Program Listing for File umap-client.h

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#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#define UMAP_SERVER_PATH "/tmp/umap-server"

/*!
 * @function    init_umap_client
 * @abstract    initializes connection with an already running mpumap service
 * @param       sock_path   Path to Unix Domain socket hosted by target
 *              mpumap service. When a NULL value is passed,
 *              a default UMAP_SERVER_PATH is used
 * @result      Exits if it fails to connect to the service.
*/
void init_umap_client(const char *sock_path);

/*!
 * @function    close_umap_client
 * @abstract    Closes an already established mpumap service connection
 * @result      Exits if no service is found to be connected with
*/
void close_umap_client();


/*!
 * @function    client_umap
 * @abstract    Functionally equivalent to mmaping a file. Should be called only
 *      after connection with target umap-service has been established using init_umap_client
 * @param       filename    Full path to the file to be memory mapped
 * @param   prot        At present it only accepts PROT_READ as we serve read-only buffers
 *              This parameter is to catch instances where users intend to use the buffer
 *              other than read-only purposes.
 * @param   flags       At present it only accepts MAP_SHARED as these buffers are supposed to
 *              be shared between multiple processes, which include the mpumap service.
 *              This is to catch cases where user intends to use it otherwise.
 * @param   addr        non-NULL value is intended for fixed address. Floating address otherwise.
 * @result      Return NULL on failure. Else return the userspace mapped address
*/
void* client_umap(
    const char *filename
  , int prot
  , int flags
  , void *addr
);


/*!
 * @function    init_umap_client
 * @abstract    Removes the mapping from the client process' address space.
 * @param       filename    Path to file that has previously been mapped
 *              by client_umap call.
 * @result      Return -1 on error, 0 On Success
*/
int client_uunmap(
    const char *filename
);

/*
 * The following mpumap client API calls provide visibility to mpumap
 * service's settings to the client. This allows clients to use these
 * values as they deem necessary. These calls need to be called after
 * establishing connection with a mpumap service through init_umap_client
 * API call.
 */
long umapcfg_get_system_page_size( void );
uint64_t umapcfg_get_max_pages_in_buffer( void );
uint64_t umapcfg_get_umap_page_size( void );
uint64_t umapcfg_get_num_fillers( void );
uint64_t umapcfg_get_num_evictors( void );
int umapcfg_get_evict_low_water_threshold( void );
int umapcfg_get_evict_high_water_threshold( void );
uint64_t umapcfg_get_max_fault_events( void );

#ifdef __cplusplus
}
#endif