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Diffstat (limited to 'erts/emulator/beam/erl_proc_sig_queue.h')
-rw-r--r-- | erts/emulator/beam/erl_proc_sig_queue.h | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_proc_sig_queue.h b/erts/emulator/beam/erl_proc_sig_queue.h new file mode 100644 index 0000000000..433e30ce4a --- /dev/null +++ b/erts/emulator/beam/erl_proc_sig_queue.h @@ -0,0 +1,665 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2018. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +/* + * Description: Process signal queue implementation. + * + * Currently the following signals are handled: + * - Messages + * - Exit + * - Monitor + * - Demonitor + * - Monitor down + * - Persistent monitor message + * - Link + * - Unlink + * - Group leader + * - Trace change + * + * The signal queue consists of three parts: + * - Outer queue (sig_inq field in process struct) + * - Middle queue (sig_qs field in process struct) + * - Inner queue (sig_qs field in process struct) + * + * Incoming signals are placed in the outer queue + * by other processes, ports, or by the runtime system + * itself. This queue is protected by the msgq process + * lock and may be accessed by any other entity. While + * a signal is located in the outer queue, it is still + * in transit between sender and receiver. + * + * The middle and the inner queues are private to the + * receiving process and can only be accessed while + * holding the main process lock. The signal changes + * from being in transit to being received while in + * the middle queue. Non-message signals are handled + * immediately upon reception while message signals + * are moved into the inner queue. + * + * In the outer and middle queues both message signals + * and non-message signals are mixed. Signals in these + * queues are referenced using two single linked lists. + * One single linked list that go through all signals + * in the queue and another single linked list that + * goes through only non-message signals. The list + * through the non-message signals is used for fast + * access to these signals in the middle queue, since + * these should be handled immediately upon reception. + * + * The inner queue consists only of one single linked + * list through the message signals. A receive + * expression can only operate on messages once they + * have entered the inner queue. + * + * Author: Rickard Green + */ + +#ifndef ERTS_PROC_SIG_QUEUE_H_TYPE__ +#define ERTS_PROC_SIG_QUEUE_H_TYPE__ + +#if 0 +# define ERTS_PROC_SIG_HARD_DEBUG +#endif + +struct erl_mesg; + +typedef struct { + struct erl_mesg *next; + union { + struct erl_mesg **next; + void *attachment; + } specific; + Eterm tag; +} ErtsSignalCommon; + +#define ERTS_SIG_HANDLE_REDS_MAX_PREFERED (CONTEXT_REDS/40) + +#ifdef ERTS_PROC_SIG_HARD_DEBUG +# define ERTS_HDBG_CHECK_SIGNAL_IN_QUEUE(P) \ + ERTS_HDBG_CHECK_SIGNAL_IN_QUEUE__((P), "") +# define ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE(P) \ + ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE__((P), "") +# define ERTS_HDBG_CHECK_SIGNAL_IN_QUEUE__(P, What) \ + erts_proc_sig_hdbg_check_in_queue((P), (What), __FILE__, __LINE__) +# define ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE__(P, What) \ + erts_proc_sig_hdbg_check_priv_queue((P), (What), __FILE__, __LINE__) +struct process; +void erts_proc_sig_hdbg_check_priv_queue(struct process *c_p, char *what, + char *file, int line); +void erts_proc_sig_hdbg_check_in_queue(struct process *c_p, char *what, + char *file, int line); +#else +# define ERTS_HDBG_CHECK_SIGNAL_IN_QUEUE(P) +# define ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE(P) +# define ERTS_HDBG_CHECK_SIGNAL_IN_QUEUE__(P, What) +#define ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE__(P, What) +#endif + +#endif + +#if !defined(ERTS_PROC_SIG_QUEUE_H__) && !defined(ERTS_PROC_SIG_QUEUE_TYPE_ONLY) +#define ERTS_PROC_SIG_QUEUE_H__ + +struct dist_entry_; + +/* + * Send operations of currently supported process signals follow... + */ + +/** + * + * @brief Send an exit signal to a process. + * + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] from Identifier of sender. + * + * @param[in] to Identifier of local process + * to send signal to. + * + * @param[in] reason Exit reason. + * + * @param[in] token Seq trace token. + * + * @param[in] normal_kills If non-zero, also normal exit + * reason will kill the receiver + * if it is not trapping exit. + * + */ +void +erts_proc_sig_send_exit(Process *c_p, Eterm from, Eterm to, + Eterm reason, Eterm token, int normal_kills); + +/** + * + * @brief Send an exit signal due to broken link to a process. + * + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] from Identifier of sender. + * + * @param[in] lnk Pointer to link structure + * from the sending side. It + * should contain information + * about receiver. + * + * @param[in] reason Exit reason. + * + * @param[in] token Seq trace token. + * + */ +void +erts_proc_sig_send_link_exit(Process *c_p, Eterm from, ErtsLink *lnk, + Eterm reason, Eterm token); + +/** + * + * @brief Send an link signal to a process. + * + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] to Identifier of receiver. + * + * @param[in] lnk Pointer to link structure to + * insert on receiver side. + * + * @return A non-zero value if + * signal was successfully + * sent. If a zero, value + * the signal was not sent + * due to the receiver not + * existing. The sender + * needs to deallocate the + * link structure. + * + */ +int +erts_proc_sig_send_link(Process *c_p, Eterm to, ErtsLink *lnk); + +/** + * + * @brief Send an unlink signal to a process. + * + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] lnk Pointer to link structure from + * the sending side. It should + * contain information about + * receiver. + */ +void +erts_proc_sig_send_unlink(Process *c_p, ErtsLink *lnk); + +/** + * + * @brief Send an exit signal due to broken link to a process. + * + * This function is used instead of erts_proc_sig_send_link_exit() + * when the signal arrives via the distribution and + * no link structure is available. + * + * @param[in] dep Distribution entry of channel + * that the signal arrived on. + * + * @param[in] from Identifier of sender. + * + * @param[in] to Identifier of receiver. + * + * @param[in] reason Exit reason. + * + * @param[in] token Seq trace token. + * + */ +void +erts_proc_sig_send_dist_link_exit(struct dist_entry_ *dep, + Eterm from, Eterm to, + Eterm reason, Eterm token); + +/** + * + * @brief Send an unlink signal to a process. + * + * This function is used instead of erts_proc_sig_send_unlink() + * when the signal arrives via the distribution and + * no link structure is available. + * + * @param[in] dep Distribution entry of channel + * that the signal arrived on. + * + * @param[in] from Identifier of sender. + * + * @param[in] to Identifier of receiver. + * + */ +void +erts_proc_sig_send_dist_unlink(struct dist_entry_ *dep, + Eterm from, Eterm to); + +/** + * + * @brief Send a monitor down signal to a process. + * + * @param[in] mon Pointer to target monitor + * structure from the sending + * side. It should contain + * information about receiver. + * + * @param[in] reason Exit reason. + * + */ +void +erts_proc_sig_send_monitor_down(ErtsMonitor *mon, Eterm reason); + +/** + * + * @brief Send a demonitor signal to a process. + * + * @param[in] mon Pointer to origin monitor + * structure from the sending + * side. It should contain + * information about receiver. + * + * @param[in] reason Exit reason. + * + */ +void +erts_proc_sig_send_demonitor(ErtsMonitor *mon); + +/** + * + * @brief Send a monitor signal to a process. + * + * @param[in] mon Pointer to target monitor + * structure to insert on + * receiver side. + * + * @param[in] to Identifier of receiver. + * + * @return A non-zero value if + * signal was successfully + * sent. If a zero, value + * the signal was not sent + * due to the receiver not + * existing. The sender + * needs to deallocate the + * monitor structure. + * + */ +int +erts_proc_sig_send_monitor(ErtsMonitor *mon, Eterm to); + +/** + * + * @brief Send a monitor down signal to a process. + * + * This function is used instead of erts_proc_sig_send_monitor_down() + * when the signal arrives via the distribution and + * no link structure is available. + * + * @param[in] dep Pointer to distribution entry + * of channel that the signal + * arrived on. + * + * @param[in] ref Reference identifying the monitor. + * + * @param[in] from Identifier of sender. + * + * @param[in] to Identifier of receiver. + * + * @param[in] reason Exit reason. + * + */ +void +erts_proc_sig_send_dist_monitor_down(DistEntry *dep, Eterm ref, + Eterm from, Eterm to, + Eterm reason); + +/** + * + * @brief Send a demonitor signal to a process. + * + * This function is used instead of erts_proc_sig_send_demonitor() + * when the signal arrives via the distribution and + * no monitor structure is available. + * + * @param[in] to Identifier of receiver. + * + * @param[in] ref Reference identifying the monitor. + * + */ +void +erts_proc_sig_send_dist_demonitor(Eterm to, Eterm ref); + +/** + * + * @brief Send a persistent monitor triggered signal to a process. + * + * Used by monitors that are not auto disabled such as for + * example 'time_offset' monitors. + * + * @param[in] type Monitor type. + * + * @param[in] key Monitor key. + * + * @param[in] from Identifier of sender. + * + * @param[in] to Identifier of receiver. + * + * @param[in] msg Message template. + * + * @param[in] msg_sz Heap size of message template. + * + */ +void +erts_proc_sig_send_persistent_monitor_msg(Uint16 type, Eterm key, + Eterm from, Eterm to, + Eterm msg, Uint msg_sz); + +/** + * + * @brief Send a trace change signal to a process. + * + * @param[in] to Identifier of receiver. + * + * @param[in] on Trace flags to enable. + * + * @param[in] off Trace flags to disable. + * + * @param[in] tracer Tracer to set. If the non-value, + * tracer will not be changed. + * + */ +void +erts_proc_sig_send_trace_change(Eterm to, Uint on, Uint off, + Eterm tracer); + +/** + * + * @brief Send a group leader signal to a process. + * + * Set group-leader of receiving process. If sent locally, + * a response message '{Ref, Result}' is sent to the original + * sender when performed where Ref is the reference passed + * as 'ref' argument, and Result is either 'true' or 'badarg'. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * NULL if signal arrived via + * distribution. + * + * @param[in] to Identifier of receiver. + * + * @param[in] gl Identifier of new group leader. + * + * @param[in] ref Reference to use in response + * message to locally sending + * process (i.e., c_p when c_p + * is non-null). + * + */ +void +erts_proc_sig_send_group_leader(Process *c_p, Eterm to, Eterm gl, + Eterm ref); + +/* + * End of send operations of currently supported process signals. + */ + + +/** + * + * @brief Handle incoming signals. + * + * Called by an ordinary scheduler in order to handle incoming + * signals for a process. The work is done on the middle part + * of the signal queue. The maximum amount of signals handled + * is limited by the amount of reductions given when calling. + * Note that a reduction does not necessarily map to a signal. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[out] statep Pointer to process state after + * signal handling. May not be NULL. + * + * @param[in,out] redsp Pointer to an integer containing + * reductions. On input, the amount + * of preferred reductions to be + * used by the call. On output, the + * amount of reductions consumed. + * + * @param[in] max_reds Absolute maximum of reductions + * to use. If the process cannot + * make progress after the preferred + * amount of reductions has been + * consumed, signal handling may + * proceed up to a maximum of + * 'max_reds' in order to make + * the process able to proceed + * with other tasks after handling + * has finished. + * + * @param[in] local_only If is zero, new signals may be + * fetched from the outer queue and + * put in the middle queue before + * signal handling is performed. If + * non-zero, no new signals will be + * fetched before handling begins. + * + * @return Returns a non-zero value, when + * no more signals to handle in the + * middle queue remain. A zero + * return value means that there + * remains signals in the middle + * queue. + */ +int +erts_proc_sig_handle_incoming(Process *c_p, erts_aint32_t *statep, + int *redsp, int max_reds, + int local_only); + +/** + * + * @brief Handle remaining signals for an exiting process + * + * Called as part of termination of a process. It will handle + * remaining signals. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in,out] redsp Pointer to an integer containing + * reductions. On input, the amount + * of maximum reductions to be + * used by the call. On output, the + * amount of reductions consumed. + * + * @return Returns a non-zero value, when + * no more signals to handle in the + * middle queue remain. A zero + * return value means that there + * remains signals in the middle + * queue. + */ +int +erts_proc_sig_handle_exit(Process *c_p, int *redsp); + +/** + * + * @brief Helper for loop_rec instruction. + * + * This function should only be called from the loop_rec + * instruction (or equivalents). It is called when loop_rec + * reach the end of the inner queue (which is the only + * part of the signal queue that receive is allowed to + * operate on). When called, this function tries to make + * more messages available in the inner queue. This by + * fetching signals from the outer queue to the middle + * queue and/or processing signals in the middle queue. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] fcalls Content of FCALLS in + * process_main() + * + * @param[in] neg_o_reds Content of neg_o_reds in + * process_main() + * + * @param[out] msgpp Pointer to pointer to next + * available message to process. + * If *msgpp == NULL, no more + * messages are available. + * + * @param[out] get_outp Pointer to an integer + * indicating how to respond + * if no more messages are + * available (msgpp). If integer + * is set to zero, loop_rec + * should jump to an appropriate + * wait instruction. If zero, + * the message queue lock remain + * locked since the test for + * more messages was done. + * If the integer is set to a + * value larger that zero, the + * process exited. If the integer + * is set to a value less than + * zero, the process is required + * to yield. + * + * + * @return The amount of reductions + * consumed. + * + */ +int +erts_proc_sig_receive_helper(Process *c_p, int fcalls, + int neg_o_reds, ErtsMessage **msgpp, + int *get_outp); + +/** + * + * @brief Fetch signals from the outer queue + * + * Fetches signals from outer queue and places them in the + * middle queue ready for signal handling. If the middle + * queue is empty, only message signals were present in the + * outer queue, and no receive tracing has been enabled on + * the process, the middle queue is bypassed and messages + * are delivered directly to the inner queue instead. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + */ +void erts_proc_sig_fetch(Process *p); + +typedef struct { + Uint size; + ErtsMessage *msgp; +} ErtsMessageInfo; + +/** + * + * @brief Prepare signal queue for inspection by process_info() + * + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + * @param[in] rp Pointer to process struct of + * process to inspect. + * + * @param[in] rp_locks Process locks held on 'rp'. + * + * @param[in] mip Pointer to array of + * ErtsMessageInfo structures. + * + */ + +Uint erts_proc_sig_prep_msgq_for_inspection(Process *c_p, + Process *rp, + ErtsProcLocks rp_locks, + ErtsMessageInfo *mip); + + +/** + * + * @brief Move message data of messages in private queues to heap + * + * Move message data of messages in private queues to the heap. + * This is part of GC of processes that uses on-heap message + * data. + * + * @param[in] c_p Pointer to process struct of + * currently executing process. + * + */ +void erts_proc_sig_move_msgs_to_heap(Process *c_p); + +/** + * + * @brief Size of signal in bytes. + * + * @param[in] sig Signal to inspect. + * + */ +Uint erts_proc_sig_signal_size(ErtsSignal *sig); + + +/** + * + * @brief Clear seq trace tokens on all signals + * + * Assumes thread progress has been blocked! + * + * @param[in] c_p Pointer to process + * + */ +void +erts_proc_sig_clear_seq_trace_tokens(Process *c_p); + +/** + * @brief Initialize this functionality + */ +void erts_proc_sig_queue_init(void); + +void +erts_proc_sig_debug_foreach_sig(Process *c_p, + void (*msg_func)(ErtsMessage *, void *), + void (*oh_func)(ErlOffHeap *, void *), + void (*mon_func)(ErtsMonitor *, void *), + void (*lnk_func)(ErtsLink *, void *), + void *arg); + +extern Process *erts_dirty_process_signal_handler; +extern Process *erts_dirty_process_signal_handler_high; +extern Process *erts_dirty_process_signal_handler_max; + +#endif /* ERTS_PROC_SIG_QUEUE_H__ */ |