ACE
6.4.2
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A wrapper around the UNIX file locking mechanism. More...
#include <File_Lock.h>
Public Member Functions | |
ACE_File_Lock (ACE_HANDLE handle=ACE_INVALID_HANDLE, bool unlink_in_destructor=true) | |
ACE_File_Lock (const ACE_TCHAR *filename, int flags, mode_t mode=0, bool unlink_in_destructor=true) | |
int | open (const ACE_TCHAR *filename, int flags, mode_t mode=0) |
~ACE_File_Lock (void) | |
Remove a File lock by releasing it and closing down the <handle_>. More... | |
int | remove (bool unlink_file=true) |
int | acquire (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | tryacquire (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | release (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
Unlock a readers/writer lock. More... | |
int | acquire_write (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | tryacquire_write (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | tryacquire_write_upgrade (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | acquire_read (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
int | tryacquire_read (short whence=0, ACE_OFF_T start=0, ACE_OFF_T len=1) |
ACE_HANDLE | get_handle (void) const |
Get underlying ACE_HANDLE for the file. More... | |
void | set_handle (ACE_HANDLE) |
void | dump (void) const |
Dump state of the object. More... | |
Public Attributes | |
ACE_ALLOC_HOOK_DECLARE | |
Declare the dynamic allocation hooks. More... | |
Protected Attributes | |
ACE_OS::ace_flock_t | lock_ |
Locking structure for OS record locks. More... | |
bool | removed_ |
bool const | unlink_in_destructor_ |
Private Member Functions | |
void | operator= (const ACE_File_Lock &) |
ACE_File_Lock (const ACE_File_Lock &) | |
A wrapper around the UNIX file locking mechanism.
Allows us to "adapt" the UNIX file locking mechanisms to work with all of our Guard stuff...
ACE_File_Lock::ACE_File_Lock | ( | ACE_HANDLE | handle = ACE_INVALID_HANDLE , |
bool | unlink_in_destructor = true |
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) |
Set the <handle_> of the File_Lock to handle. Note that this constructor assumes ownership of the handle and will close it down in <remove>. If you want the handle to stay open when <remove> is called make sure to call <dup> on the handle. If you don't want the file unlinked in the destructor pass a zero value for <unlink_in_destructor>.
ACE_File_Lock::ACE_File_Lock | ( | const ACE_TCHAR * | filename, |
int | flags, | ||
mode_t | mode = 0 , |
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bool | unlink_in_destructor = true |
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) |
Open the filename with flags and mode and set the result to <handle_>. If you don't want the file unlinked in the destructor pass a false value for unlink_in_destructor.
ACE_File_Lock::~ACE_File_Lock | ( | void | ) |
Remove a File lock by releasing it and closing down the <handle_>.
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private |
Note, for interface uniformity with other synchronization wrappers we include the acquire() method. This is implemented as a write-lock to be on the safe-side...
Acquire a read lock, but block if a writer hold the lock. Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
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inline |
Acquire a write lock, but block if any readers or a writer hold the lock.
void ACE_File_Lock::dump | ( | void | ) | const |
Dump state of the object.
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inline |
Get underlying ACE_HANDLE for the file.
int ACE_File_Lock::open | ( | const ACE_TCHAR * | filename, |
int | flags, | ||
mode_t | mode = 0 |
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) |
Open the filename with flags and mode and set the result to <handle_>.
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private |
Unlock a readers/writer lock.
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inline |
Remove a File lock by releasing it and closing down the <handle_>. If unlink_file is true then we unlink the file.
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inline |
Set underlying ACE_HANDLE. Note that this method assumes ownership of the handle and will close it down in <remove>. If you want the handle to stay open when <remove> is called make sure to call <dup> on the handle before closing it. You are responsible for the closing the existing handle before overwriting it.
Note, for interface uniformity with other synchronization wrappers we include the <tryacquire> method. This is implemented as a write-lock to be on the safe-side... Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
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inline |
Conditionally acquire a read lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
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inline |
Conditionally acquire a write lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
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inline |
Conditionally upgrade to a write lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
ACE_File_Lock::ACE_ALLOC_HOOK_DECLARE |
Declare the dynamic allocation hooks.
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protected |
Locking structure for OS record locks.
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protected |
Keeps track of whether <remove> has been called yet to avoid multiple <remove> calls, e.g., explicitly and implicitly in the destructor. This flag isn't protected by a lock, so make sure that you don't have multiple threads simultaneously calling <remove> on the same object, which is a bad idea anyway...
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protected |
Keeps track of whether to unlink the underlying file in the destructor.