[#BloombergLP-bslmt-ReadLockGuard-2constructor-06]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslmt.adoc[bslmt]::xref:BloombergLP/bslmt/ReadLockGuard.adoc[ReadLockGuard]::ReadLockGuard
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:mrdocs:

Constructors

== Synopses

Declared in `<bslmt_readlockguard.h>`

Create a scoped guard that conditionally manages the specified `lock` (if non‐null) and invokes `lock‐>lockRead()`. Supplying a null `lock` has no effect. The behavior is undefined unless `lock` (if non‐null) is not already locked by this thread. Note that `lock` must remain valid throughout the lifetime of this guard, or until `release` is called.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
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explicit
xref:BloombergLP/bslmt/ReadLockGuard/2constructor-088.adoc[ReadLockGuard](T* lock);
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[.small]#xref:BloombergLP/bslmt/ReadLockGuard/2constructor-088.adoc[_» more..._]#

Create a scoped guard that conditionally manages the specified `lock` (if non‐null) and invokes `lock‐>lockRead()` if the specified `alreadyLockedFlag` is `false`. Supplying a null `lock` has no effect. The behavior is undefined unless the state of `lock` (if non‐null) is consistent with `alreadyLockedFlag`. Note that `alreadyLockedFlag` is used to indicate whether `lock` is in an already‐locked state when passed, so if `alreadyLockedFlag` is `true` the `lock` method will _not_ be called on the supplied `lock`. Also note that `lock` must remain valid throughout the lifetime of this guard, or until `release` is called.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
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xref:BloombergLP/bslmt/ReadLockGuard/2constructor-080.adoc[ReadLockGuard](
    T* lock,
    bool alreadyLockedFlag);
----

[.small]#xref:BloombergLP/bslmt/ReadLockGuard/2constructor-080.adoc[_» more..._]#


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