Standardise debug variables

This makes all debug options stored in a single struct rather than in
various places, changes/fixes the behaviour of existing options, and
introduces some new options.

* Fixes damage issues with `-Drender-tree` texture (by removing scissor)
* Offsets the render tree overlay's `y` position for those who have
swaybar at the top
* Replaces `-Ddamage=rerender` with `-Dnodamage`
* Replaces `-Ddamage=highlight` with `-Dhighlight-damage`
* Replaces `-Dtxn-debug` with `-Dtxn-wait`
* Introduces `-Dnoatomic`
* Removes the `create_time` and `ms_arranging` figures from transactions
and the log message. Transactions are created after arranging and the
create time is of no significance.
* Fixes `-Dtxn-debug` (now `-Dtxn-wait`) not working.

7 files changed, 63 insertions, 77 deletions

diff --git a/include/sway/debug.h b/include/sway/debug.h
index 38d4eccd..5dcd9e00 100644
--- a/include/sway/debug.h
+++ b/include/sway/debug.h
@@ -1,15 +1,18 @@
 #ifndef SWAY_DEBUG_H
 #define SWAY_DEBUG_H
+#include <stdbool.h>
 
-// Tree
-extern bool enable_debug_tree;
-void update_debug_tree();
+struct sway_debug {
+	bool highlight_damage; // Highlight regions of the screen being damaged
+	bool noatomic;         // Ignore atomic layout updates
+	bool nodamage;         // Render the full output on each frame
+	bool render_tree;      // Render the tree overlay
+	bool txn_timings;      // Log verbose messages about transactions
+	bool txn_wait;         // Always wait for the timeout before applying
+};
 
-// Damage
-extern const char *damage_debug;
+extern struct sway_debug debug;
 
-// Transactions
-extern int txn_timeout_ms;
-extern bool txn_debug;
+void update_debug_tree();
 
 #endif
diff --git a/include/sway/server.h b/include/sway/server.h
index b93584b6..1e20f2c8 100644
--- a/include/sway/server.h
+++ b/include/sway/server.h
@@ -54,8 +54,7 @@ struct sway_server {
 	struct wl_listener server_decoration;
 	struct wl_list decorations; // sway_server_decoration::link
 
-	bool debug_txn_timings;
-
+	size_t txn_timeout_ms;
 	list_t *transactions;
 	list_t *dirty_containers;
 };
diff --git a/sway/debug-tree.c b/sway/debug-tree.c
index f3465afe..b47a403b 100644
--- a/sway/debug-tree.c
+++ b/sway/debug-tree.c
@@ -3,8 +3,10 @@
 #include <wlr/render/wlr_texture.h>
 #include <wlr/util/log.h>
 #include "config.h"
+#include "sway/debug.h"
 #include "sway/input/input-manager.h"
 #include "sway/input/seat.h"
+#include "sway/output.h"
 #include "sway/server.h"
 #include "sway/tree/container.h"
 #include "sway/tree/layout.h"
@@ -12,6 +14,8 @@
 #include "config.h"
 #include "pango.h"
 
+struct sway_debug debug;
+
 static const char *layout_to_str(enum sway_container_layout layout) {
 	switch (layout) {
 	case L_HORIZ:
@@ -69,10 +73,8 @@ static int draw_container(cairo_t *cairo, struct sway_container *container,
 	return height;
 }
 
-bool enable_debug_tree = false;
-
 void update_debug_tree() {
-	if (!enable_debug_tree) {
+	if (!debug.render_tree) {
 		return;
 	}
 
diff --git a/sway/desktop/render.c b/sway/desktop/render.c
index 7c48d0d2..8fc642a6 100644
--- a/sway/desktop/render.c
+++ b/sway/desktop/render.c
@@ -816,8 +816,6 @@ static void render_floating(struct sway_output *soutput,
 	}
 }
 
-const char *damage_debug = NULL;
-
 void output_render(struct sway_output *output, struct timespec *when,
 		pixman_region32_t *damage) {
 	struct wlr_output *wlr_output = output->wlr_output;
@@ -831,21 +829,17 @@ void output_render(struct sway_output *output, struct timespec *when,
 
 	wlr_renderer_begin(renderer, wlr_output->width, wlr_output->height);
 
-	bool damage_whole_before_swap = false;
 	if (!pixman_region32_not_empty(damage)) {
 		// Output isn't damaged but needs buffer swap
 		goto renderer_end;
 	}
 
-	if (damage_debug != NULL) {
-		if (strcmp(damage_debug, "highlight") == 0) {
-			wlr_renderer_clear(renderer, (float[]){1, 1, 0, 1});
-			damage_whole_before_swap = true;
-		} else if (strcmp(damage_debug, "rerender") == 0) {
-			int width, height;
-			wlr_output_transformed_resolution(wlr_output, &width, &height);
-			pixman_region32_union_rect(damage, damage, 0, 0, width, height);
-		}
+	if (debug.highlight_damage) {
+		wlr_renderer_clear(renderer, (float[]){1, 1, 0, 1});
+	} else if (debug.nodamage) {
+		int width, height;
+		wlr_output_transformed_resolution(wlr_output, &width, &height);
+		pixman_region32_union_rect(damage, damage, 0, 0, width, height);
 	}
 
 	struct sway_container *workspace = output_get_active_workspace(output);
@@ -919,12 +913,12 @@ render_overlay:
 	render_drag_icons(output, damage, &root_container.sway_root->drag_icons);
 
 renderer_end:
-	if (root_container.sway_root->debug_tree) {
+	if (debug.render_tree) {
+		wlr_renderer_scissor(renderer, NULL);
 		wlr_render_texture(renderer, root_container.sway_root->debug_tree,
-			wlr_output->transform_matrix, 0, 0, 1);
+			wlr_output->transform_matrix, 0, 40, 1);
 	}
-
-	if (damage_whole_before_swap || root_container.sway_root->debug_tree) {
+	if (debug.highlight_damage) {
 		int width, height;
 		wlr_output_transformed_resolution(wlr_output, &width, &height);
 		pixman_region32_union_rect(damage, damage, 0, 0, width, height);
diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
index c300558a..219f5362 100644
--- a/sway/desktop/transaction.c
+++ b/sway/desktop/transaction.c
@@ -1,5 +1,6 @@
 #define _POSIX_C_SOURCE 200809L
 #include <errno.h>
+#include <limits.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -16,26 +17,12 @@
 #include "list.h"
 #include "log.h"
 
-/**
- * How long we should wait for views to respond to the configure before giving
- * up and applying the transaction anyway.
- */
-int txn_timeout_ms = 200;
-
-/**
- * If enabled, sway will always wait for the transaction timeout before
- * applying it, rather than applying it when the views are ready. This allows us
- * to observe the rendered state while a transaction is in progress.
- */
-bool txn_debug = false;
-
 struct sway_transaction {
 	struct wl_event_source *timer;
 	list_t *instructions;   // struct sway_transaction_instruction *
 	size_t num_waiting;
 	size_t num_configures;
 	uint32_t con_ids;       // Bitwise XOR of view container IDs
-	struct timespec create_time;
 	struct timespec commit_time;
 };
 
@@ -53,9 +40,6 @@ static struct sway_transaction *transaction_create() {
 		return NULL;
 	}
 	transaction->instructions = create_list();
-	if (server.debug_txn_timings) {
-		clock_gettime(CLOCK_MONOTONIC, &transaction->create_time);
-	}
 	return transaction;
 }
 
@@ -149,19 +133,14 @@ static void transaction_add_container(struct sway_transaction *transaction,
  */
 static void transaction_apply(struct sway_transaction *transaction) {
 	wlr_log(WLR_DEBUG, "Applying transaction %p", transaction);
-	if (server.debug_txn_timings) {
+	if (debug.txn_timings) {
 		struct timespec now;
 		clock_gettime(CLOCK_MONOTONIC, &now);
-		struct timespec *create = &transaction->create_time;
 		struct timespec *commit = &transaction->commit_time;
-		float ms_arranging = (commit->tv_sec - create->tv_sec) * 1000 +
-			(commit->tv_nsec - create->tv_nsec) / 1000000.0;
-		float ms_waiting = (now.tv_sec - commit->tv_sec) * 1000 +
+		float ms = (now.tv_sec - commit->tv_sec) * 1000 +
 			(now.tv_nsec - commit->tv_nsec) / 1000000.0;
-		float ms_total = ms_arranging + ms_waiting;
-		wlr_log(WLR_DEBUG, "Transaction %p: %.1fms arranging, %.1fms waiting, "
-			"%.1fms total (%.1f frames if 60Hz)", transaction,
-			ms_arranging, ms_waiting, ms_total, ms_total / (1000.0f / 60));
+		wlr_log(WLR_DEBUG, "Transaction %p: %.1fms waiting "
+				"(%.1f frames if 60Hz)", transaction, ms, ms / (1000.0f / 60));
 	}
 
 	// Apply the instruction state to the container's current state
@@ -310,25 +289,30 @@ static void transaction_commit(struct sway_transaction *transaction) {
 		con->instruction = instruction;
 	}
 	transaction->num_configures = transaction->num_waiting;
-	if (server.debug_txn_timings) {
+	if (debug.txn_timings) {
 		clock_gettime(CLOCK_MONOTONIC, &transaction->commit_time);
 	}
+	if (debug.noatomic) {
+		transaction->num_waiting = 0;
+	} else if (debug.txn_wait) {
+		// Force the transaction to time out even if all views are ready.
+		// We do this by inflating the waiting counter.
+		transaction->num_waiting += 1000000;
+	}
 
 	if (transaction->num_waiting) {
 		// Set up a timer which the views must respond within
 		transaction->timer = wl_event_loop_add_timer(server.wl_event_loop,
 				handle_timeout, transaction);
 		if (transaction->timer) {
-			wl_event_source_timer_update(transaction->timer, txn_timeout_ms);
+			wl_event_source_timer_update(transaction->timer,
+					server.txn_timeout_ms);
 		} else {
 			wlr_log(WLR_ERROR, "Unable to create transaction timer (%s). "
 					"Some imperfect frames might be rendered.",
 					strerror(errno));
-			handle_timeout(transaction);
+			transaction->num_waiting = 0;
 		}
-	} else {
-		wlr_log(WLR_DEBUG,
-				"Transaction %p has nothing to wait for", transaction);
 	}
 
 	// The debug tree shows the pending/live tree. Here is a good place to
@@ -341,7 +325,7 @@ static void set_instruction_ready(
 		struct sway_transaction_instruction *instruction) {
 	struct sway_transaction *transaction = instruction->transaction;
 
-	if (server.debug_txn_timings) {
+	if (debug.txn_timings) {
 		struct timespec now;
 		clock_gettime(CLOCK_MONOTONIC, &now);
 		struct timespec *start = &transaction->commit_time;
@@ -352,15 +336,12 @@ static void set_instruction_ready(
 				transaction->num_configures - transaction->num_waiting + 1,
 				transaction->num_configures, ms,
 				instruction->container->name);
-
 	}
 
 	// If the transaction has timed out then its num_waiting will be 0 already.
 	if (transaction->num_waiting > 0 && --transaction->num_waiting == 0) {
-		if (!txn_debug) {
-			wlr_log(WLR_DEBUG, "Transaction %p is ready", transaction);
-			wl_event_source_timer_update(transaction->timer, 0);
-		}
+		wlr_log(WLR_DEBUG, "Transaction %p is ready", transaction);
+		wl_event_source_timer_update(transaction->timer, 0);
 	}
 
 	instruction->container->instruction = NULL;
diff --git a/sway/main.c b/sway/main.c
index 54f48340..7a1afd4c 100644
--- a/sway/main.c
+++ b/sway/main.c
@@ -235,14 +235,20 @@ static void drop_permissions(bool keep_caps) {
 }
 
 void enable_debug_flag(const char *flag) {
-	if (strcmp(flag, "render-tree") == 0) {
-		enable_debug_tree = true;
-	} else if (strncmp(flag, "damage=", 7) == 0) {
-		damage_debug = &flag[7];
-	} else if (strcmp(flag, "txn-debug") == 0) {
-		txn_debug = true;
+	if (strcmp(flag, "highlight-damage") == 0) {
+		debug.highlight_damage = true;
+	} else if (strcmp(flag, "noatomic") == 0) {
+		debug.noatomic = true;
+	} else if (strcmp(flag, "nodamage") == 0) {
+		debug.nodamage = true;
+	} else if (strcmp(flag, "render-tree") == 0) {
+		debug.render_tree = true;
+	} else if (strcmp(flag, "txn-wait") == 0) {
+		debug.txn_wait = true;
+	} else if (strcmp(flag, "txn-timings") == 0) {
+		debug.txn_timings = true;
 	} else if (strncmp(flag, "txn-timeout=", 12) == 0) {
-		txn_timeout_ms = atoi(&flag[12]);
+		server.txn_timeout_ms = atoi(&flag[12]);
 	}
 }
 
diff --git a/sway/server.c b/sway/server.c
index e8dc63be..00acaa01 100644
--- a/sway/server.c
+++ b/sway/server.c
@@ -128,10 +128,11 @@ bool server_init(struct sway_server *server) {
 		return false;
 	}
 
-	const char *debug = getenv("SWAY_DEBUG");
-	if (debug != NULL && strcmp(debug, "txn_timings") == 0) {
-		server->debug_txn_timings = true;
+	// This may have been set already via -Dtxn-timeout
+	if (!server->txn_timeout_ms) {
+		server->txn_timeout_ms = 200;
 	}
+
 	server->dirty_containers = create_list();
 	server->transactions = create_list();