/* * thread.h - Thread and related operations definition. * * Author Ghassan Almaless (2008,2009,2010,2011,2012) * Alain Greiner (2016,2017,2018,2019,2020) * * Copyright (c) UPMC Sorbonne Universites * * This file is part of ALMOS-MKH. * * ALMOS-MKH is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2.0 of the License. * * ALMOS-MKH is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ALMOS-MKH; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef _THREAD_H_ #define _THREAD_H_ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*************************************************************************************** * These macros are used to compose or decompose the global thread identifier (TRDID) * to or from cluster identifier / local thread index (CXY , LTID) **************************************************************************************/ #define LTID_FROM_TRDID( trdid ) (ltid_t)(trdid & 0x0000FFFF) #define CXY_FROM_TRDID( trdid ) (cxy_t)(trdid >> 16) #define TRDID( cxy , ltid ) (trdid_t)((cxy << 16) | ltid ) /*************************************************************************************** * This enum defines the thread types. **************************************************************************************/ typedef enum { THREAD_USER = 0, /*! user thread (pthread) */ THREAD_RPC = 1, /*! kernel thread executing pending RPCs */ THREAD_DEV = 2, /*! kernel thread executing I/O device commands */ THREAD_IDLE = 3, /*! kernel idle thread */ } thread_type_t; /*************************************************************************************** * This defines the thread flags bit-vector. **************************************************************************************/ #define THREAD_FLAG_DETACHED 0x0001 /*! This thread is detached from parent */ #define THREAD_FLAG_JOIN_DONE 0x0002 /*! Parent thread made a join request */ #define THREAD_FLAG_KILL_DONE 0x0004 /*! This thread received a kill request */ #define THREAD_FLAG_REQ_ACK 0x0010 /*! Acknowledge required from scheduler */ #define THREAD_FLAG_REQ_DELETE 0x0020 /*! Destruction required from scheduler */ /*************************************************************************************** * This defines the thread blocking causes bit-vector. **************************************************************************************/ #define THREAD_BLOCKED_GLOBAL 0x0001 /*! ANY : deactivated / wait activation */ #define THREAD_BLOCKED_IO 0x0002 /*! USR : wait IO operation completion */ #define THREAD_BLOCKED_MAPPER 0x0004 /*! ??? : wait mapper */ #define THREAD_BLOCKED_EXIT 0x0008 /*! USR : blocked in join / wait exit */ #define THREAD_BLOCKED_JOIN 0x0010 /*! USR : blocked in exit / wait join */ #define THREAD_BLOCKED_SEM 0x0020 /*! USR : wait semaphore */ #define THREAD_BLOCKED_PAGE 0x0040 /*! ??? : wait page access */ #define THREAD_BLOCKED_IDLE 0x0080 /*! RPC : wait RPC_FIFO non empty */ #define THREAD_BLOCKED_USERSYNC 0x0100 /*! USR : wait cond / mutex / barrier */ #define THREAD_BLOCKED_RPC 0x0200 /*! ANY : wait RPC completion */ #define THREAD_BLOCKED_ISR 0x0400 /*! DEV : wait hardware IRQ */ #define THREAD_BLOCKED_WAIT 0x0800 /*! USR : wait child process termination */ #define THREAD_BLOCKED_LOCK 0x1000 /*! ANY : wait queuelock or rwlock */ #define THREAD_BLOCKED_CLIENT 0x2000 /*! DEV : wait clients queue non empty */ #define THREAD_BLOCKED_ALARM 0x4000 /*! ANY : wait a timer based alarm */ /*************************************************************************************** * This structure defines a thread descriptor. * It is used for both the user threads and the kernel threads. * In a process, a user thread is identified by a unique TRDID (thread identifier): * - The TRDID 16 LSB bits contain the LTID (Local Thread Index). * - The TRDID 16 MSB bits contain the CXY of cluster containing the thread. * For the main thread the LTID value is always 0, in the owner cluster. * The LTID is used to index the th_tbl[] array in the local process descriptor. * This TRDID is computed by the process_register_thread() function, when the user * thread is registered in the local copy of the process descriptor. * * Implementation notes: * * (1) Don't modify the first 4 fields order, as this order is used by the * hal_kentry assembly code for the TSAR architectures. * * (2) Most of the thread state is private and accessed only by this thread, * but some fields are shared, and can be modified by other threads. * - the "blocked" bit_vector can be modified by another thread * running in another cluster (using atomic instructions), * to change this thread scheduling status. * - the "flags" bit_vector can be modified by another thread * running in another cluster (using atomic instructions), * to register requests such as ACK or DELETE. * - the "join_xp" field can be modified by the joining thread, * and this rendez-vous is protected by the dedicated "join_lock". * * (3) When this thread is blocked on a shared resource (queuelock, condvar, * or chdev), it registers in the associated waiting queue, using the * "wait_list" (local list) or "wait_xlist" (trans-cluster list) fields. * * (4) The thread_info_t structure is defined in the shared_almos.h file in the * /kernel/syscall/shared_include directory. **************************************************************************************/ #define THREAD_SIGNATURE 0xDEADBEEF typedef struct thread_s { void * cpu_context; /*! CPU context used by sched_yield */ void * fpu_context; /*! FPU context used by sched_yield */ void * uzone_current; /*! used by hal_do_syscall & hal_do_except */ void * uzone_previous; /*! used by hal_do_syscall & hal_do_except */ intptr_t k_stack_base; /*! kernel stack base address */ uint32_t k_stack_size; /*! kernel stack size (bytes) */ uint32_t trdid; /*! thread index (cxy.ltid) */ thread_type_t type; /*! thread type */ uint32_t quantum; /*! number of clock ticks given to thread */ uint32_t ticks_nr; /*! number of ticks used */ uint32_t time_last_check; /*! last cpu_time_stamp */ core_t * core; /*! pointer to the owner core */ process_t * process; /*! pointer on local process descriptor */ xptr_t parent; /*! extended pointer on parent thread */ remote_busylock_t join_lock; /*! lock protecting the join/exit */ xptr_t join_xp; /*! joining/killer thread extended pointer */ void * exit_status; /*! status returned to joiniy thread */ uint32_t * ack_rsp_count; /*! pointer on acknowledge response counter */ vseg_t * user_stack_vseg; /*! local pointer on user stack vseg */ void * entry_func; /*! pointer on thread entry function */ void * entry_args; /*! pthread : pointer on arguments */ uint32_t flags; /*! bit vector of flags */ uint32_t blocked; /*! bit vector of blocking causes */ error_t errno; /*! errno value set by last system call */ uint32_t utls; /*! user thread local storage */ bool_t fork_user; /*! user defined placement for next fork() */ cxy_t fork_cxy; /*! target cluster for next fork() */ list_entry_t sched_list; /*! member of threads attached to same core */ chdev_t * chdev; /*! chdev pointer (for a DEV thread only) */ alarm_t alarm; /*! embedded timer based alarm */ reg_t save_sr; /*! used by sched_yield() function */ ioc_command_t ioc_cmd; /*! IOC device generic command */ txt_command_t txt_cmd; /*! TXT device generic command */ nic_command_t nic_cmd; /*! NIC device generic command */ mmc_command_t mmc_cmd; /*! MMC device generic command */ dma_command_t dma_cmd; /*! DMA device generic command */ fbf_command_t fbf_cmd; /*! FBF device generic command */ xptr_t rpc_client_xp; /*! client thread (for a RPC thread only) */ list_entry_t wait_list; /*! member of a local waiting queue */ xlist_entry_t wait_xlist; /*! member of a trans-cluster waiting queue */ xlist_entry_t tmp_xlist; /*! member of a trans-cluster kleenex queue */ uint32_t busylocks; /*! number of taken busylocks */ #if DEBUG_BUSYLOCK_TYPE xlist_entry_t busylocks_root; /*! root of xlist of taken busylocks */ #endif thread_info_t info; /*! embedded thread_info_t */ uint32_t signature; /*! for kernel stack overflow detection */ } thread_t; /*************************************************************************************** * This macro returns a pointer on the calling thread from the core hardware register. **************************************************************************************/ #define CURRENT_THREAD (hal_get_current_thread()) /*************************************************************************************** * This function returns a printable string for a thread type. *************************************************************************************** * @ type : thread type. * returns pointer on string. **************************************************************************************/ const char * thread_type_str( thread_type_t type ); /*************************************************************************************** * This function is used by the pthread_create() system call to create a "new" thread * in an existing process. It allocates memory for an user thread descriptor in the * local cluster, and initializes it from information contained in the arguments. * The CPU context is initialized from scratch. * It is registered in the local process descriptor specified by the argument. * The THREAD_BLOCKED_GLOBAL bit is set => the thread must be activated by the caller * to start at the next scheduling point. *************************************************************************************** * @ pid : process identifier. * @ start_func : pointer on entry function. * @ start_args : pointer on function argument (can be NULL). * @ attr : pointer on pthread attributes descriptor. * @ new_thread : [out] address of buffer for new thread descriptor pointer. * @ returns 0 if success / returns ENOMEM if error. **************************************************************************************/ error_t thread_user_create( pid_t pid, void * start_func, void * start_arg, pthread_attr_t * attr, thread_t ** new_thread ); /*************************************************************************************** * This function is used by the sys_fork() syscall to create the "child" main thread * in the local cluster. It is called, generally through the RPC_PROCESS_MAKE_FORK, * by the process_make_fork() function. It allocates memory from the local cluster * for a "child" thread descriptor, and initializes it from the "parent" thread * descriptor defined by the argument. * The new thread is attached to the core that has the lowest load in local cluster. * It is registered in the "child" process defined by the argument. * This new thread inherits its user stack from the parent thread, as it uses the * Copy-On-Write mechanism to get a private stack when required. * The content of the parent kernel stack is copied into the child kernel stack, as * the Copy-On-Write mechanism cannot be used for kernel segments (because kernel * uses physical addressing on some architectures). * The CPU and FPU execution contexts are created and linked to the new thread. * but the actual context copy is NOT done, and is done by the sys_fork() function. * The THREAD_BLOCKED_GLOBAL bit is set => the thread must be activated to start. *************************************************************************************** * @ parent_thread_xp : extended pointer on parent thread descriptor. * @ child_process : local pointer on child process descriptor. * @ child_thread : [out] address of buffer for child thread descriptor pointer. * @ returns 0 if success / returns -1 if error. **************************************************************************************/ error_t thread_user_fork( xptr_t parent_thread_xp, process_t * child_process, thread_t ** child_thread ); /*************************************************************************************** * This function is called by the process_make_exec() function to re-initialise the * calling thread descriptor, that will become the new process main thread, from * the process descriptor, and from the & arguments. * - The calling thread TRDID is not modified. * - The kernel stack (currently in use) is not modified. * - It calls the hal_cpu_context_init() to re-initialize the thread CPU context. * - It calls the hal_do_cpu_restore() to force execution of the new user code. *************************************************************************************** * @ argc : actual number of main thread arguments. * @ argv : user space pointer on array of pointers on arguments. **************************************************************************************/ void thread_user_exec( uint32_t argc, intptr_t argv ); /*************************************************************************************** * This function allocates memory for a kernel thread descriptor in the local cluster, * and initializes it from arguments values. * It is called by kernel_init() to statically create all DEV server threads * It is also called to dynamically create RPC threads when required. * The THREAD_BLOCKED_GLOBAL bit is set, and the thread must be activated to start. *************************************************************************************** * @ new_thread : address of buffer for new thread pointer. * @ type : kernel thread type. * @ func : pointer on function. * @ args : function arguments. * @ core_lid : local core index. * @ returns 0 if success / returns ENOMEM if error **************************************************************************************/ error_t thread_kernel_create( thread_t ** new_thread, thread_type_t type, void * func, void * args, lid_t core_lid ); /*************************************************************************************** * This function is called by the kernel_init() function to initialize the IDLE thread * descriptor from arguments values. * The THREAD_BLOCKED_GLOBAL bit is set, and the thread must be activated to start. * It returns a kernel panic if failure. *************************************************************************************** * @ thread : pointer on existing thread descriptor. * @ type : kernel thread type. * @ func : pointer on function. * @ args : function arguments. * @ core_lid : local core index. **************************************************************************************/ void thread_idle_init( thread_t * thread, thread_type_t type, void * func, void * args, lid_t core_lid ); /*************************************************************************************** * This low-level function is called by the sched_handle_signals() function when a * thread is marked for delete. It removes the thread identified by the * argument from the process th_tbl[], and releases all physical memory allocated for * this. This includes the thread descriptor itself, the associated CPU and FPU context, * and the physical memory allocated for an user thread stack. * This function does not remove the thread from the scheduler, as this is done by * the scheduler itself. *************************************************************************************** * @ thread : pointer on the thread descriptor to release. * @ return the number of threads registered in the process th_tbl[] before deletion. **************************************************************************************/ uint32_t thread_destroy( thread_t * thread ); /*************************************************************************************** * This function defines the code of the thread executed by all cores after kernel_init, * or when no other thread is runnable for a given core. * It enter and infinite loop in wich: * - it unmask the IRQs * - it optionally calls the hal_core_sleep() function to reduce the power consumption * (this behavior is controlled by the CONFIG_THREAD_IDLE_MODE_SLEEP flag). * - it call the sched_yield() function to find another runnable thread. * * TODO: In the TSAR architecture the hal_core_sleep() function forces the core to * low-power mode. Any IRQ will force the core to exit this low-power mode, but no ISR * is executed. We must analyse if we have the same behaviour for I86 architectures... **************************************************************************************/ void thread_idle_func( void ); /*************************************************************************************** * This function is used by a "blocker" thread running in the same cluster as a "target" * thread to request the scheduler of the target thread to acknowledge that the target * thread is blocked and not running, at the next context switch. * This function executes atomically the following actions : * - it set the request_pending boolean in the target scheduler descriptor. * - it set the REQ_ACK flag in the "flags" field of the target thread descriptor. * - It registers the responses counter pointer in the target thread descriptor. * The request_pending flag is handled as a set/reset flip-flop by the "blocker" thread * and by the "target" scheduler. *************************************************************************************** * @ target : local pointer on target thread. * @ ack_rsp_count : local pointer on responses counter. **************************************************************************************/ void thread_set_req_ack( thread_t * target, uint32_t * ack_rsp_count ); /*************************************************************************************** * This function is used by the sched_handle_signal() function executed by the * scheduler of a "target" thread to reset a "blocked not running" acknowledge request * in both the target thread descriptor, and in the target thread scheduler. *************************************************************************************** * @ target : local pointer on target thread. **************************************************************************************/ void thread_reset_req_ack( thread_t * target ); /*************************************************************************************** * This function is used by the four sys_thread_cancel(), sys_thread_exit(), * sys_kill() and sys_exit() system calls to mark for delete a given thread. * It set the THREAD_BLOCKED_GLOBAL bit and set the THREAD_FLAG_REQ_DELETE bit in the * thread descriptor identified by the argument, to ask the scheduler * to asynchronously delete the target thread, at the next scheduling point. * The calling thread can run in any cluster, as it uses remote accesses. * This function makes a kernel panic if the target thread is the main thread, * because the main thread deletion will cause the process deletion, and a process * must be deleted by the parent process, running the wait function. * If the target thread is running in "attached" mode, and the argument * is false, this function implements the required sychronisation with the joining * thread, blocking the killer thread until the pthread_join() syscall is executed * by the joining thread. *************************************************************************************** * @ thread_xp : extended pointer on the target thread. * @ is_forced : the deletion does not depends on the attached mode. **************************************************************************************/ void thread_delete_request( xptr_t thread_xp, bool_t is_forced ); /*************************************************************************************** * This function registers a blocking cause defined by the argument * in a remote thread descriptor identified by the argument. * We need an extended pointer, because this function can be called by another thread * than the target thread, executing the sys_kill() function. * WARNING : this function does not deschedule the target thread, and the descheduling * must be explicitely forced by a sched_yield(). *************************************************************************************** * @ thread_xp : extended pointer on remote thread descriptor. * @ cause : mask defining the cause (one hot). **************************************************************************************/ void thread_block( xptr_t thread_xp, uint32_t cause ); /*************************************************************************************** * This function resets the bit identified by the argument in a remote * thread descriptor identified by the argument. * We need an extended pointer, because the client thread of an I/O operation on a * given device is generally not in the same cluster as the associated server thread. * WARNING : this function does not reschedule the remote thread. * The scheduling can be forced by sending an IPI to the core running the remote thread. *************************************************************************************** * @ thread_xp : extended pointer the remote thread. * @ cause : mask defining the cause (one hot). * @ return non zero if the bit-vector was actually modified / return 0 otherwise **************************************************************************************/ uint32_t thread_unblock( xptr_t thread_xp, uint32_t cause ); /*************************************************************************************** * This function updates the calling thread user_time or kernel_time counters. *************************************************************************************** * @ thread : local pointer on target thread. * @ is_user : update user time if true / update kernel time if false **************************************************************************************/ void thread_time_update( thread_t * thread, bool_t is_user ); /*************************************************************************************** * This function returns the extended pointer on a thread descriptor identified * by its thread identifier, and process identifier. * It can be called by any thread running in any cluster. *************************************************************************************** * @ pid : process identifier. * @ trdid : thread identifier. * @ return the extended pointer if thread found / return XPTR_NULL if not found. **************************************************************************************/ xptr_t thread_get_xptr( pid_t pid, trdid_t trdid ); /*************************************************************************************** * This function checks that the thread identified by the argument does hold * any busylock (local or remote). * If the xlist of taken busylocks is not empty, it displays the set of taken locks, * and makes a kernel panic. *************************************************************************************** * @ thread : local pointer on target thread. * @ func_str : faulty function name. **************************************************************************************/ void thread_assert_can_yield( thread_t * thread, const char * func_str ); /*************************************************************************************** * This debug function display the list of busylocks (local or remote) * currently owned by a the thread identified by the argument. * The argument is printed in header (can be the calling function name). * WARNING : the DEBUG_BUSYLOCK parameter must be set in the kernel_config.h file. *************************************************************************************** * @ thread_xp : extended pointer on target thread. * @ string : defines the calling context. **************************************************************************************/ void thread_display_busylocks( xptr_t thread_xp, const char * string ); #endif /* _THREAD_H_ */