Downgrades a complex lock from exclusive-write mode to shared-read mode.
#include <sys/lock_def.h>void lock_write_to_read ( lock_addr)
complex_lock_t lock_addr;
| Item | Description |
|---|---|
| lock_addr | Specifies the address of the lock word to be downgraded from exclusive-write to shared-read mode. |
The lock_write_to_read kernel service downgrades the specified complex lock from exclusive-write mode to shared-read mode. The calling kernel thread must hold the lock in exclusive-write mode.
Once the lock has been downgraded to shared-read mode, other kernel threads will also be able to acquire it in shared-read mode.
The lock_write_to_read kernel service can be called from the process environment only.
The lock_write_to_read kernel service has no return values.