if another read lock is held at the
time of the call. See the documentation for <code>read_recursive</code> for details.</p>
<p>This function does not block.</p>
</div></div><h3id='impl-5'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLockRecursiveTimed.html"title="trait lock_api::RawRwLockRecursiveTimed">RawRwLockRecursiveTimed</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-5'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#576-618'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.try_read_recursive_for'class="method"><codeid='try_read_recursive_for.v'>pub fn <ahref='#method.try_read_recursive_for'class='fnname'>try_read_recursive_for</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Duration"title="type lock_api::RawRwLockTimed::Duration">Duration</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#588-598'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the shared access when it is dropped.</p>
<p>This method is guaranteed to succeed without blocking if another read
lock is held at the time of the call. See the documentation for
<code>read_recursive</code> for details.</p>
</div><h4id='method.try_read_recursive_until'class="method"><codeid='try_read_recursive_until.v'>pub fn <ahref='#method.try_read_recursive_until'class='fnname'>try_read_recursive_until</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Instant"title="type lock_api::RawRwLockTimed::Instant">Instant</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockReadGuard.html"title="struct lock_api::RwLockReadGuard">RwLockReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#607-617'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with shared read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the shared access when it is dropped.</p>
</div></div><h3id='impl-6'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLockUpgrade.html"title="trait lock_api::RawRwLockUpgrade">RawRwLockUpgrade</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-6'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#620-661'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.upgradable_read'class="method"><codeid='upgradable_read.v'>pub fn <ahref='#method.upgradable_read'class='fnname'>upgradable_read</a>(&self) -><aclass="struct"href="../lock_api/struct.RwLockUpgradableReadGuard.html"title="struct lock_api::RwLockUpgradableReadGuard">RwLockUpgradableReadGuard</a><R, T></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#639-643'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Locks this <code>RwLock</code> with upgradable read access, blocking the current thread
until it can be acquired.</p>
<p>The calling thread will be blocked until there are no more writers or other
upgradable reads which hold the lock. There may be other readers currently
inside the lock when this method returns.</p>
<p>Returns an RAII guard which will release this thread's shared access
once it is dropped.</p>
</div><h4id='method.try_upgradable_read'class="method"><codeid='try_upgradable_read.v'>pub fn <ahref='#method.try_upgradable_read'class='fnname'>try_upgradable_read</a>(&self) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockUpgradableReadGuard.html"title="struct lock_api::RwLockUpgradableReadGuard">RwLockUpgradableReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#653-660'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with upgradable read access.</p>
<p>If the access could not be granted at this time, then <code>None</code> is returned.
Otherwise, an RAII guard is returned which will release the shared access
when it is dropped.</p>
<p>This function does not block.</p>
</div></div><h3id='impl-7'class='impl'><codeclass='in-band'>impl<R: <aclass="trait"href="../lock_api/trait.RawRwLockUpgradeTimed.html"title="trait lock_api::RawRwLockUpgradeTimed">RawRwLockUpgradeTimed</a>, T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>><aclass="struct"href="../lock_api/struct.RwLock.html"title="struct lock_api::RwLock">RwLock</a><R, T></code><ahref='#impl-7'class='anchor'></a><aclass='srclink'href='../src/lock_api/rwlock.rs.html#663-701'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.try_upgradable_read_for'class="method"><codeid='try_upgradable_read_for.v'>pub fn <ahref='#method.try_upgradable_read_for'class='fnname'>try_upgradable_read_for</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Duration"title="type lock_api::RawRwLockTimed::Duration">Duration</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockUpgradableReadGuard.html"title="struct lock_api::RwLockUpgradableReadGuard">RwLockUpgradableReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#671-681'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with upgradable read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
release the shared access when it is dropped.</p>
</div><h4id='method.try_upgradable_read_until'class="method"><codeid='try_upgradable_read_until.v'>pub fn <ahref='#method.try_upgradable_read_until'class='fnname'>try_upgradable_read_until</a>(<br> &self, <br> timeout: R::<aclass="type"href="../lock_api/trait.RawRwLockTimed.html#associatedtype.Instant"title="type lock_api::RawRwLockTimed::Instant">Instant</a><br>) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"title="enum core::option::Option">Option</a><<aclass="struct"href="../lock_api/struct.RwLockUpgradableReadGuard.html"title="struct lock_api::RwLockUpgradableReadGuard">RwLockUpgradableReadGuard</a><R, T>></code><aclass='srclink'href='../src/lock_api/rwlock.rs.html#690-700'title='goto source code'>[src]</a></h4><divclass='docblock'><p>Attempts to acquire this <code>RwLock</code> with upgradable read access until a timeout
is reached.</p>
<p>If the access could not be granted before the timeout expires, then
<code>None</code> is returned. Otherwise, an RAII guard is returned which will
</div></div><h3id='impl-TryFrom%3CU%3E'class='impl'><codeclass='in-band'>impl<T, U><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T <spanclass="where fmt-newline">where<br> U: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>, </span></code><ahref='#impl-TryFrom%3CU%3E'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#571-577'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='associatedtype.Error'class="type"><codeid='Error.t'>type <ahref='https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error'class="type">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/nightly/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></code></h4><divclass='docblock'><p>The type returned in the event of a conversion error.</p>
</div><h4id='method.try_from'class="method hidden"><codeid='try_from.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#tymethod.try_from'class='fnname'>try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="type"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#574-576'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3id='impl-Into%3CU%3E'class='impl'><codeclass='in-band'>impl<T, U><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><U> for T <spanclass="where fmt-newline">where<br> U: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html"title="trait core::convert::From">From</a><T>, </span></code><ahref='#impl-Into%3CU%3E'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#543-548'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.into'class="method hidden"><codeid='into.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/convert/trait.Into.html#tymethod.into'class='fnname'>into</a>(self) -> U</code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#545-547'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3id='impl-TryInto%3CU%3E'class='impl'><codeclass='in-band'>impl<T, U><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T <spanclass="where fmt-newline">where<br> U: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>, </span></code><ahref='#impl-TryInto%3CU%3E'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#559-566'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='associatedtype.Error-1'class="type"><codeid='Error.t-1'>type <ahref='https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#associatedtype.Error'class="type">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="type"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></code></h4><divclass='docblock'><p>The type returned in the event of a conversion error.</p>
</div><h4id='method.try_into'class="method hidden"><codeid='try_into.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#tymethod.try_into'class='fnname'>try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="type"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/convert.rs.html#563-565'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3id='impl-Borrow%3CT%3E'class='impl'><codeclass='in-band'>impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html"title="trait core::borrow::Borrow">Borrow</a><T> for T <spanclass="where fmt-newline">where<br> T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>, </span></code><ahref='#impl-Borrow%3CT%3E'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#213-215'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.borrow'class="method hidden"><codeid='borrow.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow'class='fnname'>borrow</a>(&self) ->&T</code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#214'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Immutably borrows from an owned value. <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></p>
</div></div><h3id='impl-BorrowMut%3CT%3E'class='impl'><codeclass='in-band'>impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html"title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T <spanclass="where fmt-newline">where<br> T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>, </span></code><ahref='#impl-BorrowMut%3CT%3E'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#218-220'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.borrow_mut'class="method hidden"><codeid='borrow_mut.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut'class='fnname'>borrow_mut</a>(&mut self) ->&mut T</code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#219'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Mutably borrows from an owned value. <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></p>
</div></div><h3id='impl-Any'class='impl'><codeclass='in-band'>impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html"title="trait core::any::Any">Any</a> for T <spanclass="where fmt-newline">where<br> T: 'static + ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>, </span></code><ahref='#impl-Any'class='anchor'></a><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/any.rs.html#100-102'title='goto source code'>[src]</a></h3><divclass='impl-items'><h4id='method.type_id'class="method hidden"><codeid='type_id.v'>fn <ahref='https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id'class='fnname'>type_id</a>(&self) -><aclass="struct"href="https://doc.rust-lang.org/nightly/core/any/struct.TypeId.html"title="struct core::any::TypeId">TypeId</a></code><aclass='srclink'href='https://doc.rust-lang.org/nightly/src/core/any.rs.html#101'title='goto source code'>[src]</a></h4><divclass='docblock hidden'><p>Gets the <code>TypeId</code> of <code>self</code>. <ahref="https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id">Read more</a></p>
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